BN_mod_exp(r,a,p,m,ctx) should not be called with r == p.

[oweals/openssl.git] / ssl / s3_srvr.c

diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c
index e23ca20bd310eff7257f0858a2b8912f1ca11296..531a49f0212ef86aa30220ae58fc758d84fe0ee8 100644 (file)
--- a/ssl/s3_srvr.c
+++ b/ssl/s3_srvr.c
@@ -153,7 +153,10 @@ int ssl3_accept(SSL *s)
                        if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
 
                        if ((s->version>>8) != 3)
-                               abort();
+                               {
+                               SSLerr(SSL_F_SSL3_ACCEPT, SSL_R_INTERNAL_ERROR);
+                               return -1;
+                               }
                        s->type=SSL_ST_ACCEPT;
 
                        if (s->init_buf == NULL)
@@ -982,7 +985,7 @@ static int ssl3_send_server_key_exchange(SSL *s)
                        dhp=cert->dh_tmp;
                        if ((dhp == NULL) && (s->cert->dh_tmp_cb != NULL))
                                dhp=s->cert->dh_tmp_cb(s,
-                                     !SSL_C_IS_EXPORT(s->s3->tmp.new_cipher),
+                                     SSL_C_IS_EXPORT(s->s3->tmp.new_cipher),
                                      SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher));
                        if (dhp == NULL)
                                {
@@ -1259,7 +1262,7 @@ static int ssl3_get_client_key_exchange(SSL *s)
                SSL3_ST_SR_KEY_EXCH_A,
                SSL3_ST_SR_KEY_EXCH_B,
                SSL3_MT_CLIENT_KEY_EXCHANGE,
-               400, /* ???? */
+               2048, /* ??? */
                &ok);
 
        if (!ok) return((int)n);
@@ -1326,11 +1329,22 @@ static int ssl3_get_client_key_exchange(SSL *s)
                        goto f_err;
                        }
 
-               if ((p[0] != (s->client_version>>8)) || (p[1] != (s->client_version & 0xff)))
+               if (!((p[0] == (s->client_version>>8)) && (p[1] == (s->client_version & 0xff))))
                        {
-                       al=SSL_AD_DECODE_ERROR;
-                       SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,SSL_R_BAD_PROTOCOL_VERSION_NUMBER);
-                       goto f_err;
+                       /* The premaster secret must contain the same version number as the
+                        * ClientHello to detect version rollback attacks (strangely, the
+                        * protocol does not offer such protection for DH ciphersuites).
+                        * However, buggy clients exist that send the negotiated protocol
+                        * version instead if the server does not support the requested
+                        * protocol version.
+                        * If SSL_OP_TLS_ROLLBACK_BUG is set, tolerate such clients. */
+                       if (!((s->options & SSL_OP_TLS_ROLLBACK_BUG) &&
+                               (p[0] == (s->version>>8)) && (p[1] == (s->version & 0xff))))
+                               {
+                               al=SSL_AD_DECODE_ERROR;
+                               SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,SSL_R_BAD_PROTOCOL_VERSION_NUMBER);
+                               goto f_err;
+                               }
                        }
 
                s->session->master_key_length=