Disable EXPORT and LOW SSLv3+ ciphers by default

Reviewed-by: Emilia Käsper <emilia@openssl.org>

diff --git a/CHANGES b/CHANGES
index a02079ff3351048ebc66d94f22e3b23e4f90f57f..e63fce2fef0a4f2f50fb464c14aae39b392b0040 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,11 @@
 
  Changes between 1.0.2f and 1.0.2g [xx XXX xxxx]
 
+  * Disable weak ciphers in SSLv3 and up in default builds of OpenSSL.
+    Builds that are not configured with "enable-weak-ssl-ciphers" will not
+    provide any "EXPORT" or "LOW" strength ciphers.
+    [Viktor Dukhovni]
+
   * Disable SSLv2 default build, default negotiation and weak ciphers.  SSLv2
     is by default disabled at build-time.  Builds that are not configured with
     "enable-ssl2" will not support SSLv2.  Even if "enable-ssl2" is used,

diff --git a/Configure b/Configure
index 6b574a35da3b4c3b9f39d72feab60ea58e3b47e7..c98107a487188f067aa8113e7a4edfebd45351f2 100755 (executable)
--- a/Configure
+++ b/Configure
@@ -58,6 +58,10 @@ my $usage="Usage: Configure [no-<cipher> ...] [enable-<cipher> ...] [experimenta
 #              library and will be loaded in run-time by the OpenSSL library.
 # sctp          include SCTP support
 # 386           generate 80386 code
+# enable-weak-ssl-ciphers
+#              Enable EXPORT and LOW SSLv3 ciphers that are disabled by
+#              default.  Note, weak SSLv2 ciphers are unconditionally
+#              disabled.
 # no-sse2      disables IA-32 SSE2 code, above option implies no-sse2
 # no-<cipher>   build without specified algorithm (rsa, idea, rc5, ...)
 # -<xxx> +<xxx> compiler options are passed through 
@@ -787,6 +791,7 @@ my %disabled = ( # "what"         => "comment" [or special keyword "experimental
                 "ssl2"           => "default",
                 "store"          => "experimental",
                 "unit-test"      => "default",
+                "weak-ssl-ciphers" => "default",
                 "zlib"           => "default",
                 "zlib-dynamic"   => "default"
               );

diff --git a/NEWS b/NEWS
index c728ca6ac1488ed84dfb618fbb41fc48cd976776..47fba26b82d4721a447773a0ffca892a5f013e81 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,7 @@
 
   Major changes between OpenSSL 1.0.2f and OpenSSL 1.0.2g [under development]
 
+      o Disable weak ciphers in SSLv3 and up in default builds of OpenSSL.
       o Disable SSLv2 default build, default negotiation and weak ciphers.
 
   Major changes between OpenSSL 1.0.2e and OpenSSL 1.0.2f [28 Jan 2016]

diff --git a/doc/apps/ciphers.pod b/doc/apps/ciphers.pod
index 8038b0514942c1bac028d9fcfbaf8ff8cdec9d82..9643b4d48ca8c14efca1286ed722afb8e50eacd1 100644 (file)
--- a/doc/apps/ciphers.pod
+++ b/doc/apps/ciphers.pod
@@ -136,34 +136,46 @@ than 128 bits, and some cipher suites with 128-bit keys.
 
 =item B<LOW>
 
-"low" encryption cipher suites, currently those using 64 or 56 bit encryption algorithms
-but excluding export cipher suites.
+Low strength encryption cipher suites, currently those using 64 or 56 bit
+encryption algorithms but excluding export cipher suites.
+As of OpenSSL 1.0.2g, these are disabled in default builds.
 
 =item B<EXP>, B<EXPORT>
 
-export encryption algorithms. Including 40 and 56 bits algorithms.
+Export strength encryption algorithms. Including 40 and 56 bits algorithms.
+As of OpenSSL 1.0.2g, these are disabled in default builds.
 
 =item B<EXPORT40>
 
-40 bit export encryption algorithms
+40-bit export encryption algorithms
+As of OpenSSL 1.0.2g, these are disabled in default builds.
 
 =item B<EXPORT56>
 
-56 bit export encryption algorithms. In OpenSSL 0.9.8c and later the set of
+56-bit export encryption algorithms. In OpenSSL 0.9.8c and later the set of
 56 bit export ciphers is empty unless OpenSSL has been explicitly configured
 with support for experimental ciphers.
+As of OpenSSL 1.0.2g, these are disabled in default builds.
 
 =item B<eNULL>, B<NULL>
 
-the "NULL" ciphers that is those offering no encryption. Because these offer no
-encryption at all and are a security risk they are disabled unless explicitly
-included.
+The "NULL" ciphers that is those offering no encryption. Because these offer no
+encryption at all and are a security risk they are not enabled via either the
+B<DEFAULT> or B<ALL> cipher strings.
+Be careful when building cipherlists out of lower-level primitives such as
+B<kRSA> or B<aECDSA> as these do overlap with the B<eNULL> ciphers.
+When in doubt, include B<!eNULL> in your cipherlist.
 
 =item B<aNULL>
 
-the cipher suites offering no authentication. This is currently the anonymous
+The cipher suites offering no authentication. This is currently the anonymous
 DH algorithms and anonymous ECDH algorithms. These cipher suites are vulnerable
 to a "man in the middle" attack and so their use is normally discouraged.
+These are excluded from the B<DEFAULT> ciphers, but included in the B<ALL>
+ciphers.
+Be careful when building cipherlists out of lower-level primitives such as
+B<kDHE> or B<AES> as these do overlap with the B<aNULL> ciphers.
+When in doubt, include B<!aNULL> in your cipherlist.
 
 =item B<kRSA>, B<RSA>
 

diff --git a/ssl/s3_lib.c b/ssl/s3_lib.c
index 6a066255d6aa84c7ed69d74ffa7a42ec6bc9f76e..4aac3b279280458853ccffaecfeb7595ec1cf9b9 100644 (file)
--- a/ssl/s3_lib.c
+++ b/ssl/s3_lib.c
@@ -198,6 +198,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      },
 
 /* Cipher 03 */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_RSA_RC4_40_MD5,
@@ -212,6 +213,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      128,
      },
+#endif
 
 /* Cipher 04 */
     {
@@ -246,6 +248,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      },
 
 /* Cipher 06 */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_RSA_RC2_40_MD5,
@@ -260,6 +263,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      128,
      },
+#endif
 
 /* Cipher 07 */
 #ifndef OPENSSL_NO_IDEA
@@ -280,6 +284,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
 #endif
 
 /* Cipher 08 */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_RSA_DES_40_CBC_SHA,
@@ -294,8 +299,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      56,
      },
+#endif
 
 /* Cipher 09 */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_RSA_DES_64_CBC_SHA,
@@ -310,6 +317,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      56,
      56,
      },
+#endif
 
 /* Cipher 0A */
     {
@@ -329,6 +337,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
 
 /* The DH ciphers */
 /* Cipher 0B */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      0,
      SSL3_TXT_DH_DSS_DES_40_CBC_SHA,
@@ -343,8 +352,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      56,
      },
+#endif
 
 /* Cipher 0C */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_DH_DSS_DES_64_CBC_SHA,
@@ -359,6 +370,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      56,
      56,
      },
+#endif
 
 /* Cipher 0D */
     {
@@ -377,6 +389,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      },
 
 /* Cipher 0E */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      0,
      SSL3_TXT_DH_RSA_DES_40_CBC_SHA,
@@ -391,8 +404,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      56,
      },
+#endif
 
 /* Cipher 0F */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_DH_RSA_DES_64_CBC_SHA,
@@ -407,6 +422,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      56,
      56,
      },
+#endif
 
 /* Cipher 10 */
     {
@@ -426,6 +442,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
 
 /* The Ephemeral DH ciphers */
 /* Cipher 11 */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_EDH_DSS_DES_40_CBC_SHA,
@@ -440,8 +457,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      56,
      },
+#endif
 
 /* Cipher 12 */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_EDH_DSS_DES_64_CBC_SHA,
@@ -456,6 +475,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      56,
      56,
      },
+#endif
 
 /* Cipher 13 */
     {
@@ -474,6 +494,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      },
 
 /* Cipher 14 */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_EDH_RSA_DES_40_CBC_SHA,
@@ -488,8 +509,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      56,
      },
+#endif
 
 /* Cipher 15 */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_EDH_RSA_DES_64_CBC_SHA,
@@ -504,6 +527,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      56,
      56,
      },
+#endif
 
 /* Cipher 16 */
     {
@@ -522,6 +546,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      },
 
 /* Cipher 17 */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_ADH_RC4_40_MD5,
@@ -536,6 +561,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      128,
      },
+#endif
 
 /* Cipher 18 */
     {
@@ -554,6 +580,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      },
 
 /* Cipher 19 */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_ADH_DES_40_CBC_SHA,
@@ -568,8 +595,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      128,
      },
+#endif
 
 /* Cipher 1A */
+#ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_ADH_DES_64_CBC_SHA,
@@ -584,6 +613,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      56,
      56,
      },
+#endif
 
 /* Cipher 1B */
     {
@@ -655,6 +685,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
 #ifndef OPENSSL_NO_KRB5
 /* The Kerberos ciphers*/
 /* Cipher 1E */
+# ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_KRB5_DES_64_CBC_SHA,
@@ -669,6 +700,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      56,
      56,
      },
+# endif
 
 /* Cipher 1F */
     {
@@ -719,6 +751,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      },
 
 /* Cipher 22 */
+# ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_KRB5_DES_64_CBC_MD5,
@@ -733,6 +766,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      56,
      56,
      },
+# endif
 
 /* Cipher 23 */
     {
@@ -783,6 +817,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      },
 
 /* Cipher 26 */
+# ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_KRB5_DES_40_CBC_SHA,
@@ -797,8 +832,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      56,
      },
+# endif
 
 /* Cipher 27 */
+# ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_KRB5_RC2_40_CBC_SHA,
@@ -813,8 +850,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      128,
      },
+# endif
 
 /* Cipher 28 */
+# ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_KRB5_RC4_40_SHA,
@@ -829,8 +868,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      128,
      },
+# endif
 
 /* Cipher 29 */
+# ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_KRB5_DES_40_CBC_MD5,
@@ -845,8 +886,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      56,
      },
+# endif
 
 /* Cipher 2A */
+# ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_KRB5_RC2_40_CBC_MD5,
@@ -861,8 +904,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      128,
      },
+# endif
 
 /* Cipher 2B */
+# ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      SSL3_TXT_KRB5_RC4_40_MD5,
@@ -877,6 +922,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      40,
      128,
      },
+# endif
 #endif                          /* OPENSSL_NO_KRB5 */
 
 /* New AES ciphersuites */
@@ -1300,6 +1346,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
 # endif
 
     /* Cipher 62 */
+# ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      TLS1_TXT_RSA_EXPORT1024_WITH_DES_CBC_SHA,
@@ -1314,8 +1361,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      56,
      56,
      },
+# endif
 
     /* Cipher 63 */
+# ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      TLS1_TXT_DHE_DSS_EXPORT1024_WITH_DES_CBC_SHA,
@@ -1330,8 +1379,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      56,
      56,
      },
+# endif
 
     /* Cipher 64 */
+# ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      TLS1_TXT_RSA_EXPORT1024_WITH_RC4_56_SHA,
@@ -1346,8 +1397,10 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      56,
      128,
      },
+# endif
 
     /* Cipher 65 */
+# ifndef OPENSSL_NO_WEAK_SSL_CIPHERS
     {
      1,
      TLS1_TXT_DHE_DSS_EXPORT1024_WITH_RC4_56_SHA,
@@ -1362,6 +1415,7 @@ OPENSSL_GLOBAL SSL_CIPHER ssl3_ciphers[] = {
      56,
      128,
      },
+# endif
 
     /* Cipher 66 */
     {