@@ -39,6 +39,7 @@ sbin_PROGRAMS = openvpn
openvpn_SOURCES = \
argv.c argv.h \
+ auth_token.c auth_token.h \
base64.c base64.h \
basic.h \
buffer.c buffer.h \
new file mode 100644
@@ -0,0 +1,333 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#elif defined(_MSC_VER)
+#include "config-msvc.h"
+#endif
+
+#include "syshead.h"
+
+#include "base64.h"
+#include "buffer.h"
+#include "crypto.h"
+#include "openvpn.h"
+#include "ssl_common.h"
+#include "auth_token.h"
+#include "push.h"
+#include "integer.h"
+
+const char *auth_token_pem_name = "OpenVPN auth-token server key";
+
+static struct key_type
+auth_token_kt(void)
+{
+ struct key_type kt;
+ /* We do not encrypt our session tokens */
+ kt.cipher = NULL;
+ kt.digest = md_kt_get("SHA256");
+
+ if (!kt.digest)
+ {
+ msg(M_WARN, "ERROR: --tls-crypt requires HMAC-SHA-256 support.");
+ return (struct key_type) { 0 };
+ }
+
+ kt.hmac_length = md_kt_size(kt.digest);
+
+ return kt;
+}
+
+
+void auth_token_write_server_key_file(const char *filename)
+{
+ write_pem_key_file(filename, auth_token_pem_name);
+}
+
+static inline bool
+auth_token_load_key(struct buffer *key, const char *key_file,
+ const char *key_inline)
+{
+ struct buffer key_pem = { 0 };
+ struct gc_arena gc = gc_new();
+ bool ret = false;
+ /*
+ * User did not specify a permanent key file, generate key data
+ * on the fly
+ */
+ if (key_file == NULL)
+ {
+ msg(M_INFO, "Using random auth-token HMAC key.");
+ uint8_t rand[BCAP(key)];
+ if (!rand_bytes(rand, BCAP(key)))
+ {
+ msg(M_WARN, "ERROR: could not generate random key");
+ }
+ else
+ {
+ buf_write(key, rand, BCAP(key));
+ ret = true;
+ }
+ goto cleanup;
+ }
+ else if (strcmp(key_file, INLINE_FILE_TAG))
+ {
+ key_pem = buffer_read_from_file(key_file, &gc);
+ if (!buf_valid(&key_pem))
+ {
+ msg(M_WARN, "ERROR: failed to read auth-token-secret file (%s)",
+ key_file);
+ goto cleanup;
+ }
+ }
+ else
+ {
+ buf_set_read(&key_pem, (const void *)key_inline, strlen(key_inline) +1);
+ }
+
+ if (!crypto_pem_decode(auth_token_pem_name, key, &key_pem))
+ {
+ msg(M_WARN, "ERROR: auth-token pem decode failed");
+ goto cleanup;
+ }
+ ret = true;
+cleanup:
+ if (key_file && strcmp(key_file, INLINE_FILE_TAG))
+ {
+ buf_clear(&key_pem);
+ }
+ gc_free(&gc);
+ return ret;
+}
+
+void
+auth_token_init_secret(struct key_ctx *key_ctx, const char *key_file,
+ const char *key_inline)
+{
+ struct key_type kt = auth_token_kt();
+
+ struct buffer server_secret_key = alloc_buf(2048);
+
+ if (!auth_token_load_key(&server_secret_key, key_file, key_inline))
+ {
+ msg(M_FATAL, "ERROR: Cannot load auth-token secret");
+ }
+
+ struct key key;
+
+ if (!buf_read(&server_secret_key, &key, sizeof(key)))
+ {
+ msg(M_FATAL, "ERROR: not enough data in auth-token secret");
+ }
+ init_key_ctx(key_ctx, &key, &kt, false, "auth-token secret");
+
+ free_buf(&server_secret_key);
+}
+
+void
+generate_auth_token(struct user_pass *up, struct tls_multi *multi)
+{
+
+ struct gc_arena gc = gc_new();
+
+ int64_t timestamp = htonll((uint64_t)now);
+ int64_t initial_timestamp = timestamp;
+
+ hmac_ctx_t *ctx = multi->opt.auth_token_key.hmac;
+ ASSERT(hmac_ctx_size(ctx) == 256/8);
+
+ if (multi->auth_token)
+ {
+ /* Just enough space to fit 8 bytes+ 1 extra to decode a non padded
+ * base64 string (multiple of 3 bytes). 9 bytes => 12 bytes base64
+ * bytes
+ */
+ char old_tstamp_decode[9];
+
+ /*
+ * reuse the same session id and timestamp and null terminate it at
+ * for base64 decode it only decodes the session id part of it
+ */
+ char *old_tsamp_initial = multi->auth_token + strlen(SESSION_ID_PREFIX);
+
+ old_tsamp_initial[12] = '\0';
+ ASSERT(openvpn_base64_decode(old_tsamp_initial, old_tstamp_decode, 9) == 9);
+ initial_timestamp = *((uint64_t *)(old_tstamp_decode));
+
+ /* free the auth-token, we will replace it with a new one */
+ free(multi->auth_token);
+ }
+ uint8_t hmac_output[256/8];
+
+ hmac_ctx_reset(ctx);
+ hmac_ctx_update(ctx, (uint8_t *) up->username, (int)strlen(up->username));
+ hmac_ctx_update(ctx, (uint8_t *) &initial_timestamp, sizeof(initial_timestamp));
+ hmac_ctx_update(ctx, (uint8_t *) ×tamp, sizeof(timestamp));
+ hmac_ctx_final(ctx, hmac_output);
+
+ /* Construct the unencoded session token */
+ struct buffer token = alloc_buf_gc(
+ 2*sizeof(uint64_t) + 256/8, &gc);
+
+ ASSERT(buf_write(&token, &initial_timestamp, sizeof(initial_timestamp)));
+ ASSERT(buf_write(&token, ×tamp, sizeof(timestamp)));
+ ASSERT(buf_write(&token, hmac_output, sizeof(hmac_output)));
+
+ char* b64output;
+ openvpn_base64_encode(BPTR(&token), BLEN(&token), &b64output);
+
+ struct buffer session_token = alloc_buf_gc(
+ strlen(SESSION_ID_PREFIX) + strlen (b64output) + 1, &gc);
+
+ ASSERT(buf_write(&session_token, SESSION_ID_PREFIX, strlen(SESSION_ID_PREFIX)));
+ ASSERT(buf_write(&session_token, b64output, (int)strlen(b64output)));
+ ASSERT(buf_write_u8(&session_token, 0));
+
+ free(b64output);
+
+ multi->auth_token = strdup((char *)BPTR(&session_token));
+
+ dmsg(D_SHOW_KEYS, "Generated token for client: %s",
+ multi->auth_token);
+
+ gc_free(&gc);
+}
+
+bool
+verify_auth_token(struct user_pass *up, struct tls_multi *multi,
+ struct tls_session *session)
+{
+ /*
+ * Base64 is <= input and input is < USER_PASS_LEN, so using USER_PASS_LEN
+ * is safe here but a bit overkill
+ */
+ char b64decoded[USER_PASS_LEN];
+ int decoded_len = openvpn_base64_decode(up->password + strlen(SESSION_ID_PREFIX),
+ b64decoded, USER_PASS_LEN);
+
+ /* Ensure that the decoded data is at least the size of the
+ * timestamp + hmac */
+ int expected_len = 2 * sizeof(int64_t) + 32;
+
+ if (decoded_len != expected_len)
+ {
+ msg(M_WARN, "ERROR: --auth-token wrong size (%d!=%d)", decoded_len, expected_len);
+ return false;
+ }
+
+ hmac_ctx_t *ctx = multi->opt.auth_token_key.hmac;
+ ASSERT(hmac_ctx_size(ctx) == 256/8);
+
+ hmac_ctx_reset(ctx);
+ hmac_ctx_update(ctx, (uint8_t *) up->username, strlen(up->username));
+ hmac_ctx_update(ctx, (uint8_t *) b64decoded, sizeof(int64_t));
+
+ uint8_t hmac_output[256/8];
+ hmac_ctx_final(ctx, hmac_output);
+
+ const uint8_t *tstamp_initial = b64decoded;
+ const uint8_t *tstamp = tstamp_initial + sizeof(int64_t);
+ const uint8_t *hmac = tstamp + sizeof(int64_t);
+
+ uint64_t timestamp = ntohll(*((uint64_t *)(tstamp)));
+ uint64_t timestamp_initial = ntohll(*((uint64_t *)(tstamp_initial)));
+
+ int validhmac = memcmp_constant_time(&hmac_output, hmac, 32);
+
+ if (validhmac != 0)
+ {
+ msg(M_WARN, "--auth-token-gen: HMAC on token from client failed");
+ return false;
+ }
+
+ bool ret = false;
+
+ /* Accept session tokens that not expired are in the acceptable range
+ * for renogiations */
+ if (now >= timestamp
+ && now < timestamp + 2 * session->opt->renegotiate_seconds)
+ {
+ ret = true;
+ }
+
+ /* We could still have a client that does not update
+ * its auth-token, so also allow the initial auth-token */
+ if (!ret && multi->auth_token_initial
+ && memcmp_constant_time(up->password, multi->auth_token_initial,
+ strlen(multi->auth_token_initial)) == 0)
+ {
+ ret = true;
+ }
+
+ /* Sanity check the initial timestamp */
+ if (timestamp < timestamp_initial)
+ {
+ msg(M_WARN, "Initial timestamp (%lld) in token from client earlier than "
+ "current timestamp (%lld). Broken/unsynchronised clock?",
+ timestamp_initial, timestamp);
+ ret = false;
+ }
+
+ if (multi->opt.auth_token_lifetime
+ && now > timestamp_initial + multi->opt.auth_token_lifetime)
+ {
+ /* auth token lifetime exceeded */
+ ret = false;
+ }
+
+ if (!ret)
+ {
+ msg(M_INFO, "--auth-token-gen: auth-token from client expired");
+ }
+
+
+ /* Generate a new auth token to be sent to the client */
+ if (ret)
+ {
+ /* If we accepted a token without prior session, i.e.
+ * initial auth via token on new connection, we need
+ * to store the auth-token in multi->auth_token, so
+ * the initial timestamp can be extracted from it
+ */
+ if (!multi->auth_token)
+ {
+ multi->auth_token = strdup(up->password);
+ }
+
+ generate_auth_token(up, multi);
+ /* Auth token already sent to client, update auth-token */
+ if (multi->auth_token_initial)
+ {
+ /*
+ * We do not explicitly schedule the sending of the
+ * control message here but control message are only
+ * postponed when the control channel is not yet fully
+ * established and furthermore since this is called in
+ * the middle of authentication, there are other messages
+ * (new data channel keys) that are sent anyway and will
+ * trigger schedueling
+ */
+ send_push_reply_auth_token(multi);
+ }
+ }
+ return ret;
+}
+
+void
+wipe_auth_token(struct tls_multi *multi)
+{
+ if (multi)
+ {
+ if (multi->auth_token)
+ {
+ secure_memzero(multi->auth_token, strlen(multi->auth_token));
+ free(multi->auth_token);
+ }
+ if (multi->auth_token_initial)
+ {
+ secure_memzero(multi->auth_token_initial,
+ strlen(multi->auth_token_initial));
+ free(multi->auth_token_initial);
+ }
+ multi->auth_token = NULL;
+ multi->auth_token_initial = NULL;
+ }
+}
new file mode 100644
@@ -0,0 +1,101 @@
+/*
+ * OpenVPN -- An application to securely tunnel IP networks
+ * over a single TCP/UDP port, with support for SSL/TLS-based
+ * session authentication and key exchange,
+ * packet encryption, packet authentication, and
+ * packet compression.
+ *
+ * Copyright (C) 2002-2018 OpenVPN Inc <sales@openvpn.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#ifndef AUTH_TOKEN_H
+#define AUTH_TOKEN_H
+
+/**
+ * Generate an auth token based on username and timestamp
+ *
+ * The idea of auth token is to be stateless, so that we can verify use it
+ * even after we have forgotten about it or server has been restarted.
+ *
+ * To achieve this even though we cannot trust the client we use HMAC
+ * to be able to verify the information.
+ *
+ * Format of the auth-token (before base64 encode)
+ *
+ * uint64 timestamp (4 bytes)|uint64 timestamp (4 bytes)|sha256-hmac(32 bytes)
+ *
+ * The first timestamp is the time the token was initially created and is used to
+ * determine the maximum renewable time of the token. We always include this even
+ * if tokens do not expire (this value is not used) to keep the code cleaner.
+ *
+ * The second timestamp is the time the token was renewed/regenerated and is used
+ * to determine if this token has been renewed in the acceptable time range
+ * (2 * renogiation timeout)
+ *
+ * The hmac is calculated over the username contactinated with the
+ * raw auth-token bytes to include authentication of the username in the token
+ *
+ * we prepend the session id with SESS_ID_ before sending it to the client
+ */
+void
+generate_auth_token(struct user_pass *up, struct tls_multi *multi);
+
+/**
+ * Verifies the auth token to be in the format that generate_auth_token
+ * create and checks if the token is valid.
+ *
+ * Also calls generate_auth_token to update the auth-token to extend
+ * its validity
+ */
+bool
+verify_auth_token(struct user_pass *up, struct tls_multi *multi,
+ struct tls_session *session);
+
+
+
+/**
+ * Loads an HMAC secret from a file or if no file is present generates a
+ * epheremal secret for the run time of the server and stores it into ctx
+ */
+void
+auth_token_init_secret(struct key_ctx *key_ctx, const char *key_file,
+ const char *key_inline);
+
+
+/**
+ * Generate a auth-token server secret key, and write to file.
+ *
+ * @param filename Filename of the server key file to create.
+ */
+void auth_token_write_server_key_file(const char *filename);
+
+
+/**
+ * Wipes the authentication token out of the memory, frees and cleans up
+ * related buffers and flags
+ *
+ * @param multi Pointer to a multi object holding the auth_token variables
+ */
+void wipe_auth_token(struct tls_multi *multi);
+
+/**
+ * The prefix given to auth tokens start with, this prefix is special
+ * cased to not show up in log files in OpenVPN 2 and 3
+ *
+ * We also prefix this with _AT_ to only act on auth token generated by us.
+ */
+#define SESSION_ID_PREFIX "SESS_ID_AT_"
+
+#endif /* AUTH_TOKEN_H */
@@ -51,6 +51,7 @@
#include "ssl_verify.h"
#include "tls_crypt.h"
#include "forward.h"
+#include "auth_token.h"
#include "memdbg.h"
@@ -1098,6 +1099,17 @@ do_genkey(const struct options *options)
msg(M_USAGE, "--tls-crypt-v2-genkey type should be \"client\" or \"server\"");
}
+
+ if (options->auth_token_gen_secret_file)
+ {
+ if (!options->auth_token_secret_file)
+ {
+ msg(M_USAGE, "--auth-gen-token-secret-genkey requires a server key "
+ "to be set via --auth-gen-token-secret to create a shared secret");
+ }
+ auth_token_write_server_key_file(options->auth_token_secret_file);
+ return true;
+ }
return false;
}
@@ -2490,7 +2502,6 @@ init_crypto_pre(struct context *c, const unsigned int flags)
rand_ctx_enable_prediction_resistance();
}
#endif
-
}
/*
@@ -2614,6 +2625,20 @@ do_init_tls_wrap_key(struct context *c)
}
+/*
+ * Initialise the auth-token key context
+ */
+static void
+do_init_auth_token_key(struct context *c)
+{
+ if (!c->options.auth_token_generate)
+ return;
+
+ auth_token_init_secret(&c->c1.ks.auth_token_key,
+ c->options.auth_token_secret_file,
+ c->options.auth_token_secret_file_inline);
+}
+
/*
* Initialize the persistent component of OpenVPN's TLS mode,
* which is preserved across SIGUSR1 resets.
@@ -2666,6 +2691,9 @@ do_init_crypto_tls_c1(struct context *c)
/* initialize tls-auth/crypt/crypt-v2 key */
do_init_tls_wrap_key(c);
+ /* initialise auth-token crypto support */
+ do_init_auth_token_key(c);
+
#if 0 /* was: #if ENABLE_INLINE_FILES -- Note that enabling this code will break restarts */
if (options->priv_key_file_inline)
{
@@ -2838,6 +2866,7 @@ do_init_crypto_tls(struct context *c, const unsigned int flags)
to.auth_user_pass_file = options->auth_user_pass_file;
to.auth_token_generate = options->auth_token_generate;
to.auth_token_lifetime = options->auth_token_lifetime;
+ to.auth_token_key = c->c1.ks.auth_token_key;
#endif
to.x509_track = options->x509_track;
@@ -4451,6 +4480,9 @@ inherit_context_child(struct context *dest,
dest->c1.authname = src->c1.authname;
dest->c1.keysize = src->c1.keysize;
+ /* inherit auth-token */
+ dest->c1.ks.auth_token_key = src->c1.ks.auth_token_key;
+
/* options */
dest->options = src->options;
options_detach(&dest->options);
@@ -68,6 +68,7 @@ struct key_schedule
struct key_ctx_bi tls_wrap_key;
struct key_ctx tls_crypt_v2_server_key;
struct buffer tls_crypt_v2_wkc; /**< Wrapped client key */
+ struct key_ctx auth_token_key;
};
/*
@@ -1286,6 +1286,7 @@ show_p2mp_parms(const struct options *o)
SHOW_BOOL(auth_user_pass_verify_script_via_file);
SHOW_BOOL(auth_token_generate);
SHOW_INT(auth_token_lifetime);
+ SHOW_STR(auth_token_secret_file);
#if PORT_SHARE
SHOW_STR(port_share_host);
SHOW_STR(port_share_port);
@@ -2334,7 +2335,11 @@ options_postprocess_verify_ce(const struct options *options, const struct connec
{
msg(M_USAGE, "--mode server requires --key-method 2");
}
-
+ if (options->auth_token_generate && !options->renegotiate_seconds)
+ {
+ msg(M_USAGE, "--auth-gen-token needs a non-infinite "
+ "--renegotiate_seconds setting");
+ }
{
const bool ccnr = (options->auth_user_pass_verify_script
|| PLUGIN_OPTION_LIST(options)
@@ -6769,6 +6774,23 @@ add_option(struct options *options,
options->auth_token_generate = true;
options->auth_token_lifetime = p[1] ? positive_atoi(p[1]) : 0;
}
+ else if (streq(p[0], "auth-gen-token-secret") && p[1] && (!p[2]
+ || (p[2] && streq(p[1], INLINE_FILE_TAG))))
+ {
+ VERIFY_PERMISSION(OPT_P_GENERAL);
+ options->auth_token_secret_file = p[1];
+
+ if (streq(p[1], INLINE_FILE_TAG) && p[2])
+ {
+ options->auth_token_secret_file_inline = p[2];
+ }
+ }
+ else if (streq(p[0], "auth-gen-token-secret-genkey") && !p[1])
+ {
+ VERIFY_PERMISSION(OPT_P_GENERAL);
+ options->auth_token_gen_secret_file = true;
+ }
+
else if (streq(p[0], "client-connect") && p[1])
{
VERIFY_PERMISSION(OPT_P_SCRIPT);
@@ -459,7 +459,11 @@ struct options
const char *auth_user_pass_verify_script;
bool auth_user_pass_verify_script_via_file;
bool auth_token_generate;
+ bool auth_token_gen_secret_file;
unsigned int auth_token_lifetime;
+ const char *auth_token_secret_file;
+ const char *auth_token_secret_file_inline;
+
#if PORT_SHARE
char *port_share_host;
char *port_share_port;
@@ -324,6 +324,37 @@ send_push_request(struct context *c)
}
#if P2MP_SERVER
+/**
+ * Prepare push option for auth-token
+ * @param tls_multi tls multi context of VPN tunnel
+ * @param gc gc arena for allocating push options
+ * @param push_list push list to where options are added
+ *
+ * @return true on success, false on failure.
+ */
+void
+prepare_auth_token_push_reply(struct tls_multi *tls_multi, struct gc_arena *gc,
+ struct push_list *push_list)
+{
+ /*
+ *If server uses --auth-gen-token and we have an auth token
+ * to send to the client
+ */
+ if (tls_multi->auth_token)
+ {
+ push_option_fmt(gc, push_list, M_USAGE,
+ "auth-token %s",
+ tls_multi->auth_token);
+ if (!tls_multi->auth_token_initial)
+ {
+ /*
+ * Save the initial auth token for clients that ignore
+ * the updates to the token
+ */
+ tls_multi->auth_token_initial = strdup(tls_multi->auth_token);
+ }
+ }
+}
/**
* Prepare push options, based on local options and available peer info.
@@ -334,7 +365,7 @@ send_push_request(struct context *c)
*
* @return true on success, false on failure.
*/
-static bool
+bool
prepare_push_reply(struct context *c, struct gc_arena *gc,
struct push_list *push_list)
{
@@ -382,6 +413,11 @@ prepare_push_reply(struct context *c, struct gc_arena *gc,
tls_multi->use_peer_id = true;
}
}
+ /*
+ * If server uses --auth-gen-token and we have an auth token
+ * to send to the client
+ */
+ prepare_auth_token_push_reply(tls_multi, gc, push_list);
/* Push cipher if client supports Negotiable Crypto Parameters */
if (tls_peer_info_ncp_ver(peer_info) >= 2 && o->ncp_enabled)
@@ -412,15 +448,6 @@ prepare_push_reply(struct context *c, struct gc_arena *gc,
tls_poor_mans_ncp(o, tls_multi->remote_ciphername);
}
- /* If server uses --auth-gen-token and we have an auth token
- * to send to the client
- */
- if (false == tls_multi->auth_token_sent && NULL != tls_multi->auth_token)
- {
- push_option_fmt(gc, push_list, M_USAGE,
- "auth-token %s", tls_multi->auth_token);
- tls_multi->auth_token_sent = true;
- }
return true;
}
@@ -431,6 +458,7 @@ send_push_options(struct context *c, struct buffer *buf,
{
struct push_entry *e = push_list->head;
+ e = push_list->head;
while (e)
{
if (e->enable)
@@ -463,7 +491,27 @@ send_push_options(struct context *c, struct buffer *buf,
return true;
}
-static bool
+void
+send_push_reply_auth_token(struct tls_multi *multi)
+{
+ struct gc_arena gc = gc_new();
+
+
+ struct push_list push_list = {};
+ prepare_auth_token_push_reply(multi, &gc, &push_list);
+
+ /* prepare auth token should always add the auth-token option */
+ struct push_entry *e = push_list.head;
+ ASSERT(e && e->enable);
+
+ /* Construct a mimimal control channel push reply message */
+ struct buffer buf = alloc_buf_gc(PUSH_BUNDLE_SIZE, &gc);
+ buf_printf(&buf, "%s, %s", push_reply_cmd, e->option);
+ send_control_channel_string_dowork(multi, BSTR(&buf), D_PUSH);
+ gc_free(&gc);
+}
+
+bool
send_push_reply(struct context *c, struct push_list *per_client_push_list)
{
struct gc_arena gc = gc_new();
@@ -69,6 +69,14 @@ void send_auth_failed(struct context *c, const char *client_reason);
void send_restart(struct context *c, const char *kill_msg);
+/**
+ * Sends a push reply message only containin the auth-token to update
+ * the auth-token on the client
+ *
+ * @param multi - The tls_multi structure belonging to the instance to push to
+ */
+void send_push_reply_auth_token(struct tls_multi *multi);
+
#endif
#endif /* if P2MP */
#endif /* ifndef PUSH_H */
@@ -59,6 +59,7 @@
#include "ssl.h"
#include "ssl_verify.h"
#include "ssl_backend.h"
+#include "auth_token.h"
#include "memdbg.h"
@@ -1368,11 +1369,7 @@ tls_multi_free(struct tls_multi *multi, bool clear)
cert_hash_free(multi->locked_cert_hash_set);
- if (multi->auth_token)
- {
- secure_memzero(multi->auth_token, AUTH_TOKEN_SIZE);
- free(multi->auth_token);
- }
+ wipe_auth_token(multi);
free(multi->remote_ciphername);
@@ -298,7 +298,6 @@ struct tls_options
/** TLS handshake wrapping state */
struct tls_wrap_ctx tls_wrap;
- /* frame parameters for TLS control channel */
struct frame frame;
/* used for username/password authentication */
@@ -306,10 +305,16 @@ struct tls_options
bool auth_user_pass_verify_script_via_file;
const char *tmp_dir;
const char *auth_user_pass_file;
- bool auth_token_generate; /**< Generate auth-tokens on successful user/pass auth,
- * set via options->auth_token_generate. */
+
+#ifdef P2MP_SERVER
+ bool auth_token_generate; /**< Generate auth-tokens on successful
+ * user/pass auth,seet via
+ * options->auth_token_generate. */
unsigned int auth_token_lifetime;
+ struct key_ctx auth_token_key;
+#endif
+
/* use the client-config-dir as a positive authenticator */
const char *client_config_dir_exclusive;
@@ -368,10 +373,6 @@ struct tls_options
/** @} name Index of key_state objects within a tls_session structure */
/** @} addtogroup control_processor */
-#define AUTH_TOKEN_SIZE 32 /**< Size of server side generated auth tokens.
- * 32 bytes == 256 bits
- */
-
/**
* Security parameter state of a single session within a VPN tunnel.
* @ingroup control_processor
@@ -539,6 +540,14 @@ struct tls_multi
* over control channel.
*/
char *peer_info;
+ char *auth_token; /**< If server sends a generated auth-token,
+ * this is the token to use for future
+ * user/pass authentications in this session.
+ */
+ char *auth_token_initial;
+ /**< The first auth-token we sent to a client, for clients that do
+ * not update their auth-token (older OpenVPN3 core versions)
+ */
#endif
/* For P_DATA_V2 */
@@ -547,13 +556,6 @@ struct tls_multi
char *remote_ciphername; /**< cipher specified in peer's config file */
- char *auth_token; /**< If server sends a generated auth-token,
- * this is the token to use for future
- * user/pass authentications in this session.
- */
- time_t auth_token_tstamp; /**< timestamp of the generated token */
- bool auth_token_sent; /**< If server uses --auth-gen-token and
- * token has been sent to client */
/*
* Our session objects.
*/
@@ -44,6 +44,7 @@
#ifdef ENABLE_CRYPTO_OPENSSL
#include "ssl_verify_openssl.h"
#endif
+#include "auth_token.h"
/** Maximum length of common name */
#define TLS_USERNAME_LEN 64
@@ -63,28 +64,6 @@ setenv_untrusted(struct tls_session *session)
setenv_link_socket_actual(session->opt->es, "untrusted", &session->untrusted_addr, SA_IP_PORT);
}
-
-/**
- * Wipes the authentication token out of the memory, frees and cleans up related buffers and flags
- *
- * @param multi Pointer to a multi object holding the auth_token variables
- */
-static void
-wipe_auth_token(struct tls_multi *multi)
-{
- if (multi)
- {
- if (multi->auth_token)
- {
- secure_memzero(multi->auth_token, AUTH_TOKEN_SIZE);
- free(multi->auth_token);
- }
- multi->auth_token = NULL;
- multi->auth_token_sent = false;
- }
-}
-
-
/*
* Remove authenticated state from all sessions in the given tunnel
*/
@@ -1253,6 +1232,7 @@ verify_user_pass_management(struct tls_session *session, const struct user_pass
}
#endif /* ifdef MANAGEMENT_DEF_AUTH */
+
/*
* Main username/password verification entry point
*/
@@ -1277,13 +1257,14 @@ verify_user_pass(struct user_pass *up, struct tls_multi *multi,
string_mod_remap_name(up->username);
string_mod(up->password, CC_PRINT, CC_CRLF, '_');
- /* If server is configured with --auth-gen-token and we have an
- * authentication token for this client, this authentication
+ /* If server is configured with --auth-gen-token and the client sends
+ * something that looks like an authentication token, this
* round will be done internally using the token instead of
* calling any external authentication modules.
*/
- if (session->opt->auth_token_generate && multi->auth_token_sent
- && NULL != multi->auth_token)
+ if (session->opt->auth_token_generate &&
+ memcmp_constant_time(SESSION_ID_PREFIX, up->password,
+ strlen(SESSION_ID_PREFIX))==0)
{
unsigned int ssl_flags = session->opt->ssl_flags;
@@ -1295,29 +1276,14 @@ verify_user_pass(struct user_pass *up, struct tls_multi *multi,
return;
}
- /* If auth-token lifetime has been enabled,
- * ensure the token has not expired
- */
- if (session->opt->auth_token_lifetime > 0
- && (multi->auth_token_tstamp + session->opt->auth_token_lifetime) < now)
+ if (!verify_auth_token(up, multi,session))
{
- msg(D_HANDSHAKE, "Auth-token for client expired\n");
wipe_auth_token(multi);
ks->authenticated = false;
+ msg(M_WARN, "TLS: Username/auth-token authentication "
+ "failed for username '%s'", up->username);
return;
}
-
- /* The core authentication of the token itself */
- if (memcmp_constant_time(multi->auth_token, up->password,
- strlen(multi->auth_token)) != 0)
- {
- ks->authenticated = false;
- tls_deauthenticate(multi);
-
- msg(D_TLS_ERRORS, "TLS Auth Error: Auth-token verification "
- "failed for username '%s' %s", up->username,
- (ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) ? "[CN SET]" : "");
- }
else
{
ks->authenticated = true;
@@ -1326,7 +1292,7 @@ verify_user_pass(struct user_pass *up, struct tls_multi *multi,
{
set_common_name(session, up->username);
}
- msg(D_HANDSHAKE, "TLS: Username/auth-token authentication "
+ msg(M_WARN, "TLS: Username/auth-token authentication "
"succeeded for username '%s' %s",
up->username,
(ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) ? "[CN SET]" : "");
@@ -1382,27 +1348,13 @@ verify_user_pass(struct user_pass *up, struct tls_multi *multi,
}
#endif
- if ((session->opt->auth_token_generate) && (NULL == multi->auth_token))
+ if ((session->opt->auth_token_generate))
{
/* Server is configured with --auth-gen-token but no token has yet
* been generated for this client. Generate one and save it.
*/
- uint8_t tok[AUTH_TOKEN_SIZE];
-
- if (!rand_bytes(tok, AUTH_TOKEN_SIZE))
- {
- msg( M_FATAL, "Failed to get enough randomness for "
- "authentication token");
- }
- /* The token should be longer than the input when
- * being base64 encoded
- */
- ASSERT(openvpn_base64_encode(tok, AUTH_TOKEN_SIZE,
- &multi->auth_token) > AUTH_TOKEN_SIZE);
- multi->auth_token_tstamp = now;
- dmsg(D_SHOW_KEYS, "Generated token for client: %s",
- multi->auth_token);
+ generate_auth_token(up, multi);
}
if ((session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME))