crypto: add GHASH implementation.

crypto/ghash_unittest.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "crypto/ghash.h"
+
+

[wtc, 2012/10/19 21:35:22]

Delete this line.

[agl, 2012/10/22 21:50:56]

Done.

+#include "testing/gtest/include/gtest/gtest.h"
+
+using namespace crypto;

[wtc, 2012/10/19 21:35:22]

We usually just put the tests inside the |crypto|
namespace.

[agl, 2012/10/22 21:50:56]

Done.

+
+namespace {
+
+// Test vectors are taken from Appendix B of
+// http://csrc.nist.gov/groups/ST/toolkit/BCM/documents/proposedmodes/gcm/gcm-spec.pdf

[wtc, 2012/10/19 21:35:22]

There is a revised version of this file. Search for gcm-revised-spec.pdf.

You can also get the revised spec from David McGrew's home page:
http://www.mindspring.com/~dmcgrew/dam.htm#GCM

+
+static const uint8 kKey1[16] = {
+  0x66, 0xe9, 0x4b, 0xd4, 0xef, 0x8a, 0x2c, 0x3b,
+  0x88, 0x4c, 0xfa, 0x59, 0xca, 0x34, 0x2b, 0x2e,
+};
+
+static const uint8 kCiphertext2[] = {
+  0x03, 0x88, 0xda, 0xce, 0x60, 0xb6, 0xa3, 0x92,
+  0xf3, 0x28, 0xc2, 0xb9, 0x71, 0xb2, 0xfe, 0x78,
+};
+
+static const uint8 kKey3[16] = {
+  0xb8, 0x3b, 0x53, 0x37, 0x08, 0xbf, 0x53, 0x5d,
+  0x0a, 0xa6, 0xe5, 0x29, 0x80, 0xd5, 0x3b, 0x78,
+};
+
+static const uint8 kCiphertext3[] = {
+  0x42, 0x83, 0x1e, 0xc2, 0x21, 0x77, 0x74, 0x24,
+  0x4b, 0x72, 0x21, 0xb7, 0x84, 0xd0, 0xd4, 0x9c,
+  0xe3, 0xaa, 0x21, 0x2f, 0x2c, 0x02, 0xa4, 0xe0,
+  0x35, 0xc1, 0x7e, 0x23, 0x29, 0xac, 0xa1, 0x2e,
+  0x21, 0xd5, 0x14, 0xb2, 0x54, 0x66, 0x93, 0x1c,
+  0x7d, 0x8f, 0x6a, 0x5a, 0xac, 0x84, 0xaa, 0x05,
+  0x1b, 0xa3, 0x0b, 0x39, 0x6a, 0x0a, 0xac, 0x97,
+  0x3d, 0x58, 0xe0, 0x91, 0x47, 0x3f, 0x59, 0x85,
+};
+
+static const uint8 kAdditional4[] = {
+  0xfe, 0xed, 0xfa, 0xce, 0xde, 0xad, 0xbe, 0xef,
+  0xfe, 0xed, 0xfa, 0xce, 0xde, 0xad, 0xbe, 0xef,
+  0xab, 0xad, 0xda, 0xd2,
+};
+
+struct TestCase {
+  const uint8* key;
+  const uint8* additional;
+  unsigned additional_length;
+  const uint8* ciphertext;
+  unsigned ciphertext_length;
+  const uint8 expected[16];
+};
+
+static const TestCase kTestCases[] = {
+  {
+    kKey1,
+    NULL,
+    0,
+    NULL,
+    0,
+    {
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    },
+  },
+  {
+    kKey1,
+    NULL,
+    0,
+    kCiphertext2,
+    sizeof(kCiphertext2),
+    {
+      0xf3, 0x8c, 0xbb, 0x1a, 0xd6, 0x92, 0x23, 0xdc,
+      0xc3, 0x45, 0x7a, 0xe5, 0xb6, 0xb0, 0xf8, 0x85,
+    },
+  },
+  {
+    kKey3,
+    NULL,
+    0,
+    kCiphertext3,
+    sizeof(kCiphertext3),
+    {
+      0x7f, 0x1b, 0x32, 0xb8, 0x1b, 0x82, 0x0d, 0x02,
+      0x61, 0x4f, 0x88, 0x95, 0xac, 0x1d, 0x4e, 0xac,
+    },
+  },
+  {
+    kKey3,
+    kAdditional4,
+    sizeof(kAdditional4),
+    kCiphertext3,
+    sizeof(kCiphertext3) - 4,
+    {
+      0x69, 0x8e, 0x57, 0xf7, 0x0e, 0x6e, 0xcc, 0x7f,
+      0xd9, 0x46, 0x3b, 0x72, 0x60, 0xa9, 0xae, 0x5f,
+    },
+  },
+};
+
+TEST(GaliosHash, TestCases) {

[wtc, 2012/10/19 21:35:22]

Galios => Galois

[agl, 2012/10/22 21:50:56]

Done. (Opps!)

+  uint8 out[16];
+
+  for (size_t i = 0; i < arraysize(kTestCases); ++i) {
+    const TestCase& test = kTestCases[i];
+
+    GaliosHash hash(test.key);
+    if (test.additional_length) {
+      hash.UpdateAdditional(test.additional, test.additional_length);
+    }
+    if (test.ciphertext_length) {
+      hash.UpdateCiphertext(test.ciphertext, test.ciphertext_length);
+    }
+    hash.Digest(out);
+    EXPECT_TRUE(0 == memcmp(out, test.expected, 16));
+  }
+}
+
+TEST(GaliosHash, TestCasesByteAtATime) {
+  uint8 out[16];
+
+  for (size_t i = 0; i < arraysize(kTestCases); ++i) {
+    const TestCase& test = kTestCases[i];
+
+    GaliosHash hash(test.key);
+    for (size_t i = 0; i < test.additional_length; ++i) {
+      hash.UpdateAdditional(test.additional + i, 1);
+    }
+    for (size_t i = 0; i < test.ciphertext_length; ++i) {
+      hash.UpdateCiphertext(test.ciphertext + i, 1);
+    }

[wtc, 2012/10/19 21:35:22]

Nit: omit the curly braces for one-line if or for loop bodies
in this file. This is the more common convention in crypto
and net.

[agl, 2012/10/22 21:50:56]

Done.

+    hash.Digest(out);
+    EXPECT_TRUE(0 == memcmp(out, test.expected, 16));
+  }
+}
+
+}  // anonymous namespace

[wtc, 2012/10/19 21:35:22]

Nit: in the code example in the Style Guide, this comment
just says
  // namespace

http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Namespaces

[agl, 2012/10/22 21:50:56]

Done.