Curve25519-donna changes.

crypto/curve25519_unittest.cc

+// Copyright (c) 2013 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/curve25519.h"
+
+#include <string>
+
+#include "crypto/random.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using std::string;

[wtc, 2013/03/06 19:21:07]

I would avoid this using statement. Is this file shared with
the internal tree?

[ramant (doing other things), 2013/03/06 20:03:12]

Done.

+
+namespace crypto {
+
+// SharedKey just tests that the basic key exchange identity holds: that both
+// parties end up with the same key.
+TEST(Curve25519, SharedKey) {
+  for (int i = 0; i < 5; i++) {
+    uint8 alice_secret[curve25519::kCryptoScalarMultCurve25519ScalarBytes];
+    crypto::RandBytes(alice_secret, sizeof(alice_secret));
+    EXPECT_TRUE(curve25519::ConvertToPrivateKey(alice_secret,
+                                                sizeof(alice_secret)));
+    string alice_key(reinterpret_cast<char*>(alice_secret),
+                     sizeof(alice_secret));
+
+    uint8 alice_public_key[curve25519::kCryptoScalarMultCurve25519Bytes];
+    uint8 alice_private_key[curve25519::kCryptoScalarMultCurve25519ScalarBytes];
+    ASSERT_EQ(static_cast<size_t>(
+        curve25519::kCryptoScalarMultCurve25519ScalarBytes), alice_key.size());
+    memcpy(alice_private_key, alice_key.data(), alice_key.size());
+    curve25519::ScalarBaseMult(alice_private_key, alice_public_key);
+
+    uint8 bob_secret[curve25519::kCryptoScalarMultCurve25519ScalarBytes];
+    crypto::RandBytes(bob_secret, sizeof(bob_secret));
+    EXPECT_TRUE(curve25519::ConvertToPrivateKey(bob_secret,
+                                                sizeof(bob_secret)));
+    string bob_key(reinterpret_cast<char*>(bob_secret), sizeof(bob_secret));
+
+    uint8 bob_public_key[curve25519::kCryptoScalarMultCurve25519Bytes];
+    uint8 bob_private_key[curve25519::kCryptoScalarMultCurve25519ScalarBytes];
+    ASSERT_EQ(static_cast<size_t>(
+        curve25519::kCryptoScalarMultCurve25519ScalarBytes), bob_key.size());
+    memcpy(bob_private_key, bob_key.data(), bob_key.size());
+    curve25519::ScalarBaseMult(bob_private_key, bob_public_key);
+
+    uint8 alice_shared_key[curve25519::kCryptoScalarMultCurve25519Bytes];
+    curve25519::ScalarMult(alice_private_key, bob_public_key, alice_shared_key);
+    string alice_shared;
+    alice_shared.assign(reinterpret_cast<char*>(alice_shared_key),
+                        sizeof(alice_shared_key));
+
+    uint8 bob_shared_key[curve25519::kCryptoScalarMultCurve25519Bytes];
+    curve25519::ScalarMult(bob_private_key, alice_public_key, bob_shared_key);
+    string bob_shared;
+    bob_shared.assign(reinterpret_cast<char*>(bob_shared_key),
+                      sizeof(bob_shared_key));
+
+    ASSERT_EQ(alice_shared, bob_shared);
+  }
+}
+
+}  // namespace crypto