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+# Overview of changes in 2.8
+
+## User-visible Changes
+
+* **Parsing Distinguished Names in certificates**
+
+  (OpenSSL backend:) OpenVPN now rejects certificates that have a null-byte
+  inside any of the field values of their subject. To avoid ambiguity in the
+  parsed subject, OpenVPN escapes the following characters by prefixing them with
+  a backslash:
+
+  * " " (space) at the start or end of a field,
+  * "#" at the start of a field,
+  * ",", "+", """, "\", "<", ">" and ";" anywhere.
+
+  As a result, if you use the option `--verify-x509-name <expected subject>`,
+  you need to prefix these characters with a backslash in your configuration.
+  The subject passed to a `--tls-verify` script is escaped in the same way and
+  you may need to adjust your script.
+
+  (Mbed TLS backend:) The behavior has not changed. Subjects with null-bytes were
+  already rejected (assuming OpenVPN was built with Mbed TLS 3.5 or later) and
+  the characters mentioned above were already escaped. However, the behavior of
+  Mbed TLS is slightly different from OpenSSL in that it also escapes "=".
+
+# Overview of changes in 2.7
+
+## New features
+
+* **Multi-socket support for servers**
+
+  OpenVPN servers now can listen on multiple sockets at the same time. Multiple
+  `--local` statements in the configuration can be used to configure this. This
+  way the same server can e.g. listen for UDP and TCP connections at the same
+  time, or listen on multiple addresses and/or ports.
+
+* **Client implementations for DNS options sent by server for Linux/BSD/macOS**
+
+  Linux, BSD and macOS versions of OpenVPN now ship with a per-platform default
+  `--dns-updown` script that implements proper handling of DNS configuration sent
+  by the server. The scripts should work on systems that use `systemd` or
+  `resolveconf` to manage the DNS setup, as well as raw `/etc/resolv.conf` files.
+  However, the exact features supported will depend on the configuration method.
+  On Linux and MacOS this should usually make split-DNS configurations supported
+  out-of-the-box now.
+
+  Note that this new script will not be used by default if a `--up` script is
+  already in use to reduce problems with backwards compatibility.
+
+  See documentation for `--dns-updown` and `--dns` for more details.
+
+* **New client implementation for DNS options sent by server for Windows**
+
+  The Windows client now uses NRPT (Name Resolution Policy Table) to handle DNS
+  configurations. This adds support for split-DNS and DNSSEC and improves the
+  compatbility with local DNS resolvers. Requires the interactive service.
+
+* **On Windows the `block-local` flag is now enforced with WFP filters.**
+
+  The `block-local` flag to `--redirect-gateway` and `--redirect-private` is now
+  also enforced via the Windows Firewall, making sure packets can't be sent to the
+  local network. This provides stronger protection against TunnelCrack-style
+  attacks.
+
+* **Windows network adapters are now generated on demand**
+
+  This means that on systems that run multiple OpenVPN connections at the same
+  time the users don't need to manually create enough network adapters anymore (in
+  addition to the ones created by the installer).
+
+* **Windows automatic service now runs as an unpriviledged user**
+
+  All tasks that need privileges are now delegated to the interactive service.
+  **NOTE** this has the risk of breaking existing setups if the Windows
+  certificate store is used (cryptoapi), and the certificates are not readable for
+  `NT SERVICE\OpenVPNService`.
+
+* **Support for new version of Linux DCO module**
+
+  The OpenVPN DCO module has been merged into the Linux kernel as of 6.16. This
+  required some API changes and OpenVPN 2.7 only supports the new API. The new
+  module is called `ovpn`. Out-of-tree builds for older kernels are available from
+  <https://github.com/OpenVPN/ovpn-backports>. Please see the release
+  announcements for further information.
+
+* **Support for server mode in win-dco driver**
+
+  On Windows the win-dco driver can now be used in server setups.
+
+* **Support for TLS client floating in DCO implementations**
+
+  The kernel modules will detect clients floating to a new IP address and notify
+  userland so both data packets (kernel) and TLS packets (sent by userland) can
+  reach the new client IP. (Actual support depends on recent-enough kernel
+  implementation)
+
+* **Enforcement of AES-GCM usage limit**
+
+  OpenVPN will now enforce the usage limits on AES-GCM with the same
+  confidentiality margin as TLS 1.3 does. This mean that renegotiation will be
+  triggered after roughly 2^28 to 2^31 packets depending of the packet size. More
+  details about usage limit of AES-GCM can be found here:
+
+  <https://datatracker.ietf.org/doc/draft-irtf-cfrg-aead-limits/>
+
+* **Epoch data keys and packet format**
+
+  This introduces the epoch data format for AEAD data channel ciphers in TLS mode
+  ciphers. This new data format has a number of improvements over the standard
+  "DATA_V2" format.
+
+  - AEAD tag at the end of packet which is more hardware implementation friendly
+  - Automatic key switchover when cipher usage limits are hit, similar to the
+    epoch data keys in (D)TLS 1.3
+  - 64 bit instead of 32 bit packet ids to allow the data channel to be ready for
+    10 GBit/s without having frequent renegotiation
+  - IV constructed with XOR instead of concatenation to not have (parts) of the
+    real IV on the wire
+
+* **Support for Epoch data channel on Windows, using the win-dco driver (2.8.0+)**
+
+* **Default ciphers in `--data-ciphers`**
+
+  Ciphers in `--data-ciphers` can contain the string DEFAULT that is replaced by
+  the default ciphers used by OpenVPN, making it easier to add an allowed cipher
+  without having to spell out the default ciphers.
+
+* **TLS alerts**
+
+  OpenVPN 2.7 will send out TLS alerts to peers informing them if the TLS session
+  shuts down or when the TLS implementation informs the peer about an error in the
+  TLS session (e.g. mismatching TLS versions). This improves the user experience
+  as the client shows an error instead of running into a timeout when the server
+  just stops responding completely.
+
+* **Support for tun/tap via unix domain socket and lwipovpn support**
+
+  To allow better testing and emulating a full client with a full network stack
+  OpenVPN now allows a program executed to provide a tun/tap device instead of
+  opening a device.
+
+  The co-developed lwipovpn program based on lwIP stack allows to simulate full IP
+  stack. An OpenVPN client using `--dev-node unix:/path/to/lwipovpn` can emulate a
+  full client that can be pinged, can serve a website and more without requiring
+  any elevated permission. This can make testing OpenVPN much easier.
+
+  For more details see [lwipovpn on Github](https://github.com/OpenVPN/lwipovpn).
+
+* **Allow overriding username with `--override-username`**
+
+  This is intended to allow using `--auth-gen-token` in scenarios where the
+  clients use certificates and multi-factor authentication. This will also
+  generate a `push "auth-token-user newusername"` directive in push replies.
+
+* **`--port-share` now properly supports IPv6**
+
+  Issues with logging of IPv6 addresses were fixed. The feature now allows IPv6
+  connections towards the proxy receiver.
+
+* **Support for Haiku OS**
+
+* **TLS1.3 support with mbedTLS (requires mbedTLS >= 3.6.4)**
+
+* **PUSH_UPDATE client support**
+
+  It is now possible to update parts of the client-side configuration (IP address,
+  routes, MTU, DNS) by sending a new server-to-client control message,
+  `PUSH_UPDATE,<options>`. See also:
+  <https://openvpn.github.io/openvpn-rfc/openvpn-wire-protocol.html>
+
+  NOTE: PUSH_UPDATE client support is currently disabled if DCO is active (on all
+  platforms).
+
+* **PUSH_UPDATE server support (minimal)**
+
+  New management interface commands `push-update-broad` and `push-update-cid` to
+  send PUSH_UPDATE option updates to all clients ("there is a new DNS server") or
+  only a specific client ID ("privileges have changed, here's a new IP address").
+
+  See doc/management-notes.txt
+
+  NOTE: PUSH_UPDATE server support is currently disabled if DCO is active
+  (on all platforms).
+
+* **Support for user-defined routing tables on Linux**
+
+  See the `--route-table` option in the manpage
+
+* **PQE support for WolfSSL**
+
+* **New environment variables for gateway redirection**
+
+  Two new environment variables have been introduced to communicate desired
+  default gateway redirection to plugins like Network Manager,
+  `route_redirect_gateway_ipv4` and `route_redirect_gateway_ipv6`. See the
+  "Environmental Variables" section in the man page
+
+* **Improved logging of service events/errors to event log on Windows.**
+
+* **Improved "Recursive Routing" check**
+
+  The check is now more granular, and will only drop
+  packets-in-tunnel if destination IP, protocol and port matches with those needed
+  to reach the VPN server. With that change, you can now use policies that direct
+  "everything that is not OpenVPN" into the tunnel, and have IP packets to the VPN
+  server address arrive as expected (no such policies are currently installed by
+  OpenVPN) (GH: OpenVPN/openvpn#669).
+
+* **COPYING: license details only relevant to our Windows installers have
+been updated and moved to the openvpn-build repo**
+
+* **Improved BYTECOUNT support**
+
+  More strictly adhere to timing interval requested, correctly support client and
+  server counters with Linux and Windows DCO offloading.
+
+* **Improve compatibility with OpenSSL 3.6.0 (do not fail t_lpback selftest)**
+
+* **New option `--tls-crypt-v2-max-age n` to check tls-crypt-v2 timestamps**
+
+  When a client is older than n days or has no timestamp, the server will reject
+  it.
+
+* **mbedTLS 4 support has been added.**
+
+  Note that with mbedTLS 4 algorithms need to be translated to mbedTLS 4 internal
+  IDs by OpenVPN, and some names might be missing.
+
+## Deprecated features
+
+* **`secret` support has been removed (by default).**
+
+  static key mode (non-TLS) is no longer considered "good and secure enough" for
+  today's requirements. Use TLS mode instead. If deploying a PKI CA is considered
+  "too complicated", using `--peer-fingerprint` makes TLS mode about as easy as
+  using `--secret`.
+
+  This mode can still be enabled by using
+  `--allow-deprecated-insecure-static-crypto` but will be removed in OpenVPN 2.8.
+
+* **Support for wintun Windows driver has been removed.**
+
+  OpenVPN 2.6 added support for the new dco-win driver, so it supported three
+  different device drivers: dco-win, wintun, and tap-windows6. OpenVPN 2.7 now
+  drops the support for wintun driver. By default all modern configs should be
+  supported by dco-win driver. In all other cases OpenVPN will fall back
+  automatically to tap-windows6 driver.
+
+* **NTLMv1 authentication support for HTTP proxies has been removed.**
+
+  This is considered an insecure method of authentication that uses obsolete
+  crypto algorithms. NTLMv2 support is still available, but will be removed in a
+  future release. When configured to authenticate with NTLMv1 (`ntlm` keyword in
+  `--http-proxy`) OpenVPN will try NTLMv2 instead.
+
+* **`persist-key` option has been enabled by default.**
+
+  All the keys will be kept in memory across restart.
+
+* **OpenSSL 1.0.2 support has been removed.**
+
+  Support for building with OpenSSL 1.0.2 has been removed. The minimum supported
+  OpenSSL version is now 1.1.0.
+
+* **mbedTLS 2.x support has been removed**
+
+  Support for building with mbedTLS 2.x has been removed (it is out of support
+  since March 2025, and the necessary compatibility code is making maintenance and
+  support for mbedTLS 4.x hard). The minimum supported mbedTLS version is now
+  3.2.1.
+
+* **Compression on send has been removed.**
+
+  OpenVPN 2.7 will never compress data before sending. Decompression of received
+  data is still supported. `--allow-compression yes` is now an alias for
+  `--allow-compression asym`.
+
+* **`--memstats` feature removed**
+
+  The `--memstats` option was largely undocumented and there is no known user of
+  this feature. This feature provided very limited statistics (number of users,
+  link bytes read/written) and we do not except any usage because of this.
+
+* **Warning when using `--push` without `--mode server`**
+
+  Using `--push` in a mode that is not `--mode server` will now print a
+  clear warning that this is an unsupported operation and might cause negotiation
+  failures.
+
+* **Warning for `--reneg-bytes` and `--reneg-packets` in DCO mode**
+
+  `--reneg-bytes` and `--reneg-packets` do not work in DCO mode, and will
+  now print an appropriate warning.
+
+* **On-connect resolving of `--remote` in `--tcp-server` mode removed**
+
+  On-connect resolving of `--remote` addresses in `--tcp-server` mode
+  was not working since 2.4, so the code was completely removed.
+
+## User-visible Changes
+
+- Default for `--topology` changed to `subnet` for `--mode server`. Previous
+  releases always used `net30` as default. This only affects configs with
+  `--mode server` or `--server` (the latter implies the former), and
+  `--dev tun`, and only if IPv4 is enabled. Note that this changes the semantics
+  of `--ifconfig`, so if you have manual settings for that in your config but
+  not set `--topology` your config might fail to parse with the new version.
+  Just adding `--topology net30` to the config should fix the problem. By
+  default `--topology` is pushed from server to client.
+- `--x509-username-field` will no longer automatically convert fieldnames to
+  uppercase. This was deprecated since OpenVPN 2.4, and has now been removed.
+- `--dh none` is now the default if `--dh` is not specified. Modern TLS
+  implementations will prefer ECDH and other more modern algorithms anyway. And
+  finite field Diffie Hellman is in the proces of being deprecated (see
+  draft-ietf-tls-deprecate-obsolete-kex)
+- `--lport 0` does not imply `--bind` anymore.
+- `--redirect-gateway` now works correctly if the VPN remote is not reachable by
+  the default gateway.
+- `--show-gateway` now supports querying the gateway for IPv4 addresses.
+- `--static-challenge` option now has a third parameter `format` that can change
+  how password and challenge response should be combined.
+- `--key` and `--cert` now accept URIs implemented in OpenSSL 3 as well as
+  optional OpenSSL 3 providers loaded using `--providers` option.
+- `--cryptoapicert` now supports issuer name as well as Windows CA template name
+  or OID as selector string.
+- TLS handshake debugging information contains much more details now when using
+  recent versions of OpenSSL.
+- The `IV_PLAT_VER` variable sent by Windows clients now contains the full
+  Windows build version to make it possible to determine the Windows 10 or
+  Windows 11 version used.
+- The `--windows-driver` option to select between various windows drivers will
+  no longer do anything - it's kept so existing configs will not become invalid,
+  but it is ignored with a warning. The default is now `ovpn-dco` if all options
+  used are compatible with DCO, with a fallback to `tap-windows6`. To force TAP
+  (for example because a server pushes DCO incompatible options), use the
+  `--disable-dco` option.
+- Apply more checks to incoming TLS handshake packets before creating new
+  state - namely, verify message ID / acked ID for "valid range for an initial
+  packet". This fixes a problem with clients that float very early but send
+  control channel packet from the pre-float IP (Github: OpenVPN/openvpn#704).
+- Use of `--dh dh2048.pem` in all sample configs has been replaced with
+  `--dh none`. The `dh2048.pem` file has been removed.
+- The startup delay in `t_client.sh` has been reduced from 3s to 1s, making a
+  noticeable difference for setups with many tests.
+- Changed from using `uncrustify` for code formatting and pre-commit checks to
+  `clang-format`. This reformatted quite a bit of code, and requires that
+  regular committers change their pre-commit checks accordingly.
+- On Linux, on interfaces where applicable, OpenVPN explicitly configures the
+  broadcast address again. This was dropped for 2.6.0 "because computers are
+  smart and can do it themselves", but the kernel netlink interface isn't, and
+  will install "0.0.0.0". This does not normally matter, but for broadcast-based
+  applications that get the address to use from "ifconfig", this change repairs
+  functionality (this has been backported to 2.6.15, but is not in earlier 2.6
+  versions).
+- `max-routes-per-client 0` used to be silently upgraded to `1`. This now
+  produces an error.
+- `ifconfig` and `ifconfig-ipv6` values are now stored in pre-connect options
+  cache, and will be restored to pre-connect values on reconnects if the server
+  stops pushing the respective option.
+- `tapctl.exe` helper binary on Windows has been reworked to improve help texts
+  (making clear that it can not only do TAP-Adapters but Win-DCO as well), add
+  printing of the hwid to all adapter outputs, and change the default adapter
+  type created to `ovpn-dco`.
+- The default for `multihome` egress interface handling has changed. 2.7.0 will
+  default to ipi_ifindex=0, that is, leave the decision to the routing/policy
+  setup of the operating system. The pre-2.7 behaviour (force egress = ingress
+  interface) can be achieved with the new `--multihome same-interface`
+  sub-option.
+- Windows `openvpn.exe` binary manifest now sets code page UTF8 - which has no
+  direct effect on OpenVPN itself, but this repairs OpenSSL file loading for
+  key/cert files with non-ASCII characters in their file names (GH:
+  OpenVPN/openvpn#920).
+- The `test-crypto` option no longer requires a `--secret` argument and will
+  automatically generate a random key.
+- The configure-time option `--enable-x509-alt-username` is no longer
+  conditional, and always-on (GH: OpenVPN/openvpn#917).
+
+## Deprecated features
+
+* **`--opt-verify` feature removed**
+
+  This option was already deprecated and it is now being converted to a no-op.
+  Using this option will only print a warning.
+
+# Overview of changes in 2.6
+
+## Project changes
+
+We want to deprecate our old Trac bug tracking system. Please report any issues
+with this release in GitHub instead: <https://github.com/OpenVPN/openvpn/issues>
+
+## New features
+
+* **Support unlimited number of connection entries and remote entries**
+
+* **New management commands to enumerate and list remote entries**
+
+  Use `remote-entry-count` and `remote-entry-get` commands from the management
+  interface to get the number of remote entries and the entries themselves.
+
+* **Keying Material Exporters (RFC 5705) based key generation**
+
+  As part of the cipher negotiation OpenVPN will automatically prefer the RFC5705
+  based key material generation to the current custom OpenVPN PRF. This feature
+  requires OpenSSL or mbed TLS 2.18+.
+
+* **Compatibility with OpenSSL in FIPS mode**
+
+  OpenVPN will now work with OpenSSL in FIPS mode. Note, no effort has been made
+  to check or implement all the requirements/recommendation of FIPS 140-2. This
+  just allows OpenVPN to be run on a system that be configured OpenSSL in FIPS
+  mode.
+
+* **`mlock` now checks available memlock-able memory**
+
+  `mlock` will now check if enough memlock-able memory has been reserved,
+  and if less than 100MB RAM are available, use setrlimit() to upgrade the limit.
+  See Trac #1390. Not available on OpenSolaris.
+
+* **Certificate pinning/verify peer fingerprint**
+
+  The `--peer-fingerprint` option has been introduced to give users an easy to use
+  alternative to the `tls-verify` for matching the fingerprint of the peer. The
+  option takes use a number of allowed SHA256 certificate fingerprints.
+
+  See the man page section "Small OpenVPN setup with peer-fingerprint" for a
+  tutorial on how to use this feature. This is also available online under
+  <https://github.com/openvpn/openvpn/blob/master/doc/man-sections/example-fingerprint.rst>
+
+* **TLS mode with self-signed certificates**
+
+  When `--peer-fingerprint` is used, the `--ca` and `--capath` option become
+  optional. This allows for small OpenVPN setups without setting up a PKI with
+  Easy-RSA or similar software.
+
+* **Deferred auth support for scripts**
+
+  The `--auth-user-pass-verify` script supports now deferred authentication.
+
+* **Pending auth support for plugins and scripts**
+
+  Both auth plugin and script can now signal pending authentication to the client
+  when using deferred authentication. The new `client-crresponse` script option
+  and `OPENVPN_PLUGIN_CLIENT_CRRESPONSE` plugin function can be used to parse a
+  client response to a `CR_TEXT` two factor challenge.
+
+  See `sample/sample-scripts/totpauth.py` for an example.
+
+* **Compatibility mode (`--compat-mode`)**
+
+  The modernisation of defaults can impact the compatibility of OpenVPN 2.6.0 with
+  older peers. The options `--compat-mode` allows UIs to provide users with an
+  easy way to still connect to older servers.
+
+* **OpenSSL 3.0 support**
+
+  OpenSSL 3.0 has been added. Most of OpenSSL 3.0 changes are not user visible but
+  improve general compatibility with OpenSSL 3.0. `--tls-cert-profile insecure`
+  has been added to allow selecting the lowest OpenSSL security level (not
+  recommended, use only if you must). OpenSSL 3.0 no longer supports the Blowfish
+  (and other deprecated) algorithm by default and the new option `--providers`
+  allows loading the legacy provider to renable these algorithms.
+
+* **Optional ciphers in `--data-ciphers`**
+
+  Ciphers in `--data-ciphers` can now be prefixed with a `?` to mark those as
+  optional and only use them if the SSL library supports them.
+
+* **Improved `--mssfix` and `--fragment` calculation**
+
+  The `--mssfix` and `--fragment` options now allow an optional `mtu` parameter to
+  specify that different overhead for IPv4/IPv6 should taken into account and the
+  resulting size is specified as the total size of the VPN packets including IP
+  and UDP headers.
+
+* **Cookie based handshake for UDP server**
+
+  Instead of allocating a connection for each client on the initial packet OpenVPN
+  server will now use an HMAC based cookie as its session id. This way the server
+  can verify it on completing the handshake without keeping state. This eliminates
+  the amplification and resource exhaustion attacks. For tls-crypt-v2 clients,
+  this requires OpenVPN 2.6 clients or later because the client needs to resend
+  its client key on completing the hand shake. The tls-crypt-v2 option allows
+  controlling if older clients are accepted.
+
+  By default the rate of initial packet responses is limited to 100 per 10s
+  interval to avoid OpenVPN servers being abused in reflection attacks (see
+  `--connect-freq-initial`).
+
+* **Data channel offloading with ovpn-dco**
+
+  2.6.0+ implements support for data-channel offloading where the data packets are
+  directly processed and forwarded in kernel space thanks to the ovpn-dco kernel
+  module. The userspace openvpn program acts purely as a control plane
+  application. Note that DCO will use DATA\_V2 packets in P2P mode, therefore, this
+  implies that peers must be running 2.6.0+ in order to have P2P-NCP which brings
+  DATA\_V2 packet support.
+
+* **Session timeout**
+
+  It is now possible to terminate a session (or all) after a specified amount of
+  seconds has passed session commencement. This behaviour can be configured using
+  `--session-timeout`. This option can be configured on the server, on the client
+  or can also be pushed.
+
+* **Inline auth username and password**
+
+  Username and password can now be specified inline in the configuration file
+  within the `<auth-user-pass></auth-user-pass>` tags. If the password is
+  missing OpenVPN will prompt for input via stdin. This applies to inline'd
+  http-proxy-user-pass too.
+
+* **Tun MTU can be pushed**
+
+  The client can now also dynamically configure its MTU and the server will try to
+  push the client MTU when the client supports it. The directive `--tun-mtu-max`
+  has been introduced to increase the maximum pushable MTU size (defaults to
+  1600).
+
+* **Dynamic TLS Crypt**
+
+  When both peers are OpenVPN 2.6.1+, OpenVPN will dynamically create a tls-crypt
+  key that is used for renegotiation. This ensure that only the previously
+  authenticated peer can do trigger renegotiation and complete renegotiations.
+
+* **Improved control channel packet size control (`max-packet-size`)**
+
+  The size of control channel is no longer tied to `--link-mtu`/`--tun-mtu` and
+  can be set using `--max-packet-size`. Sending large control channel frames is
+  also optimised by allowing 6 outstanding packets instead of just 4.
+  `max-packet-size` will also set `mssfix` to try to limit data-channel packets as
+  well.
+
+## Deprecated features
+
+* **`inetd` has been removed**
+
+  This was a very limited and not-well-tested way to run OpenVPN, on TCP and TAP
+  mode only.
+
+* **`verify-hash` has been deprecated**
+
+  This option has very limited usefulness and should be replaced by either a
+  better `--ca` configuration or with a `--tls-verify` script.
+
+* **`secret` has been deprecated**
+
+  Static key mode (non-TLS) is no longer considered "good and secure enough" for
+  today's requirements. Use TLS mode instead. If deploying a PKI CA is considered
+  "too complicated", using `--peer-fingerprint` makes TLS mode about as easy as
+  using `--secret`.
+
+* **`ncp-disable` has been removed**
+
+  This option mainly served a role as debug option when NCP was first introduced.
+  It should now no longer be necessary.
+
+* **TLS 1.0 and 1.1 are deprecated**
+
+  `tls-version-min` is set to 1.2 by default. OpenVPN 2.6.0 defaults to a minimum
+  TLS version of 1.2 as TLS 1.0 and 1.1 should be generally avoided. Note that
+  OpenVPN versions older than 2.3.7 use TLS 1.0 only.
+
+* **`--cipher` argument is no longer appended to `--data-ciphers` by default**
+
+  Data cipher negotiation has been introduced in 2.4.0 and been
+  significantly improved in 2.5.0. The implicit fallback to the cipher specified
+  in `--cipher` has been removed. Effectively, `--cipher` is a no-op in TLS mode
+  now, and will only have an effect in pre-shared-key mode (`--secret`). From now
+  on `--cipher` should not be used in new configurations for TLS mode. Should
+  backwards compatibility with older OpenVPN peers be required, please see the
+  `--compat-mode` instead.
+
+* **`--prng` has beeen removed**
+
+  OpenVPN used to implement its own PRNG based on a hash. However implementing a
+  PRNG is better left to a crypto library. So we use the PRNG mbed TLS or OpenSSL
+  now.
+
+* **`--keysize` has been removed**
+
+  The `--keysize` option was only useful to change the key length when using the
+  BF, CAST6 or RC2 ciphers. For all other ciphers the key size is fixed with the
+  chosen cipher. As OpenVPN v2.6 no longer supports any of these variable length
+  ciphers, this option was removed as well to avoid confusion.
+
+* **Compression no longer enabled by default**
+
+  Unless an explicit compression option is specified in the configuration,
+  `--allow-compression` defaults to `no` in OpeNVPN 2.6.0. By default, OpenVPN 2.5
+  still allowed a server to enable compression by pushing compression related
+  options.
+
+* **PF (Packet Filtering) support has been removed**
+
+  The built-in PF functionality has been removed from the code base. This feature
+  wasn't really easy to use and was long unmaintained. This implies that also
+  `--management-client-pf` and any other compile time or run time related option
+  do not exist any longer.
+
+* **Option conflict checking is being deprecated and phased out**
+
+  The static option checking (OCC) is no longer useful in typical setups that
+  negotiate most connection parameters. The `--opt-verify` and `--occ-disable`
+  options are deprecated, and the configure option `--enable-strict-options` has
+  been removed. Logging of mismatched options has been moved to debug logging
+  (verb 7).
+
+## User-visible Changes
+
+- CHACHA20-POLY1305 is included in the default of `--data-ciphers` when
+  available.
+- Option `--prng` is ignored as we rely on the SSL library random number
+  generator.
+- Option `--nobind` is default when `--client` or `--pull` is used in the
+  configuration
+- `link_mtu` parameter is removed from environment or replaced with 0 when
+  scripts are called with parameters. This parameter is unreliable and no longer
+  internally calculated.
+- control channel packet maximum size is no longer influenced by
+  `--link-mtu`/`--tun-mtu` and must be set by `--max-packet-size` now. The
+  default is 1250 for the control channel size.
+- In point-to-point OpenVPN setups (no `--server`), using `--explict-exit-notiy`
+  on one end would terminate the other side at session end. This is considered a
+  no longer useful default and has been changed to "restart on reception of
+  explicit-exit-notify message". If the old behaviour is still desired,
+  `--remap-usr1 SIGTERM` can be used.
+- FreeBSD tun interfaces with `--topology subnet` are now put into real subnet
+  mode (IFF_BROADCAST instead of IFF_POINTOPOINT) - this might upset software
+  that enumerates interfaces, looking for "broadcast capable?" and expecting
+  certain results. Normal uses should not see any difference.
+- The default configurations will no longer allow connections to OpenVPN 2.3.x
+  peer or earlier, use the new `--compat-mode` option if you need compatibility
+  with older versions. See the manual page on the `--compat-mode` for details.
+- The `client-pending-auth` management command now requires also the key id. The
+  management version has been changed to 5 to indicate this change.
+- (OpenVPN 2.6.2) A client will now refuse a connection if pushed compression
+  settings will contradict the setting of allow-compression as this almost
+  always results in a non-working connection.
+- The "kill" by addr management command now requires also the protocol as string
+  e.g. "udp", "tcp".
+
+## Common errors with OpenSSL 3.0 and OpenVPN 2.6
+
+Both OpenVPN 2.6 and OpenSSL 3.0 tighten the security considerable, so some
+configuration will no longer work. This section will cover the most common
+causes and error message we have seen and explain their reason and temporary
+workarounds. You should fix the underlying problems as soon as possible since
+these workaround are not secure and will eventually stop working in a future
+update.
+
+- weak SHA1 or MD5 signature on certificates
+
+  This will happen on either loading of certificates or on connection to a
+  server:
+
+      OpenSSL: error:0A00018E:SSL routines::ca md too weak
+      Cannot load certificate file cert.crt
+      Exiting due to fatal error
+
+  OpenSSL 3.0 no longer allows weak signatures on certificates. You can
+  downgrade your security to allow them by using `--tls-cert-profile insecure`
+  but should replace/regenerate these certificates as soon as possible.
+
+- 1024 bit RSA certificates, 1024 bit DH parameters, other weak keys
+
+  This happens if you use private keys or other cryptographic material that does
+  not meet today's cryptographic standards anymore. Messages are similar to:
+
+      OpenSSL: error:0A00018F:SSL routines::ee key too small
+      OpenSSL: error:1408518A:SSL routines:ssl3_ctx_ctrl:dh key too small
+
+  DH parameters (`--dh`) can be regenerated with `openssl dhparam 2048`. For
+  other cryptographic keys, these keys and certificates need to be regenerated.
+  TLS Security level can be temporarily lowered with `--tls-cert-profile legacy`
+  or even `--tls-cert-profile insecure`.
+
+- Connecting to a OpenVPN 2.3.x server or allowing OpenVPN 2.3.x or earlier
+  clients
+
+  This will normally result in messages like:
+
+      OPTIONS ERROR: failed to negotiate cipher with server. Add the server's cipher ('AES-128-CBC') to --data-ciphers (currently 'AES-256-GCM:AES-128-GCM:CHACHA20-POLY1305') if you want to connect to this server.
+
+  or
+
+      client/127.0.0.1:49954 SENT CONTROL [client]: 'AUTH_FAILED,Data channel cipher negotiation failed (no shared cipher)' (status=1)
+
+  You can manually add the missing cipher to the `--data-ciphers`. The standard
+  ciphers should be included as well, e.g.
+  `--data-ciphers AES-256-GCM:AES-128-GCM:?Chacha20-Poly1305:?AES-128-CBC`. You
+  can also use the `--compat-mode` option. Note that these message may also
+  indicate other cipher configuration problems. See the data channel cipher
+  negotiation manual section for more details. (Available online under
+  <https://github.com/OpenVPN/openvpn/blob/master/doc/man-sections/cipher-negotiation.rst>)
+
+- Use of a legacy or deprecated cipher (e.g. 64bit block ciphers)
+
+  OpenSSL 3.0 no longer supports a number of insecure and outdated ciphers in
+  its default configuration. Some of these ciphers are known to be vulnerable
+  (SWEET32 attack).
+
+  This will typically manifest itself in messages like:
+
+      OpenSSL: error:0308010C:digital envelope routines::unsupported
+      Cipher algorithm 'BF-CBC' not found
+      Unsupported cipher in --data-ciphers: BF-CBC
+
+  If your OpenSSL distribution comes with the legacy provider (see also
+  `man OSSL_PROVIDER-legacy`), you can load it with
+  `--providers legacy default`. This will re-enable the old algorithms.
+
+- OpenVPN version not supporting TLS 1.2 or later
+
+  The default in OpenVPN 2.6 and also in many distributions is now TLS 1.2 or
+  later. Connecting to a peer that does not support this will results in
+  messages like:
+
+      TLS error: Unsupported protocol.
+
+  This typically indicates that client and server have no common TLS version
+  enabled. This can be caused by mismatched tls-version-min and tls-version-max
+  options on client and server. If your OpenVPN client is between v2.3.6 and
+  v2.3.2 try adding `tls-version-min 1.0` to the client configuration to use
+  TLS 1.0+ instead of TLS 1.0 only.
+
+      OpenSSL: error:0A000102:SSL routines::unsupported protocol
+
+  This can be an OpenVPN 2.3.6 or earlier version. `compat-version 2.3.0` will
+  enable TLS 1.0 support if supported by the OpenSSL distribution. Note that on
+  some Linux distributions enabling TLS 1.1 or 1.0 is not possible.
+
+# Overview of changes in 2.5
+
+## New features
+
+* **Client-specific tls-crypt keys (`--tls-crypt-v2`)**
+
+  `tls-crypt-v2` adds the ability to supply each client with a unique tls-crypt
+  key. This allows large organisations and VPN providers to profit from the same
+  DoS and TLS stack protection that small deployments can already achieve using
+  `tls-auth` or `tls-crypt`.
+
+* **ChaCha20-Poly1305 cipher support**
+
+  Added support for using the ChaCha20-Poly1305 cipher in the OpenVPN data
+  channel.
+
+* **Improved Data channel cipher negotiation**
+
+  The option `ncp-ciphers` has been renamed to `data-ciphers`. The old name is
+  still accepted. The change in name signals that `data-ciphers` is the preferred
+  way to configure data channel ciphers and the data prefix is chosen to avoid the
+  ambiguity that exists with `--cipher` for the data cipher and `tls-cipher` for
+  the TLS ciphers.
+
+  OpenVPN clients will now signal all supported ciphers from the `data-ciphers`
+  option to the server via `IV_CIPHERS`. OpenVPN servers will select the first
+  common cipher from the `data-ciphers` list instead of blindly pushing the first
+  cipher of the list. This allows to use a configuration like
+  `data-ciphers ChaCha20-Poly1305:AES-256-GCM` on the server that prefers
+  ChaCha20-Poly1305 but uses it only if the client supports it.
+
+  See the data channel negotiation section in the manual for more details.
+
+* **Removal of BF-CBC support in default configuration:**
+
+  By default OpenVPN 2.5 will only accept AES-256-GCM and AES-128-GCM as data
+  ciphers. OpenVPN 2.4 allows AES-256-GCM,AES-128-GCM and BF-CBC when no --cipher
+  and --ncp-ciphers options are present. Accepting BF-CBC can be enabled by adding
+
+  > data-ciphers AES-256-GCM:AES-128-GCM:BF-CBC
+
+  and when you need to support very old peers also
+
+  > data-ciphers-fallback BF-CBC
+
+  To offer backwards compatibility with older configs an *explicit*
+
+  > cipher BF-CBC
+
+  in the configuration will be automatically translated into adding BF-CBC to the
+  data-ciphers option and setting data-ciphers-fallback to BF-CBC (as in the
+  example commands above). We strongly recommend to switching away from BF-CBC to
+  a more secure cipher.
+
+* **Asynchronous (deferred) authentication support for auth-pam plugin.**
+
+  See src/plugins/auth-pam/README.auth-pam for details.
+
+* **Deferred client-connect**
+
+  The `--client-connect` option and the connect plugin API allow
+  asynchronous/deferred return of the configuration file in the same way as the
+  auth-plugin.
+
+* **Faster connection setup**
+
+  A client will signal in the `IV_PROTO` variable that it is in pull mode. This
+  allows the server to push the configuration options to the client without
+  waiting for a `PULL_REQUEST` message. The feature is automatically enabled if
+  both client and server support it and significantly reduces the connection setup
+  time by avoiding one extra packet round-trip and 1s of internal event delays.
+
+* **Netlink support**
+
+  On Linux, if configured without `--enable-iproute2`, configuring IP addresses
+  and adding/removing routes is now done via the netlink(3) kernel interface. This
+  is much faster than calling `ifconfig` or `route` and also enables OpenVPN to
+  run with less privileges.
+
+  If configured with --enable-iproute2, the `ip` command is used (as in 2.4).
+  Support for `ifconfig` and `route` is gone.
+
+* **Wintun support**
+
+  On Windows, OpenVPN can now use `wintun` devices. They are faster than the
+  traditional `tap9` tun/tap devices, but do not provide `--dev tap` mode - so the
+  official installers contain both. To use a wintun device, add
+  `--windows-driver wintun` to your config (and use of the interactive service is
+  required as wintun needs SYSTEM privileges to enable access).
+
+* **IPv6-only operation**
+
+  It is now possible to have only IPv6 addresses inside the VPN tunnel, and
+  IPv6-only address pools (2.4 always required IPv4 config/pools and IPv6 was the
+  "optional extra").
+
+* **Improved Windows 10 detection**
+
+  Correctly log OS on Windows 10 now.
+
+* **Linux VRF support**
+
+  Using the new `--bind-dev` option, the OpenVPN outside socket can now be put
+  into a Linux VRF. See the "Virtual Routing and Forwarding" documentation in the
+  man page.
+
+* **TLS 1.3 support**
+
+  TLS 1.3 support has been added to OpenVPN. Currently, this requires OpenSSL
+  1.1.1+. The options `--tls-ciphersuites` and `--tls-groups` have been added to
+  fine tune TLS protocol options. Most of the improvements were also backported to
+  OpenVPN 2.4 as part of the maintainance releases.
+
+* **Support setting DHCP search domain**
+
+  A new option `--dhcp-option DOMAIN-SEARCH my.example.com` has been defined, and
+  Windows support for it is implemented (tun/tap only, no wintun support yet).
+  Other platforms need to support this via `--up` script (Linux) or GUI
+  (OSX/Tunnelblick).
+
+* **per-client changing of `--data-ciphers` or `data-ciphers-fallback`**
+
+  Via client-connect script/dir (NOTE: this only changes preference of ciphers
+  for NCP, but can not override what the client announces as "willing to accept").
+
+* **Handle setting of tun/tap interface MTU on Windows**
+
+  If IPv6 is in use, MTU must be >= 1280 (Windows enforces IETF requirements)
+
+* **Add support for OpenSSL engines to access private key material (like TPM).**
+
+* **HMAC based auth-token support**
+
+  The `--auth-gen-token` support has been improved and now generates HMAC based
+  user token. If the optional `--auth-gen-token-secret` option is used clients
+  will be able to seamlessly reconnect to a different server using the same secret
+  file or to the same server after a server restart.
+
+* **Improved support for pending authentication**
+
+  The protocol has been enhanced to be able to signal that the authentication
+  should use a secondary authentication via web (like SAML) or a two factor
+  authentication without disconnecting the OpenVPN session with AUTH_FAILED. The
+  session will instead be stay in a authenticated state and wait for the second
+  factor authentication to complete.
+
+  This feature currently requires usage of the managent interface on both client
+  and server side. See the `management-notes.txt` `client-pending-auth` and
+  `cr-response` commands for more details.
+
+* **VLAN support**
+
+  OpenVPN servers in TAP mode can now use 802.1q tagged VLANs on the TAP interface
+  to separate clients into different groups that can then be handled differently
+  (different subnets / DHCP, firewall zones, ...) further down the network. See
+  the new options `--vlan-tagging`, `--vlan-accept`, `--vlan-pvid`.
+
+  802.1q tagging on the client side TAP interface is not handled today (= tags are
+  just forwarded transparently to the server).
+
+* **Support building of .msi installers for Windows**
+
+* **Allow unicode search string in `--cryptoapicert` option (Windows)**
+
+* **Support IPv4 configs with /31 netmasks now**
+
+  (By no longer trying to configure `broadcast x.x.x.x` in ifconfig calls, /31
+  support "just works")
+
+* **New option `--block-ipv6` to reject all IPv6 packets (ICMPv6)**
+
+  This is useful if the VPN service has no IPv6, but the clients might have (LAN),
+  to avoid client connections to IPv6-enabled servers leaking "around" the
+  IPv4-only VPN.
+
+* **`--ifconfig-ipv6` and `--ifconfig-ipv6-push` accept hostnames**
+
+  `--ifconfig-ipv6` and `--ifconfig-ipv6-push` will now accept hostnames and do
+  a DNS lookup to get the IPv6 address to use.
+
+## Deprecated features
+
+For an up-to-date list of all deprecated options, see this wiki page:
+<https://community.openvpn.net/openvpn/wiki/DeprecatedOptions>
+
+- `ncp-disable` has been deprecated.
+
+  With the improved and matured data channel cipher negotiation, the use of
+  `ncp-disable` should not be necessary anymore.
+
+- `inetd` has been deprecated.
+
+  This is a very limited and not-well-tested way to
+  run OpenVPN, on TCP and TAP mode only, which complicates the code quite a bit
+  for little gain. To be removed in OpenVPN 2.6 (unless users protest).
+
+- `no-iv` has been removed.
+
+  This option was made into a NOOP option with OpenVPN
+  2.4. This has now been completely removed.
+
+- `--client-cert-not-required` has been removed
+
+  This option will now cause server configurations to not start.
+  Use `--verify-client-cert none` instead.
+
+- `--ifconfig-pool-linear` has been removed.
+
+  This option is removed. Use `--topology p2p` or `--topology subnet` instead.
+
+- `--compress xxx` is considered risky and is warned against, see below.
+
+- `--key-method 1` has been removed
+
+## User-visible Changes
+
+- If multiple connect handlers are used (client-connect, ccd, connect plugin)
+  and one of the handler succeeds but a subsequent fails, the
+  client-disconnect-script is now called immediately. Previously it was called,
+  when the VPN session was terminated.
+- Support for building with OpenSSL 1.0.1 has been removed. The minimum
+  supported OpenSSL version is now 1.0.2.
+- The GET_CONFIG management state is omitted if the server pushes the client
+  configuration almost immediately as result of the faster connection setup
+  feature.
+- `--compress` is nowadays considered risky, because attacks exist leveraging
+  compression-inside-crypto to reveal plaintext (VORACLE). So by default,
+  `--compress xxx` will now accept incoming compressed packets (for
+  compatibility with peers that have not been upgraded yet), but will not use
+  compression outgoing packets. This can be controlled with the new option
+  `--allow-compression yes|no|asym`.
+- Stop changing `--txlen` aways from OS defaults unless explicitly specified in
+  config file. OS defaults nowadays are actually larger then what we used to
+  configure, so our defaults sometimes caused packet drops = bad performance.
+- remove `--writepid` pid file on exit now
+- plugin-auth-pam now logs via OpenVPN logging method, no longer to stderr (this
+  means you'll have log messages in syslog or openvpn log file now)
+- use ISO 8601 time format for file based logging now (YYYY-MM-DD hh:mm:dd)
+  (syslog is not affected, nor is `--machine-readable-output`)
+- `--clr-verify` now loads all CRLs if more than one CRL is in the same file
+  (OpenSSL backend only, mbedTLS always did that)
+- when `--auth-user-pass file` has no password, and the management interface is
+  active, query management interface (instead of trying console query, which
+  does not work on windows)
+- skip expired certificates in Windows certificate store (`--cryptoapicert`)
+- `--socks-proxy` + `--proto udp*` will now allways use IPv4, even if IPv6 is
+  requested and available. Our SOCKS code does not handle IPv6+UDP, and before
+  that change it would just fail in non-obvious ways.
+- TCP listen() backlog queue is now set to 32 - this helps TCP servers that
+  receive lots of "invalid" connects by TCP port scanners
+- do no longer print OCC warnings ("option mismatch") about `key-method`,
+  `keydir`, `tls-auth` and `cipher` - these are either gone now, or negotiated,
+  and the warnings do not serve a useful purpose.
+- `dhcp-option DNS` and `dhcp-option DNS6` are now treated identically (= both
+  accept an IPv4 or IPv6 address for the nameserver)
+
+## Maintainer-visible changes
+
+- the man page is now in maintained in .rst format, so building the openvpn.8
+  manpage from a git checkout now requires python-docutils (if this is missing,
+  the manpage will not be built - which is not considered an error generally,
+  but for package builders or `make distcheck` it is). Release tarballs contain
+  the openvpn.8 file, so unless some .rst is changed, doc-utils are not needed
+  for building.
+- OCC support can no longer be disabled
+- AEAD support is now required in the crypto library
+- `--disable-server` has been removed from configure (so it is no longer
+  possible to build a client-/p2p-only OpenVPN binary) - the saving in code size
+  no longer outweighs the extra maintenance effort.
+- `--enable-iproute2` will disable netlink(3) support, so maybe remove that from
+  package building configs (see above)
+- support building with MSVC 2019
+- cmocka based unit tests are now only run if cmocka is installed externally
+  (2.4 used to ship a local git submodule which was painful to maintain)
+- `--disable-crypto` configure option has been removed. OpenVPN is now always
+  built with crypto support, which makes the code much easier to maintain. This
+  does not affect `--cipher none` to do a tunnel without encryption.
+- `--disable-multi` configure option has been removed
+
+# Overview of changes in 2.4
+
+## New features
+
+* **Seamless client IP/port floating**
+
+  Added new packet format P_DATA_V2, which includes peer-id. If both the server
+  and client support it, the client sends all data packets in the new format. When
+  a data packet arrives, the server identifies peer by peer-id. If peer's ip/port
+  has changed, server assumes that client has floated, verifies HMAC and updates
+  ip/port in internal structs. This allows the connection to be immediately
+  restored, instead of requiring a TLS handshake before the server accepts packets
+  from the new client ip/port.
+
+* **Data channel cipher negotiation**
+
+  Data channel ciphers (`--cipher`) are now by default negotiated. If a client
+  advertises support for Negotiable Crypto Parameters (NCP), the server will
+  choose a cipher (by default AES-256-GCM) for the data channel, and tell the
+  client to use that cipher. Data channel cipher negotiation can be controlled
+  using `--ncp-ciphers` and `--ncp-disable`.
+
+  A more limited version also works in client-to-server and server-to-client
+  scenarios where one of the end points uses a v2.4 client or server and the other
+  side uses an older version. In such scenarios the v2.4 side will change to the
+  `--cipher` set by the remote side, if permitted by by `--ncp-ciphers`. For
+  example, a v2.4 client with `--cipher BF-CBC` and
+  `ncp-ciphers AES-256-GCM:AES-256-CBC` can connect to both a v2.3 server with
+  `cipher BF-CBC` as well as a server with `cipher AES-256-CBC` in its config. The
+  other way around, a v2.3 client with either `cipher BF-CBC` or
+  `cipher AES-256-CBC` can connect to a v2.4 server with e.g. `cipher BF-CBC` and
+  `ncp-ciphers AES-256-GCM:AES-256-CBC` in its config. For this to work it
+  requires that OpenVPN was built without disabling OCC support.
+
+* **AEAD (GCM) data channel cipher support**
+
+  The data channel now supports AEAD ciphers (currently only GCM). The AEAD packet
+  format has a smaller crypto overhead than the CBC packet format, (e.g. 20 bytes
+  per packet for AES-128-GCM instead of 36 bytes per packet for AES-128-CBC +
+  HMAC-SHA1).
+
+* **ECDH key exchange**
+
+  The TLS control channel now supports for elliptic curve diffie-hellmann key
+  exchange (ECDH).
+
+* **Improved Certificate Revocation List (CRL) processing**
+
+  CRLs are now handled by the crypto library (OpenSSL or mbed TLS), instead of
+  inside OpenVPN itself. The crypto library implementations are more strict than
+  the OpenVPN implementation was. This might reject peer certificates that would
+  previously be accepted. If this occurs, OpenVPN will log the crypto library's
+  error description.
+
+* **Dualstack round-robin DNS client connect**
+
+  Instead of only using the first address of each `--remote` OpenVPN will now try
+  all addresses (IPv6 and IPv4) of a `--remote` entry.
+
+* **Support for providing IPv6 DNS servers**
+
+  A new DHCP sub-option `DNS6` is added alongside with the already existing `DNS`
+  sub-option. This is used to provide DNS resolvers available over IPv6. This may
+  be pushed to clients where `--up` scripts and `--plugin` can act upon it through
+  the `foreign_option_<n>` environment variables.
+
+  Support for the Windows client picking up this new sub-option is added, however
+  IPv6 DNS resolvers need to be configured via `netsh` which requires
+  administrator privileges unless the new interactive services on Windows is being
+  used. If the interactive service is used, this service will execute `netsh` in
+  the background with the proper privileges.
+
+* **New improved Windows Background service**
+
+  The new OpenVPNService is based on openvpnserv2, a complete rewrite of the
+  OpenVPN service wrapper. It is intended for launching OpenVPN instances that
+  should be up at all times, instead of being manually launched by a user.
+  OpenVPNService is able to restart individual OpenVPN processes if they crash,
+  and it also works properly on recent Windows versions. OpenVPNServiceLegacy
+  tends to work poorly, if at all, on newer Windows versions (8+) and its use is
+  not recommended.
+
+* **New interactive Windows service**
+
+  The installer starts OpenVPNServiceInteractive automatically and configures it
+  to start at system startup.
+
+  The interactive Windows service allows unprivileged users to start OpenVPN
+  connections in the global config directory (usually C:\Program
+  Files\OpenVPN\config) using OpenVPN GUI without any extra configuration.
+
+  Users who belong to the built-in Administrator group or to the local "OpenVPN
+  Administrator" group can also store configuration files under
+  %USERPROFILE%\OpenVPN\config for use with the interactive service.
+
+* **redirect-gateway ipv6**
+
+  OpenVPN has now feature parity between IPv4 and IPv6 for redirect gateway
+  including the handling of overlapping IPv6 routes with IPv6 remote VPN server
+  address.
+
+* **LZ4 Compression and pushable compression**
+
+  Additionally to LZO compression OpenVPN now also supports LZ4 compression.
+  Compression options are now pushable from the server.
+
+* **Filter pulled options client-side: pull-filter**
+
+  New option to explicitly allow or reject options pushed by the server. May be
+  used multiple times and is applied in the order specified.
+
+* **Per-client remove push options: push-remove**
+
+  New option to remove options on a per-client basis from the "push" list (more
+  fine-grained than `--push-reset`).
+
+* **Http proxy password inside config file**
+
+  Http proxy passwords can be specified with the inline file option
+  `<http-proxy-user-pass>` .. `</http-proxy-user-pass>`
+
+* **Windows version detection**
+
+  Windows version is detected, logged and possibly signalled to server
+  (`IV_PLAT_VER=<nn>` if `--push-peer-info` is set on client).
+
+* **Authentication tokens**
+
+  In situations where it is not suitable to save user passwords on the client,
+  OpenVPN has support for pushing a --auth-token since v2.3. This option is pushed
+  from the server to the client with a token value to be used instead of the users
+  password. For this to work, the authentication plug-in would need to implement
+  this support as well. In OpenVPN 2.4 --auth-gen-token is introduced, which will
+  allow the OpenVPN server to generate a random token and push it to the client
+  without any changes to the authentication modules. When the clients need to
+  re-authenticate the OpenVPN server will do the authentication internally,
+  instead of sending the re-authentication request to the authentication module .
+  This feature is especially useful in configurations which use One Time Password
+  (OTP) authentication schemes, as this allows the tunnel keys to be renegotiated
+  regularly without any need to supply new OTP codes.
+
+* **keying-material-exporter**
+
+  Keying Material Exporter [RFC-5705] allow additional keying material to be
+  derived from existing TLS channel.
+
+* **Android platform support**
+
+  Support for running on Android using Android's VPNService API has been added.
+  See doc/android.txt for more details. This support is primarily used in the
+  OpenVPN for Android app (<https://github.com/schwabe/ics-openvpn>)
+
+* **AIX platform support**
+
+  AIX platform support has been added. The support only includes tap devices since
+  AIX does not provide tun interface.
+
+* **Control channel encryption (`--tls-crypt`)**
+
+  Use a pre-shared static key (like the `--tls-auth` key) to encrypt control
+  channel packets. Provides more privacy, some obfuscation and poor-man's
+  post-quantum security.
+
+* **Asynchronous push reply**
+
+  Plug-ins providing support for deferred authentication can benefit from a more
+  responsive authentication where the server sends PUSH\_REPLY immediately once the
+  authentication result is ready, instead of waiting for the client to to send
+  PUSH\_REQUEST once more. This requires OpenVPN to be built with
+  `./configure --enable-async-push`. This is a compile-time only switch.
+
+## Deprecated features
+
+For an up-to-date list of all deprecated options, see this wiki page:
+<https://community.openvpn.net/openvpn/wiki/DeprecatedOptions>
+
+- `--key-method 1` is deprecated in OpenVPN 2.4 and will be removed in v2.5.
+  Migrate away from `--key-method 1` as soon as possible. The recommended
+  approach is to remove the `--key-method` option from the configuration files,
+  OpenVPN will then use `--key-method 2` by default. Note that this requires
+  changing the option in both the client and server side configs.
+- `--tls-remote` is removed in OpenVPN 2.4, as indicated in the v2.3 man-pages.
+  Similar functionality is provided via `--verify-x509-name`, which does the
+  same job in a better way.
+- `--compat-names` and `--no-name-remapping` were deprecated in OpenVPN 2.3 and
+  will be removed in v2.5. All scripts and plug-ins depending on the old
+  non-standard X.509 subject formatting must be updated to the standardized
+  formatting. See the man page for more information.
+- `--no-iv` is deprecated in OpenVPN 2.4 and will be removed in v2.5.
+- `--keysize` is deprecated in OpenVPN 2.4 and will be removed in v2.6 together
+  with the support of ciphers with cipher block size less than 128-bits.
+- `--comp-lzo` is deprecated in OpenVPN 2.4. Use `--compress` instead.
+- `--ifconfig-pool-linear` has been deprecated since OpenVPN 2.1 and will be
+  removed in v2.5. Use `--topology p2p` instead.
+- `--client-cert-not-required` is deprecated in OpenVPN 2.4 and will be removed
+  in v2.5. Use `--verify-client-cert none` for a functional equivalent.
+- `--ns-cert-type` is deprecated in OpenVPN 2.3.18 and v2.4. It will be removed
+  in v2.5. Use the far better `--remote-cert-tls` option which replaces this
+  feature.
+
+## User-visible Changes
+
+- When using ciphers with cipher blocks less than 128-bits, OpenVPN will
+  complain loudly if the configuration uses ciphers considered weak, such as the
+  SWEET32 attack vector. In such scenarios, OpenVPN will by default renegotiate
+  for each 64MB of transported data (`--reneg-bytes`). This renegotiation can be
+  disabled, but is HIGHLY DISCOURAGED.
+
+- For certificate DNs with duplicate fields, e.g. "OU=one,OU=two", both fields
+  are now exported to the environment, where each second and later occurrence of
+  a field get `_$N` appended to it's field name, starting at N=1. For the
+  example above, that would result in e.g. `X509_0_OU=one`, `X509_0_OU_1=two`. Note
+  that this breaks setups that rely on the fact that OpenVPN would previously
+  (incorrectly) only export the last occurrence of a field.
+
+- `proto udp` and `proto tcp` now use both IPv4 and IPv6. The new options
+  `proto udp4` and `proto tcp4` use IPv4 only.
+
+- `--sndbuf` and `--recvbuf` default now to OS defaults instead of 64k
+
+- OpenVPN exits with an error if an option has extra parameters; previously they
+  were silently ignored
+
+- `--tls-auth` always requires OpenVPN static key files and will no longer work
+  with free form files
+
+- `--proto udp6/tcp6` in server mode will now try to always listen to both IPv4
+  and IPv6 on platforms that allow it. Use `--bind ipv6only` to explicitly
+  listen only on IPv6.
+
+- Removed `--enable-password-save` from configure. This option is now always
+  enabled.
+
+- Stricter default TLS cipher list (override with `--tls-cipher`), that now also
+  disables:
+
+  - Non-ephemeral key exchange using static (EC)DH keys
+  - DSS private keys
+
+- mbed TLS builds: changed the `tls_digest_N` values exported to the script
+  environment to be equal to the ones exported by OpenSSL builds, namely the
+  certificate fingerprint (was the hash of the 'to be signed' data).
+
+- mbed TLS builds: minimum RSA key size is now 2048 bits. Shorter keys will not
+  be accepted, both local and from the peer.
+
+- `--connect-timeout` now specifies the timeout until the first TLS packet is
+  received (identical to `--server-poll-timeout`) and this timeout now includes
+  the removed socks proxy timeout and http proxy timeout.
+
+  In `--static` mode `connect-timeout` specifies the timeout for TCP and proxy
+  connection establishment
+
+- `--connect-retry-max` now specifies the maximum number of unsuccessful
+  attempts of each remote/connection entry before exiting.
+
+- `--http-proxy-timeout` and the static non-changeable socks timeout (5s) have
+  been folded into a "unified" `--connect-timeout` which covers all steps needed
+  to connect to the server, up to the start of the TLS exchange. The default
+  value has been raised to 120s, to handle slow http/socks proxies graciously.
+  The old "fail TCP fast" behaviour can be achieved by adding
+  "`--connect-timeout 10`" to the client config.
+
+- `--http-proxy-retry` and `--sock-proxy-retry` have been removed. Proxy
+  connections will now behave like regular connection entries and generate a
+  USR1 on failure.
+
+- `--connect-retry` gets an optional second argument that specifies the maximum
+  time in seconds to wait between reconnection attempts when an exponential
+  backoff is triggered due to repeated retries. Default = 300 seconds.
+
+- Data channel cipher negotiation (see New features section) can override
+  ciphers configured in the config file. Use `--ncp-disable` if you do not want
+  this behavior.
+
+- All tun devices on all platforms are always considered to be IPv6 capable. The
+  `--tun-ipv6` option is ignored (behaves like it is always on).
+
+- On the client side recursively routed packets, which have the same destination
+  as the VPN server, are dropped. This can be disabled with
+  --allow-recursive-routing option.
+
+- On Windows, when the `--register-dns` option is set, OpenVPN no longer
+  restarts the `dnscache` service - this had unwanted side effects, and seems to
+  be no longer necessary with currently supported Windows versions.
+
+- If no flags are given, and the interactive Windows service is used, "def1" is
+  implicitly set (because "delete and later reinstall the existing default
+  route" does not work well here). If not using the service, the old behaviour
+  is kept.
+
+- OpenVPN now reloads a CRL only if the modication time or file size has
+  changed, instead of for each new connection. This reduces the connection setup
+  time, in particular when using large CRLs.
+
+- OpenVPN now ships with more up-to-date systemd unit files which take advantage
+  of the improved service management as well as some hardening steps. The
+  configuration files are picked up from the /etc/openvpn/server/ and
+  /etc/openvpn/client/ directories (depending on unit file). This also avoids
+  these new unit files and how they work to collide with older pre-existing unit
+  files.
+
+- Using `--no-iv` (which is generally not a recommended setup) will require
+  explicitly disabling NCP with `--disable-ncp`. This is intentional because NCP
+  will by default use AES-GCM, which requires an IV - so we want users of that
+  option to consciously reconsider.
+
+## Maintainer-visible changes
+
+- OpenVPN no longer supports building with crypto support, but without TLS
+  support. As a consequence, `OPENSSL_CRYPTO_{CFLAGS,LIBS}` and
+  `OPENSSL_SSL_{CFLAGS,LIBS}` have been merged into `OPENSSL_{CFLAGS,LIBS}`.
+  This is particularly relevant for maintainers who build their own OpenSSL
+  library, e.g. when cross-compiling.
+- Linux distributions using systemd is highly encouraged to ship these new unit
+  files instead of older ones, to provide a unified behaviour across systemd
+  based Linux distributions.
+- With OpenVPN 2.4, the project has moved over to depend on and actively use the
+  official C99 standard (-std=c99). This may fail on some older compiler/libc
+  header combinations. In most of these situations it is recommended to use
+  -std=gnu99 in CFLAGS. This is known to be needed when doing i386/i686 builds
+  on RHEL5.
+
+# Version 2.4.5
+
+## New features
+
+- The new option `--tls-cert-profile` can be used to restrict the set of allowed
+  crypto algorithms in TLS certificates in mbed TLS builds. The default profile
+  is 'legacy' for now, which allows SHA1+, RSA-1024+ and any elliptic curve
+  certificates. The default will be changed to the 'preferred' profile in the
+  future, which requires SHA2+, RSA-2048+ and any curve.
+
+# Version 2.4.3
+
+## New features
+
+- Support building with OpenSSL 1.1 now (in addition to older versions)
+- On Win10, set low interface metric for TAP adapter when block-outside-dns is
+  in use, to make Windows prefer the TAP adapter for DNS queries (avoiding large
+  delays)
+
+## Security
+
+- CVE-2017-7522: Fix `--x509-track` post-authentication remote DoS A client
+  could crash a v2.4+ mbedtls server, if that server uses the `--x509-track`
+  option and the client has a correct, signed and unrevoked certificate that
+  contains an embedded NUL in the certificate subject. Discovered and reported
+  to the OpenVPN security team by Guido Vranken.
+- CVE-2017-7521: Fix post-authentication remote-triggerable memory leaks A
+  client could cause a server to leak a few bytes each time it connects to the
+  server. That can eventually cause the server to run out of memory, and thereby
+  causing the server process to terminate. Discovered and reported to the
+  OpenVPN security team by Guido Vranken. (OpenSSL builds only.)
+- CVE-2017-7521: Fix a potential post-authentication remote code execution
+  attack on servers that use the `--x509-username-field` option with an X.509
+  extension field (option argument prefixed with `ext:`). A client that can
+  cause a server to run out-of-memory (see above) might be able to cause the
+  server to double free, which in turn might lead to remote code execution.
+  Discovered and reported to the OpenVPN security team by Guido Vranken.
+  (OpenSSL builds only.)
+- CVE-2017-7520: Pre-authentication remote crash/information disclosure for
+  clients. If clients use a HTTP proxy with NTLM authentication (i.e.
+  `--http-proxy <server> <port> [<authfile>|'auto'|'auto-nct'] ntlm2`), a
+  man-in-the-middle attacker between the client and the proxy can cause the
+  client to crash or disclose at most 96 bytes of stack memory. The disclosed
+  stack memory is likely to contain the proxy password. If the proxy password is
+  not reused, this is unlikely to compromise the security of the OpenVPN tunnel
+  itself. Clients who do not use the `--http-proxy` option with ntlm2
+  authentication are not affected.
+- CVE-2017-7508: Fix remotely-triggerable ASSERT() on malformed IPv6 packet.
+  This can be used to remotely shutdown an openvpn server or client, if IPv6 and
+  `--mssfix` are enabled and the IPv6 networks used inside the VPN are known.
+- Fix null-pointer dereference when talking to a malicious http proxy that
+  returns a malformed `Proxy-Authenticate:` headers for digest auth.
+- Fix overflow check for long `--tls-cipher` option
+- Windows: Pass correct buffer size to `GetModuleFileNameW()` (OSTIF/Quarkslabs
+  audit, finding 5.6)
+
+## User-visible Changes
+
+- `--verify-hash` can now take an optional flag which changes the hashing
+  algorithm. It can be either SHA1 or SHA256. The default if not provided is
+  SHA1 to preserve backwards compatibility with existing configurations.
+- Restrict the supported `--x509-username-field` extension fields to
+  subjectAltName and issuerAltName. Other extensions probably didn't work
+  anyway, and would cause OpenVPN to crash when a client connects.
+
+## Bugfixes
+
+- Fix fingerprint calculation in mbed TLS builds. This means that mbed TLS users
+  of OpenVPN 2.4.0, v2.4.1 and v2.4.2 that rely on the values of the
+  `tls_digest_*` env vars, or that use `--verify-hash` will have to change the
+  fingerprint values they check against. The security impact of the incorrect
+  calculation is very minimal; the last few bytes (max 4, typically 4) are not
+  verified by the fingerprint. We expect no real-world impact,
+  because users that used this feature before will notice that it has suddenly
+  stopped working, and users that didn't will notice that connection setup fails
+  if they specify correct fingerprints.
+
+- Fix edge case with NCP when the server sends an empty PUSH_REPLY message back,
+  and the client would not initialize it's data channel crypto layer properly
+  (trac #903)
+
+- Fix SIGSEGV on unaligned buffer access on OpenBSD/Sparc64
+
+- Fix TCP_NODELAY on OpenBSD
+
+- Remove erroneous limitation on max number of args for `--plugin`
+
+- Fix NCP behaviour on TLS reconnect (Server would not send a proper "cipher
+  ..." message back to the client, leading to client and server using different
+  ciphers) (trac #887)
+
+# Version 2.4.2
+
+## Bugfixes
+
+- Fix memory leak introduced in OpenVPN 2.4.1: if `--remote-cert-tls` is used,
+  we leaked some memory on each TLS (re)negotiation.
+
+## Security
+
+- Fix a pre-authentication denial-of-service attack on both clients and servers.
+  By sending a too-large control packet, OpenVPN 2.4.0 or v2.4.1 can be forced
+  to hit an ASSERT() and stop the process. If `--tls-auth` or `--tls-crypt` is
+  used, only attackers that have the `--tls-auth` or `--tls-crypt` key can mount
+  an attack. (OSTIF/Quarkslab audit finding 5.1, CVE-2017-7478)
+- Fix an authenticated remote DoS vulnerability that could be triggered by
+  causing a packet id roll over. An attack is rather inefficient; a peer would
+  need to get us to send at least about 196 GB of data. (OSTIF/Quarkslab audit
+  finding 5.2, CVE-2017-7479)
+
+# Version 2.4.1
+
+- `--remote-cert-ku` now only requires the certificate to have at least the bits
+  set of one of the values in the supplied list, instead of requiring an exact
+  match to one of the values in the list.
+- `--remote-cert-tls` now only requires that a keyUsage is present in the
+  certificate, and leaves the verification of the value up to the crypto
+  library, which has more information (i.e. the key exchange method in use) to
+  verify that the keyUsage is correct.
+- `--ns-cert-type` is deprecated. Use `--remote-cert-tls` instead. The
+  nsCertType x509 extension is very old, and barely used. `--remote-cert-tls`
+  uses the far more common keyUsage and extendedKeyUsage extension instead. Make
+  sure your certificates carry these to be able to use `--remote-cert-tls`.
diff --git a/Changes.rst b/Changes.rst
deleted file mode 100644
index fe81909..0000000
--- a/Changes.rst
+++ /dev/null
@@ -1,1480 +0,0 @@ 
-Overview of changes in 2.8
-==========================
-User-visible Changes
---------------------
-Parsing Distinguished Names in certificates
-    (OpenSSL backend:) OpenVPN now rejects certificates that have a null-byte
-    inside any of the field values of their subject. To avoid ambiguity in the
-    parsed subject, OpenVPN escapes the following characters by prefixing them with
-    a backslash:
-     * " " (space) at the start or end of a field,
-     * "#" at the start of a field,
-     * ",", "+", """, "\", "<", ">" and ";" anywhere.
-
-    As a result, if you use the option ``--verify-x509-name <expected subject>``,
-    you need to prefix these characters with a backslash in your configuration.
-    The subject passed to a ``--tls-verify`` script is escaped in the same way and
-    you may need to adjust your script.
-
-    (Mbed TLS backend:) The behavior has not changed. Subjects with null-bytes were
-    already rejected (assuming OpenVPN was built with Mbed TLS 3.5 or later) and
-    the characters mentioned above were already escaped. However, the behavior of
-    Mbed TLS is slightly different from OpenSSL in that it also escapes "=".
-
-
-Overview of changes in 2.7
-==========================
-New features
-------------
-Multi-socket support for servers
-    OpenVPN servers now can listen on multiple sockets at the same time.
-    Multiple ``--local`` statements in the configuration can be used to
-    configure this. This way the same server can e.g. listen for UDP
-    and TCP connections at the same time, or listen on multiple addresses
-    and/or ports.
-
-Client implementations for DNS options sent by server for Linux/BSD/macOS
-    Linux, BSD and macOS versions of OpenVPN now ship with a per-platform
-    default ``--dns-updown`` script that implements proper handling of
-    DNS configuration sent by the server.  The scripts should work on
-    systems that use ``systemd`` or ``resolveconf`` to manage the DNS
-    setup, as well as raw ``/etc/resolv.conf`` files. However, the exact
-    features supported will depend on the configuration method.
-    On Linux and MacOS this should usually make split-DNS configurations
-    supported out-of-the-box now.
-
-    Note that this new script will not be used by default if a ``--up``
-    script is already in use to reduce problems with
-    backwards compatibility.
-
-    See documentation for ``--dns-updown`` and ``--dns`` for more details.
-
-New client implementation for DNS options sent by server for Windows
-    The Windows client now uses NRPT (Name Resolution Policy Table) to
-    handle DNS configurations. This adds support for split-DNS and DNSSEC
-    and improves the compatbility with local DNS resolvers. Requires the
-    interactive service.
-
-On Windows the ``block-local`` flag is now enforced with WFP filters.
-    The ``block-local`` flag to ``--redirect-gateway`` and
-    ``--redirect-private`` is now also enforced via the Windows Firewall,
-    making sure packets can't be sent to the local network.
-    This provides stronger protection against TunnelCrack-style attacks.
-
-Windows network adapters are now generated on demand
-    This means that on systems that run multiple OpenVPN connections at
-    the same time the users don't need to manually create enough network
-    adapters anymore (in addition to the ones created by the installer).
-
-Windows automatic service now runs as an unpriviledged user
-    All tasks that need privileges are now delegated to the interactive
-    service.
-    **NOTE** this has the risk of breaking existing setups if the
-    Windows certificate store is used (cryptoapi), and the certificates
-    are not readable for ``NT SERVICE\OpenVPNService``.
-
-Support for new version of Linux DCO module
-    The OpenVPN DCO module has been merged into the Linux kernel as of
-    6.16.  This required some API changes and OpenVPN 2.7 only supports
-    the new API. The new module is called ``ovpn``. Out-of-tree builds
-    for older kernels are available from
-    https://github.com/OpenVPN/ovpn-backports. Please
-    see the release announcements for further information.
-
-Support for server mode in win-dco driver
-    On Windows the win-dco driver can now be used in server setups.
-
-Support for TLS client floating in DCO implementations
-    The kernel modules will detect clients floating to a new IP address
-    and notify userland so both data packets (kernel) and TLS packets
-    (sent by userland) can reach the new client IP.
-    (Actual support depends on recent-enough kernel implementation)
-
-Enforcement of AES-GCM usage limit
-    OpenVPN will now enforce the usage limits on AES-GCM with the same
-    confidentiality margin as TLS 1.3 does. This mean that renegotiation will
-    be triggered after roughly 2^28 to 2^31 packets depending of the packet
-    size. More details about usage limit of AES-GCM can be found here:
-
-    https://datatracker.ietf.org/doc/draft-irtf-cfrg-aead-limits/
-
-Epoch data keys and packet format
-    This introduces the epoch data format for AEAD data channel
-    ciphers in TLS mode ciphers. This new data format has a number of
-    improvements over the standard "DATA_V2" format.
-
-    - AEAD tag at the end of packet which is more hardware implementation
-      friendly
-    - Automatic key switchover when cipher usage limits are hit, similar to
-      the epoch data keys in (D)TLS 1.3
-    - 64 bit instead of 32 bit packet ids to allow the data channel to be
-      ready for 10 GBit/s without having frequent renegotiation
-    - IV constructed with XOR instead of concatenation to not have (parts) of
-      the real IV on the wire
-
-Support for Epoch data channel on Windows, using the win-dco driver (2.8.0+)
-
-Default ciphers in ``--data-ciphers``
-    Ciphers in ``--data-ciphers`` can contain the string DEFAULT that is
-    replaced by the default ciphers used by OpenVPN, making it easier to
-    add an allowed cipher without having to spell out the default ciphers.
-
-TLS alerts
-    OpenVPN 2.7 will send out TLS alerts to peers informing them if the TLS
-    session shuts down or when the TLS implementation informs the peer about
-    an error in the TLS session (e.g. mismatching TLS versions). This improves
-    the user experience as the client shows an error instead of running into
-    a timeout when the server just stops responding completely.
-
-Support for tun/tap via unix domain socket and lwipovpn support
-    To allow better testing and emulating a full client with a full
-    network stack OpenVPN now allows a program executed to provide
-    a tun/tap device instead of opening a device.
-
-    The co-developed lwipovpn program based on lwIP stack allows to
-    simulate full IP stack. An OpenVPN client using
-    ``--dev-node unix:/path/to/lwipovpn`` can emulate a full client that
-    can be pinged, can serve a website and more without requiring any
-    elevated permission. This can make testing OpenVPN much easier.
-
-    For more details see
-    `lwipovpn on Github <https://github.com/OpenVPN/lwipovpn>`_.
-
-Allow overriding username with ``--override-username``
-    This is intended to allow using ``--auth-gen-token`` in scenarios where the
-    clients use certificates and multi-factor authentication.  This will
-    also generate a ``push "auth-token-user newusername"`` directive in
-    push replies.
-
-``--port-share`` now properly supports IPv6
-    Issues with logging of IPv6 addresses were fixed. The feature now allows
-    IPv6 connections towards the proxy receiver.
-
-Support for Haiku OS
-
-TLS1.3 support with mbedTLS (requires mbedTLS >= 3.6.4)
-
-PUSH_UPDATE client support
-    It is now possible to update parts of the client-side configuration
-    (IP address, routes, MTU, DNS) by sending a new server-to-client
-    control message, ``PUSH_UPDATE,<options>``.
-    See also: https://openvpn.github.io/openvpn-rfc/openvpn-wire-protocol.html
-    NOTE: PUSH_UPDATE client support is currently disabled if DCO
-    is active (on all platforms).
-
-PUSH_UPDATE server support (minimal)
-    New management interface commands ``push-update-broad`` and
-    ``push-update-cid`` to send PUSH_UPDATE option updates to all
-    clients ("there is a new DNS server") or only a specific client ID
-    ("privileges have changed, here's a new IP address").  See
-    doc/management-notes.txt
-    NOTE: PUSH_UPDATE server support is currently disabled if DCO
-    is active (on all platforms).
-
-Support for user-defined routing tables on Linux
-    See the ``--route-table`` option in the manpage
-
-PQE support for WolfSSL
-
-Two new environment variables have been introduced to communicate desired
-    default gateway redirection to plugins like Network Manager,
-    ``route_redirect_gateway_ipv4`` and ``route_redirect_gateway_ipv6``.
-    See the "Environmental Variables" section in the man page
-
-Improved logging of service events/errors to event log on Windows.
-
-"Recursive Routing" check is now more granular, and will only drop
-   packets-in-tunnel if destination IP, protocol and port matches with
-   those needed to reach the VPN server.  With that change, you can now
-   use policies that direct "everything that is not OpenVPN" into the
-   tunnel, and have IP packets to the VPN server address arrive as
-   expected (no such policies are currently installed by OpenVPN)
-   (GH: OpenVPN/openvpn#669).
-
-COPYING: license details only relevant to our Windows installers have
-   been updated and moved to the openvpn-build repo
-
-Improved BYTECOUNT support - more strictly adhere to timing interval
-   requested, correctly support client and server counters with Linux and
-   Windows DCO offloading.
-
-Improve compatibility with OpenSSL 3.6.0 (do not fail t_lpback selftest)
-
-New option ``--tls-crypt-v2-max-age n`` to check tls-crypt-v2 timestamps
-   (When a client is older than n days or has no timestamp, the server
-    will reject it)
-
-mbedTLS 4 support has been added.
-   Note that with mbedTLS 4 algorithms need to be translated to
-   mbedTLS 4 internal IDs by OpenVPN, and some names might be
-   missing.
-
-
-Deprecated features
--------------------
-``secret`` support has been removed (by default).
-    static key mode (non-TLS) is no longer considered "good and secure enough"
-    for today's requirements.  Use TLS mode instead.  If deploying a PKI CA
-    is considered "too complicated", using ``--peer-fingerprint`` makes
-    TLS mode about as easy as using ``--secret``.
-
-    This mode can still be enabled by using
-    ``--allow-deprecated-insecure-static-crypto`` but will be removed in
-    OpenVPN 2.8.
-
-Support for wintun Windows driver has been removed.
-    OpenVPN 2.6 added support for the new dco-win driver, so it supported
-    three different device drivers: dco-win, wintun, and tap-windows6.
-    OpenVPN 2.7 now drops the support for wintun driver. By default
-    all modern configs should be supported by dco-win driver. In all
-    other cases OpenVPN will fall back automatically to tap-windows6
-    driver.
-
-NTLMv1 authentication support for HTTP proxies has been removed.
-    This is considered an insecure method of authentication that uses
-    obsolete crypto algorithms.
-    NTLMv2 support is still available, but will be removed in a future
-    release.
-    When configured to authenticate with NTLMv1 (``ntlm`` keyword in
-    ``--http-proxy``) OpenVPN will try NTLMv2 instead.
-
-``persist-key`` option has been enabled by default.
-    All the keys will be kept in memory across restart.
-
-OpenSSL 1.0.2 support has been removed.
-    Support for building with OpenSSL 1.0.2 has been removed. The minimum
-    supported OpenSSL version is now 1.1.0.
-
-mbedTLS 2.x support has been removed
-    Support for building with mbedTLS 2.x has been removed (it is out
-    of support since March 2025, and the necessary compatibility code
-    is making maintenance and support for mbedTLS 4.x hard).
-    The minimum supported mbedTLS version is now 3.2.1.
-
-Compression on send has been removed.
-    OpenVPN 2.7 will never compress data before sending. Decompression of
-    received data is still supported.
-    ``--allow-compression yes`` is now an alias for
-    ``--allow-compression asym``.
-
-``--memstats`` feature removed
-    The ``--memstats`` option was largely undocumented and there is no known
-    user of this feature.  This feature provided very limited statistics
-    (number of users, link bytes read/written) and we do not except any
-    usage because of this.
-
-Using ``--push`` in a mode that is not ``--mode server`` will now print a
-    clear warning that this is an unsupported operation and might cause
-    negotiation failures.
-
-``--reneg-bytes`` and ``--reneg-packets`` do not work in DCO mode, and will
-    now print an appropriate warning.
-
-On-connect resolving of ``--remote`` addresses in ``--tcp-server`` mode
-    was not working since 2.4, so the code was completely removed.
-
-
-User-visible Changes
---------------------
-- Default for ``--topology`` changed to ``subnet`` for ``--mode server``.
-  Previous releases always used ``net30`` as default. This only affects
-  configs with ``--mode server`` or ``--server`` (the latter implies the
-  former), and ``--dev tun``, and only if IPv4 is enabled.
-  Note that this changes the semantics of ``--ifconfig``, so if you have
-  manual settings for that in your config but not set ``--topology``
-  your config might fail to parse with the new version. Just adding
-  ``--topology net30`` to the config should fix the problem.
-  By default ``--topology`` is pushed from server to client.
-
-- ``--x509-username-field`` will no longer automatically convert fieldnames to
-  uppercase. This was deprecated since OpenVPN 2.4, and has now been removed.
-
-- ``--dh none`` is now the default if ``--dh`` is not specified. Modern TLS
-  implementations will prefer ECDH and other more modern algorithms anyway.
-  And finite field Diffie Hellman is in the proces of being deprecated
-  (see draft-ietf-tls-deprecate-obsolete-kex)
-
-- ``--lport 0`` does not imply ``--bind`` anymore.
-
-- ``--redirect-gateway`` now works correctly if the VPN remote is not
-  reachable by the default gateway.
-
-- ``--show-gateway`` now supports querying the gateway for IPv4 addresses.
-
-- ``--static-challenge`` option now has a third parameter ``format`` that
-  can change how password and challenge response should be combined.
-
-- ``--key`` and ``--cert`` now accept URIs implemented in OpenSSL 3 as well as
-  optional OpenSSL 3 providers loaded using ``--providers`` option.
-
-- ``--cryptoapicert`` now supports issuer name as well as Windows CA template
-  name or OID as selector string.
-
-- TLS handshake debugging information contains much more details now when
-  using recent versions of OpenSSL.
-
-- The ``IV_PLAT_VER`` variable sent by Windows clients now contains the
-  full Windows build version to make it possible to determine the
-  Windows 10 or Windows 11 version used.
-
-- The ``--windows-driver`` option to select between various windows
-  drivers will no longer do anything - it's kept so existing configs
-  will not become invalid, but it is ignored with a warning.  The default
-  is now ``ovpn-dco`` if all options used are compatible with DCO, with
-  a fallback to ``tap-windows6``.  To force TAP (for example because a
-  server pushes DCO incompatible options), use the ``--disable-dco``
-  option.
-
-- Apply more checks to incoming TLS handshake packets before creating
-  new state - namely, verify message ID / acked ID for "valid range for
-  an initial packet".  This fixes a problem with clients that float
-  very early but send control channel packet from the pre-float IP
-  (Github: OpenVPN/openvpn#704).
-
-- Use of ``--dh dh2048.pem`` in all sample configs has been replaced
-  with ``--dh none``.  The ``dh2048.pem`` file has been removed.
-
-- The startup delay in ``t_client.sh`` has been reduced from 3s to 1s,
-  making a noticeable difference for setups with many tests.
-
-- Changed from using ``uncrustify`` for code formatting and pre-commit checks
-  to ``clang-format``.  This reformatted quite a bit of code, and requires
-  that regular committers change their pre-commit checks accordingly.
-
-- On Linux, on interfaces where applicable, OpenVPN explicitly configures
-  the broadcast address again.  This was dropped for 2.6.0 "because
-  computers are smart and can do it themselves", but the kernel netlink
-  interface isn't, and will install "0.0.0.0".  This does not normally
-  matter, but for broadcast-based applications that get the address to
-  use from "ifconfig", this change repairs functionality (this has
-  been backported to 2.6.15, but is not in earlier 2.6 versions).
-
-- ``max-routes-per-client 0`` used to be silently upgraded to ``1``.  This
-  now produces an error.
-
-- ``ifconfig`` and ``ifconfig-ipv6`` values are now stored in pre-connect
-  options cache, and will be restored to pre-connect values on reconnects
-  if the server stops pushing the respective option.
-
-- ``tapctl.exe`` helper binary on Windows has been reworked to improve
-  help texts (making clear that it can not only do TAP-Adapters but
-  Win-DCO as well), add printing of the hwid to all adapter outputs, and
-  change the default adapter type created to ``ovpn-dco``.
-
-- The default for ``multihome`` egress interface handling has changed.
-  2.7.0 will default to ipi_ifindex=0, that is, leave the decision to the
-  routing/policy setup of the operating system.  The pre-2.7 behaviour
-  (force egress = ingress interface) can be achieved with the new
-  ``--multihome same-interface`` sub-option.
-
-- Windows ``openvpn.exe`` binary manifest now sets code page UTF8 - which
-  has no direct effect on OpenVPN itself, but this repairs OpenSSL file
-  loading for key/cert files with non-ASCII characters in their file names
-  (GH: OpenVPN/openvpn#920).
-
-- The ``test-crypto`` option no longer requires a ``--secret`` argument and
-  will automatically generate a random key.
-
-- The configure-time option ``--enable-x509-alt-username`` is no longer
-  conditional, and always-on (GH: OpenVPN/openvpn#917).
-
-
-Deprecated features
--------------------
-``--opt-verify`` feature removed
-    This option was already deprecated and it is now being converted to a
-    no-op. Using this option will only print a warning.
-
-
-Overview of changes in 2.6
-==========================
-
-Project changes
----------------
-
-We want to deprecate our old Trac bug tracking system.
-Please report any issues with this release in GitHub
-instead: https://github.com/OpenVPN/openvpn/issues
-
-New features
-------------
-Support unlimited number of connection entries and remote entries
-
-New management commands to enumerate and list remote entries
-    Use ``remote-entry-count`` and ``remote-entry-get``
-    commands from the management interface to get the number of
-    remote entries and the entries themselves.
-
-Keying Material Exporters (RFC 5705) based key generation
-    As part of the cipher negotiation OpenVPN will automatically prefer
-    the RFC5705 based key material generation to the current custom
-    OpenVPN PRF. This feature requires OpenSSL or mbed TLS 2.18+.
-
-Compatibility with OpenSSL in FIPS mode
-    OpenVPN will now work with OpenSSL in FIPS mode. Note, no effort
-    has been made to check or implement all the
-    requirements/recommendation of FIPS 140-2. This just allows OpenVPN
-    to be run on a system that be configured OpenSSL in FIPS mode.
-
-``mlock`` will now check if enough memlock-able memory has been reserved,
-    and if less than 100MB RAM are available, use setrlimit() to upgrade
-    the limit.  See Trac #1390.  Not available on OpenSolaris.
-
-Certificate pinning/verify peer fingerprint
-    The ``--peer-fingerprint`` option has been introduced to give users an
-    easy to use alternative to the ``tls-verify`` for matching the
-    fingerprint of the peer. The option takes use a number of allowed
-    SHA256 certificate fingerprints.
-
-    See the man page section "Small OpenVPN setup with peer-fingerprint"
-    for a tutorial on how to use this feature. This is also available online
-    under https://github.com/openvpn/openvpn/blob/master/doc/man-sections/example-fingerprint.rst
-
-TLS mode with self-signed certificates
-    When ``--peer-fingerprint`` is used, the ``--ca`` and ``--capath`` option
-    become optional. This allows for small OpenVPN setups without setting up
-    a PKI with Easy-RSA or similar software.
-
-Deferred auth support for scripts
-    The ``--auth-user-pass-verify`` script supports now deferred authentication.
-
-Pending auth support for plugins and scripts
-    Both auth plugin and script can now signal pending authentication to
-    the client when using deferred authentication. The new ``client-crresponse``
-    script option and ``OPENVPN_PLUGIN_CLIENT_CRRESPONSE`` plugin function can
-    be used to parse a client response to a ``CR_TEXT`` two factor challenge.
-
-    See ``sample/sample-scripts/totpauth.py`` for an example.
-
-Compatibility mode (``--compat-mode``)
-    The modernisation of defaults can impact the compatibility of OpenVPN 2.6.0
-    with older peers. The options ``--compat-mode`` allows UIs to provide users
-    with an easy way to still connect to older servers.
-
-OpenSSL 3.0 support
-    OpenSSL 3.0 has been added. Most of OpenSSL 3.0 changes are not user visible but
-    improve general compatibility with OpenSSL 3.0. ``--tls-cert-profile insecure``
-    has been added to allow selecting the lowest OpenSSL security level (not
-    recommended, use only if you must). OpenSSL 3.0 no longer supports the Blowfish
-    (and other deprecated) algorithm by default and the new option ``--providers``
-    allows loading the legacy provider to renable these algorithms.
-
-Optional ciphers in ``--data-ciphers``
-    Ciphers in ``--data-ciphers`` can now be prefixed with a ``?`` to mark
-    those as optional and only use them if the SSL library supports them.
-
-
-Improved ``--mssfix`` and ``--fragment`` calculation
-    The ``--mssfix`` and ``--fragment`` options now allow an optional :code:`mtu`
-    parameter to specify that different overhead for IPv4/IPv6 should taken into
-    account and the resulting size is specified as the total size of the VPN packets
-    including IP and UDP headers.
-
-Cookie based handshake for UDP server
-    Instead of allocating a connection for each client on the initial packet
-    OpenVPN server will now use an HMAC based cookie as its session id. This
-    way the server can verify it on completing the handshake without keeping
-    state. This eliminates the amplification and resource exhaustion attacks.
-    For tls-crypt-v2 clients, this requires OpenVPN 2.6 clients or later
-    because the client needs to resend its client key on completing the hand
-    shake. The tls-crypt-v2 option allows controlling if older clients are
-    accepted.
-
-    By default the rate of initial packet responses is limited to 100 per 10s
-    interval to avoid OpenVPN servers being abused in reflection attacks
-    (see ``--connect-freq-initial``).
-
-Data channel offloading with ovpn-dco
-    2.6.0+ implements support for data-channel offloading where the data packets
-    are directly processed and forwarded in kernel space thanks to the ovpn-dco
-    kernel module. The userspace openvpn program acts purely as a control plane
-    application. Note that DCO will use DATA_V2 packets in P2P mode, therefore,
-    this implies that peers must be running 2.6.0+ in order to have P2P-NCP
-    which brings DATA_V2 packet support.
-
-Session timeout
-    It is now possible to terminate a session (or all) after a specified amount
-    of seconds has passed session commencement. This behaviour can be configured
-    using ``--session-timeout``. This option can be configured on the server, on
-    the client or can also be pushed.
-
-Inline auth username and password
-    Username and password can now be specified inline in the configuration file
-    within the <auth-user-pass></auth-user-pass> tags. If the password is
-    missing OpenVPN will prompt for input via stdin. This applies to inline'd
-    http-proxy-user-pass too.
-
-Tun MTU can be pushed
-    The  client can now also dynamically configure its MTU and the server
-    will try to push the client MTU when the client supports it. The
-    directive ``--tun-mtu-max`` has been introduced to increase the maximum
-    pushable MTU size (defaults to 1600).
-
-Dynamic TLS Crypt
-    When both peers are OpenVPN 2.6.1+, OpenVPN will dynamically create
-    a tls-crypt key that is used for renegotiation. This ensure that only the
-    previously authenticated peer can do trigger renegotiation and complete
-    renegotiations.
-
-Improved control channel packet size control (``max-packet-size``)
-    The size of control channel is no longer tied to
-    ``--link-mtu``/``--tun-mtu`` and can be set using ``--max-packet-size``.
-    Sending large control channel frames is also optimised by allowing 6
-    outstanding packets instead of just 4. ``max-packet-size`` will also set
-    ``mssfix`` to try to limit data-channel packets as well.
-
-Deprecated features
--------------------
-``inetd`` has been removed
-    This was a very limited and not-well-tested way to run OpenVPN, on TCP
-    and TAP mode only.
-
-``verify-hash`` has been deprecated
-    This option has very limited usefulness and should be replaced by either
-    a better ``--ca`` configuration or with a ``--tls-verify`` script.
-
-``secret`` has been deprecated
-    static key mode (non-TLS) is no longer considered "good and secure enough"
-    for today's requirements.  Use TLS mode instead.  If deploying a PKI CA
-    is considered "too complicated", using ``--peer-fingerprint`` makes
-    TLS mode about as easy as using ``--secret``.
-
-``ncp-disable`` has been removed
-    This option mainly served a role as debug option when NCP was first
-    introduced. It should now no longer be necessary.
-
-TLS 1.0 and 1.1 are deprecated
-    ``tls-version-min`` is set to 1.2 by default.  OpenVPN 2.6.0 defaults
-    to a minimum TLS version of 1.2 as TLS 1.0 and 1.1 should be generally
-    avoided. Note that OpenVPN versions older than 2.3.7 use TLS 1.0 only.
-
-``--cipher`` argument is no longer appended to ``--data-ciphers``
-    by default. Data cipher negotiation has been introduced in 2.4.0
-    and been significantly improved in 2.5.0. The implicit fallback
-    to the cipher specified in ``--cipher`` has been removed.
-    Effectively, ``--cipher`` is a no-op in TLS mode now, and will
-    only have an effect in pre-shared-key mode (``--secret``).
-    From now on ``--cipher`` should not be used in new configurations
-    for TLS mode.
-    Should backwards compatibility with older OpenVPN peers be
-    required, please see the ``--compat-mode`` instead.
-
-``--prng`` has beeen removed
-    OpenVPN used to implement its own PRNG based on a hash. However implementing
-    a PRNG is better left to a crypto library. So we use the PRNG
-    mbed TLS or OpenSSL now.
-
-``--keysize`` has been removed
-    The ``--keysize`` option was only useful to change the key length when using the
-    BF, CAST6 or RC2 ciphers. For all other ciphers the key size is fixed with the
-    chosen cipher. As OpenVPN v2.6 no longer supports any of these variable length
-    ciphers, this option was removed as well to avoid confusion.
-
-Compression no longer enabled by default
-    Unless an explicit compression option is specified in the configuration,
-    ``--allow-compression`` defaults to ``no`` in OpeNVPN 2.6.0.
-    By default, OpenVPN 2.5 still allowed a server to enable compression by
-    pushing compression related options.
-
-PF (Packet Filtering) support has been removed
-   The built-in PF functionality has been removed from the code base. This
-   feature wasn't really easy to use and was long unmaintained.
-   This implies that also ``--management-client-pf`` and any other compile
-   time or run time related option do not exist any longer.
-
-Option conflict checking is being deprecated and phased out
-    The static option checking (OCC) is no longer useful in typical setups
-    that negotiate most connection parameters. The ``--opt-verify`` and
-    ``--occ-disable`` options are deprecated, and the configure option
-    ``--enable-strict-options`` has been removed. Logging of mismatched
-    options has been moved to debug logging (verb 7).
-
-User-visible Changes
---------------------
-- CHACHA20-POLY1305 is included in the default of ``--data-ciphers`` when available.
-- Option ``--prng`` is ignored as we rely on the SSL library random number generator.
-- Option ``--nobind`` is default when ``--client`` or ``--pull`` is used in the configuration
-- :code:`link_mtu` parameter is removed from environment or replaced with 0 when scripts are
-  called with parameters. This parameter is unreliable and no longer internally calculated.
-
-- control channel packet maximum size is no longer influenced by
-  ``--link-mtu``/``--tun-mtu`` and must be set by ``--max-packet-size`` now.
-  The default is 1250 for the control channel size.
-
-- In point-to-point OpenVPN setups (no ``--server``), using
-  ``--explict-exit-notiy`` on one end would terminate the other side at
-  session end.  This is considered a no longer useful default and has
-  been changed to "restart on reception of explicit-exit-notify message".
-  If the old behaviour is still desired, ``--remap-usr1 SIGTERM`` can be used.
-
-- FreeBSD tun interfaces with ``--topology subnet`` are now put into real
-  subnet mode (IFF_BROADCAST instead of IFF_POINTOPOINT) - this might upset
-  software that enumerates interfaces, looking for "broadcast capable?" and
-  expecting certain results.  Normal uses should not see any difference.
-
-- The default configurations will no longer allow connections to OpenVPN 2.3.x
-  peer or earlier, use the new ``--compat-mode`` option if you need
-  compatibility with older versions. See the manual page on the
-  ``--compat-mode`` for details.
-
-- The ``client-pending-auth`` management command now requires also the
-  key id. The management version has been changed to 5 to indicate this change.
-
-- (OpenVPN 2.6.2) A client will now refuse a connection if pushed compression
-  settings will contradict the setting of allow-compression as this almost
-  always results in a non-working connection.
-
-- The "kill" by addr management command now requires also the protocol
-  as string e.g. "udp", "tcp".
-
-Common errors with OpenSSL 3.0 and OpenVPN 2.6
-----------------------------------------------
-Both OpenVPN 2.6 and OpenSSL 3.0 tighten the security considerable, so some
-configuration will no longer work. This section will cover the most common
-causes and error message we have seen and explain their reason and temporary
-workarounds. You should fix the underlying problems as soon as possible since
-these workaround are not secure and will eventually stop working in a future
-update.
-
-- weak SHA1 or MD5 signature on certificates
-
-  This will happen on either loading of certificates or on connection
-  to a server::
-
-      OpenSSL: error:0A00018E:SSL routines::ca md too weak
-      Cannot load certificate file cert.crt
-      Exiting due to fatal error
-
-  OpenSSL 3.0 no longer allows weak signatures on certificates. You can
-  downgrade your security to allow them by using ``--tls-cert-profile insecure``
-  but should replace/regenerate these certificates as soon as possible.
-
-
-- 1024 bit RSA certificates, 1024 bit DH parameters, other weak keys
-
-  This happens if you use private keys or other cryptographic material that
-  does not meet today's cryptographic standards anymore. Messages are similar
-  to::
-
-      OpenSSL: error:0A00018F:SSL routines::ee key too small
-      OpenSSL: error:1408518A:SSL routines:ssl3_ctx_ctrl:dh key too small
-
-  DH parameters (``--dh``) can be regenerated with ``openssl dhparam 2048``.
-  For other cryptographic keys, these keys and certificates need to be
-  regenerated. TLS Security level can be temporarily lowered with
-  ``--tls-cert-profile legacy`` or even ``--tls-cert-profile insecure``.
-
-- Connecting to a OpenVPN 2.3.x server or allowing OpenVPN 2.3.x or earlier
-  clients
-
-  This will normally result in messages like::
-
-     OPTIONS ERROR: failed to negotiate cipher with server.  Add the server's cipher ('AES-128-CBC') to --data-ciphers (currently 'AES-256-GCM:AES-128-GCM:CHACHA20-POLY1305') if you want to connect to this server.
-
-     or
-
-     client/127.0.0.1:49954 SENT CONTROL [client]: 'AUTH_FAILED,Data channel cipher negotiation failed (no shared cipher)' (status=1)
-
-  You can manually add the missing cipher to the ``--data-ciphers``. The
-  standard ciphers should be included as well, e.g.
-  ``--data-ciphers AES-256-GCM:AES-128-GCM:?Chacha20-Poly1305:?AES-128-CBC``.
-  You can also use the ``--compat-mode`` option. Note that these message may
-  also indicate other cipher configuration problems. See the data channel
-  cipher negotiation manual section for more details. (Available online under
-  https://github.com/OpenVPN/openvpn/blob/master/doc/man-sections/cipher-negotiation.rst)
-
-- Use of a legacy or deprecated cipher (e.g. 64bit block ciphers)
-
-  OpenSSL 3.0 no longer supports a number of insecure and outdated ciphers in
-  its default configuration. Some of these ciphers are known to be vulnerable (SWEET32 attack).
-
-  This will typically manifest itself in messages like::
-
-      OpenSSL: error:0308010C:digital envelope routines::unsupported
-      Cipher algorithm 'BF-CBC' not found
-      Unsupported cipher in --data-ciphers: BF-CBC
-
-  If your OpenSSL distribution comes with the legacy provider (see
-  also ``man OSSL_PROVIDER-legacy``), you can load it with
-  ``--providers legacy default``.  This will re-enable the old algorithms.
-
-- OpenVPN version not supporting TLS 1.2 or later
-
-  The default in OpenVPN 2.6 and also in many distributions is now TLS 1.2 or
-  later. Connecting to a peer that does not support this will results in
-  messages like::
-
-    TLS error: Unsupported protocol. This typically indicates that client and
-    server have no common TLS version enabled. This can be caused by mismatched
-    tls-version-min and tls-version-max options on client and server. If your
-    OpenVPN client is between v2.3.6 and v2.3.2 try adding tls-version-min 1.0
-    to the client configuration to use TLS 1.0+ instead of TLS 1.0 only
-    OpenSSL: error:0A000102:SSL routines::unsupported protocol
-
-  This can be an OpenVPN 2.3.6 or earlier version. ``compat-version 2.3.0`` will
-  enable TLS 1.0 support if supported by the OpenSSL distribution. Note that
-  on some Linux distributions enabling TLS 1.1 or 1.0 is not possible.
-
-
-
-Overview of changes in 2.5
-==========================
-
-New features
-------------
-Client-specific tls-crypt keys (``--tls-crypt-v2``)
-    ``tls-crypt-v2`` adds the ability to supply each client with a unique
-    tls-crypt key.  This allows large organisations and VPN providers to profit
-    from the same DoS and TLS stack protection that small deployments can
-    already achieve using ``tls-auth`` or ``tls-crypt``.
-
-ChaCha20-Poly1305 cipher support
-    Added support for using the ChaCha20-Poly1305 cipher in the OpenVPN data
-    channel.
-
-Improved Data channel cipher negotiation
-    The option ``ncp-ciphers`` has been renamed to ``data-ciphers``.
-    The old name is still accepted. The change in name signals that
-    ``data-ciphers`` is the preferred way to configure data channel
-    ciphers and the data prefix is chosen to avoid the ambiguity that
-    exists with ``--cipher`` for the data cipher and ``tls-cipher``
-    for the TLS ciphers.
-
-    OpenVPN clients will now signal all supported ciphers from the
-    ``data-ciphers`` option to the server via ``IV_CIPHERS``. OpenVPN
-    servers will select the first common cipher from the ``data-ciphers``
-    list instead of blindly pushing the first cipher of the list. This
-    allows to use a configuration like
-    ``data-ciphers ChaCha20-Poly1305:AES-256-GCM`` on the server that
-    prefers ChaCha20-Poly1305 but uses it only if the client supports it.
-
-    See the data channel negotiation section in the manual for more details.
-
-Removal of BF-CBC support in default configuration:
-    By default OpenVPN 2.5 will only accept AES-256-GCM and AES-128-GCM as
-    data ciphers. OpenVPN 2.4 allows AES-256-GCM,AES-128-GCM and BF-CBC when
-    no --cipher and --ncp-ciphers options are present. Accepting BF-CBC can be
-    enabled by adding
-
-        data-ciphers AES-256-GCM:AES-128-GCM:BF-CBC
-
-    and when you need to support very old peers also
-
-        data-ciphers-fallback BF-CBC
-
-    To offer backwards compatibility with older configs an *explicit*
-
-        cipher BF-CBC
-
-    in the configuration will be automatically translated into adding BF-CBC
-    to the data-ciphers option and setting data-ciphers-fallback to BF-CBC
-    (as in the example commands above). We strongly recommend to switching
-    away from BF-CBC to a more secure cipher.
-
-Asynchronous (deferred) authentication support for auth-pam plugin.
-    See src/plugins/auth-pam/README.auth-pam for details.
-
-Deferred client-connect
-    The ``--client-connect`` option and the connect plugin API allow
-    asynchronous/deferred return of the configuration file in the same way
-    as the auth-plugin.
-
-Faster connection setup
-    A client will signal in the ``IV_PROTO`` variable that it is in pull
-    mode. This allows the server to push the configuration options to
-    the client without waiting for a ``PULL_REQUEST`` message. The feature
-    is automatically enabled if both client and server support it and
-    significantly reduces the connection setup time by avoiding one
-    extra packet round-trip and 1s of internal event delays.
-
-Netlink support
-    On Linux, if configured without ``--enable-iproute2``, configuring IP
-    addresses and adding/removing routes is now done via the netlink(3)
-    kernel interface.  This is much faster than calling ``ifconfig`` or
-    ``route`` and also enables OpenVPN to run with less privileges.
-
-    If configured with --enable-iproute2, the ``ip`` command is used
-    (as in 2.4).  Support for ``ifconfig`` and ``route`` is gone.
-
-Wintun support
-    On Windows, OpenVPN can now use ``wintun`` devices.  They are faster
-    than the traditional ``tap9`` tun/tap devices, but do not provide
-    ``--dev tap`` mode - so the official installers contain both.  To use
-    a wintun device, add ``--windows-driver wintun`` to your config
-    (and use of the interactive service is required as wintun needs
-    SYSTEM privileges to enable access).
-
-IPv6-only operation
-    It is now possible to have only IPv6 addresses inside the VPN tunnel,
-    and IPv6-only address pools (2.4 always required IPv4 config/pools
-    and IPv6 was the "optional extra").
-
-Improved Windows 10 detection
-    Correctly log OS on Windows 10 now.
-
-Linux VRF support
-    Using the new ``--bind-dev`` option, the OpenVPN outside socket can
-    now be put into a Linux VRF.  See the "Virtual Routing and Forwarding"
-    documentation in the man page.
-
-TLS 1.3 support
-    TLS 1.3 support has been added to OpenVPN.  Currently, this requires
-    OpenSSL 1.1.1+.
-    The options ``--tls-ciphersuites`` and ``--tls-groups`` have been
-    added to fine tune TLS protocol options.  Most of the improvements
-    were also backported to OpenVPN 2.4 as part of the maintainance
-    releases.
-
-Support setting DHCP search domain
-    A new option ``--dhcp-option DOMAIN-SEARCH my.example.com`` has been
-    defined, and Windows support for it is implemented (tun/tap only, no
-    wintun support yet).  Other platforms need to support this via ``--up``
-    script (Linux) or GUI (OSX/Tunnelblick).
-
-per-client changing of ``--data-ciphers`` or ``data-ciphers-fallback``
-    from client-connect script/dir (NOTE: this only changes preference of
-    ciphers for NCP, but can not override what the client announces as
-    "willing to accept")
-
-Handle setting of tun/tap interface MTU on Windows
-    If IPv6 is in use, MTU must be >= 1280 (Windows enforces IETF requirements)
-
-Add support for OpenSSL engines to access private key material (like TPM).
-
-HMAC based auth-token support
-    The ``--auth-gen-token`` support has been improved and now generates HMAC
-    based user token. If the optional ``--auth-gen-token-secret`` option is
-    used clients will be able to seamlessly reconnect to a different server
-    using the same secret file or to the same server after a server restart.
-
-Improved support for pending authentication
-    The protocol has been enhanced to be able to signal that
-    the authentication should use a secondary authentication
-    via web (like SAML) or a two factor authentication without
-    disconnecting the OpenVPN session with AUTH_FAILED. The
-    session will instead be stay in a authenticated state and
-    wait for the second factor authentication to complete.
-
-    This feature currently requires usage of the managent interface
-    on both client and server side. See the ``management-notes.txt``
-    ``client-pending-auth`` and ``cr-response`` commands for more
-    details.
-
-VLAN support
-    OpenVPN servers in TAP mode can now use 802.1q tagged VLANs
-    on the TAP interface to separate clients into different groups
-    that can then be handled differently (different subnets / DHCP,
-    firewall zones, ...) further down the network.  See the new
-    options ``--vlan-tagging``, ``--vlan-accept``, ``--vlan-pvid``.
-
-    802.1q tagging on the client side TAP interface is not handled
-    today (= tags are just forwarded transparently to the server).
-
-Support building of .msi installers for Windows
-
-Allow unicode search string in ``--cryptoapicert`` option (Windows)
-
-Support IPv4 configs with /31 netmasks now
-    (By no longer trying to configure ``broadcast x.x.x.x`` in
-    ifconfig calls, /31 support "just works")
-
-New option ``--block-ipv6`` to reject all IPv6 packets (ICMPv6)
-    this is useful if the VPN service has no IPv6, but the clients
-    might have (LAN), to avoid client connections to IPv6-enabled
-    servers leaking "around" the IPv4-only VPN.
-
-``--ifconfig-ipv6`` and ``--ifconfig-ipv6-push`` will now accept
-    hostnames and do a DNS lookup to get the IPv6 address to use
-
-
-Deprecated features
--------------------
-For an up-to-date list of all deprecated options, see this wiki page:
-https://community.openvpn.net/openvpn/wiki/DeprecatedOptions
-
-- ``ncp-disable`` has been deprecated
-    With the improved and matured data channel cipher negotiation, the use
-    of ``ncp-disable`` should not be necessary anymore.
-
-- ``inetd`` has been deprecated
-  This is a very limited and not-well-tested way to run OpenVPN, on TCP
-  and TAP mode only, which complicates the code quite a bit for little gain.
-  To be removed in OpenVPN 2.6 (unless users protest).
-
-- ``no-iv`` has been removed
-  This option was made into a NOOP option with OpenVPN 2.4.  This has now
-  been completely removed.
-
-- ``--client-cert-not-required`` has been removed
-  This option will now cause server configurations to not start.  Use
-  ``--verify-client-cert none`` instead.
-
-- ``--ifconfig-pool-linear`` has been removed
-  This option is removed.  Use ``--topology p2p`` or ``--topology subnet``
-  instead.
-
-- ``--compress xxx`` is considered risky and is warned against, see below.
-
-- ``--key-method 1`` has been removed
-
-
-User-visible Changes
---------------------
-- If multiple connect handlers are used (client-connect, ccd, connect
-  plugin) and one of the handler succeeds but a subsequent fails, the
-  client-disconnect-script is now called immediately. Previously it
-  was called, when the VPN session was terminated.
-
-- Support for building with OpenSSL 1.0.1 has been removed. The minimum
-  supported OpenSSL version is now 1.0.2.
-
-- The GET_CONFIG management state is omitted if the server pushes
-  the client configuration almost immediately as result of the
-  faster connection setup feature.
-
-- ``--compress`` is nowadays considered risky, because attacks exist
-  leveraging compression-inside-crypto to reveal plaintext (VORACLE).  So
-  by default, ``--compress xxx`` will now accept incoming compressed
-  packets (for compatibility with peers that have not been upgraded yet),
-  but will not use compression outgoing packets.  This can be controlled with
-  the new option ``--allow-compression yes|no|asym``.
-
-- Stop changing ``--txlen`` aways from OS defaults unless explicitly specified
-  in config file.  OS defaults nowadays are actually larger then what we used
-  to configure, so our defaults sometimes caused packet drops = bad performance.
-
-- remove ``--writepid`` pid file on exit now
-
-- plugin-auth-pam now logs via OpenVPN logging method, no longer to stderr
-  (this means you'll have log messages in syslog or openvpn log file now)
-
-- use ISO 8601 time format for file based logging now (YYYY-MM-DD hh:mm:dd)
-  (syslog is not affected, nor is ``--machine-readable-output``)
-
-- ``--clr-verify`` now loads all CRLs if more than one CRL is in the same
-  file (OpenSSL backend only, mbedTLS always did that)
-
-- when ``--auth-user-pass file`` has no password, and the management interface
-  is active, query management interface (instead of trying console query,
-  which does not work on windows)
-
-- skip expired certificates in Windows certificate store (``--cryptoapicert``)
-
-- ``--socks-proxy`` + ``--proto udp*`` will now allways use IPv4, even if
-  IPv6 is requested and available.  Our SOCKS code does not handle IPv6+UDP,
-  and before that change it would just fail in non-obvious ways.
-
-- TCP listen() backlog queue is now set to 32 - this helps TCP servers that
-  receive lots of "invalid" connects by TCP port scanners
-
-- do no longer print OCC warnings ("option mismatch") about ``key-method``,
-  ``keydir``, ``tls-auth`` and ``cipher`` - these are either gone now, or
-  negotiated, and the warnings do not serve a useful purpose.
-
-- ``dhcp-option DNS`` and ``dhcp-option DNS6`` are now treated identically
-  (= both accept an IPv4 or IPv6 address for the nameserver)
-
-
-Maintainer-visible changes
---------------------------
-- the man page is now in maintained in .rst format, so building the openvpn.8
-  manpage from a git checkout now requires python-docutils (if this is missing,
-  the manpage will not be built - which is not considered an error generally,
-  but for package builders or ``make distcheck`` it is).  Release tarballs
-  contain the openvpn.8 file, so unless some .rst is changed, doc-utils are
-  not needed for building.
-
-- OCC support can no longer be disabled
-
-- AEAD support is now required in the crypto library
-
-- ``--disable-server`` has been removed from configure (so it is no longer
-  possible to build a client-/p2p-only OpenVPN binary) - the saving in code
-  size no longer outweighs the extra maintenance effort.
-
-- ``--enable-iproute2`` will disable netlink(3) support, so maybe remove
-  that from package building configs (see above)
-
-- support building with MSVC 2019
-
-- cmocka based unit tests are now only run if cmocka is installed externally
-  (2.4 used to ship a local git submodule which was painful to maintain)
-
-- ``--disable-crypto`` configure option has been removed.  OpenVPN is now always
-  built with crypto support, which makes the code much easier to maintain.
-  This does not affect ``--cipher none`` to do a tunnel without encryption.
-
-- ``--disable-multi`` configure option has been removed
-
-
-
-Overview of changes in 2.4
-==========================
-
-
-New features
-------------
-Seamless client IP/port floating
-    Added new packet format P_DATA_V2, which includes peer-id. If both the
-    server and client support it, the client sends all data packets in
-    the new format. When a data packet arrives, the server identifies peer
-    by peer-id. If peer's ip/port has changed, server assumes that
-    client has floated, verifies HMAC and updates ip/port in internal structs.
-    This allows the connection to be immediately restored, instead of requiring
-    a TLS handshake before the server accepts packets from the new client
-    ip/port.
-
-Data channel cipher negotiation
-    Data channel ciphers (``--cipher``) are now by default negotiated.  If a
-    client advertises support for Negotiable Crypto Parameters (NCP), the
-    server will choose a cipher (by default AES-256-GCM) for the data channel,
-    and tell the client to use that cipher.  Data channel cipher negotiation
-    can be controlled using ``--ncp-ciphers`` and ``--ncp-disable``.
-
-    A more limited version also works in client-to-server and server-to-client
-    scenarios where one of the end points uses a v2.4 client or server and the
-    other side uses an older version.  In such scenarios the v2.4 side will
-    change to the ``--cipher`` set by the remote side, if permitted by by
-    ``--ncp-ciphers``.  For example, a v2.4 client with ``--cipher BF-CBC``
-    and ``ncp-ciphers AES-256-GCM:AES-256-CBC`` can connect to both a v2.3
-    server with ``cipher BF-CBC`` as well as a server with
-    ``cipher AES-256-CBC`` in its config.  The other way around, a v2.3 client
-    with either ``cipher BF-CBC`` or ``cipher AES-256-CBC`` can connect to a
-    v2.4 server with e.g. ``cipher BF-CBC`` and
-    ``ncp-ciphers AES-256-GCM:AES-256-CBC`` in its config.  For this to work
-    it requires that OpenVPN was built without disabling OCC support.
-
-AEAD (GCM) data channel cipher support
-    The data channel now supports AEAD ciphers (currently only GCM).  The AEAD
-    packet format has a smaller crypto overhead than the CBC packet format,
-    (e.g. 20 bytes per packet for AES-128-GCM instead of 36 bytes per packet
-    for AES-128-CBC + HMAC-SHA1).
-
-ECDH key exchange
-    The TLS control channel now supports for elliptic curve diffie-hellmann
-    key exchange (ECDH).
-
-Improved Certificate Revocation List (CRL) processing
-    CRLs are now handled by the crypto library (OpenSSL or mbed TLS), instead
-    of inside OpenVPN itself.  The crypto library implementations are more
-    strict than the OpenVPN implementation was.  This might reject peer
-    certificates that would previously be accepted.  If this occurs, OpenVPN
-    will log the crypto library's error description.
-
-Dualstack round-robin DNS client connect
-    Instead of only using the first address of each ``--remote`` OpenVPN
-    will now try all addresses (IPv6 and IPv4) of a ``--remote`` entry.
-
-Support for providing IPv6 DNS servers
-    A new DHCP sub-option ``DNS6`` is added alongside with the already existing
-    ``DNS`` sub-option.  This is used to provide DNS resolvers available over
-    IPv6.  This may be pushed to clients where `` --up`` scripts and ``--plugin``
-    can act upon it through the ``foreign_option_<n>`` environment variables.
-
-    Support for the Windows client picking up this new sub-option is added,
-    however IPv6 DNS resolvers need to be configured via ``netsh`` which requires
-    administrator privileges unless the new interactive services on Windows is
-    being used.  If the interactive service is used, this service will execute
-    ``netsh`` in the background with the proper privileges.
-
-New improved Windows Background service
-    The new OpenVPNService is based on openvpnserv2, a complete rewrite of the OpenVPN
-    service wrapper. It is intended for launching OpenVPN instances that should be
-    up at all times, instead of being manually launched by a user. OpenVPNService is
-    able to restart individual OpenVPN processes if they crash, and it also works
-    properly on recent Windows versions. OpenVPNServiceLegacy tends to work poorly,
-    if at all, on newer Windows versions (8+) and its use is not recommended.
-
-New interactive Windows service
-    The installer starts OpenVPNServiceInteractive automatically and configures
-    it to start	at system startup.
-
-    The interactive Windows service allows unprivileged users to start
-    OpenVPN connections in the global config directory (usually
-    C:\\Program Files\\OpenVPN\\config) using OpenVPN GUI without any
-    extra configuration.
-
-    Users who belong to the built-in Administrator group or to the
-    local "OpenVPN Administrator" group can also store configuration
-    files under %USERPROFILE%\\OpenVPN\\config for use with the
-    interactive service.
-
-redirect-gateway ipv6
-    OpenVPN has now feature parity between IPv4 and IPv6 for redirect
-    gateway including the handling of overlapping IPv6 routes with
-    IPv6 remote VPN server address.
-
-LZ4 Compression and pushable compression
-    Additionally to LZO compression OpenVPN now also supports LZ4 compression.
-    Compression options are now pushable from the server.
-
-Filter pulled options client-side: pull-filter
-    New option to explicitly allow or reject options pushed by the server.
-    May be used multiple times and is applied in the order specified.
-
-Per-client remove push options: push-remove
-    New option to remove options on a per-client basis from the "push" list
-    (more fine-grained than ``--push-reset``).
-
-Http proxy password inside config file
-    Http proxy passwords can be specified with the inline file option
-    ``<http-proxy-user-pass>`` .. ``</http-proxy-user-pass>``
-
-Windows version detection
-    Windows version is detected, logged and possibly signalled to server
-    (IV_PLAT_VER=<nn> if ``--push-peer-info`` is set on client).
-
-Authentication tokens
-    In situations where it is not suitable to save user passwords on the client,
-    OpenVPN has support for pushing a --auth-token since v2.3.  This option is
-    pushed from the server to the client with a token value to be used instead
-    of the users password.  For this to work, the authentication plug-in would
-    need to implement this support as well.  In OpenVPN 2.4 --auth-gen-token
-    is introduced, which will allow the OpenVPN server to generate a random
-    token and push it to the client without any changes to the authentication
-    modules.  When the clients need to re-authenticate the OpenVPN server will
-    do the authentication internally, instead of sending the re-authentication
-    request to the authentication module .  This feature is especially
-    useful in configurations which use One Time Password (OTP) authentication
-    schemes, as this allows the tunnel keys to be renegotiated regularly without
-    any need to supply new OTP codes.
-
-keying-material-exporter
-    Keying Material Exporter [RFC-5705] allow additional keying material to be
-    derived from existing TLS channel.
-
-Android platform support
-    Support for running on Android using Android's VPNService API has been added.
-    See doc/android.txt for more details. This support is primarily used in
-    the OpenVPN for Android app (https://github.com/schwabe/ics-openvpn)
-
-AIX platform support
-    AIX platform support has been added. The support only includes tap
-    devices since AIX does not provide tun interface.
-
-Control channel encryption (``--tls-crypt``)
-    Use a pre-shared static key (like the ``--tls-auth`` key) to encrypt control
-    channel packets.  Provides more privacy, some obfuscation and poor-man's
-    post-quantum security.
-
-Asynchronous push reply
-    Plug-ins providing support for deferred authentication can benefit from a more
-    responsive authentication where the server sends PUSH_REPLY immediately once
-    the authentication result is ready, instead of waiting for the client to
-    to send PUSH_REQUEST once more.  This requires OpenVPN to be built with
-    ``./configure --enable-async-push``.  This is a compile-time only switch.
-
-
-Deprecated features
--------------------
-For an up-to-date list of all deprecated options, see this wiki page:
-https://community.openvpn.net/openvpn/wiki/DeprecatedOptions
-
-- ``--key-method 1`` is deprecated in OpenVPN 2.4 and will be removed in v2.5.
-  Migrate away from ``--key-method 1`` as soon as possible.  The recommended
-  approach is to remove the ``--key-method`` option from the configuration
-  files, OpenVPN will then use ``--key-method 2`` by default.  Note that this
-  requires changing the option in both the client and server side configs.
-
-- ``--tls-remote`` is removed in OpenVPN 2.4, as indicated in the v2.3
-  man-pages.  Similar functionality is provided via ``--verify-x509-name``,
-  which does the same job in a better way.
-
-- ``--compat-names`` and ``--no-name-remapping`` were deprecated in OpenVPN 2.3
-  and will be removed in v2.5.  All scripts and plug-ins depending on the old
-  non-standard X.509 subject formatting must be updated to the standardized
-  formatting.  See the man page for more information.
-
-- ``--no-iv`` is deprecated in OpenVPN 2.4 and will be removed in v2.5.
-
-- ``--keysize`` is deprecated in OpenVPN 2.4 and will be removed in v2.6
-  together with the support of ciphers with cipher block size less than
-  128-bits.
-
-- ``--comp-lzo`` is deprecated in OpenVPN 2.4.  Use ``--compress`` instead.
-
-- ``--ifconfig-pool-linear`` has been deprecated since OpenVPN 2.1 and will be
-  removed in v2.5.  Use ``--topology p2p`` instead.
-
-- ``--client-cert-not-required`` is deprecated in OpenVPN 2.4 and will be removed
-  in v2.5.  Use ``--verify-client-cert none`` for a functional equivalent.
-
-- ``--ns-cert-type`` is deprecated in OpenVPN 2.3.18 and v2.4.  It will be removed
-  in v2.5.  Use the far better ``--remote-cert-tls`` option which replaces this
-  feature.
-
-
-User-visible Changes
---------------------
-- When using ciphers with cipher blocks less than 128-bits,
-  OpenVPN will complain loudly if the configuration uses ciphers considered
-  weak, such as the SWEET32 attack vector.  In such scenarios, OpenVPN will by
-  default renegotiate for each 64MB of transported data (``--reneg-bytes``).
-  This renegotiation can be disabled, but is HIGHLY DISCOURAGED.
-
-- For certificate DNs with duplicate fields, e.g. "OU=one,OU=two", both fields
-  are now exported to the environment, where each second and later occurrence
-  of a field get _$N appended to it's field name, starting at N=1.  For the
-  example above, that would result in e.g. X509_0_OU=one, X509_0_OU_1=two.
-  Note that this breaks setups that rely on the fact that OpenVPN would
-  previously (incorrectly) only export the last occurrence of a field.
-
-- ``proto udp`` and ``proto tcp`` now use both IPv4 and IPv6. The new
-  options ``proto udp4`` and ``proto tcp4`` use IPv4 only.
-
-- ``--sndbuf`` and ``--recvbuf`` default now to OS defaults instead of 64k
-
-- OpenVPN exits with an error if an option has extra parameters;
-  previously they were silently ignored
-
-- ``--tls-auth`` always requires OpenVPN static key files and will no
-  longer work with free form files
-
-- ``--proto udp6/tcp6`` in server mode will now try to always listen to
-  both IPv4 and IPv6 on platforms that allow it. Use ``--bind ipv6only``
-  to explicitly listen only on IPv6.
-
-- Removed ``--enable-password-save`` from configure. This option is now
-  always enabled.
-
-- Stricter default TLS cipher list (override with ``--tls-cipher``), that now
-  also disables:
-
-  * Non-ephemeral key exchange using static (EC)DH keys
-  * DSS private keys
-
-- mbed TLS builds: changed the tls_digest_N values exported to the script
-  environment to be equal to the ones exported by OpenSSL builds, namely
-  the certificate fingerprint (was the hash of the 'to be signed' data).
-
-- mbed TLS builds: minimum RSA key size is now 2048 bits.  Shorter keys will
-  not be accepted, both local and from the peer.
-
-- ``--connect-timeout`` now specifies the timeout until the first TLS packet
-  is received (identical to ``--server-poll-timeout``) and this timeout now
-  includes the removed socks proxy timeout and http proxy timeout.
-
-  In ``--static`` mode ``connect-timeout`` specifies the timeout for TCP and
-  proxy connection establishment
-
-- ``--connect-retry-max`` now specifies the maximum number of unsuccessful
-  attempts of each remote/connection entry before exiting.
-
-- ``--http-proxy-timeout`` and the static non-changeable socks timeout (5s)
-  have been folded into a "unified" ``--connect-timeout`` which covers all
-  steps needed to connect to the server, up to the start of the TLS exchange.
-  The default value has been raised to 120s, to handle slow http/socks
-  proxies graciously.  The old "fail TCP fast" behaviour can be achieved by
-  adding "``--connect-timeout 10``" to the client config.
-
-- ``--http-proxy-retry`` and ``--sock-proxy-retry`` have been removed. Proxy connections
-  will now behave like regular connection entries and generate a USR1 on failure.
-
-- ``--connect-retry`` gets an optional second argument that specifies the maximum
-  time in seconds to wait between reconnection attempts when an exponential
-  backoff is triggered due to repeated retries. Default = 300 seconds.
-
-- Data channel cipher negotiation (see New features section) can override
-  ciphers configured in the config file.  Use ``--ncp-disable`` if you do not want
-  this behavior.
-
-- All tun devices on all platforms are always considered to be IPv6
-  capable. The ``--tun-ipv6`` option is ignored (behaves like it is always
-  on).
-
-- On the client side recursively routed packets, which have the same destination
-  as the VPN server, are dropped. This can be disabled with
-  --allow-recursive-routing option.
-
-- On Windows, when the ``--register-dns`` option is set, OpenVPN no longer
-  restarts the ``dnscache`` service - this had unwanted side effects, and
-  seems to be no longer necessary with currently supported Windows versions.
-
-- If no flags are given, and the interactive Windows service is used, "def1"
-  is implicitly set (because "delete and later reinstall the existing
-  default route" does not work well here).  If not using the service,
-  the old behaviour is kept.
-
-- OpenVPN now reloads a CRL only if the modication time or file size has
-  changed, instead of for each new connection.  This reduces the connection
-  setup time, in particular when using large CRLs.
-
-- OpenVPN now ships with more up-to-date systemd unit files which take advantage
-  of the improved service management as well as some hardening steps.  The
-  configuration files are picked up from the /etc/openvpn/server/ and
-  /etc/openvpn/client/ directories (depending on unit file).  This also avoids
-  these new unit files and how they work to collide with older pre-existing
-  unit files.
-
-- Using ``--no-iv`` (which is generally not a recommended setup) will
-  require explicitly disabling NCP with ``--disable-ncp``.  This is
-  intentional because NCP will by default use AES-GCM, which requires
-  an IV - so we want users of that option to consciously reconsider.
-
-
-Maintainer-visible changes
---------------------------
-- OpenVPN no longer supports building with crypto support, but without TLS
-  support.  As a consequence, OPENSSL_CRYPTO_{CFLAGS,LIBS} and
-  OPENSSL_SSL_{CFLAGS,LIBS} have been merged into OPENSSL_{CFLAGS,LIBS}.  This
-  is particularly relevant for maintainers who build their own OpenSSL library,
-  e.g. when cross-compiling.
-
-- Linux distributions using systemd is highly encouraged to ship these new unit
-  files instead of older ones, to provide a unified behaviour across systemd
-  based Linux distributions.
-
-- With OpenVPN 2.4, the project has moved over to depend on and actively use
-  the official C99 standard (-std=c99).  This may fail on some older compiler/libc
-  header combinations.  In most of these situations it is recommended to
-  use -std=gnu99 in CFLAGS.  This is known to be needed when doing
-  i386/i686 builds on RHEL5.
-
-
-Version 2.4.5
-=============
-
-New features
-------------
-- The new option ``--tls-cert-profile`` can be used to restrict the set of
-  allowed crypto algorithms in TLS certificates in mbed TLS builds.  The
-  default profile is 'legacy' for now, which allows SHA1+, RSA-1024+ and any
-  elliptic curve certificates.  The default will be changed to the 'preferred'
-  profile in the future, which requires SHA2+, RSA-2048+ and any curve.
-
-
-Version 2.4.3
-=============
-
-New features
-------------
-- Support building with OpenSSL 1.1 now (in addition to older versions)
-
-- On Win10, set low interface metric for TAP adapter when block-outside-dns
-  is in use, to make Windows prefer the TAP adapter for DNS queries
-  (avoiding large delays)
-
-
-Security
---------
-- CVE-2017-7522: Fix ``--x509-track`` post-authentication remote DoS
-  A client could crash a v2.4+ mbedtls server, if that server uses the
-  ``--x509-track`` option and the client has a correct, signed and unrevoked
-  certificate that contains an embedded NUL in the certificate subject.
-  Discovered and reported to the OpenVPN security team by Guido Vranken.
-
-- CVE-2017-7521: Fix post-authentication remote-triggerable memory leaks
-  A client could cause a server to leak a few bytes each time it connects to the
-  server.  That can eventually cause the server to run out of memory, and thereby
-  causing the server process to terminate. Discovered and reported to the
-  OpenVPN security team by Guido Vranken.  (OpenSSL builds only.)
-
-- CVE-2017-7521: Fix a potential post-authentication remote code execution
-  attack on servers that use the ``--x509-username-field`` option with an X.509
-  extension field (option argument prefixed with ``ext:``).  A client that can
-  cause a server to run out-of-memory (see above) might be able to cause the
-  server to double free, which in turn might lead to remote code execution.
-  Discovered and reported to the OpenVPN security team by Guido Vranken.
-  (OpenSSL builds only.)
-
-- CVE-2017-7520: Pre-authentication remote crash/information disclosure for
-  clients. If clients use a HTTP proxy with NTLM authentication (i.e.
-  ``--http-proxy <server> <port> [<authfile>|'auto'|'auto-nct'] ntlm2``),
-  a man-in-the-middle attacker between the client and the proxy can cause
-  the client to crash or disclose at most 96 bytes of stack memory. The
-  disclosed stack memory is likely to contain the proxy password. If the
-  proxy password is not reused, this is unlikely to compromise the security
-  of the OpenVPN tunnel itself.  Clients who do not use the ``--http-proxy``
-  option with ntlm2 authentication are not affected.
-
-- CVE-2017-7508: Fix remotely-triggerable ASSERT() on malformed IPv6 packet.
-  This can be used to remotely shutdown an openvpn server or client, if
-  IPv6 and ``--mssfix`` are enabled and the IPv6 networks used inside the VPN
-  are known.
-
-- Fix null-pointer dereference when talking to a malicious http proxy
-  that returns a malformed ``Proxy-Authenticate:`` headers for digest auth.
-
-- Fix overflow check for long ``--tls-cipher`` option
-
-- Windows: Pass correct buffer size to ``GetModuleFileNameW()``
-  (OSTIF/Quarkslabs audit, finding 5.6)
-
-
-User-visible Changes
---------------------
-- ``--verify-hash`` can now take an optional flag which changes the hashing
-  algorithm. It can be either SHA1 or SHA256.  The default if not provided is
-  SHA1 to preserve backwards compatibility with existing configurations.
-
-- Restrict the supported ``--x509-username-field`` extension fields to subjectAltName
-  and issuerAltName.  Other extensions probably didn't work anyway, and would
-  cause OpenVPN to crash when a client connects.
-
-
-Bugfixes
---------
-- Fix fingerprint calculation in mbed TLS builds.  This means that mbed TLS users
-  of OpenVPN 2.4.0, v2.4.1 and v2.4.2 that rely on the values of the
-  ``tls_digest_*`` env vars, or that use ``--verify-hash`` will have to change
-  the fingerprint values they check against.  The security impact of the
-  incorrect calculation is very minimal; the last few bytes (max 4, typically
-  4) are not verified by the fingerprint.  We expect no real-world impact,
-  because users that used this feature before will notice that it has suddenly
-  stopped working, and users that didn't will notice that connection setup
-  fails if they specify correct fingerprints.
-
-- Fix edge case with NCP when the server sends an empty PUSH_REPLY message
-  back, and the client would not initialize it's data channel crypto layer
-  properly (trac #903)
-
-- Fix SIGSEGV on unaligned buffer access on OpenBSD/Sparc64
-
-- Fix TCP_NODELAY on OpenBSD
-
-- Remove erroneous limitation on max number of args for ``--plugin``
-
-- Fix NCP behaviour on TLS reconnect (Server would not send a proper
-  "cipher ..." message back to the client, leading to client and server
-  using different ciphers) (trac #887)
-
-
-Version 2.4.2
-=============
-
-Bugfixes
---------
-- Fix memory leak introduced in OpenVPN 2.4.1: if ``--remote-cert-tls`` is
-  used, we leaked some memory on each TLS (re)negotiation.
-
-
-Security
---------
-- Fix a pre-authentication denial-of-service attack on both clients and
-  servers.  By sending a too-large control packet, OpenVPN 2.4.0 or v2.4.1 can
-  be forced to hit an ASSERT() and stop the process.  If ``--tls-auth`` or
-  ``--tls-crypt`` is used, only attackers that have the ``--tls-auth`` or
-  ``--tls-crypt`` key can mount an attack.
-  (OSTIF/Quarkslab audit finding 5.1, CVE-2017-7478)
-
-- Fix an authenticated remote DoS vulnerability that could be triggered by
-  causing a packet id roll over.  An attack is rather inefficient; a peer
-  would need to get us to send at least about 196 GB of data.
-  (OSTIF/Quarkslab audit finding 5.2, CVE-2017-7479)
-
-
-Version 2.4.1
-=============
-- ``--remote-cert-ku`` now only requires the certificate to have at least the
-  bits set of one of the values in the supplied list, instead of requiring an
-  exact match to one of the values in the list.
-- ``--remote-cert-tls`` now only requires that a keyUsage is present in the
-  certificate, and leaves the verification of the value up to the crypto
-  library, which has more information (i.e. the key exchange method in use)
-  to verify that the keyUsage is correct.
-- ``--ns-cert-type`` is deprecated.  Use ``--remote-cert-tls`` instead.
-  The nsCertType x509 extension is very old, and barely used.
-  ``--remote-cert-tls`` uses the far more common keyUsage and extendedKeyUsage
-  extension instead.  Make sure your certificates carry these to be able to
-  use ``--remote-cert-tls``.
-
diff --git a/Makefile.am b/Makefile.am
index feeaabb..66252e6 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -59,7 +59,7 @@ 
 dist_doc_DATA = \
 	README \
 	README.mbedtls \
-	Changes.rst \
+	Changes.md \
 	COPYRIGHT.GPL \
 	COPYING