commit 5f3d93e4a336c590d7b56a889dde4a93b725e058
author Matt Caswell <matt@openssl.org> Fri Nov 06 16:31:21 2015 +0000
committer Matt Caswell <matt@openssl.org> Fri Nov 20 15:47:02 2015 +0000
tree 2056664415cc39f4c2e8aede23cbde220886d2fc
parent 2cc7acd273bc39f1360aed52400d18bb65b88a95

Ensure all EVP calls have their returns checked where appropriate

There are lots of calls to EVP functions from within libssl There were
various places where we should probably check the return value but don't.
This adds these checks.

Reviewed-by: Richard Levitte <levitte@openssl.org>

ssl/s3_enc.c

diff --git a/ssl/s3_enc.c b/ssl/s3_enc.c
index 02e07ba..1a5aaec 100644
--- a/ssl/s3_enc.c
+++ b/ssl/s3_enc.c
@@ -253,7 +253,7 @@
             EVP_CIPHER_CTX_init(s->enc_read_ctx);
         dd = s->enc_read_ctx;
 
-        if (!ssl_replace_hash(&s->read_hash, m)) {
+        if (ssl_replace_hash(&s->read_hash, m) == NULL) {
                 SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
                 goto err2;
         }
@@ -286,7 +286,7 @@
              */
             EVP_CIPHER_CTX_init(s->enc_write_ctx);
         dd = s->enc_write_ctx;
-        if (!ssl_replace_hash(&s->write_hash, m)) {
+        if (ssl_replace_hash(&s->write_hash, m) == NULL) {
                 SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
                 goto err2;
         }
@@ -617,19 +617,21 @@
         return 0;
 
     npad = (48 / n) * n;
-    if (sender != NULL)
-        EVP_DigestUpdate(&ctx, sender, len);
-    EVP_DigestUpdate(&ctx, s->session->master_key,
-                     s->session->master_key_length);
-    EVP_DigestUpdate(&ctx, ssl3_pad_1, npad);
-    EVP_DigestFinal_ex(&ctx, md_buf, &i);
+    if ((sender != NULL && EVP_DigestUpdate(&ctx, sender, len) <= 0)
+            || EVP_DigestUpdate(&ctx, s->session->master_key,
+                                s->session->master_key_length) <= 0
+            || EVP_DigestUpdate(&ctx, ssl3_pad_1, npad) <= 0
+            || EVP_DigestFinal_ex(&ctx, md_buf, &i) <= 0
 
-    EVP_DigestInit_ex(&ctx, EVP_MD_CTX_md(&ctx), NULL);
-    EVP_DigestUpdate(&ctx, s->session->master_key,
-                     s->session->master_key_length);
-    EVP_DigestUpdate(&ctx, ssl3_pad_2, npad);
-    EVP_DigestUpdate(&ctx, md_buf, i);
-    EVP_DigestFinal_ex(&ctx, p, &ret);
+            || EVP_DigestInit_ex(&ctx, EVP_MD_CTX_md(&ctx), NULL) <= 0
+            || EVP_DigestUpdate(&ctx, s->session->master_key,
+                                s->session->master_key_length) <= 0
+            || EVP_DigestUpdate(&ctx, ssl3_pad_2, npad) <= 0
+            || EVP_DigestUpdate(&ctx, md_buf, i) <= 0
+            || EVP_DigestFinal_ex(&ctx, p, &ret) <= 0) {
+        SSLerr(SSL_F_SSL3_HANDSHAKE_MAC, ERR_R_INTERNAL_ERROR);
+        ret = 0;
+    }
 
     EVP_MD_CTX_cleanup(&ctx);
 
@@ -660,24 +662,31 @@
 
     EVP_MD_CTX_init(&ctx);
     for (i = 0; i < 3; i++) {
-        EVP_DigestInit_ex(&ctx, s->ctx->sha1, NULL);
-        EVP_DigestUpdate(&ctx, salt[i], strlen((const char *)salt[i]));
-        EVP_DigestUpdate(&ctx, p, len);
-        EVP_DigestUpdate(&ctx, &(s->s3->client_random[0]), SSL3_RANDOM_SIZE);
-        EVP_DigestUpdate(&ctx, &(s->s3->server_random[0]), SSL3_RANDOM_SIZE);
-        EVP_DigestFinal_ex(&ctx, buf, &n);
+        if (EVP_DigestInit_ex(&ctx, s->ctx->sha1, NULL) <= 0
+                || EVP_DigestUpdate(&ctx, salt[i],
+                                    strlen((const char *)salt[i])) <= 0
+                || EVP_DigestUpdate(&ctx, p, len) <= 0
+                || EVP_DigestUpdate(&ctx, &(s->s3->client_random[0]),
+                                    SSL3_RANDOM_SIZE) <= 0
+                || EVP_DigestUpdate(&ctx, &(s->s3->server_random[0]),
+                                    SSL3_RANDOM_SIZE) <= 0
+                || EVP_DigestFinal_ex(&ctx, buf, &n) <= 0
 
-        EVP_DigestInit_ex(&ctx, s->ctx->md5, NULL);
-        EVP_DigestUpdate(&ctx, p, len);
-        EVP_DigestUpdate(&ctx, buf, n);
-        EVP_DigestFinal_ex(&ctx, out, &n);
+                || EVP_DigestInit_ex(&ctx, s->ctx->md5, NULL) <= 0
+                || EVP_DigestUpdate(&ctx, p, len) <= 0
+                || EVP_DigestUpdate(&ctx, buf, n) <= 0
+                || EVP_DigestFinal_ex(&ctx, out, &n) <= 0) {
+            SSLerr(SSL_F_SSL3_GENERATE_MASTER_SECRET, ERR_R_INTERNAL_ERROR);
+            ret = 0;
+            break;
+        }
         out += n;
         ret += n;
     }
     EVP_MD_CTX_cleanup(&ctx);
 
 #ifdef OPENSSL_SSL_TRACE_CRYPTO
-    if (s->msg_callback) {
+    if (ret > 0 && s->msg_callback) {
         s->msg_callback(2, s->version, TLS1_RT_CRYPTO_PREMASTER,
                         p, len, s, s->msg_callback_arg);
         s->msg_callback(2, s->version, TLS1_RT_CRYPTO_CLIENT_RANDOM,