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_key_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(mode,
  52                             raw_key,
  53                             data,
  54                             tag_length_bits / 8,
  55                             CryptoData(params->iv()),
  56                             CryptoData(params->optionalAdditionalData()),
  57                             GetAesGcmAlgorithmFromKeySize(raw_key.size()),
  58                             buffer);
  59 }
  60
  61 class AesGcmImplementation : public AesAlgorithm {
  62  public:
  63   AesGcmImplementation() : AesAlgorithm("GCM") {}
  64
  65   virtual Status Encrypt(const blink::WebCryptoAlgorithm& algorithm,
  66                          const blink::WebCryptoKey& key,
  67                          const CryptoData& data,
  68                          std::vector<uint8_t>* buffer) const OVERRIDE {
  69     return AesGcmEncryptDecrypt(ENCRYPT, algorithm, key, data, buffer);
  70   }
  71
  72   virtual Status Decrypt(const blink::WebCryptoAlgorithm& algorithm,
  73                          const blink::WebCryptoKey& key,
  74                          const CryptoData& data,
  75                          std::vector<uint8_t>* buffer) const OVERRIDE {
  76     return AesGcmEncryptDecrypt(DECRYPT, algorithm, key, data, buffer);
  77   }
  78 };
  79
  80 }  // namespace
  81
  82 AlgorithmImplementation* CreatePlatformAesGcmImplementation() {
  83   return new AesGcmImplementation;
  84 }
  85
  86 }  // namespace webcrypto
  87
  88 }  // namespace content