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>

1 files changed, 30 insertions, 15 deletions

diff --git a/ssl/s3_cbc.c b/ssl/s3_cbc.c
index f7997eaae3..5225222913 100644
--- a/ssl/s3_cbc.c
+++ b/ssl/s3_cbc.c
@@ -172,8 +172,9 @@ char ssl3_cbc_record_digest_supported(const EVP_MD_CTX *ctx)
  * functions, above, we know that data_plus_mac_size is large enough to contain
  * a padding byte and MAC. (If the padding was invalid, it might contain the
  * padding too. )
+ * Returns 1 on success or 0 on error
  */
-void ssl3_cbc_digest_record(const EVP_MD_CTX *ctx,
+int ssl3_cbc_digest_record(const EVP_MD_CTX *ctx,
                             unsigned char *md_out,
                             size_t *md_out_size,
                             const unsigned char header[13],
@@ -217,7 +218,8 @@ void ssl3_cbc_digest_record(const EVP_MD_CTX *ctx,
 
     switch (EVP_MD_CTX_type(ctx)) {
     case NID_md5:
-        MD5_Init((MD5_CTX *)md_state.c);
+        if (MD5_Init((MD5_CTX *)md_state.c) <= 0)
+            return 0;
         md_final_raw = tls1_md5_final_raw;
         md_transform =
             (void (*)(void *ctx, const unsigned char *block))MD5_Transform;
@@ -226,28 +228,32 @@ void ssl3_cbc_digest_record(const EVP_MD_CTX *ctx,
         length_is_big_endian = 0;
         break;
     case NID_sha1:
-        SHA1_Init((SHA_CTX *)md_state.c);
+        if (SHA1_Init((SHA_CTX *)md_state.c) <= 0)
+            return 0;
         md_final_raw = tls1_sha1_final_raw;
         md_transform =
             (void (*)(void *ctx, const unsigned char *block))SHA1_Transform;
         md_size = 20;
         break;
     case NID_sha224:
-        SHA224_Init((SHA256_CTX *)md_state.c);
+        if (SHA224_Init((SHA256_CTX *)md_state.c) <= 0)
+            return 0;
         md_final_raw = tls1_sha256_final_raw;
         md_transform =
             (void (*)(void *ctx, const unsigned char *block))SHA256_Transform;
         md_size = 224 / 8;
         break;
     case NID_sha256:
-        SHA256_Init((SHA256_CTX *)md_state.c);
+        if (SHA256_Init((SHA256_CTX *)md_state.c) <= 0)
+            return 0;
         md_final_raw = tls1_sha256_final_raw;
         md_transform =
             (void (*)(void *ctx, const unsigned char *block))SHA256_Transform;
         md_size = 32;
         break;
     case NID_sha384:
-        SHA384_Init((SHA512_CTX *)md_state.c);
+        if (SHA384_Init((SHA512_CTX *)md_state.c) <= 0)
+            return 0;
         md_final_raw = tls1_sha512_final_raw;
         md_transform =
             (void (*)(void *ctx, const unsigned char *block))SHA512_Transform;
@@ -256,7 +262,8 @@ void ssl3_cbc_digest_record(const EVP_MD_CTX *ctx,
         md_length_size = 16;
         break;
     case NID_sha512:
-        SHA512_Init((SHA512_CTX *)md_state.c);
+        if (SHA512_Init((SHA512_CTX *)md_state.c) <= 0)
+            return 0;
         md_final_raw = tls1_sha512_final_raw;
         md_transform =
             (void (*)(void *ctx, const unsigned char *block))SHA512_Transform;
@@ -272,7 +279,7 @@ void ssl3_cbc_digest_record(const EVP_MD_CTX *ctx,
         OPENSSL_assert(0);
         if (md_out_size)
             *md_out_size = -1;
-        return;
+        return 0;
     }
 
     OPENSSL_assert(md_length_size <= MAX_HASH_BIT_COUNT_BYTES);
@@ -410,7 +417,7 @@ void ssl3_cbc_digest_record(const EVP_MD_CTX *ctx,
              */
             if (header_length <= md_block_size) {
                 /* Should never happen */
-                return;
+                return 0;
             }
             overhang = header_length - md_block_size;
             md_transform(md_state.c, header);
@@ -491,26 +498,34 @@ void ssl3_cbc_digest_record(const EVP_MD_CTX *ctx,
     }
 
     EVP_MD_CTX_init(&md_ctx);
-    EVP_DigestInit_ex(&md_ctx, ctx->digest, NULL /* engine */ );
+    if (EVP_DigestInit_ex(&md_ctx, ctx->digest, NULL /* engine */ ) <= 0)
+        goto err;
     if (is_sslv3) {
         /* We repurpose |hmac_pad| to contain the SSLv3 pad2 block. */
         memset(hmac_pad, 0x5c, sslv3_pad_length);
 
-        EVP_DigestUpdate(&md_ctx, mac_secret, mac_secret_length);
-        EVP_DigestUpdate(&md_ctx, hmac_pad, sslv3_pad_length);
-        EVP_DigestUpdate(&md_ctx, mac_out, md_size);
+        if (EVP_DigestUpdate(&md_ctx, mac_secret, mac_secret_length) <= 0
+                || EVP_DigestUpdate(&md_ctx, hmac_pad, sslv3_pad_length) <= 0
+                || EVP_DigestUpdate(&md_ctx, mac_out, md_size) <= 0)
+            goto err;
     } else {
         /* Complete the HMAC in the standard manner. */
         for (i = 0; i < md_block_size; i++)
             hmac_pad[i] ^= 0x6a;
 
-        EVP_DigestUpdate(&md_ctx, hmac_pad, md_block_size);
-        EVP_DigestUpdate(&md_ctx, mac_out, md_size);
+        if (EVP_DigestUpdate(&md_ctx, hmac_pad, md_block_size) <= 0
+                || EVP_DigestUpdate(&md_ctx, mac_out, md_size) <= 0)
+            goto err;
     }
     ret = EVP_DigestFinal(&md_ctx, md_out, &md_out_size_u);
     if (ret && md_out_size)
         *md_out_size = md_out_size_u;
     EVP_MD_CTX_cleanup(&md_ctx);
+
+    return 1;
+err:
+    EVP_MD_CTX_cleanup(&md_ctx);
+    return 0;
 }
 
 /*