Add a helper routine so that evp_test can compare memory without producing

spurious output when checking for error conditions.
Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NMatthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/6899)

test/evp_test.c

@@ -74,6 +74,27 @@ static int find_key(EVP_PKEY **ppk, const char *name, KEY_LIST *lst);
 
 static int parse_bin(const char *value, unsigned char **buf, size_t *buflen);
 
+/*
+ * Compare two memory regions for equality, returning zero if they differ.
+ * However, if there is expected to be an error and the actual error
+ * matches then the memory is expected to be different so handle this
+ * case without producing unnecessary test framework output.
+ */
+static int memory_err_compare(EVP_TEST *t, const char *err,
+                              const void *expected, size_t expected_len,
+                              const void *got, size_t got_len)
+{
+    int r;
+
+    if (t->expected_err != NULL && strcmp(t->expected_err, err) == 0)
+        r = !TEST_mem_ne(expected, expected_len, got, got_len);
+    else
+        r = TEST_mem_eq(expected, expected_len, got, got_len);
+    if (!r)
+        t->err = err;
+    return r;
+}
+
 /*
  * Structure used to hold a list of blocks of memory to test
  * calls to "update" like functions.
@@ -397,10 +418,11 @@ static int digest_test_run(EVP_TEST *t)
         t->err = "DIGEST_LENGTH_MISMATCH";
         goto err;
     }
-    if (!TEST_mem_eq(expected->output, expected->output_len, got, got_len)) {
-        t->err = "DIGEST_MISMATCH";
+    if (!memory_err_compare(t, "DIGEST_MISMATCH",
+                            expected->output, expected->output_len,
+                            got, got_len))
         goto err;
-    }
+
     t->err = NULL;
 
  err:
@@ -688,11 +710,9 @@ static int cipher_test_enc(EVP_TEST *t, int enc,
         t->err = "CIPHERFINAL_ERROR";
         goto err;
     }
-    if (!TEST_mem_eq(expected_out, out_len,
-                     tmp + out_misalign, tmplen + tmpflen)) {
-        t->err = "VALUE_MISMATCH";
+    if (!memory_err_compare(t, "VALUE_MISMATCH", expected_out, out_len,
+                            tmp + out_misalign, tmplen + tmpflen))
         goto err;
-    }
     if (enc && expected->aead) {
         unsigned char rtag[16];
 
@@ -705,11 +725,10 @@ static int cipher_test_enc(EVP_TEST *t, int enc,
             t->err = "TAG_RETRIEVE_ERROR";
             goto err;
         }
-        if (!TEST_mem_eq(expected->tag, expected->tag_len,
-                         rtag, expected->tag_len)) {
-            t->err = "TAG_VALUE_MISMATCH";
+        if (!memory_err_compare(t, "TAG_VALUE_MISMATCH",
+                                expected->tag, expected->tag_len,
+                                rtag, expected->tag_len))
             goto err;
-        }
     }
     t->err = NULL;
     ok = 1;
@@ -950,8 +969,9 @@ static int mac_test_run(EVP_TEST *t)
         goto err;
     }
     if (!EVP_DigestSignFinal(mctx, got, &got_len)
-            || !TEST_mem_eq(expected->output, expected->output_len,
-                            got, got_len)) {
+            || !memory_err_compare(t, "TEST_MAC_ERR",
+                                   expected->output, expected->output_len,
+                                   got, got_len)) {
         t->err = "TEST_MAC_ERR";
         goto err;
     }
@@ -1108,10 +1128,11 @@ static int pkey_test_run(EVP_TEST *t)
         t->err = "KEYOP_ERROR";
         goto err;
     }
-    if (!TEST_mem_eq(expected->output, expected->output_len, got, got_len)) {
-        t->err = "KEYOP_MISMATCH";
+    if (!memory_err_compare(t, "KEYOP_MISMATCH",
+                            expected->output, expected->output_len,
+                            got, got_len))
         goto err;
-    }
+
     t->err = NULL;
  err:
     OPENSSL_free(got);
@@ -1226,10 +1247,10 @@ static int pderive_test_run(EVP_TEST *t)
         t->err = "DERIVE_ERROR";
         goto err;
     }
-    if (!TEST_mem_eq(expected->output, expected->output_len, got, got_len)) {
-        t->err = "SHARED_SECRET_MISMATCH";
+    if (!memory_err_compare(t, "SHARED_SECRET_MISMATCH",
+                            expected->output, expected->output_len,
+                            got, got_len))
         goto err;
-    }
 
     t->err = NULL;
  err:
@@ -1444,11 +1465,10 @@ static int pbe_test_run(EVP_TEST *t)
             goto err;
         }
     }
-    if (!TEST_mem_eq(expected->key, expected->key_len,
-                     key, expected->key_len)) {
-        t->err = "KEY_MISMATCH";
+    if (!memory_err_compare(t, "KEY_MISMATCH", expected->key, expected->key_len,
+                            key, expected->key_len))
         goto err;
-    }
+
     t->err = NULL;
 err:
     OPENSSL_free(key);
@@ -1559,11 +1579,10 @@ static int encode_test_run(EVP_TEST *t)
 
         EVP_ENCODE_CTX_free(encode_ctx);
 
-        if (!TEST_mem_eq(expected->output, expected->output_len,
-                         encode_out, output_len)) {
-            t->err = "BAD_ENCODING";
+        if (!memory_err_compare(t, "BAD_ENCODING",
+                                expected->output, expected->output_len,
+                                encode_out, output_len))
             goto err;
-        }
     }
 
     if (!TEST_ptr(decode_out =
@@ -1585,8 +1604,9 @@ static int encode_test_run(EVP_TEST *t)
     output_len += chunk_len;
 
     if (expected->encoding != BASE64_INVALID_ENCODING
-            && !TEST_mem_eq(expected->input, expected->input_len,
-                            decode_out, output_len)) {
+            && !memory_err_compare(t, "BAD_DECODING",
+                                   expected->input, expected->input_len,
+                                   decode_out, output_len)) {
         t->err = "BAD_DECODING";
         goto err;
     }
@@ -1687,10 +1707,11 @@ static int kdf_test_run(EVP_TEST *t)
         t->err = "KDF_DERIVE_ERROR";
         goto err;
     }
-    if (!TEST_mem_eq(expected->output, expected->output_len, got, got_len)) {
-        t->err = "KDF_MISMATCH";
+    if (!memory_err_compare(t, "KDF_MISMATCH",
+                            expected->output, expected->output_len,
+                            got, got_len))
         goto err;
-    }
+
     t->err = NULL;
 
  err:
@@ -2079,11 +2100,12 @@ static int digestsign_test_run(EVP_TEST *t)
         t->err = "DIGESTSIGNFINAL_ERROR";
         goto err;
     }
-    if (!TEST_mem_eq(expected->output, expected->output_len, got, got_len)) {
-        t->err = "SIGNATURE_MISMATCH";
+    if (!memory_err_compare(t, "SIGNATURE_MISMATCH",
+                            expected->output, expected->output_len,
+                            got, got_len))
         goto err;
-    }
 
+    t->err = NULL;
  err:
     OPENSSL_free(got);
     return 1;
@@ -2156,11 +2178,12 @@ static int oneshot_digestsign_test_run(EVP_TEST *t)
         t->err = "DIGESTSIGN_ERROR";
         goto err;
     }
-    if (!TEST_mem_eq(expected->output, expected->output_len, got, got_len)) {
-        t->err = "SIGNATURE_MISMATCH";
+    if (!memory_err_compare(t, "SIGNATURE_MISMATCH",
+                            expected->output, expected->output_len,
+                            got, got_len))
         goto err;
-    }
 
+    t->err = NULL;
  err:
     OPENSSL_free(got);
     return 1;