Validate ClientHello session_id field length and send alert on failure
[openssl.git] / ssl / s3_srvr.c
index 65d7a359b36ab59e629d7fea0144cb9248585ff8..7eb7ea681eb0fd46fc417f66de9478a843f92d39 100644 (file)
@@ -1,4 +1,4 @@
-/* ssl/s3_srvr.c -*- mode:C; c-file-style: "eay" -*- */
+/* ssl/s3_srvr.c */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -383,7 +383,6 @@ int ssl3_accept(SSL *s)
                      */
                     if (al != TLS1_AD_UNKNOWN_PSK_IDENTITY)
                         SSLerr(SSL_F_SSL3_ACCEPT, SSL_R_CLIENTHELLO_TLSEXT);
-                    ret = SSL_TLSEXT_ERR_ALERT_FATAL;
                     ret = -1;
                     s->state = SSL_ST_ERR;
                     goto end;
@@ -692,15 +691,6 @@ int ssl3_accept(SSL *s)
 
         case SSL3_ST_SR_CERT_VRFY_A:
         case SSL3_ST_SR_CERT_VRFY_B:
-            /*
-             * This *should* be the first time we enable CCS, but be
-             * extra careful about surrounding code changes. We need
-             * to set this here because we don't know if we're
-             * expecting a CertificateVerify or not.
-             */
-            if (!s->s3->change_cipher_spec)
-                s->s3->flags |= SSL3_FLAGS_CCS_OK;
-            /* we should decide if we expected this one */
             ret = ssl3_get_cert_verify(s);
             if (ret <= 0)
                 goto end;
@@ -720,11 +710,10 @@ int ssl3_accept(SSL *s)
         case SSL3_ST_SR_NEXT_PROTO_A:
         case SSL3_ST_SR_NEXT_PROTO_B:
             /*
-             * Enable CCS for resumed handshakes with NPN.
-             * In a full handshake with NPN, we end up here through
-             * SSL3_ST_SR_CERT_VRFY_B, where SSL3_FLAGS_CCS_OK was
-             * already set. Receiving a CCS clears the flag, so make
-             * sure not to re-enable it to ban duplicates.
+             * Enable CCS for NPN. Receiving a CCS clears the flag, so make
+             * sure not to re-enable it to ban duplicates. This *should* be the
+             * first time we have received one - but we check anyway to be
+             * cautious.
              * s->s3->change_cipher_spec is set when a CCS is
              * processed in s3_pkt.c, and remains set until
              * the client's Finished message is read.
@@ -743,10 +732,8 @@ int ssl3_accept(SSL *s)
         case SSL3_ST_SR_FINISHED_A:
         case SSL3_ST_SR_FINISHED_B:
             /*
-             * Enable CCS for resumed handshakes without NPN.
-             * In a full handshake, we end up here through
-             * SSL3_ST_SR_CERT_VRFY_B, where SSL3_FLAGS_CCS_OK was
-             * already set. Receiving a CCS clears the flag, so make
+             * Enable CCS for handshakes without NPN. In NPN the CCS flag has
+             * already been set. Receiving a CCS clears the flag, so make
              * sure not to re-enable it to ban duplicates.
              * s->s3->change_cipher_spec is set when a CCS is
              * processed in s3_pkt.c, and remains set until
@@ -979,7 +966,7 @@ int ssl3_check_client_hello(SSL *s)
 
 int ssl3_get_client_hello(SSL *s)
 {
-    int i, j, ok, al, ret = -1;
+    int i, j, ok, al, ret = -1, cookie_valid = 0;
     unsigned int cookie_len;
     long n;
     unsigned long id;
@@ -1077,6 +1064,12 @@ int ssl3_get_client_hello(SSL *s)
         goto f_err;
     }
 
+    if ((j < 0) || (j > SSL_MAX_SSL_SESSION_ID_LENGTH)) {
+        al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_LENGTH_MISMATCH);
+        goto f_err;
+    }
+
     s->hit = 0;
     /*
      * Versions before 0.9.7 always allow clients to resume sessions in
@@ -1167,8 +1160,7 @@ int ssl3_get_client_hello(SSL *s)
                 SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_COOKIE_MISMATCH);
                 goto f_err;
             }
-
-            ret = 2;
+            cookie_valid = 1;
         }
 
         p += cookie_len;
@@ -1276,7 +1268,7 @@ int ssl3_get_client_hello(SSL *s)
 #ifndef OPENSSL_NO_TLSEXT
     /* TLS extensions */
     if (s->version >= SSL3_VERSION) {
-        if (!ssl_parse_clienthello_tlsext(s, &p, d, n, &al)) {
+        if (!ssl_parse_clienthello_tlsext(s, &p, d + n, &al)) {
             /* 'al' set by ssl_parse_clienthello_tlsext */
             SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_PARSE_TLSEXT);
             goto f_err;
@@ -1504,8 +1496,7 @@ int ssl3_get_client_hello(SSL *s)
         }
     }
 
-    if (ret < 0)
-        ret = 1;
+    ret = cookie_valid ? 2 : 1;
     if (0) {
  f_err:
         ssl3_send_alert(s, SSL3_AL_FATAL, al);
@@ -1515,7 +1506,7 @@ int ssl3_get_client_hello(SSL *s)
 
     if (ciphers != NULL)
         sk_SSL_CIPHER_free(ciphers);
-    return (ret);
+    return ret;
 }
 
 int ssl3_send_server_hello(SSL *s)
@@ -1999,14 +1990,22 @@ int ssl3_send_server_key_exchange(SSL *s)
                 for (num = 2; num > 0; num--) {
                     EVP_MD_CTX_set_flags(&md_ctx,
                                          EVP_MD_CTX_FLAG_NON_FIPS_ALLOW);
-                    EVP_DigestInit_ex(&md_ctx, (num == 2)
-                                      ? s->ctx->md5 : s->ctx->sha1, NULL);
-                    EVP_DigestUpdate(&md_ctx, &(s->s3->client_random[0]),
-                                     SSL3_RANDOM_SIZE);
-                    EVP_DigestUpdate(&md_ctx, &(s->s3->server_random[0]),
-                                     SSL3_RANDOM_SIZE);
-                    EVP_DigestUpdate(&md_ctx, &(d[4]), n);
-                    EVP_DigestFinal_ex(&md_ctx, q, (unsigned int *)&i);
+                    if (EVP_DigestInit_ex(&md_ctx,
+                                          (num == 2) ? s->ctx->md5
+                                                     : s->ctx->sha1,
+                                          NULL) <= 0
+                        || EVP_DigestUpdate(&md_ctx, &(s->s3->client_random[0]),
+                                            SSL3_RANDOM_SIZE) <= 0
+                        || EVP_DigestUpdate(&md_ctx, &(s->s3->server_random[0]),
+                                            SSL3_RANDOM_SIZE) <= 0
+                        || EVP_DigestUpdate(&md_ctx, &(d[4]), n) <= 0
+                        || EVP_DigestFinal_ex(&md_ctx, q,
+                                              (unsigned int *)&i) <= 0) {
+                        SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,
+                               ERR_LIB_EVP);
+                        al = SSL_AD_INTERNAL_ERROR;
+                        goto f_err;
+                    }
                     q += i;
                     j += i;
                 }
@@ -2036,16 +2035,17 @@ int ssl3_send_server_key_exchange(SSL *s)
 #ifdef SSL_DEBUG
                 fprintf(stderr, "Using hash %s\n", EVP_MD_name(md));
 #endif
-                EVP_SignInit_ex(&md_ctx, md, NULL);
-                EVP_SignUpdate(&md_ctx, &(s->s3->client_random[0]),
-                               SSL3_RANDOM_SIZE);
-                EVP_SignUpdate(&md_ctx, &(s->s3->server_random[0]),
-                               SSL3_RANDOM_SIZE);
-                EVP_SignUpdate(&md_ctx, &(d[4]), n);
-                if (!EVP_SignFinal(&md_ctx, &(p[2]),
-                                   (unsigned int *)&i, pkey)) {
+                if (EVP_SignInit_ex(&md_ctx, md, NULL) <= 0
+                        || EVP_SignUpdate(&md_ctx, &(s->s3->client_random[0]),
+                                          SSL3_RANDOM_SIZE) <= 0
+                        || EVP_SignUpdate(&md_ctx, &(s->s3->server_random[0]),
+                                          SSL3_RANDOM_SIZE) <= 0
+                        || EVP_SignUpdate(&md_ctx, &(d[4]), n) <= 0
+                        || EVP_SignFinal(&md_ctx, &(p[2]),
+                                         (unsigned int *)&i, pkey) <= 0) {
                     SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE, ERR_LIB_EVP);
-                    goto err;
+                    al = SSL_AD_INTERNAL_ERROR;
+                    goto f_err;
                 }
                 s2n(i, p);
                 n += i + 2;
@@ -2435,6 +2435,7 @@ int ssl3_get_client_key_exchange(SSL *s)
         int padl, outl;
         krb5_timestamp authtime = 0;
         krb5_ticket_times ttimes;
+        int kerr = 0;
 
         EVP_CIPHER_CTX_init(&ciph_ctx);
 
@@ -2538,23 +2539,27 @@ int ssl3_get_client_key_exchange(SSL *s)
         {
             SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,
                    SSL_R_DECRYPTION_FAILED);
-            goto err;
+            kerr = 1;
+            goto kclean;
         }
         if (outl > SSL_MAX_MASTER_KEY_LENGTH) {
             SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,
                    SSL_R_DATA_LENGTH_TOO_LONG);
-            goto err;
+            kerr = 1;
+            goto kclean;
         }
         if (!EVP_DecryptFinal_ex(&ciph_ctx, &(pms[outl]), &padl)) {
             SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,
                    SSL_R_DECRYPTION_FAILED);
-            goto err;
+            kerr = 1;
+            goto kclean;
         }
         outl += padl;
         if (outl > SSL_MAX_MASTER_KEY_LENGTH) {
             SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,
                    SSL_R_DATA_LENGTH_TOO_LONG);
-            goto err;
+            kerr = 1;
+            goto kclean;
         }
         if (!((pms[0] == (s->client_version >> 8))
               && (pms[1] == (s->client_version & 0xff)))) {
@@ -2571,7 +2576,8 @@ int ssl3_get_client_key_exchange(SSL *s)
             if (!(s->options & SSL_OP_TLS_ROLLBACK_BUG)) {
                 SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,
                        SSL_AD_DECODE_ERROR);
-                goto err;
+                kerr = 1;
+                goto kclean;
             }
         }
 
@@ -2597,6 +2603,11 @@ int ssl3_get_client_key_exchange(SSL *s)
          *  kssl_ctx = kssl_ctx_free(kssl_ctx);
          *  if (s->kssl_ctx)  s->kssl_ctx = NULL;
          */
+
+ kclean:
+        OPENSSL_cleanse(pms, sizeof(pms));
+        if (kerr)
+            goto err;
     } else
 #endif                          /* OPENSSL_NO_KRB5 */
 
@@ -2793,7 +2804,7 @@ int ssl3_get_client_key_exchange(SSL *s)
 
         if (s->session->psk_identity != NULL)
             OPENSSL_free(s->session->psk_identity);
-        s->session->psk_identity = BUF_strdup((char *)p);
+        s->session->psk_identity = BUF_strndup((char *)p, i);
         if (s->session->psk_identity == NULL) {
             SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);
             goto psk_err;
@@ -2880,7 +2891,15 @@ int ssl3_get_client_key_exchange(SSL *s)
             pk = s->cert->pkeys[SSL_PKEY_GOST01].privatekey;
 
         pkey_ctx = EVP_PKEY_CTX_new(pk, NULL);
-        EVP_PKEY_decrypt_init(pkey_ctx);
+        if (pkey_ctx == NULL) {
+            al = SSL_AD_INTERNAL_ERROR;
+            SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);
+            goto f_err;
+        }
+        if (EVP_PKEY_decrypt_init(pkey_ctx) <= 0) {
+            SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
+            goto gerr;
+        }
         /*
          * If client certificate is present and is of the same type, maybe
          * use it for key exchange.  Don't mind errors from
@@ -2915,6 +2934,7 @@ int ssl3_get_client_key_exchange(SSL *s)
                                                         s->
                                                         session->master_key,
                                                         premaster_secret, 32);
+        OPENSSL_cleanse(premaster_secret, sizeof(premaster_secret));
         /* Check if pubkey from client certificate was used */
         if (EVP_PKEY_CTX_ctrl
             (pkey_ctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 2, NULL) > 0)
@@ -2963,39 +2983,31 @@ int ssl3_get_cert_verify(SSL *s)
     EVP_MD_CTX mctx;
     EVP_MD_CTX_init(&mctx);
 
+    /*
+     * We should only process a CertificateVerify message if we have received
+     * a Certificate from the client. If so then |s->session->peer| will be non
+     * NULL. In some instances a CertificateVerify message is not required even
+     * if the peer has sent a Certificate (e.g. such as in the case of static
+     * DH). In that case the ClientKeyExchange processing will skip the
+     * CertificateVerify state so we should not arrive here.
+     */
+    if (s->session->peer == NULL) {
+        ret = 1;
+        goto end;
+    }
+
     n = s->method->ssl_get_message(s,
                                    SSL3_ST_SR_CERT_VRFY_A,
                                    SSL3_ST_SR_CERT_VRFY_B,
-                                   -1, SSL3_RT_MAX_PLAIN_LENGTH, &ok);
+                                   SSL3_MT_CERTIFICATE_VERIFY,
+                                   SSL3_RT_MAX_PLAIN_LENGTH, &ok);
 
     if (!ok)
         return ((int)n);
 
-    if (s->session->peer != NULL) {
-        peer = s->session->peer;
-        pkey = X509_get_pubkey(peer);
-        type = X509_certificate_type(peer, pkey);
-    } else {
-        peer = NULL;
-        pkey = NULL;
-    }
-
-    if (s->s3->tmp.message_type != SSL3_MT_CERTIFICATE_VERIFY) {
-        s->s3->tmp.reuse_message = 1;
-        if (peer != NULL) {
-            al = SSL_AD_UNEXPECTED_MESSAGE;
-            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_MISSING_VERIFY_MESSAGE);
-            goto f_err;
-        }
-        ret = 1;
-        goto end;
-    }
-
-    if (peer == NULL) {
-        SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_NO_CLIENT_CERT_RECEIVED);
-        al = SSL_AD_UNEXPECTED_MESSAGE;
-        goto f_err;
-    }
+    peer = s->session->peer;
+    pkey = X509_get_pubkey(peer);
+    type = X509_certificate_type(peer, pkey);
 
     if (!(type & EVP_PKT_SIGN)) {
         SSLerr(SSL_F_SSL3_GET_CERT_VERIFY,
@@ -3004,12 +3016,6 @@ int ssl3_get_cert_verify(SSL *s)
         goto f_err;
     }
 
-    if (s->s3->change_cipher_spec) {
-        SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_CCS_RECEIVED_EARLY);
-        al = SSL_AD_UNEXPECTED_MESSAGE;
-        goto f_err;
-    }
-
     /* we now have a signature that we need to verify */
     p = (unsigned char *)s->init_msg;
     /* Check for broken implementations of GOST ciphersuites */
@@ -3137,7 +3143,17 @@ int ssl3_get_cert_verify(SSL *s)
         unsigned char signature[64];
         int idx;
         EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new(pkey, NULL);
-        EVP_PKEY_verify_init(pctx);
+        if (pctx == NULL) {
+            al = SSL_AD_INTERNAL_ERROR;
+            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, ERR_R_MALLOC_FAILURE);
+            goto f_err;
+        }
+        if (EVP_PKEY_verify_init(pctx) <= 0) {
+            EVP_PKEY_CTX_free(pctx);
+            al = SSL_AD_INTERNAL_ERROR;
+            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, ERR_R_INTERNAL_ERROR);
+            goto f_err;
+        }
         if (i != 64) {
             fprintf(stderr, "GOST signature length is %d", i);
         }