From patchwork Tue Aug 11 22:55:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arne Schwabe X-Patchwork-Id: 1378 Return-Path: Delivered-To: patchwork@openvpn.net Delivered-To: patchwork@openvpn.net Received: from director10.mail.ord1d.rsapps.net ([172.27.255.8]) by backend30.mail.ord1d.rsapps.net with LMTP id 6OG9BHG5M1/JNgAAIUCqbw for ; Wed, 12 Aug 2020 05:42:09 -0400 Received: from proxy3.mail.iad3a.rsapps.net ([172.27.255.8]) by director10.mail.ord1d.rsapps.net with LMTP id UOB7A3G5M1/QSgAApN4f7A (envelope-from ) for ; Wed, 12 Aug 2020 05:42:09 -0400 Received: from smtp8.gate.iad3a ([172.27.255.8]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) by proxy3.mail.iad3a.rsapps.net with LMTP id 0DVDOXC5M18JUwAAYaqY3Q ; Wed, 12 Aug 2020 05:42:08 -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: smtp8.gate.iad3a.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: 16839f3c-dc80-11ea-aa99-525400b8fe03-1-1 Received: from [216.105.38.7] ([216.105.38.7:54512] helo=lists.sourceforge.net) by smtp8.gate.iad3a.rsapps.net (envelope-from ) (ecelerity 4.2.38.62370 r(:)) with ESMTPS (cipher=DHE-RSA-AES256-GCM-SHA384) id DA/A6-23508-079B33F5; Wed, 12 Aug 2020 05:42:08 -0400 Received: from [127.0.0.1] (helo=sfs-ml-1.v29.lw.sourceforge.com) by sfs-ml-1.v29.lw.sourceforge.com with esmtp (Exim 4.90_1) (envelope-from ) id 1k5nFz-0002Q6-E1; Wed, 12 Aug 2020 09:41:15 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k5nFw-0002Pk-9m for openvpn-devel@lists.sourceforge.net; Wed, 12 Aug 2020 09:41:12 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Message-Id:Date:Subject:To:From:Sender:Reply-To:Cc: MIME-Version:Content-Type:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=+kqsNFxxq9P84J3zk7hcNgFnds5JSTnGu5KGAIu7jRY=; b=lYeTvyo5u5YsazcxjqIDEZsSaZ cdK6RTtuTn9lOTbXdb4QIQLO1nMX2w2D4hd2+Fs1SO9xuEjIGm4Dyx4dyFz8Zvlr7j6WMyJdIiZ+3 7tq1HDf+pI6aPC2ciMnSj+/Wz5l99BxrZuV8gpWiUPN1Y8uVjiZiFw7L9//Vw7KBpkEo=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Message-Id:Date:Subject:To:From:Sender:Reply-To:Cc:MIME-Version: Content-Type:Content-Transfer-Encoding:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=+kqsNFxxq9P84J3zk7hcNgFnds5JSTnGu5KGAIu7jRY=; b=AKV7yH3+BCupQjNJi6loAEaG/V 9QjUXZ7sjly5ZAHgx1L5K35rMOlcozKsZzMoDM3B0n6A+km0PaqcxvKuzkhTRVNQokE3XtoxnHcx6 +VUI23zWE1cGuZwugY0DKo/b7QnkobruAiEoan6ARTHWb98A4eXJfMFiqFtJULDtz6/Q=; Received: from mail.blinkt.de ([192.26.174.232]) by sfi-mx-4.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92.2) id 1k5nFs-00Ab5q-6b for openvpn-devel@lists.sourceforge.net; Wed, 12 Aug 2020 09:41:12 +0000 Received: from kamera.blinkt.de ([2001:638:502:390:20c:29ff:fec8:535c]) by mail.blinkt.de with smtp (Exim 4.94 (FreeBSD)) (envelope-from ) id 1k5nFi-000AQe-Jq for openvpn-devel@lists.sourceforge.net; Wed, 12 Aug 2020 11:40:58 +0200 Received: (nullmailer pid 19665 invoked by uid 10006); Wed, 12 Aug 2020 08:55:39 -0000 From: Arne Schwabe To: openvpn-devel@lists.sourceforge.net Date: Wed, 12 Aug 2020 10:55:37 +0200 Message-Id: <20200812085539.19620-1-arne@rfc2549.org> X-Mailer: git-send-email 2.17.1 X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. 0.0 URIBL_BLOCKED ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [URIs: rfc2549.org] 0.0 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: 1k5nFs-00Ab5q-6b Subject: [Openvpn-devel] [PATCH 1/3] Refactor key_state_export_keying_material functions 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: , MIME-Version: 1.0 Errors-To: openvpn-devel-bounces@lists.sourceforge.net X-getmail-retrieved-from-mailbox: Inbox This refactors the common code between mbed SSL and OpenSSL into export_user_keying_material and also prepares the backend functions to export more than one key. Also fix checking the return value of SSL_export_keying_material only 1 is a sucess, -1 is also an error. Signed-off-by: Arne Schwabe --- src/openvpn/ssl.c | 33 ++++++++++++++++++++++++- src/openvpn/ssl_backend.h | 18 ++++++++++++-- src/openvpn/ssl_mbedtls.c | 22 ++++++----------- src/openvpn/ssl_openssl.c | 51 +++++++++++++++++++++------------------ 4 files changed, 83 insertions(+), 41 deletions(-) diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c index f16114c2..390114e1 100644 --- a/src/openvpn/ssl.c +++ b/src/openvpn/ssl.c @@ -2412,6 +2412,37 @@ error: return false; } +static void +export_user_keying_material(struct key_state_ssl *ssl, + struct tls_session *session) +{ + if (session->opt->ekm_size > 0) + { + unsigned int size = session->opt->ekm_size; + struct gc_arena gc = gc_new(); + + unsigned char *ekm; + if ((ekm = key_state_export_keying_material(ssl, session, + EXPORT_KEY_USER, &gc))) + { + unsigned int len = (size * 2) + 2; + + const char *key = format_hex_ex(ekm, size, len, 0, NULL, &gc); + setenv_str(session->opt->es, "exported_keying_material", key); + + dmsg(D_TLS_DEBUG_MED, "%s: exported keying material: %s", + __func__, key); + secure_memzero(ekm, size); + } + else + { + msg(M_WARN, "WARNING: Export keying material failed!"); + setenv_del(session->opt->es, "exported_keying_material"); + } + gc_free(&gc); + } +} + /** * Handle reading key data, peer-info, username/password, OCC * from the TLS control channel (cleartext). @@ -2541,7 +2572,7 @@ key_method_2_read(struct buffer *buf, struct tls_multi *multi, struct tls_sessio if ((ks->authenticated > KS_AUTH_FALSE) && plugin_defined(session->opt->plugins, OPENVPN_PLUGIN_TLS_FINAL)) { - key_state_export_keying_material(&ks->ks_ssl, session); + export_user_keying_material(&ks->ks_ssl, session); if (plugin_call(session->opt->plugins, OPENVPN_PLUGIN_TLS_FINAL, NULL, NULL, session->opt->es) != OPENVPN_PLUGIN_FUNC_SUCCESS) { diff --git a/src/openvpn/ssl_backend.h b/src/openvpn/ssl_backend.h index 7f52ab1e..8faaefd5 100644 --- a/src/openvpn/ssl_backend.h +++ b/src/openvpn/ssl_backend.h @@ -389,18 +389,32 @@ void key_state_ssl_free(struct key_state_ssl *ks_ssl); void backend_tls_ctx_reload_crl(struct tls_root_ctx *ssl_ctx, const char *crl_file, bool crl_inline); + +/* defines the different RFC5705 that are used in OpenVPN */ +enum export_key_identifier { + EXPORT_KEY_USER +}; + /** * Keying Material Exporters [RFC 5705] allows additional keying material to be * derived from existing TLS channel. This exported keying material can then be * used for a variety of purposes. * + * Note + * * @param ks_ssl The SSL channel's state info * @param session The session associated with the given key_state + * @param key The key to export. + * @param gc gc_arena that might be used to allocate a string + * @returns The exported key material, the caller may zero the + * string but should not free it */ -void +unsigned char* key_state_export_keying_material(struct key_state_ssl *ks_ssl, - struct tls_session *session) __attribute__((nonnull)); + struct tls_session *session, + enum export_key_identifier export_key, + struct gc_arena *gc) __attribute__((nonnull)); /**************************************************************************/ /** @addtogroup control_tls diff --git a/src/openvpn/ssl_mbedtls.c b/src/openvpn/ssl_mbedtls.c index 9c874788..8ae6ec7b 100644 --- a/src/openvpn/ssl_mbedtls.c +++ b/src/openvpn/ssl_mbedtls.c @@ -231,24 +231,18 @@ mbedtls_ssl_export_keys_cb(void *p_expkey, const unsigned char *ms, } #endif /* HAVE_EXPORT_KEYING_MATERIAL */ -void +unsigned char * key_state_export_keying_material(struct key_state_ssl *ssl, - struct tls_session *session) + struct tls_session *session, + enum export_key_identifier key_id, + struct gc_arena *gc) { - if (ssl->exported_key_material) + if (key_id == EXPORT_KEY_USER) { - unsigned int size = session->opt->ekm_size; - struct gc_arena gc = gc_new(); - unsigned int len = (size * 2) + 2; - - const char *key = format_hex_ex(ssl->exported_key_material, - size, len, 0, NULL, &gc); - setenv_str(session->opt->es, "exported_keying_material", key); - - dmsg(D_TLS_DEBUG_MED, "%s: exported keying material: %s", - __func__, key); - gc_free(&gc); + return ssl->exported_key_material; } + + return NULL; } diff --git a/src/openvpn/ssl_openssl.c b/src/openvpn/ssl_openssl.c index 5ba74402..1aad4f89 100644 --- a/src/openvpn/ssl_openssl.c +++ b/src/openvpn/ssl_openssl.c @@ -158,35 +158,38 @@ tls_ctx_initialised(struct tls_root_ctx *ctx) return NULL != ctx->ctx; } -void +unsigned char * key_state_export_keying_material(struct key_state_ssl *ssl, - struct tls_session *session) + struct tls_session *session, + enum export_key_identifier key_id, + struct gc_arena *gc) + { - if (session->opt->ekm_size > 0) - { - unsigned int size = session->opt->ekm_size; - struct gc_arena gc = gc_new(); - unsigned char *ekm = (unsigned char *) gc_malloc(size, true, &gc); + const char *label; + size_t label_size, ekm_size; - if (SSL_export_keying_material(ssl->ssl, ekm, size, - session->opt->ekm_label, - session->opt->ekm_label_size, - NULL, 0, 0)) - { - unsigned int len = (size * 2) + 2; + if (key_id == EXPORT_KEY_USER) + { + label = session->opt->ekm_label; + label_size = session->opt->ekm_label_size; + ekm_size = session->opt->ekm_size; + } + else + { + ASSERT(0); + } - const char *key = format_hex_ex(ekm, size, len, 0, NULL, &gc); - setenv_str(session->opt->es, "exported_keying_material", key); + unsigned char *ekm = (unsigned char *) gc_malloc(ekm_size, true, gc); - dmsg(D_TLS_DEBUG_MED, "%s: exported keying material: %s", - __func__, key); - } - else - { - msg(M_WARN, "WARNING: Export keying material failed!"); - setenv_del(session->opt->es, "exported_keying_material"); - } - gc_free(&gc); + if (SSL_export_keying_material(ssl->ssl, ekm, ekm_size, label, + label_size, NULL, 0, 0) == 1) + { + return ekm; + } + else + { + secure_memzero(ekm, ekm_size); + return NULL; } }