From patchwork Tue Jul 6 03:57:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arne Schwabe X-Patchwork-Id: 1877 Return-Path: Delivered-To: patchwork@openvpn.net Delivered-To: patchwork@openvpn.net Received: from director12.mail.ord1d.rsapps.net ([172.30.191.6]) by backend30.mail.ord1d.rsapps.net with LMTP id EL3hAK1h5GD7LAAAIUCqbw (envelope-from ) for ; Tue, 06 Jul 2021 09:59:09 -0400 Received: from proxy8.mail.ord1d.rsapps.net ([172.30.191.6]) by director12.mail.ord1d.rsapps.net with LMTP id IEW9AK1h5GDlKQAAIasKDg (envelope-from ) for ; Tue, 06 Jul 2021 09:59:09 -0400 Received: from smtp20.gate.ord1d ([172.30.191.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) by proxy8.mail.ord1d.rsapps.net with LMTPS id mGifAK1h5GAhbwAAGdz6CA (envelope-from ) for ; Tue, 06 Jul 2021 09:59:09 -0400 X-Spam-Threshold: 95 X-Spam-Score: 0 X-Spam-Flag: NO X-Virus-Scanned: OK X-Orig-To: openvpnslackdevel@openvpn.net X-Originating-Ip: [216.105.38.7] Authentication-Results: smtp20.gate.ord1d.rsapps.net; iprev=pass policy.iprev="216.105.38.7"; spf=pass smtp.mailfrom="openvpn-devel-bounces@lists.sourceforge.net" smtp.helo="lists.sourceforge.net"; dkim=fail (signature verification failed) header.d=sourceforge.net; dkim=fail (signature verification failed) header.d=sf.net; dmarc=none (p=nil; dis=none) header.from=rfc2549.org X-Suspicious-Flag: YES X-Classification-ID: 54b9975e-de62-11eb-bea1-525400b8bfda-1-1 Received: from [216.105.38.7] ([216.105.38.7:38560] helo=lists.sourceforge.net) by smtp20.gate.ord1d.rsapps.net (envelope-from ) (ecelerity 4.2.38.62370 r(:)) with ESMTPS (cipher=DHE-RSA-AES256-GCM-SHA384) id 02/E7-14210-BA164E06; Tue, 06 Jul 2021 09:59:08 -0400 Received: from [127.0.0.1] (helo=sfs-ml-4.v29.lw.sourceforge.com) by sfs-ml-4.v29.lw.sourceforge.com with esmtp (Exim 4.90_1) (envelope-from ) id 1m0lad-0007Uh-1O; Tue, 06 Jul 2021 13:58:19 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-4.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m0lab-0007UW-O1 for openvpn-devel@lists.sourceforge.net; Tue, 06 Jul 2021 13:58:17 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Subject:To:From:Sender:Reply-To:Cc:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=qQz3IQN2V1/HGySG0KcMng4NHX/kHbqismrbPtg1JVc=; b=ch1okGyxv7vEQh94u+UOxPo2zF IeWOnje3hueumuhLKvdyzgMtxP53zapx69BTMys/TZJqTdSOhqqdiapn4QbN1ztMAonZ8QUAMY3EX zsPV9WNArKsmxoHnSRUwYdbQ7AJlDDdYTbkXx4TK26/KXlhftIUoTlRgY+3rQILZd14U=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-Id: Date:Subject:To:From:Sender:Reply-To:Cc:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=qQz3IQN2V1/HGySG0KcMng4NHX/kHbqismrbPtg1JVc=; b=gg6+gd5QHfw7MLvtIUgi/iFsLz 1bXvi7ZxojOoVFP6zh7EBUxXdUjQ7q/CgbQRqVaPFIp+dLqLbAcE/xqQ0lh9if9+miSCVxcBPhIUU EPltaDCHDAHZuF3UoiyZpUjXNaLtV2UozN5KDhrDiS8LvZs9XUEdwVaUqe5Dk3h/mVts=; Received: from mail.blinkt.de ([192.26.174.232]) by sfi-mx-1.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92.3) id 1m0laU-00CJzf-Pk for openvpn-devel@lists.sourceforge.net; Tue, 06 Jul 2021 13:58:17 +0000 Received: from kamera.blinkt.de ([2001:638:502:390:20c:29ff:fec8:535c]) by mail.blinkt.de with smtp (Exim 4.94.2 (FreeBSD)) (envelope-from ) id 1m0laI-000Kul-Ey for openvpn-devel@lists.sourceforge.net; Tue, 06 Jul 2021 15:57:58 +0200 Received: (nullmailer pid 3134590 invoked by uid 10006); Tue, 06 Jul 2021 13:57:58 -0000 From: Arne Schwabe To: openvpn-devel@lists.sourceforge.net Date: Tue, 6 Jul 2021 15:57:58 +0200 Message-Id: <20210706135758.3134542-1-arne@rfc2549.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210520151148.2565578-7-arne@rfc2549.org> References: <20210520151148.2565578-7-arne@rfc2549.org> MIME-Version: 1.0 X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. 0.2 HEADER_FROM_DIFFERENT_DOMAINS From and EnvelopeFrom 2nd level mail domains are different 0.0 SPF_NONE SPF: sender does not publish an SPF Record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record X-Headers-End: 1m0laU-00CJzf-Pk Subject: [Openvpn-devel] [PATCH v3 7/9] Cleanup handling of initial auth token X-BeenThere: openvpn-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: openvpn-devel-bounces@lists.sourceforge.net X-getmail-retrieved-from-mailbox: Inbox This changes that auth_token_initial is set when the token is initially generated instead when pushing the token. Even I do not know anymore why I did it in this way in the first place. Also use multi->auth_token_initial as source for the sesssion ID since it should now always be available. Since the change makes auth_token_initial always available we need to add a check to only send a PUSH reply to update the token on renegotiations. The old code relied on multi->auth_token not being set in this case. This commit also removes the workaround for old OpenVPN clients. These were only available as commercial OpenVPN Connect client and not in use anymore. Patch V2: rebase. Patch V3: fix formatting, clarifying commit message, remove initial token workaround for old v3. Signed-off-by: Arne Schwabe --- doc/man-sections/server-options.rst | 4 +-- src/openvpn/auth_token.c | 34 ++++++++++++---------- src/openvpn/push.c | 8 ----- src/openvpn/ssl_common.h | 4 +-- src/openvpn/ssl_verify.c | 6 ++-- tests/unit_tests/openvpn/test_auth_token.c | 7 +++-- 6 files changed, 32 insertions(+), 31 deletions(-) diff --git a/doc/man-sections/server-options.rst b/doc/man-sections/server-options.rst index 047f2270f..1ab00e81b 100644 --- a/doc/man-sections/server-options.rst +++ b/doc/man-sections/server-options.rst @@ -35,7 +35,7 @@ fast hardware. SSL/TLS authentication must be used in this mode. token is reached or after not being renewed for more than 2 \* ``reneg-sec`` seconds. Clients will be sent renewed tokens on every TLS renogiation to keep the client's token updated. This is done to - invalidate a token if a client is disconnected for a sufficently long + invalidate a token if a client is disconnected for a sufficiently long time, while at the same time permitting much longer token lifetimes for active clients. @@ -46,7 +46,7 @@ fast hardware. SSL/TLS authentication must be used in this mode. When the :code:`external-auth` keyword is present the normal authentication method will always be called even if auth-token succeeds. Normally other authentications method are skipped if auth-token - verification suceeds or fails. + verification succeeds or fails. This option postpones this decision to the external authentication methods and checks the validity of the account and do other checks. diff --git a/src/openvpn/auth_token.c b/src/openvpn/auth_token.c index 0ea6d1832..a681d726f 100644 --- a/src/openvpn/auth_token.c +++ b/src/openvpn/auth_token.c @@ -109,11 +109,11 @@ add_session_token_env(struct tls_session *session, struct tls_multi *multi, /* * No session before, generate a new session token for the new session */ - if (!multi->auth_token) + if (!multi->auth_token_initial) { generate_auth_token(up, multi); } - session_id_source = multi->auth_token; + session_id_source = multi->auth_token_initial; } /* * In the auth-token the auth token is already base64 encoded @@ -184,7 +184,7 @@ generate_auth_token(const struct user_pass *up, struct tls_multi *multi) uint8_t sessid[AUTH_TOKEN_SESSION_ID_LEN]; - if (multi->auth_token) + if (multi->auth_token_initial) { /* 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 @@ -192,11 +192,14 @@ generate_auth_token(const struct user_pass *up, struct tls_multi *multi) */ char old_tstamp_decode[9]; + /* Make a copy of the string to not modify multi->auth_token_initial */ + char* initial_token_copy = string_alloc(multi->auth_token_initial, &gc); + /* * 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_sessid = multi->auth_token + strlen(SESSION_ID_PREFIX); + char *old_sessid = initial_token_copy + strlen(SESSION_ID_PREFIX); char *old_tsamp_initial = old_sessid + AUTH_TOKEN_SESSION_ID_LEN*8/6; old_tsamp_initial[12] = '\0'; @@ -212,10 +215,6 @@ generate_auth_token(const struct user_pass *up, struct tls_multi *multi) old_tsamp_initial[0] = '\0'; ASSERT(openvpn_base64_decode(old_sessid, sessid, AUTH_TOKEN_SESSION_ID_LEN)==AUTH_TOKEN_SESSION_ID_LEN); - - - /* free the auth-token, we will replace it with a new one */ - free(multi->auth_token); } else if (!rand_bytes(sessid, AUTH_TOKEN_SESSION_ID_LEN)) { @@ -272,11 +271,22 @@ generate_auth_token(const struct user_pass *up, struct tls_multi *multi) free(b64output); + /* free the auth-token if defined, we will replace it with a new one */ + free(multi->auth_token); multi->auth_token = strdup((char *)BPTR(&session_token)); dmsg(D_SHOW_KEYS, "Generated token for client: %s (%s)", multi->auth_token, up->username); + if (!multi->auth_token_initial) + { + /* + * Save the initial auth token to continue using the same session ID + * and timestamp in updates + */ + multi->auth_token_initial = strdup(multi->auth_token); + } + gc_free(&gc); } @@ -353,13 +363,7 @@ verify_auth_token(struct user_pass *up, struct tls_multi *multi, bool in_renog_time = now >= timestamp && now < timestamp + 2 * session->opt->renegotiate_seconds; - /* We could still have a client that does not update - * its auth-token, so also allow the initial auth-token */ - bool initialtoken = multi->auth_token_initial - && memcmp_constant_time(up->password, multi->auth_token_initial, - strlen(multi->auth_token_initial)) == 0; - - if (!in_renog_time && !initialtoken) + if (!in_renog_time) { ret |= AUTH_TOKEN_EXPIRED; } diff --git a/src/openvpn/push.c b/src/openvpn/push.c index f4957f147..53cb7ca6f 100644 --- a/src/openvpn/push.c +++ b/src/openvpn/push.c @@ -527,14 +527,6 @@ prepare_auth_token_push_reply(struct tls_multi *tls_multi, struct gc_arena *gc, 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); - } } } diff --git a/src/openvpn/ssl_common.h b/src/openvpn/ssl_common.h index 43d6276be..1914a0015 100644 --- a/src/openvpn/ssl_common.h +++ b/src/openvpn/ssl_common.h @@ -597,8 +597,8 @@ struct tls_multi * 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) + /**< The first auth-token we sent to a client. We use this to remember + * the session ID and initial timestamp when generating new auth-token. */ #define AUTH_TOKEN_HMAC_OK (1<<0) /**< Auth-token sent from client has valid hmac */ diff --git a/src/openvpn/ssl_verify.c b/src/openvpn/ssl_verify.c index bbb1878a3..61dde1791 100644 --- a/src/openvpn/ssl_verify.c +++ b/src/openvpn/ssl_verify.c @@ -1639,7 +1639,9 @@ verify_user_pass(struct user_pass *up, struct tls_multi *multi, * Otherwise the auth-token get pushed out as part of the "normal" * push-reply */ - if (multi->auth_token_initial) + bool is_renegotiation = session->key[KS_PRIMARY].key_id != 0; + + if (multi->auth_token_initial && !is_renegotiation) { /* * We do not explicitly schedule the sending of the @@ -1648,7 +1650,7 @@ verify_user_pass(struct user_pass *up, struct tls_multi *multi, * 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 + * trigger scheduling */ send_push_reply_auth_token(multi); } diff --git a/tests/unit_tests/openvpn/test_auth_token.c b/tests/unit_tests/openvpn/test_auth_token.c index 4030052e0..a504eed91 100644 --- a/tests/unit_tests/openvpn/test_auth_token.c +++ b/tests/unit_tests/openvpn/test_auth_token.c @@ -174,7 +174,10 @@ auth_token_test_timeout(void **state) now = 100000; generate_auth_token(&ctx->up, &ctx->multi); + strcpy(ctx->up.password, ctx->multi.auth_token); + free(ctx->multi.auth_token_initial); + ctx->multi.auth_token_initial = NULL; /* No time has passed */ assert_int_equal(verify_auth_token(&ctx->up, &ctx->multi, ctx->session), @@ -244,10 +247,10 @@ auth_token_test_known_keys(void **state) now = 0; /* Preload the session id so the same session id is used here */ - ctx->multi.auth_token = strdup(now0key0); + ctx->multi.auth_token_initial = strdup(now0key0); /* Zero the hmac part to ensure we have a newly generated token */ - zerohmac(ctx->multi.auth_token); + zerohmac(ctx->multi.auth_token_initial); generate_auth_token(&ctx->up, &ctx->multi);