[Openvpn-devel,M] Change in openvpn[master]: Remove ability to use configurations without TLS by default

diff --git a/Changes.rst b/Changes.rst
index 77bcef2..3676dce 100644
--- a/Changes.rst
+++ b/Changes.rst
@@ -1,3 +1,15 @@ 
+Overview of changes in 2.7
+==========================
+``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.
+
 Overview of changes in 2.6
 ==========================
 
diff --git a/doc/man-sections/encryption-options.rst b/doc/man-sections/encryption-options.rst
index abc73d9..3b26782 100644
--- a/doc/man-sections/encryption-options.rst
+++ b/doc/man-sections/encryption-options.rst
@@ -69,20 +69,20 @@ 
      $ openvpn --tls-crypt-v2 v2crypt-server.key --genkey tls-crypt-v2-client v2crypt-client-1.key
 
   * Generating *Shared Secret Keys*
-    Generate a shared secret, for use with the ``--secret``, ``--tls-auth``
+    Generate a shared secret, for use with the ``--tls-auth``
     or ``--tls-crypt`` options.
 
     Syntax:
     ::
 
-       $ openvpn --genkey secret|tls-crypt|tls-auth keyfile
+       $ openvpn --genkey tls-crypt|tls-auth keyfile
 
-    The key is saved in ``keyfile``. All three variants (``--secret``,
-    ``tls-crypt`` and ``tls-auth``) generate the same type of key. The
-    aliases are added for convenience.
+    The key is saved in ``keyfile``. Both variants (``tls-crypt`` and
+    ``tls-auth``) generate the same type of key. The aliases are added for
+    convenience.
 
-    If using this for ``--secret``, this file must be shared with the peer
-    over a pre-existing secure channel such as ``scp``\(1).
+    This file must be shared with the peer over a pre-existing secure
+    channel such as ``scp``\(1).
 
   * Generating *TLS Crypt v2 Server key*
     Generate a ``--tls-crypt-v2`` key to be used by an OpenVPN server.
diff --git a/doc/man-sections/inline-files.rst b/doc/man-sections/inline-files.rst
index 01e4a84..f46301e 100644
--- a/doc/man-sections/inline-files.rst
+++ b/doc/man-sections/inline-files.rst
@@ -3,7 +3,7 @@ 
 
 OpenVPN allows including files in the main configuration for the ``--ca``,
 ``--cert``, ``--dh``, ``--extra-certs``, ``--key``, ``--pkcs12``,
-``--secret``, ``--crl-verify``, ``--http-proxy-user-pass``, ``--tls-auth``,
+``--crl-verify``, ``--http-proxy-user-pass``, ``--tls-auth``,
 ``--auth-gen-token-secret``, ``--peer-fingerprint``, ``--tls-crypt``,
 ``--tls-crypt-v2`` and ``--verify-hash`` options.
 
diff --git a/doc/man-sections/link-options.rst b/doc/man-sections/link-options.rst
index 14e76b4..c3d35b1 100644
--- a/doc/man-sections/link-options.rst
+++ b/doc/man-sections/link-options.rst
@@ -226,10 +226,7 @@ 
   Ping remote over the TCP/UDP control channel if no packets have been
   sent for at least ``n`` seconds (specify ``--ping`` on both peers to
   cause ping packets to be sent in both directions since OpenVPN ping
-  packets are not echoed like IP ping packets). When used in one of
-  OpenVPN's secure modes (where ``--secret``, ``--tls-server`` or
-  ``--tls-client`` is specified), the ping packet will be
-  cryptographically secure.
+  packets are not echoed like IP ping packets).
 
   This option has two intended uses:
 
@@ -428,8 +425,7 @@ 
   received by the prior session.
 
   This option only makes sense when replay protection is enabled (the
-  default) and you are using either ``--secret`` (shared-secret key mode)
-  or TLS mode with ``--tls-auth``.
+  default) and you are using TLS mode with ``--tls-auth``.
 
 --session-timeout n
   Raises :code:`SIGTERM` for the client instance after ``n`` seconds since
diff --git a/doc/man-sections/protocol-options.rst b/doc/man-sections/protocol-options.rst
index 8134157..cac09e4 100644
--- a/doc/man-sections/protocol-options.rst
+++ b/doc/man-sections/protocol-options.rst
@@ -73,9 +73,7 @@ 
   configured on the data channel, however, later versions usually
   ignored this directive in favour of a negotiated cipher.
   Starting with 2.6.0, this option is always ignored in TLS mode
-  when it comes to configuring the cipher and will only control the
-  cipher for ``--secret`` pre-shared-key mode (note: this mode is
-  deprecated and strictly not recommended).
+  when it comes to configuring the cipher.
 
   If you wish to specify the cipher to use on the data channel,
   please see ``--data-ciphers`` (for regular negotiation) and
@@ -182,7 +180,7 @@ 
 
 --key-direction
   Alternative way of specifying the optional direction parameter for the
-  ``--tls-auth`` and ``--secret`` options. Useful when using inline files
+  ``--tls-auth`` option. Useful when using inline files
   (See section on inline files).
 
 --data-ciphers cipher-list
@@ -234,55 +232,6 @@ 
   have been configured with ``--enable-small``
   (typically used on routers or other embedded devices).
 
---secret args
-  **DEPRECATED** Enable Static Key encryption mode (non-TLS). Use pre-shared secret
-  ``file`` which was generated with ``--genkey``.
-
-  Valid syntaxes:
-  ::
-
-     secret file
-     secret file direction
-
-  The optional ``direction`` parameter enables the use of 4 distinct keys
-  (HMAC-send, cipher-encrypt, HMAC-receive, cipher-decrypt), so that each
-  data flow direction has a different set of HMAC and cipher keys. This
-  has a number of desirable security properties including eliminating
-  certain kinds of DoS and message replay attacks.
-
-  When the ``direction`` parameter is omitted, 2 keys are used
-  bidirectionally, one for HMAC and the other for encryption/decryption.
-
-  The ``direction`` parameter should always be complementary on either
-  side of the connection, i.e. one side should use :code:`0` and the other
-  should use :code:`1`, or both sides should omit it altogether.
-
-  The ``direction`` parameter requires that ``file`` contains a 2048 bit
-  key. While pre-1.5 versions of OpenVPN generate 1024 bit key files, any
-  version of OpenVPN which supports the ``direction`` parameter, will also
-  support 2048 bit key file generation using the ``--genkey`` option.
-
-  Static key encryption mode has certain advantages, the primary being
-  ease of configuration.
-
-  There are no certificates or certificate authorities or complicated
-  negotiation handshakes and protocols. The only requirement is that you
-  have a pre-existing secure channel with your peer (such as ``ssh``) to
-  initially copy the key. This requirement, along with the fact that your
-  key never changes unless you manually generate a new one, makes it
-  somewhat less secure than TLS mode (see below). If an attacker manages
-  to steal your key, everything that was ever encrypted with it is
-  compromised. Contrast that to the perfect forward secrecy features of
-  TLS mode (using Diffie Hellman key exchange), where even if an attacker
-  was able to steal your private key, he would gain no information to help
-  him decrypt past sessions.
-
-  Another advantageous aspect of Static Key encryption mode is that it is
-  a handshake-free protocol without any distinguishing signature or
-  feature (such as a header or protocol handshake sequence) that would
-  mark the ciphertext packets as being generated by OpenVPN. Anyone
-  eavesdropping on the wire would see nothing but random-looking data.
-
 --tran-window n
   Transition window -- our old key can live this many seconds after a new
   a key renegotiation begins (default :code:`3600` seconds). This feature
diff --git a/doc/man-sections/server-options.rst b/doc/man-sections/server-options.rst
index 6b9ad21..c1d3dc8 100644
--- a/doc/man-sections/server-options.rst
+++ b/doc/man-sections/server-options.rst
@@ -406,7 +406,7 @@ 
   Options that will be compared for compatibility include ``dev-type``,
   ``link-mtu``, ``tun-mtu``, ``proto``, ``ifconfig``,
   ``comp-lzo``, ``fragment``, ``keydir``, ``cipher``,
-  ``auth``, ``keysize``, ``secret``, ``no-replay``,
+  ``auth``, ``keysize``, ``no-replay``,
   ``tls-auth``, ``key-method``, ``tls-server``
   and ``tls-client``.
 
diff --git a/doc/man-sections/tls-options.rst b/doc/man-sections/tls-options.rst
index d51aff7..908a42a 100644
--- a/doc/man-sections/tls-options.rst
+++ b/doc/man-sections/tls-options.rst
@@ -295,8 +295,24 @@ 
   Older versions (up to OpenVPN 2.3) supported a freeform passphrase file.
   This is no longer supported in newer versions (v2.4+).
 
-  See the ``--secret`` option for more information on the optional
-  ``direction`` parameter.
+  The optional ``direction`` parameter enables the use of 2 distinct keys
+  (HMAC-send, HMAC-receive), so that each
+  data flow direction has a different HMAC key. This has a number of desirable
+  security properties including eliminating certain kinds of DoS and message
+  replay attacks.
+
+  When the ``direction`` parameter is omitted, the same key is used
+  bidirectionally.
+
+  The ``direction`` parameter should always be complementary on either
+  side of the connection, i.e. one side should use :code:`0` and the other
+  should use :code:`1`, or both sides should omit it altogether.
+
+  The ``direction`` parameter requires that ``file`` contains a 2048 bit
+  key. While pre-1.5 versions of OpenVPN generate 1024 bit key files, any
+  version of OpenVPN which supports the ``direction`` parameter, will also
+  support 2048 bit key file generation using the ``--genkey`` option.
+
 
   ``--tls-auth`` is recommended when you are running OpenVPN in a mode
   where it is listening for packets from any IP address, such as when
diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index d168163..bce6846 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -532,12 +532,6 @@ 
     "\n"
     "Data Channel Encryption Options (must be compatible between peers):\n"
     "(These options are meaningful for both Static Key & TLS-mode)\n"
-    "--secret f [d]  : (DEPRECATED) Enable Static Key encryption mode (non-TLS).\n"
-    "                  Use shared secret file f, generate with --genkey.\n"
-    "                  The optional d parameter controls key directionality.\n"
-    "                  If d is specified, use separate keys for each\n"
-    "                  direction, set d=0 on one side of the connection,\n"
-    "                  and d=1 on the other side.\n"
     "--auth alg      : Authenticate packets with HMAC using message\n"
     "                  digest algorithm alg (default=%s).\n"
     "                  (usually adds 16 or 20 bytes per packet)\n"
@@ -622,13 +616,11 @@ 
     "                  and DoS attacks.\n"
     "                  f (required) is a shared-secret key file.\n"
     "                  The optional d parameter controls key directionality,\n"
-    "                  see --secret option for more info.\n"
     "--tls-crypt key : Add an additional layer of authenticated encryption on top\n"
     "                  of the TLS control channel to hide the TLS certificate,\n"
     "                  provide basic post-quantum security and protect against\n"
     "                  attacks on the TLS stack and DoS attacks.\n"
     "                  key (required) provides the pre-shared key file.\n"
-    "                  see --secret option for more info.\n"
     "--tls-crypt-v2 key : For clients: use key as a client-specific tls-crypt key.\n"
     "                  For servers: use key to decrypt client-specific keys.  For\n"
     "                  key generation (--genkey tls-crypt-v2-client): use key to\n"
@@ -762,7 +754,7 @@ 
     "\n"
     "Generate a new key :\n"
     "--genkey secret file   : Generate a new random key of type and write to file\n"
-    "                         (for use with --secret, --tls-auth or --tls-crypt)."
+    "                         (for use with --tls-auth or --tls-crypt)."
 #ifdef ENABLE_FEATURE_TUN_PERSIST
     "\n"
     "Tun/tap config mode (available with linux 2.4+):\n"
@@ -2837,11 +2829,20 @@ 
 
     if (!options->tls_server && !options->tls_client)
     {
-        msg(M_INFO, "DEPRECATION: No tls-client or tls-server option in "
-            "configuration detected. OpenVPN 2.7 will remove the "
+        int msglevel = M_USAGE;
+        if (options->allow_deprecated_insecure_static_crypto)
+        {
+            msglevel = M_INFO;
+        }
+
+        msg(msglevel, "DEPRECATION: No tls-client or tls-server option in "
+            "configuration detected. OpenVPN 2.8 will remove the "
             "functionality to run a VPN without TLS. "
             "See the examples section in the manual page for "
-            "examples of a similar quick setup with peer-fingerprint.");
+            "examples of a similar quick setup with peer-fingerprint."
+            "OpenVPN 2.7 allow using this configuration when using "
+            "--allow-deprecated-insecure-static-crypto but you should move"
+            "to proper configuration as soon as possible.");
     }
 
     if (options->ssl_flags & (SSLF_CLIENT_CERT_NOT_REQUIRED|SSLF_CLIENT_CERT_OPTIONAL))
@@ -8550,6 +8551,12 @@ 
             }
         }
     }
+    else if (streq(p[0], "allow-deprecated-insecure-static-crypto"))
+    {
+        VERIFY_PERMISSION(OPT_P_GENERAL);
+        options->allow_deprecated_insecure_static_crypto = true;
+
+    }
     else if (streq(p[0], "genkey") && !p[4])
     {
         VERIFY_PERMISSION(OPT_P_GENERAL);
diff --git a/src/openvpn/options.h b/src/openvpn/options.h
index f5890b9..33d17ca 100644
--- a/src/openvpn/options.h
+++ b/src/openvpn/options.h
@@ -552,6 +552,7 @@ 
     /* Cipher parms */
     const char *shared_secret_file;
     bool shared_secret_file_inline;
+    bool allow_deprecated_insecure_static_crypto;
     int key_direction;
     const char *ciphername;
     bool enable_ncp_fallback;      /**< If defined fall back to
diff --git a/tests/t_lpback.sh b/tests/t_lpback.sh
index 482016a..68df2a6 100755
--- a/tests/t_lpback.sh
+++ b/tests/t_lpback.sh
@@ -97,7 +97,7 @@ 
 for cipher in ${CIPHERS}
 do
     test_start "Testing cipher ${cipher}... "
-    ( "${openvpn}" --test-crypto --secret key.$$ --cipher ${cipher} ) >log.$$ 2>&1
+    ( "${openvpn}" --test-crypto --secret key.$$  --allow-deprecated-insecure-static-crypto --cipher ${cipher} ) >log.$$ 2>&1
     test_end $? log.$$
 done