[openssl-commits] [openssl] OpenSSL_1_1_0-stable update

[Matt Caswell]

The branch OpenSSL_1_1_0-stable has been updated
       via  d717edf80ed3494a5a25c0b82ce61e5885de68ac (commit)
      from  fd91e61f522b236d80347f0910f778314fb6ae18 (commit)


- Log -----------------------------------------------------------------
commit d717edf80ed3494a5a25c0b82ce61e5885de68ac
Author: Matt Caswell <matt at openssl.org>
Date:   Wed Apr 12 17:02:42 2017 +0100

    Don't fail the connection in SSLv3 if server selects ECDHE
    
    ECDHE is not properly defined for SSLv3. Commit fe55c4a2 prevented ECDHE
    from being selected in that protocol. However, historically, servers do
    still select ECDHE anyway so that commit causes interoperability problems.
    Clients that previously worked when talking to an SSLv3 server could now
    fail.
    
    This commit introduces an exception which enables a client to continue in
    SSLv3 if the server selected ECDHE.
    
    (cherry picked from commit 8af91fd9d08487e0dffb6ccac5f42633c964f3f0)
    
    Reviewed-by: Tim Hudson <tjh at openssl.org>
    (Merged from https://github.com/openssl/openssl/pull/3734)

-----------------------------------------------------------------------

Summary of changes:
 ssl/ssl_lib.c            |  2 +-
 ssl/ssl_locl.h           |  2 +-
 ssl/statem/statem_clnt.c |  4 ++--
 ssl/t1_lib.c             | 20 ++++++++++++++++----
 4 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index 9f9dce6..f706c27 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -1944,7 +1944,7 @@ STACK_OF(SSL_CIPHER) *SSL_get1_supported_ciphers(SSL *s)
     ssl_set_client_disabled(s);
     for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) {
         const SSL_CIPHER *c = sk_SSL_CIPHER_value(ciphers, i);
-        if (!ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_SUPPORTED)) {
+        if (!ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_SUPPORTED, 0)) {
             if (!sk)
                 sk = sk_SSL_CIPHER_new_null();
             if (!sk)
diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h
index eb7e8c9..de4a520 100644
--- a/ssl/ssl_locl.h
+++ b/ssl/ssl_locl.h
@@ -2070,7 +2070,7 @@ __owur size_t tls12_get_psigalgs(SSL *s, int sent, const unsigned char **psigs);
 __owur int tls12_check_peer_sigalg(const EVP_MD **pmd, SSL *s,
                                    const unsigned char *sig, EVP_PKEY *pkey);
 void ssl_set_client_disabled(SSL *s);
-__owur int ssl_cipher_disabled(SSL *s, const SSL_CIPHER *c, int op);
+__owur int ssl_cipher_disabled(SSL *s, const SSL_CIPHER *c, int op, int echde);
 
 __owur int ssl_add_clienthello_use_srtp_ext(SSL *s, unsigned char *p, int *len,
                                             int maxlen);
diff --git a/ssl/statem/statem_clnt.c b/ssl/statem/statem_clnt.c
index a2a6684..c4963f5 100644
--- a/ssl/statem/statem_clnt.c
+++ b/ssl/statem/statem_clnt.c
@@ -1038,7 +1038,7 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
      * If it is a disabled cipher we either didn't send it in client hello,
      * or it's not allowed for the selected protocol. So we return an error.
      */
-    if (ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_CHECK)) {
+    if (ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_CHECK, 1)) {
         al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_WRONG_CIPHER_RETURNED);
         goto f_err;
@@ -2919,7 +2919,7 @@ int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk, unsigned char *p)
     for (i = 0; i < sk_SSL_CIPHER_num(sk); i++) {
         c = sk_SSL_CIPHER_value(sk, i);
         /* Skip disabled ciphers */
-        if (ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_SUPPORTED))
+        if (ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_SUPPORTED, 0))
             continue;
         j = s->method->put_cipher_by_char(c, p);
         p += j;
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 3f9702b..377ed32 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -863,19 +863,31 @@ void ssl_set_client_disabled(SSL *s)
  * @s: SSL connection that you want to use the cipher on
  * @c: cipher to check
  * @op: Security check that you want to do
+ * @ecdhe: If set to 1 then TLSv1 ECDHE ciphers are also allowed in SSLv3
  *
  * Returns 1 when it's disabled, 0 when enabled.
  */
-int ssl_cipher_disabled(SSL *s, const SSL_CIPHER *c, int op)
+int ssl_cipher_disabled(SSL *s, const SSL_CIPHER *c, int op, int ecdhe)
 {
     if (c->algorithm_mkey & s->s3->tmp.mask_k
         || c->algorithm_auth & s->s3->tmp.mask_a)
         return 1;
     if (s->s3->tmp.max_ver == 0)
         return 1;
-    if (!SSL_IS_DTLS(s) && ((c->min_tls > s->s3->tmp.max_ver)
-                            || (c->max_tls < s->s3->tmp.min_ver)))
-        return 1;
+    if (!SSL_IS_DTLS(s)) {
+        int min_tls = c->min_tls;
+
+        /*
+         * For historical reasons we will allow ECHDE to be selected by a server
+         * in SSLv3 if we are a client
+         */
+        if (min_tls == TLS1_VERSION && ecdhe
+                && (c->algorithm_mkey & (SSL_kECDHE | SSL_kECDHEPSK)) != 0)
+            min_tls = SSL3_VERSION;
+
+        if ((min_tls > s->s3->tmp.max_ver) || (c->max_tls < s->s3->tmp.min_ver))
+            return 1;
+    }
     if (SSL_IS_DTLS(s) && (DTLS_VERSION_GT(c->min_dtls, s->s3->tmp.max_ver)
                            || DTLS_VERSION_LT(c->max_dtls, s->s3->tmp.min_ver)))
         return 1;