diff --git a/libweave/external/crypto/p224_spake_unittest.cc b/libweave/external/crypto/p224_spake_unittest.cc
new file mode 100644
index 0000000..15b5be2
--- /dev/null
+++ b/libweave/external/crypto/p224_spake_unittest.cc
@@ -0,0 +1,174 @@
+// Copyright (c) 2011 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/p224_spake.h"
+
+#include <string>
+
+#include "base/logging.h"
+#include "base/strings/string_number_conversions.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace crypto {
+
+namespace {
+
+std::string HexEncodeString(const std::string& binary_data) {
+  return base::HexEncode(binary_data.c_str(), binary_data.size());
+}
+
+bool RunExchange(P224EncryptedKeyExchange* client,
+                 P224EncryptedKeyExchange* server,
+                 bool is_password_same) {
+  for (;;) {
+    std::string client_message, server_message;
+    client_message = client->GetNextMessage();
+    server_message = server->GetNextMessage();
+
+    P224EncryptedKeyExchange::Result client_result, server_result;
+    client_result = client->ProcessMessage(server_message);
+    server_result = server->ProcessMessage(client_message);
+
+    // Check that we never hit the case where only one succeeds.
+    EXPECT_EQ(client_result == P224EncryptedKeyExchange::kResultSuccess,
+              server_result == P224EncryptedKeyExchange::kResultSuccess);
+
+    if (client_result == P224EncryptedKeyExchange::kResultFailed ||
+        server_result == P224EncryptedKeyExchange::kResultFailed) {
+      return false;
+    }
+
+    EXPECT_EQ(is_password_same,
+              client->GetUnverifiedKey() == server->GetUnverifiedKey());
+
+    if (client_result == P224EncryptedKeyExchange::kResultSuccess &&
+        server_result == P224EncryptedKeyExchange::kResultSuccess) {
+      return true;
+    }
+
+    EXPECT_EQ(P224EncryptedKeyExchange::kResultPending, client_result);
+    EXPECT_EQ(P224EncryptedKeyExchange::kResultPending, server_result);
+  }
+}
+
+const char kPassword[] = "foo";
+
+}  // namespace
+
+TEST(MutualAuth, CorrectAuth) {
+  P224EncryptedKeyExchange client(
+      P224EncryptedKeyExchange::kPeerTypeClient, kPassword);
+  P224EncryptedKeyExchange server(
+      P224EncryptedKeyExchange::kPeerTypeServer, kPassword);
+
+  EXPECT_TRUE(RunExchange(&client, &server, true));
+  EXPECT_EQ(client.GetKey(), server.GetKey());
+}
+
+TEST(MutualAuth, IncorrectPassword) {
+  P224EncryptedKeyExchange client(
+      P224EncryptedKeyExchange::kPeerTypeClient,
+      kPassword);
+  P224EncryptedKeyExchange server(
+      P224EncryptedKeyExchange::kPeerTypeServer,
+      "wrongpassword");
+
+  EXPECT_FALSE(RunExchange(&client, &server, false));
+}
+
+TEST(MutualAuth, ExpectedValues) {
+  P224EncryptedKeyExchange client(P224EncryptedKeyExchange::kPeerTypeClient,
+                                  kPassword);
+  client.SetXForTesting("Client x");
+  P224EncryptedKeyExchange server(P224EncryptedKeyExchange::kPeerTypeServer,
+                                  kPassword);
+  server.SetXForTesting("Server x");
+
+  std::string client_message = client.GetNextMessage();
+  EXPECT_EQ(
+      "3508EF7DECC8AB9F9C439FBB0154288BBECC0A82E8448F4CF29554EB"
+      "BE9D486686226255EAD1D077C635B1A41F46AC91D7F7F32CED9EC3E0",
+      HexEncodeString(client_message));
+
+  std::string server_message = server.GetNextMessage();
+  EXPECT_EQ(
+      "A3088C18B75D2C2B107105661AEC85424777475EB29F1DDFB8C14AFB"
+      "F1603D0DF38413A00F420ACF2059E7997C935F5A957A193D09A2B584",
+      HexEncodeString(server_message));
+
+  EXPECT_EQ(P224EncryptedKeyExchange::kResultPending,
+            client.ProcessMessage(server_message));
+  EXPECT_EQ(P224EncryptedKeyExchange::kResultPending,
+            server.ProcessMessage(client_message));
+
+  EXPECT_EQ(client.GetUnverifiedKey(), server.GetUnverifiedKey());
+  // Must stay the same. External implementations should be able to pair with.
+  EXPECT_EQ(
+      "CE7CCFC435CDA4F01EC8826788B1F8B82EF7D550A34696B371096E64"
+      "C487D4FE193F7D1A6FF6820BC7F807796BA3889E8F999BBDEFC32FFA",
+      HexEncodeString(server.GetUnverifiedKey()));
+
+  EXPECT_TRUE(RunExchange(&client, &server, true));
+  EXPECT_EQ(client.GetKey(), server.GetKey());
+}
+
+TEST(MutualAuth, Fuzz) {
+  static const unsigned kIterations = 40;
+
+  for (unsigned i = 0; i < kIterations; i++) {
+    P224EncryptedKeyExchange client(
+        P224EncryptedKeyExchange::kPeerTypeClient, kPassword);
+    P224EncryptedKeyExchange server(
+        P224EncryptedKeyExchange::kPeerTypeServer, kPassword);
+
+    // We'll only be testing small values of i, but we don't want that to bias
+    // the test coverage. So we disperse the value of i by multiplying by the
+    // FNV, 32-bit prime, producing a poor-man's PRNG.
+    const uint32 rand = i * 16777619;
+
+    for (unsigned round = 0;; round++) {
+      std::string client_message, server_message;
+      client_message = client.GetNextMessage();
+      server_message = server.GetNextMessage();
+
+      if ((rand & 1) == round) {
+        const bool server_or_client = rand & 2;
+        std::string* m = server_or_client ? &server_message : &client_message;
+        if (rand & 4) {
+          // Truncate
+          *m = m->substr(0, (i >> 3) % m->size());
+        } else {
+          // Corrupt
+          const size_t bits = m->size() * 8;
+          const size_t bit_to_corrupt = (rand >> 3) % bits;
+          const_cast<char*>(m->data())[bit_to_corrupt / 8] ^=
+              1 << (bit_to_corrupt % 8);
+        }
+      }
+
+      P224EncryptedKeyExchange::Result client_result, server_result;
+      client_result = client.ProcessMessage(server_message);
+      server_result = server.ProcessMessage(client_message);
+
+      // If we have corrupted anything, we expect the authentication to fail,
+      // although one side can succeed if we happen to corrupt the second round
+      // message to the other.
+      ASSERT_FALSE(
+          client_result == P224EncryptedKeyExchange::kResultSuccess &&
+          server_result == P224EncryptedKeyExchange::kResultSuccess);
+
+      if (client_result == P224EncryptedKeyExchange::kResultFailed ||
+          server_result == P224EncryptedKeyExchange::kResultFailed) {
+        break;
+      }
+
+      ASSERT_EQ(P224EncryptedKeyExchange::kResultPending,
+                client_result);
+      ASSERT_EQ(P224EncryptedKeyExchange::kResultPending,
+                server_result);
+    }
+  }
+}
+
+}  // namespace crypto