Implement QUIC key extraction.

net/quic/crypto/crypto_utils_test.cc

Index: net/quic/crypto/crypto_utils_test.cc
diff --git a/net/quic/crypto/crypto_utils_test.cc b/net/quic/crypto/crypto_utils_test.cc
index 17eb19250eeb76eac53e0f394911aec61722d4e2..37ac583314a927fdb62412fe9a2ea6ddd9b88a2c 100644
--- a/net/quic/crypto/crypto_utils_test.cc
+++ b/net/quic/crypto/crypto_utils_test.cc
@@ -4,6 +4,7 @@
 
 #include "net/quic/crypto/crypto_utils.h"
 
+#include "net/quic/test_tools/quic_test_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace net {
@@ -44,6 +45,87 @@ TEST(CryptoUtilsTest, NormalizeHostname) {
   }
 }
 
+TEST(CryptoUtilsTest, TestExportKeyingMaterial) {
+  const struct TestVector {
+    // Input (strings of hexadecimal digits):
+    const char* subkey_secret;
+    const char* label;
+    const char* context;
+    size_t result_len;
+
+    // Expected output (string of hexadecimal digits):
+    const char* expected;  // Null if it should fail.
+  } test_vector[] = {
+    // Try a typical input
+    { "4823c1189ecc40fce888fbb4cf9ae6254f19ba12e6d9af54788f195a6f509ca3",
+      "e934f78d7a71dd85420fceeb8cea0317",
+      "b8d766b5d3c8aba0009c7ed3de553eba53b4de1030ea91383dcdf724cd8b7217",
+      32,
+      "a9979da0d5f1c1387d7cbe68f5c4163ddb445a03c4ad6ee72cb49d56726d679e"
+    },
+    // Don't let the label contain nulls
+    { "14fe51e082ffee7d1b4d8d4ab41f8c55",
+      "3132333435363700",
+      "58585858585858585858585858585858",
+      16,
+      NULL
+    },
+    // Make sure nulls in the context are fine
+    { "d862c2e36b0a42f7827c67ebc8d44df7",
+      "7a5b95e4e8378123",
+      "4142434445464700",
+      16,
+      "12d418c6d0738a2e4d85b2d0170f76e1"
+    },
+    // ... and give a different result than without
+    { "d862c2e36b0a42f7827c67ebc8d44df7",
+      "7a5b95e4e8378123",
+      "41424344454647",
+      16,
+      "abfa1c479a6e3ffb98a11dee7d196408"
+    },
+    // Try weird lengths
+    { "d0ec8a34f6cc9a8c96",
+      "49711798cc6251",
+      "933d4a2f30d22f089cfba842791116adc121e0",
+      23,
+      "c9a46ed0757bd1812f1f21b4d41e62125fec8364a21db7"
+    },
+  };
+
+  for (size_t i = 0; i < arraysize(test_vector); i++) {
+    // Decode the test vector.
+    string subkey_secret;
+    string label;
+    string context;
+    ASSERT_TRUE(DecodeHexString(test_vector[i].subkey_secret, &subkey_secret));
+    ASSERT_TRUE(DecodeHexString(test_vector[i].label, &label));
+    ASSERT_TRUE(DecodeHexString(test_vector[i].context, &context));
+    size_t result_len = test_vector[i].result_len;
+    bool expect_ok = test_vector[i].expected != NULL;
+    string expected;
+    if (expect_ok) {
+      ASSERT_TRUE(DecodeHexString(test_vector[i].expected, &expected));
+    }
+
+    string result;
+    bool ok = CryptoUtils::ExportKeyingMaterial(subkey_secret,
+                                                label,
+                                                context,
+                                                result_len,
+                                                &result);
+    EXPECT_EQ(expect_ok, ok);
+    if (expect_ok) {
+      EXPECT_EQ(result_len, result.length());
+      test::CompareCharArraysWithHexError("HKDF output",
+                                          result.data(),
+                                          result.length(),
+                                          expected.data(),
+                                          expected.length());
+    }
+  }
+}
+
 }  // namespace
 }  // namespace test
 }  // namespace net