content/child/webcrypto/openssl/sha_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 #include <openssl/sha.h>
   8
   9 #include "base/logging.h"
  10 #include "base/stl_util.h"
  11 #include "content/child/webcrypto/algorithm_implementation.h"
  12 #include "content/child/webcrypto/crypto_data.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
  19 namespace content {
  20
  21 namespace webcrypto {
  22
  23 namespace {
  24
  25 // Implementation of blink::WebCryptoDigester, an internal Blink detail not
  26 // part of WebCrypto, that allows chunks of data to be streamed in before
  27 // computing a SHA-* digest (as opposed to ShaImplementation, which computes
  28 // digests over complete messages)
  29 class DigestorOpenSsl : public blink::WebCryptoDigestor {
  30  public:
  31   explicit DigestorOpenSsl(blink::WebCryptoAlgorithmId algorithm_id)
  32       : initialized_(false),
  33         digest_context_(EVP_MD_CTX_create()),
  34         algorithm_id_(algorithm_id) {}
  35
  36   bool consume(const unsigned char* data, unsigned int size) override {
  37     return ConsumeWithStatus(data, size).IsSuccess();
  38   }
  39
  40   Status ConsumeWithStatus(const unsigned char* data, unsigned int size) {
  41     crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE);
  42     Status error = Init();
  43     if (!error.IsSuccess())
  44       return error;
  45
  46     if (!EVP_DigestUpdate(digest_context_.get(), data, size))
  47       return Status::OperationError();
  48
  49     return Status::Success();
  50   }
  51
  52   bool finish(unsigned char*& result_data,
  53               unsigned int& result_data_size) override {
  54     Status error = FinishInternal(result_, &result_data_size);
  55     if (!error.IsSuccess())
  56       return false;
  57     result_data = result_;
  58     return true;
  59   }
  60
  61   Status FinishWithVectorAndStatus(std::vector<uint8_t>* result) {
  62     const int hash_expected_size = EVP_MD_CTX_size(digest_context_.get());
  63     result->resize(hash_expected_size);
  64     unsigned char* const hash_buffer = vector_as_array(result);
  65     unsigned int hash_buffer_size;  // ignored
  66     return FinishInternal(hash_buffer, &hash_buffer_size);
  67   }
  68
  69  private:
  70   Status Init() {
  71     if (initialized_)
  72       return Status::Success();
  73
  74     const EVP_MD* digest_algorithm = GetDigest(algorithm_id_);
  75     if (!digest_algorithm)
  76       return Status::ErrorUnsupported();
  77
  78     if (!digest_context_.get())
  79       return Status::OperationError();
  80
  81     if (!EVP_DigestInit_ex(digest_context_.get(), digest_algorithm, NULL))
  82       return Status::OperationError();
  83
  84     initialized_ = true;
  85     return Status::Success();
  86   }
  87
  88   Status FinishInternal(unsigned char* result, unsigned int* result_size) {
  89     crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE);
  90     Status error = Init();
  91     if (!error.IsSuccess())
  92       return error;
  93
  94     const int hash_expected_size = EVP_MD_CTX_size(digest_context_.get());
  95     if (hash_expected_size <= 0)
  96       return Status::ErrorUnexpected();
  97     DCHECK_LE(hash_expected_size, EVP_MAX_MD_SIZE);
  98
  99     if (!EVP_DigestFinal_ex(digest_context_.get(), result, result_size) ||
 100         static_cast<int>(*result_size) != hash_expected_size)
 101       return Status::OperationError();
 102
 103     return Status::Success();
 104   }
 105
 106   bool initialized_;
 107   crypto::ScopedEVP_MD_CTX digest_context_;
 108   blink::WebCryptoAlgorithmId algorithm_id_;
 109   unsigned char result_[EVP_MAX_MD_SIZE];
 110 };
 111
 112 class ShaImplementation : public AlgorithmImplementation {
 113  public:
 114   Status Digest(const blink::WebCryptoAlgorithm& algorithm,
 115                 const CryptoData& data,
 116                 std::vector<uint8_t>* buffer) const override {
 117     DigestorOpenSsl digestor(algorithm.id());
 118     Status error = digestor.ConsumeWithStatus(data.bytes(), data.byte_length());
 119     // http://crbug.com/366427: the spec does not define any other failures for
 120     // digest, so none of the subsequent errors are spec compliant.
 121     if (!error.IsSuccess())
 122       return error;
 123     return digestor.FinishWithVectorAndStatus(buffer);
 124   }
 125 };
 126
 127 }  // namespace
 128
 129 AlgorithmImplementation* CreatePlatformShaImplementation() {
 130   return new ShaImplementation();
 131 }
 132
 133 scoped_ptr<blink::WebCryptoDigestor> CreatePlatformDigestor(
 134     blink::WebCryptoAlgorithmId algorithm) {
 135   return scoped_ptr<blink::WebCryptoDigestor>(new DigestorOpenSsl(algorithm));
 136 }
 137
 138 }  // namespace webcrypto
 139
 140 }  // namespace content