content/child/webcrypto/openssl/aes_gcm_openssl.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 <vector>
   6 #include <openssl/evp.h>
   7
   8 #include "base/logging.h"
   9 #include "base/stl_util.h"
  10 #include "content/child/webcrypto/crypto_data.h"
  11 #include "content/child/webcrypto/openssl/aes_algorithm_openssl.h"
  12 #include "content/child/webcrypto/openssl/key_openssl.h"
  13 #include "content/child/webcrypto/openssl/util_openssl.h"
  14 #include "content/child/webcrypto/status.h"
  15 #include "content/child/webcrypto/webcrypto_util.h"
  16 #include "crypto/openssl_util.h"
  17 #include "crypto/scoped_openssl_types.h"
  18 #include "third_party/WebKit/public/platform/WebCryptoAlgorithmParams.h"
  19
  20 namespace content {
  21
  22 namespace webcrypto {
  23
  24 namespace {
  25
  26 const EVP_AEAD* GetAesGcmAlgorithmFromKeySize(unsigned int key_size_bytes) {
  27   switch (key_size_bytes) {
  28     case 16:
  29       return EVP_aead_aes_128_gcm();
  30     case 32:
  31       return EVP_aead_aes_256_gcm();
  32     default:
  33       return NULL;
  34   }
  35 }
  36
  37 Status AesGcmEncryptDecrypt(EncryptOrDecrypt mode,
  38                             const blink::WebCryptoAlgorithm& algorithm,
  39                             const blink::WebCryptoKey& key,
  40                             const CryptoData& data,
  41                             std::vector<uint8_t>* buffer) {
  42   const std::vector<uint8_t>& raw_key =
  43       SymKeyOpenSsl::Cast(key)->raw_key_data();
  44   const blink::WebCryptoAesGcmParams* params = algorithm.aesGcmParams();
  45
  46   unsigned int tag_length_bits;
  47   Status status = GetAesGcmTagLengthInBits(params, &tag_length_bits);
  48   if (status.IsError())
  49     return status;
  50
  51   return AeadEncryptDecrypt(
  52       mode, raw_key, data, tag_length_bits / 8, CryptoData(params->iv()),
  53       CryptoData(params->optionalAdditionalData()),
  54       GetAesGcmAlgorithmFromKeySize(raw_key.size()), buffer);
  55 }
  56
  57 class AesGcmImplementation : public AesAlgorithm {
  58  public:
  59   AesGcmImplementation() : AesAlgorithm("GCM") {}
  60
  61   Status Encrypt(const blink::WebCryptoAlgorithm& algorithm,
  62                  const blink::WebCryptoKey& key,
  63                  const CryptoData& data,
  64                  std::vector<uint8_t>* buffer) const override {
  65     return AesGcmEncryptDecrypt(ENCRYPT, algorithm, key, data, buffer);
  66   }
  67
  68   Status Decrypt(const blink::WebCryptoAlgorithm& algorithm,
  69                  const blink::WebCryptoKey& key,
  70                  const CryptoData& data,
  71                  std::vector<uint8_t>* buffer) const override {
  72     return AesGcmEncryptDecrypt(DECRYPT, algorithm, key, data, buffer);
  73   }
  74 };
  75
  76 }  // namespace
  77
  78 AlgorithmImplementation* CreatePlatformAesGcmImplementation() {
  79   return new AesGcmImplementation;
  80 }
  81
  82 }  // namespace webcrypto
  83
  84 }  // namespace content