Add tests for low-level AES functions.

May as well. Depending on the implementation chosen in cipher/e_aes.c,
AES_encrypt may or may not be hit, so test this entry point explicitly.

Change-Id: Icb02bf3f4b6e5ecbb9e5111f44fbb1b267ead6c3
Reviewed-on: https://boringssl-review.googlesource.com/5312
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/crypto/aes/CMakeLists.txt b/crypto/aes/CMakeLists.txt
index 490f40a..90d9921 100644
--- a/crypto/aes/CMakeLists.txt
+++ b/crypto/aes/CMakeLists.txt
@@ -60,3 +60,12 @@
 perlasm(aes-armv4.${ASM_EXT} asm/aes-armv4.pl)
 perlasm(bsaes-armv7.${ASM_EXT} asm/bsaes-armv7.pl)
 perlasm(aesv8-armx.${ASM_EXT} asm/aesv8-armx.pl)
+
+add_executable(
+  aes_test
+
+  aes_test.cc
+  $<TARGET_OBJECTS:test_support>
+)
+
+target_link_libraries(aes_test crypto)
diff --git a/crypto/aes/aes_test.cc b/crypto/aes/aes_test.cc
new file mode 100644
index 0000000..e488d81
--- /dev/null
+++ b/crypto/aes/aes_test.cc
@@ -0,0 +1,102 @@
+/* Copyright (c) 2015, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <stdio.h>
+#include <string.h>
+
+#include <openssl/aes.h>
+#include <openssl/crypto.h>
+
+
+static bool TestAES(const uint8_t *key, size_t key_len,
+                    const uint8_t plaintext[AES_BLOCK_SIZE],
+                    const uint8_t ciphertext[AES_BLOCK_SIZE]) {
+  AES_KEY aes_key;
+  if (AES_set_encrypt_key(key, key_len * 8, &aes_key) != 0) {
+    fprintf(stderr, "AES_set_encrypt_key failed\n");
+    return false;
+  }
+
+  // Test encryption.
+  uint8_t block[AES_BLOCK_SIZE];
+  AES_encrypt(plaintext, block, &aes_key);
+  if (memcmp(block, ciphertext, AES_BLOCK_SIZE) != 0) {
+    fprintf(stderr, "AES_encrypt gave the wrong output\n");
+    return false;
+  }
+
+  // Test in-place encryption.
+  memcpy(block, plaintext, AES_BLOCK_SIZE);
+  AES_encrypt(block, block, &aes_key);
+  if (memcmp(block, ciphertext, AES_BLOCK_SIZE) != 0) {
+    fprintf(stderr, "AES_encrypt gave the wrong output\n");
+    return false;
+  }
+
+  if (AES_set_decrypt_key(key, key_len * 8, &aes_key) != 0) {
+    fprintf(stderr, "AES_set_decrypt_key failed\n");
+    return false;
+  }
+
+  // Test decryption.
+  AES_decrypt(ciphertext, block, &aes_key);
+  if (memcmp(block, plaintext, AES_BLOCK_SIZE) != 0) {
+    fprintf(stderr, "AES_decrypt gave the wrong output\n");
+    return false;
+  }
+
+  // Test in-place decryption.
+  memcpy(block, ciphertext, AES_BLOCK_SIZE);
+  AES_decrypt(block, block, &aes_key);
+  if (memcmp(block, plaintext, AES_BLOCK_SIZE) != 0) {
+    fprintf(stderr, "AES_decrypt gave the wrong output\n");
+    return false;
+  }
+  return true;
+}
+
+int main() {
+  CRYPTO_library_init();
+
+  // Test vectors from FIPS-197, Appendix C.
+  if (!TestAES((const uint8_t *)"\x00\x01\x02\x03\x04\x05\x06\x07"
+                                "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
+               128 / 8,
+               (const uint8_t *)"\x00\x11\x22\x33\x44\x55\x66\x77"
+                                "\x88\x99\xaa\xbb\xcc\xdd\xee\xff",
+               (const uint8_t *)"\x69\xc4\xe0\xd8\x6a\x7b\x04\x30"
+                                "\xd8\xcd\xb7\x80\x70\xb4\xc5\x5a") ||
+      !TestAES((const uint8_t *)"\x00\x01\x02\x03\x04\x05\x06\x07"
+                                "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
+                                "\x10\x11\x12\x13\x14\x15\x16\x17",
+               192 / 8,
+               (const uint8_t *)"\x00\x11\x22\x33\x44\x55\x66\x77"
+                                "\x88\x99\xaa\xbb\xcc\xdd\xee\xff",
+               (const uint8_t *)"\xdd\xa9\x7c\xa4\x86\x4c\xdf\xe0"
+                                "\x6e\xaf\x70\xa0\xec\x0d\x71\x91") ||
+      !TestAES((const uint8_t *)"\x00\x01\x02\x03\x04\x05\x06\x07"
+                                "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
+                                "\x10\x11\x12\x13\x14\x15\x16\x17"
+                                "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
+               256 / 8,
+               (const uint8_t *)"\x00\x11\x22\x33\x44\x55\x66\x77"
+                                "\x88\x99\xaa\xbb\xcc\xdd\xee\xff",
+               (const uint8_t *)"\x8e\xa2\xb7\xca\x51\x67\x45\xbf"
+                                "\xea\xfc\x49\x90\x4b\x49\x60\x89")) {
+    return false;
+  }
+
+  printf("PASS\n");
+  return 0;
+}
diff --git a/util/all_tests.json b/util/all_tests.json
index 94f2b37..eb40ed9 100644
--- a/util/all_tests.json
+++ b/util/all_tests.json
@@ -1,4 +1,5 @@
 [
+	["crypto/aes/aes_test"],
 	["crypto/base64/base64_test"],
 	["crypto/bio/bio_test"],
 	["crypto/bn/bn_test"],