Allow the server to change the ciphersuite on resume
[openssl.git] / ssl / statem / statem_clnt.c
index ab77ba05e9ff4416e56f36f3a3c44bb1a84131ee..7dd921eeff0757c4b42fdca60ffe4cfd7171a2b1 100644 (file)
@@ -517,7 +517,8 @@ WRITE_TRAN ossl_statem_client_write_transition(SSL *s)
              */
             return WRITE_TRAN_FINISHED;
         }
-        /* Renegotiation - fall through */
+        /* Renegotiation */
+        /* fall thru */
     case TLS_ST_BEFORE:
         st->hand_state = TLS_ST_CW_CLNT_HELLO;
         return WRITE_TRAN_CONTINUE;
@@ -1182,7 +1183,6 @@ int tls_construct_client_hello(SSL *s, WPACKET *pkt)
 
     /* TLS extensions */
     if (!tls_construct_extensions(s, pkt, SSL_EXT_CLIENT_HELLO, NULL, 0, &al)) {
-        ssl3_send_alert(s, SSL3_AL_FATAL, al);
         SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
         return 0;
     }
@@ -1268,9 +1268,26 @@ static int set_client_ciphersuite(SSL *s, const unsigned char *cipherchars)
     if (s->session->cipher != NULL)
         s->session->cipher_id = s->session->cipher->id;
     if (s->hit && (s->session->cipher_id != c->id)) {
-        SSLerr(SSL_F_SET_CLIENT_CIPHERSUITE,
-               SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED);
-        return 0;
+        if (SSL_IS_TLS13(s)) {
+            /*
+             * In TLSv1.3 it is valid for the server to select a different
+             * ciphersuite as long as the hash is the same.
+             */
+            if (ssl_md(c->algorithm2)
+                    != ssl_md(s->session->cipher->algorithm2)) {
+                SSLerr(SSL_F_SET_CLIENT_CIPHERSUITE,
+                       SSL_R_CIPHERSUITE_DIGEST_HAS_CHANGED);
+                return 0;
+            }
+        } else {
+            /*
+             * Prior to TLSv1.3 resuming a session always meant using the same
+             * ciphersuite.
+             */
+            SSLerr(SSL_F_SET_CLIENT_CIPHERSUITE,
+                   SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED);
+            return 0;
+        }
     }
     s->s3->tmp.new_cipher = c;
 
@@ -1365,7 +1382,8 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
     /* TLS extensions */
     if (PACKET_remaining(pkt) == 0) {
         PACKET_null_init(&extpkt);
-    } else if (!PACKET_as_length_prefixed_2(pkt, &extpkt)) {
+    } else if (!PACKET_as_length_prefixed_2(pkt, &extpkt)
+               || PACKET_remaining(pkt) != 0) {
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_BAD_LENGTH);
         goto f_err;
@@ -1373,7 +1391,7 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
 
     context = SSL_IS_TLS13(s) ? SSL_EXT_TLS1_3_SERVER_HELLO
                               : SSL_EXT_TLS1_2_SERVER_HELLO;
-    if (!tls_collect_extensions(s, &extpkt, context, &extensions, &al, NULL))
+    if (!tls_collect_extensions(s, &extpkt, context, &extensions, &al, NULL, 1))
         goto f_err;
 
     s->hit = 0;
@@ -1525,7 +1543,7 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
     }
 #endif
 
-    if (!tls_parse_all_extensions(s, context, extensions, NULL, 0, &al))
+    if (!tls_parse_all_extensions(s, context, extensions, NULL, 0, &al, 1))
         goto f_err;
 
 #ifndef OPENSSL_NO_SCTP
@@ -1609,19 +1627,35 @@ static MSG_PROCESS_RETURN tls_process_hello_retry_request(SSL *s, PACKET *pkt)
         goto f_err;
     }
 
-    if (!PACKET_as_length_prefixed_2(pkt, &extpkt)) {
+    if (!PACKET_as_length_prefixed_2(pkt, &extpkt)
+               /* Must have a non-empty extensions block */
+            || PACKET_remaining(&extpkt) == 0
+               /* Must be no trailing data after extensions */
+            || PACKET_remaining(pkt) != 0) {
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_HELLO_RETRY_REQUEST, SSL_R_BAD_LENGTH);
         goto f_err;
     }
 
     if (!tls_collect_extensions(s, &extpkt, SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST,
-                                &extensions, &al, NULL)
+                                &extensions, &al, NULL, 1)
             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST,
-                                         extensions, NULL, 0, &al))
+                                         extensions, NULL, 0, &al, 1))
         goto f_err;
 
     OPENSSL_free(extensions);
+    extensions = NULL;
+
+    if (s->ext.tls13_cookie_len == 0 && s->s3->tmp.pkey != NULL) {
+        /*
+         * We didn't receive a cookie or a new key_share so the next
+         * ClientHello will not change
+         */
+        al = SSL_AD_ILLEGAL_PARAMETER;
+        SSLerr(SSL_F_TLS_PROCESS_HELLO_RETRY_REQUEST,
+               SSL_R_NO_CHANGE_FOLLOWING_HRR);
+        goto f_err;
+    }
 
     /*
      * Re-initialise the Transcript Hash. We're going to prepopulate it with
@@ -1672,7 +1706,8 @@ MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
     if ((SSL_IS_TLS13(s) && !PACKET_get_1(pkt, &context))
             || context != 0
             || !PACKET_get_net_3(pkt, &cert_list_len)
-            || PACKET_remaining(pkt) != cert_list_len) {
+            || PACKET_remaining(pkt) != cert_list_len
+            || PACKET_remaining(pkt) == 0) {
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, SSL_R_LENGTH_MISMATCH);
         goto f_err;
@@ -1711,9 +1746,10 @@ MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
             }
             if (!tls_collect_extensions(s, &extensions,
                                         SSL_EXT_TLS1_3_CERTIFICATE, &rawexts,
-                                        &al, NULL)
-                    || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE,
-                                                 rawexts, x, chainidx, &al)) {
+                                        &al, NULL, chainidx == 0)
+                || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE,
+                                             rawexts, x, chainidx, &al,
+                                             PACKET_remaining(pkt) == 0)) {
                 OPENSSL_free(rawexts);
                 goto f_err;
             }
@@ -1770,7 +1806,7 @@ MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
 
     if (pkey == NULL || EVP_PKEY_missing_parameters(pkey)) {
         x = NULL;
-        al = SSL3_AL_FATAL;
+        al = SSL_AD_INTERNAL_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
                SSL_R_UNABLE_TO_FIND_PUBLIC_KEY_PARAMETERS);
         goto f_err;
@@ -1908,7 +1944,6 @@ static int tls_process_ske_srp(SSL *s, PACKET *pkt, EVP_PKEY **pkey, int *al)
     }
 
     if (!srp_verify_server_param(s, al)) {
-        *al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_SKE_SRP, SSL_R_BAD_SRP_PARAMETERS);
         return 0;
     }
@@ -1967,7 +2002,7 @@ static int tls_process_ske_dhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey, int *al)
 
     /* test non-zero pubkey */
     if (BN_is_zero(bnpub_key)) {
-        *al = SSL_AD_DECODE_ERROR;
+        *al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, SSL_R_BAD_DH_VALUE);
         goto err;
     }
@@ -1980,7 +2015,7 @@ static int tls_process_ske_dhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey, int *al)
     p = g = NULL;
 
     if (DH_check_params(dh, &check_bits) == 0 || check_bits != 0) {
-        *al = SSL_AD_DECODE_ERROR;
+        *al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, SSL_R_BAD_DH_VALUE);
         goto err;
     }
@@ -2055,7 +2090,7 @@ static int tls_process_ske_ecdhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey, int *al)
      * invalid curve. ECParameters is 3 bytes.
      */
     if (!tls1_check_curve(s, ecparams, 3)) {
-        *al = SSL_AD_DECODE_ERROR;
+        *al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_TLS_PROCESS_SKE_ECDHE, SSL_R_WRONG_CURVE);
         return 0;
     }
@@ -2104,7 +2139,7 @@ static int tls_process_ske_ecdhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey, int *al)
     if (!EVP_PKEY_set1_tls_encodedpoint(s->s3->peer_tmp,
                                         PACKET_data(&encoded_pt),
                                         PACKET_remaining(&encoded_pt))) {
-        *al = SSL_AD_DECODE_ERROR;
+        *al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_TLS_PROCESS_SKE_ECDHE, SSL_R_BAD_ECPOINT);
         return 0;
     }
@@ -2181,7 +2216,7 @@ MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt)
         if (!PACKET_get_sub_packet(&save_param_start, &params,
                                    PACKET_remaining(&save_param_start) -
                                    PACKET_remaining(pkt))) {
-            al = SSL_AD_INTERNAL_ERROR;
+            al = SSL_AD_DECODE_ERROR;
             SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
             goto err;
         }
@@ -2340,9 +2375,9 @@ MSG_PROCESS_RETURN tls_process_certificate_request(SSL *s, PACKET *pkt)
         }
         if (!tls_collect_extensions(s, &extensions,
                                     SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
-                                    &rawexts, &al, NULL)
+                                    &rawexts, &al, NULL, 1)
             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
-                                         rawexts, NULL, 0, &al)) {
+                                         rawexts, NULL, 0, &al, 1)) {
             OPENSSL_free(rawexts);
             goto err;
         }
@@ -2499,12 +2534,13 @@ MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt)
         PACKET extpkt;
 
         if (!PACKET_as_length_prefixed_2(pkt, &extpkt)
+                || PACKET_remaining(pkt) != 0
                 || !tls_collect_extensions(s, &extpkt,
                                            SSL_EXT_TLS1_3_NEW_SESSION_TICKET,
-                                           &exts, &al, NULL)
+                                           &exts, &al, NULL, 1)
                 || !tls_parse_all_extensions(s,
                                              SSL_EXT_TLS1_3_NEW_SESSION_TICKET,
-                                             exts, NULL, 0, &al)) {
+                                             exts, NULL, 0, &al, 1)) {
             SSLerr(SSL_F_TLS_PROCESS_NEW_SESSION_TICKET, SSL_R_BAD_EXTENSION);
             goto f_err;
         }
@@ -2729,7 +2765,7 @@ static int tls_construct_cke_psk_preamble(SSL *s, WPACKET *pkt, int *al)
     identitylen = strlen(identity);
     if (identitylen > PSK_MAX_IDENTITY_LEN) {
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE, ERR_R_INTERNAL_ERROR);
-        *al = SSL_AD_HANDSHAKE_FAILURE;
+        *al = SSL_AD_INTERNAL_ERROR;
         goto err;
     }
 
@@ -3116,7 +3152,7 @@ int tls_construct_client_key_exchange(SSL *s, WPACKET *pkt)
         if (!tls_construct_cke_srp(s, pkt, &al))
             goto err;
     } else if (!(alg_k & SSL_kPSK)) {
-        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
+        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
         SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
         goto err;
     }
@@ -3435,6 +3471,11 @@ MSG_PROCESS_RETURN tls_process_hello_req(SSL *s, PACKET *pkt)
         return MSG_PROCESS_ERROR;
     }
 
+    if ((s->options & SSL_OP_NO_RENEGOTIATION)) {
+        ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
+        return MSG_PROCESS_FINISHED_READING;
+    }
+
     /*
      * This is a historical discrepancy (not in the RFC) maintained for
      * compatibility reasons. If a TLS client receives a HelloRequest it will
@@ -3456,7 +3497,8 @@ static MSG_PROCESS_RETURN tls_process_encrypted_extensions(SSL *s, PACKET *pkt)
     PACKET extensions;
     RAW_EXTENSION *rawexts = NULL;
 
-    if (!PACKET_as_length_prefixed_2(pkt, &extensions)) {
+    if (!PACKET_as_length_prefixed_2(pkt, &extensions)
+            || PACKET_remaining(pkt) != 0) {
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_ENCRYPTED_EXTENSIONS, SSL_R_LENGTH_MISMATCH);
         goto err;
@@ -3464,9 +3506,9 @@ static MSG_PROCESS_RETURN tls_process_encrypted_extensions(SSL *s, PACKET *pkt)
 
     if (!tls_collect_extensions(s, &extensions,
                                 SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS, &rawexts,
-                                &al, NULL)
+                                &al, NULL, 1)
             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
-                                         rawexts, NULL, 0, &al))
+                                         rawexts, NULL, 0, &al, 1))
         goto err;
 
     OPENSSL_free(rawexts);