net/quic/crypto/chacha20_poly1305_decrypter_test.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/quic/crypto/chacha20_poly1305_decrypter.h"
   6
   7 #include "net/quic/test_tools/quic_test_utils.h"
   8
   9 using base::StringPiece;
  10
  11 namespace {
  12
  13 // The test vectors come from draft-agl-tls-chacha20poly1305-04 Section 7.
  14
  15 // Each test vector consists of six strings of lowercase hexadecimal digits.
  16 // The strings may be empty (zero length). A test vector with a NULL |key|
  17 // marks the end of an array of test vectors.
  18 struct TestVector {
  19   // Input:
  20   const char* key;
  21   const char* iv;
  22   const char* aad;
  23   const char* ct;
  24
  25   // Expected output:
  26   const char* pt;  // An empty string "" means decryption succeeded and
  27                    // the plaintext is zero-length. NULL means decryption
  28                    // failed.
  29 };
  30
  31 const TestVector test_vectors[] = {
  32   { "4290bcb154173531f314af57f3be3b5006da371ece272afa1b5dbdd110"
  33         "0a1007",
  34     "cd7cf67be39c794a",
  35     "87e229d4500845a079c0",
  36     "e3e446f7ede9a19b62a4677dabf4e3d24b876bb28475",  // "3896e1d6" truncated.
  37     "86d09974840bded2a5ca"
  38   },
  39   // Modify the ciphertext (ChaCha20 encryption output).
  40   { "4290bcb154173531f314af57f3be3b5006da371ece272afa1b5dbdd110"
  41         "0a1007",
  42     "cd7cf67be39c794a",
  43     "87e229d4500845a079c0",
  44     "f3e446f7ede9a19b62a4677dabf4e3d24b876bb28475",  // "3896e1d6" truncated.
  45     NULL  // FAIL
  46   },
  47   // Modify the ciphertext (Poly1305 authenticator).
  48   { "4290bcb154173531f314af57f3be3b5006da371ece272afa1b5dbdd110"
  49         "0a1007",
  50     "cd7cf67be39c794a",
  51     "87e229d4500845a079c0",
  52     "e3e446f7ede9a19b62a4677dabf4e3d24b876bb28476",  // "3896e1d6" truncated.
  53     NULL  // FAIL
  54   },
  55   // Modify the associated data.
  56   { "4290bcb154173531f314af57f3be3b5006da371ece272afa1b5dbdd110"
  57         "0a1007",
  58     "dd7cf67be39c794a",
  59     "87e229d4500845a079c0",
  60     "e3e446f7ede9a19b62a4677dabf4e3d24b876bb28475",  // "3896e1d6" truncated.
  61     NULL  // FAIL
  62   },
  63   { NULL }
  64 };
  65
  66 }  // namespace
  67
  68 namespace net {
  69 namespace test {
  70
  71 // DecryptWithNonce wraps the |Decrypt| method of |decrypter| to allow passing
  72 // in an nonce and also to allocate the buffer needed for the plaintext.
  73 QuicData* DecryptWithNonce(ChaCha20Poly1305Decrypter* decrypter,
  74                            StringPiece nonce,
  75                            StringPiece associated_data,
  76                            StringPiece ciphertext) {
  77   size_t plaintext_size = ciphertext.length();
  78   scoped_ptr<char[]> plaintext(new char[plaintext_size]);
  79
  80   if (!decrypter->Decrypt(nonce, associated_data, ciphertext,
  81                           reinterpret_cast<unsigned char*>(plaintext.get()),
  82                           &plaintext_size)) {
  83     return NULL;
  84   }
  85   return new QuicData(plaintext.release(), plaintext_size, true);
  86 }
  87
  88 TEST(ChaCha20Poly1305DecrypterTest, Decrypt) {
  89   if (!ChaCha20Poly1305Decrypter::IsSupported()) {
  90     LOG(INFO) << "ChaCha20+Poly1305 not supported. Test skipped.";
  91     return;
  92   }
  93
  94   for (size_t i = 0; test_vectors[i].key != NULL; i++) {
  95     // If not present then decryption is expected to fail.
  96     bool has_pt = test_vectors[i].pt;
  97
  98     // Decode the test vector.
  99     string key;
 100     string iv;
 101     string aad;
 102     string ct;
 103     string pt;
 104     ASSERT_TRUE(DecodeHexString(test_vectors[i].key, &key));
 105     ASSERT_TRUE(DecodeHexString(test_vectors[i].iv, &iv));
 106     ASSERT_TRUE(DecodeHexString(test_vectors[i].aad, &aad));
 107     ASSERT_TRUE(DecodeHexString(test_vectors[i].ct, &ct));
 108     if (has_pt) {
 109       ASSERT_TRUE(DecodeHexString(test_vectors[i].pt, &pt));
 110     }
 111
 112     ChaCha20Poly1305Decrypter decrypter;
 113     ASSERT_TRUE(decrypter.SetKey(key));
 114     scoped_ptr<QuicData> decrypted(DecryptWithNonce(
 115         &decrypter, iv,
 116         // This deliberately tests that the decrypter can handle an AAD that
 117         // is set to NULL, as opposed to a zero-length, non-NULL pointer.
 118         StringPiece(aad.length() ? aad.data() : NULL, aad.length()), ct));
 119     if (!decrypted.get()) {
 120       EXPECT_FALSE(has_pt);
 121       continue;
 122     }
 123     EXPECT_TRUE(has_pt);
 124
 125     ASSERT_EQ(pt.length(), decrypted->length());
 126     test::CompareCharArraysWithHexError("plaintext", decrypted->data(),
 127                                         pt.length(), pt.data(), pt.length());
 128   }
 129 }
 130
 131 }  // namespace test
 132 }  // namespace net