GnuTLS 3.6.7 cipher strings
authorJeremy Harris <jgh146exb@wizmail.org>
Thu, 25 Apr 2019 17:24:33 +0000 (18:24 +0100)
committerHeiko Schlittermann (HS12-RIPE) <hs@schlittermann.de>
Mon, 2 Sep 2019 22:17:43 +0000 (00:17 +0200)
(cherry picked from commits d9acfc1ce657eb2f6463b9c6f63cd5)

WARNING: This changes user-visible and configuration-visible behaviour.
 Read the ChangeLog!
(cherry picked from commit 656b804e099a4704bd6071241a85bc1e0cc85887)
(cherry picked from commit bf9375eaa85bfa0dbb973aa03accbe5f21808732)

doc/doc-txt/ChangeLog
src/src/tls-gnu.c
test/confs/2019
test/log/5821
test/runtest

index 70fdc9510d5259112b827d7ff6ab02502e011a47..445755dc61269f6430d01281202deb42e197f0fd 100644 (file)
@@ -56,6 +56,15 @@ JH/13 Bug 2386: Fix builds with Dane under LibreSSL 2.9.0 onward.  Some old
       API was removed, so update to use the newer ones.
 
 
+JH/16 GnuTLS: rework ciphersuite strings under recent library versions.  Thanks
+      to changes apparently associated with TLS1.3 handling some of the APIs
+      previously used were either nonfunctional or inappropriate.  Strings
+      like TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM__AEAD:256
+      and TLS1.2:ECDHE_SECP256R1__RSA_SHA256__AES_128_CBC__SHA256:128 replace
+      the previous TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256 .
+      This affects log line X= elements, the $tls_{in,out}_cipher variables,
+      and the use of specific cipher names in the encrypted= ACL condition.
+
 
 Exim version 4.92
 -----------------
index de2d70c0990b8f76aa7e07470407a8ef6b799706..af815d224db13240317ffb0354ccc13d07b82909 100644 (file)
@@ -67,6 +67,9 @@ require current GnuTLS, then we'll drop support for the ancient libraries).
 #if GNUTLS_VERSION_NUMBER >= 0x030109
 # define SUPPORT_CORK
 #endif
+#if GNUTLS_VERSION_NUMBER >= 0x03010a
+# define SUPPORT_GNUTLS_SESS_DESC
+#endif
 #if GNUTLS_VERSION_NUMBER >= 0x030506 && !defined(DISABLE_OCSP)
 # define SUPPORT_SRV_OCSP_STACK
 #endif
@@ -1487,23 +1490,61 @@ state->peerdn = NULL;
 cipher = gnutls_cipher_get(state->session);
 protocol = gnutls_protocol_get_version(state->session);
 mac = gnutls_mac_get(state->session);
-kx = gnutls_kx_get(state->session);
-
-string_format(cipherbuf, sizeof(cipherbuf),
-    "%s:%s:%d",
-    gnutls_protocol_get_name(protocol),
-    gnutls_cipher_suite_get_name(kx, cipher, mac),
-    (int) gnutls_cipher_get_key_size(cipher) * 8);
-
-/* I don't see a way that spaces could occur, in the current GnuTLS
-code base, but it was a concern in the old code and perhaps older GnuTLS
-releases did return "TLS 1.0"; play it safe, just in case. */
-for (p = cipherbuf; *p != '\0'; ++p)
-  if (isspace(*p))
-    *p = '-';
+kx =
+#ifdef GNUTLS_TLS1_3
+    protocol >= GNUTLS_TLS1_3 ? 0 :
+#endif
+  gnutls_kx_get(state->session);
+
 old_pool = store_pool;
-store_pool = POOL_PERM;
-state->ciphersuite = string_copy(cipherbuf);
+  {
+  store_pool = POOL_PERM;
+
+#ifdef SUPPORT_GNUTLS_SESS_DESC
+    {
+    gstring * g = NULL;
+    uschar * s = US gnutls_session_get_desc(state->session), c;
+
+    /* Nikos M suggests we use this by preference.  It returns like:
+    (TLS1.3)-(ECDHE-SECP256R1)-(RSA-PSS-RSAE-SHA256)-(AES-256-GCM)
+
+    For partial back-compat, put a colon after the TLS version, replace the
+    )-( grouping with __, replace in-group - with _ and append the :keysize. */
+
+    /* debug_printf("peer_status: gnutls_session_get_desc %s\n", s); */
+
+    for (s++; (c = *s) && c != ')'; s++) g = string_catn(g, s, 1);
+    g = string_catn(g, US":", 1);
+    if (*s) s++;               /* now on _ between groups */
+    while ((c = *s))
+      {
+      for (*++s && ++s; (c = *s) && c != ')'; s++) g = string_catn(g, c == '-' ? US"_" : s, 1);
+      /* now on ) closing group */
+      if ((c = *s) && *++s == '-') g = string_catn(g, US"__", 2);
+      /* now on _ between groups */
+      }
+    g = string_catn(g, US":", 1);
+    g = string_cat(g, string_sprintf("%d", (int) gnutls_cipher_get_key_size(cipher) * 8));
+    state->ciphersuite = string_from_gstring(g);
+    }
+#else
+  state->ciphersuite = string_sprintf("%s:%s:%d",
+      gnutls_protocol_get_name(protocol),
+      gnutls_cipher_suite_get_name(kx, cipher, mac),
+      (int) gnutls_cipher_get_key_size(cipher) * 8);
+
+  /* I don't see a way that spaces could occur, in the current GnuTLS
+  code base, but it was a concern in the old code and perhaps older GnuTLS
+  releases did return "TLS 1.0"; play it safe, just in case. */
+
+  for (uschar * p = state->ciphersuite; *p; p++) if (isspace(*p)) *p = '-';
+#endif
+
+/* debug_printf("peer_status: ciphersuite %s\n", state->ciphersuite); */
+
+  state->tlsp->cipher = state->ciphersuite;
+  state->tlsp->bits = gnutls_cipher_get_key_size(cipher) * 8;
+  }
 store_pool = old_pool;
 state->tlsp->cipher = state->ciphersuite;
 
index fdc030c23b6930f5de4dffe7a9c3939105a285af..bd2cf5a6a3a8463eb8813599a0504d4a250971b3 100644 (file)
@@ -29,14 +29,7 @@ begin acl
 check_recipient:
   accept  hosts = :
   deny    hosts = HOSTIPV4
-         !encrypted = AES256-SHA:\
-                      AES256-GCM-SHA384:\
-                      IDEA-CBC-MD5:\
-                      DES-CBC3-SHA:\
-                      DHE_RSA_AES_256_CBC_SHA1:\
-                      DHE_RSA_3DES_EDE_CBC_SHA:\
-                      RSA_AES_256_CBC_SHA1 :\
-                     ECDHE_RSA_AES_256_GCM_SHA384
+         !encrypted = *
   accept
 
 
index 1ce642635577adcd155e9d5d9a4da144f3fc6c74..b95cfbe44fba2e040435eb3c16ea3b4eed8098d3 100644 (file)
@@ -8,7 +8,7 @@
 1999-03-02 09:44:33 10HmbB-0005vi-00 => CALLER@localhost.test.ex R=client T=send_to_server H=localhost.test.ex [127.0.0.1] X=TLS1.x:ke-RSA-AES256-SHAnnn:xxx CV=yes DN="CN=server1.example.com" C="250 OK id=10HmbC-0005vi-00"
 1999-03-02 09:44:33 10HmbB-0005vi-00 Completed
 1999-03-02 09:44:33 10HmbD-0005vi-00 <= CALLER@myhost.test.ex U=CALLER P=local S=sss for CALLER@dane256ee.test.ex
-1999-03-02 09:44:33 10HmbD-0005vi-00 => CALLER@dane256ee.test.ex R=client T=send_to_server H=dane256ee.test.ex [ip4.ip4.ip4.ip4] X=TLS1.2:RSA_CAMELLIA_256_GCM_SHA384:256 CV=dane DN="CN=server1.example.com" C="250 OK id=10HmbE-0005vi-00"
+1999-03-02 09:44:33 10HmbD-0005vi-00 => CALLER@dane256ee.test.ex R=client T=send_to_server H=dane256ee.test.ex [ip4.ip4.ip4.ip4] X=TLS1.2:RSA_CAMELLIA_256_GCM-SHAnnn:256 CV=dane DN="CN=server1.example.com" C="250 OK id=10HmbE-0005vi-00"
 1999-03-02 09:44:33 10HmbD-0005vi-00 Completed
 
 ******** SERVER ********
@@ -26,6 +26,6 @@
 1999-03-02 09:44:33 10HmbC-0005vi-00 => :blackhole: <CALLER@localhost.test.ex> R=server
 1999-03-02 09:44:33 10HmbC-0005vi-00 Completed
 1999-03-02 09:44:33 "rcpt ACL"
-1999-03-02 09:44:33 10HmbE-0005vi-00 <= <> H=the.local.host.name (myhost.test.ex) [ip4.ip4.ip4.ip4] P=esmtps X=TLS1.2:RSA_CAMELLIA_256_GCM_SHA384:256 CV=no S=sss id=E10HmbD-0005vi-00@myhost.test.ex for CALLER@dane256ee.test.ex
+1999-03-02 09:44:33 10HmbE-0005vi-00 <= <> H=the.local.host.name (myhost.test.ex) [ip4.ip4.ip4.ip4] P=esmtps X=TLS1.2:RSA_CAMELLIA_256_GCM-SHAnnn:256 CV=no S=sss id=E10HmbD-0005vi-00@myhost.test.ex for CALLER@dane256ee.test.ex
 1999-03-02 09:44:33 10HmbE-0005vi-00 => :blackhole: <CALLER@dane256ee.test.ex> R=server
 1999-03-02 09:44:33 10HmbE-0005vi-00 Completed
index dafca16ecf16ed3b399803d535fe5d1db2f562ab..b6c73bbe07c8b7786abf675bf95fd5c31d3b2dca 100755 (executable)
@@ -595,11 +595,18 @@ RESET_AFTER_EXTRA_LINE_READ:
 
   # GnuTLS have seen:
   #   TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256
+  #   TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM__AEAD:256
+  #   TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256
+  #   TLS1.3:ECDHE_PSK_SECP256R1__AES_256_GCM__AEAD:256
   #
   #   TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256
   #   TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128
   #   TLS1.2:RSA_AES_256_CBC_SHA1:256 (canonical)
   #   TLS1.2:DHE_RSA_AES_128_CBC_SHA1:128
+  #   TLS1.2:ECDHE_SECP256R1__RSA_SHA256__AES_256_GCM:256
+  #   TLS1.2:ECDHE_SECP256R1__RSA_SHA256__AES_128_CBC__SHA256:128
+  #   TLS1.2:ECDHE_SECP256R1__ECDSA_SHA512__AES_256_GCM:256
+  #   TLS1.2:RSA__CAMELLIA_256_GCM:256 (leave the cipher name)
   #
   #   X=TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256
   #   X=TLS1.2:RSA_AES_256_CBC_SHA1:256
@@ -611,11 +618,21 @@ RESET_AFTER_EXTRA_LINE_READ:
   #   DHE-RSA-AES256-SHA
   # picking latter as canonical simply because regex easier that way.
   s/\bDHE_RSA_AES_128_CBC_SHA1:128/RSA-AES256-SHA1:256/g;
-  s/TLS1.[0123]:((EC)?DHE_)?(RSA|ECDSA)_AES_(256|128)_(CBC|GCM)_SHA(1|256|384):(256|128)/TLS1.x:ke-$3-AES256-SHAnnn:xxx/g;
+  s/TLS1.[0123]:                                               # TLS version
+       ((EC)?DHE(_((?<psk>PSK)_)?(SECP256R1|X25519))?__?)?     # key-exchange
+       ((?<auth>RSA|ECDSA)((_PSS_RSAE)?_SHA(512|256))?__?)?    # authentication
+       AES_(256|128)_(CBC|GCM)                                 # cipher
+       (__?SHA(1|256|384))?:                                   # PRF
+       (256|128)                                               # cipher strength
+    /"TLS1.x:ke-"
+       . (defined($+{psk}) ? $+{psk} : "")
+       . (defined($+{auth}) ? $+{auth} : "")
+       . "-AES256-SHAnnn:xxx"/genx;
+  s/TLS1.2:RSA__CAMELLIA_256_GCM(_SHA384)?:256/TLS1.2:RSA_CAMELLIA_256_GCM-SHAnnn:256/g;
   s/\b(ECDHE-(RSA|ECDSA)-AES256-SHA|DHE-RSA-AES256-SHA256)\b/ke-$2-AES256-SHAnnn/g;
 
   # GnuTLS library error message changes
-  s/No certificate was found/The peer did not send any certificate/g;
+  s/(No certificate was found|Certificate is required)/The peer did not send any certificate/g;
 #(dodgy test?)  s/\(certificate verification failed\): invalid/\(gnutls_handshake\): The peer did not send any certificate./g;
   s/\(gnutls_priority_set\): No or insufficient priorities were set/\(gnutls_handshake\): Could not negotiate a supported cipher suite/g;
   s/\(gnutls_handshake\): \KNo supported cipher suites have been found.$/Could not negotiate a supported cipher suite./;
@@ -1254,7 +1271,7 @@ RESET_AFTER_EXTRA_LINE_READ:
     s/(DKIM: validation error: )error:[0-9A-F]{8}:rsa routines:(?:(?i)int_rsa_verify|CRYPTO_internal):(?:bad signature|algorithm mismatch)$/$1Public key signature verification has failed./;
 
     # gnutls version variances
-    if (/TLS error on connection \(recv\): .* Decode error/)
+    if (/TLS error on connection \(recv\): .* (Decode error|peer did not send any certificate)/)
       {
       my $prev = $_;
       $_ = <IN>;