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// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <sechash.h>
#include <vector>
#include "base/stl_util.h"
#include "components/webcrypto/algorithm_implementation.h"
#include "components/webcrypto/crypto_data.h"
#include "components/webcrypto/nss/util_nss.h"
#include "components/webcrypto/status.h"
#include "components/webcrypto/webcrypto_util.h"
#include "crypto/nss_util.h"
#include "crypto/scoped_nss_types.h"
namespace webcrypto {
namespace {
HASH_HashType WebCryptoAlgorithmToNSSHashType(
blink::WebCryptoAlgorithmId algorithm) {
switch (algorithm) {
case blink::WebCryptoAlgorithmIdSha1:
return HASH_AlgSHA1;
case blink::WebCryptoAlgorithmIdSha256:
return HASH_AlgSHA256;
case blink::WebCryptoAlgorithmIdSha384:
return HASH_AlgSHA384;
case blink::WebCryptoAlgorithmIdSha512:
return HASH_AlgSHA512;
default:
// Not a digest algorithm.
return HASH_AlgNULL;
}
}
// Implementation of blink::WebCryptoDigester, an internal Blink detail not
// part of WebCrypto, that allows chunks of data to be streamed in before
// computing a SHA-* digest (as opposed to ShaImplementation, which computes
// digests over complete messages)
class DigestorNSS : public blink::WebCryptoDigestor {
public:
explicit DigestorNSS(blink::WebCryptoAlgorithmId algorithm_id)
: hash_context_(NULL), algorithm_id_(algorithm_id) {}
~DigestorNSS() override {
if (!hash_context_)
return;
HASH_Destroy(hash_context_);
hash_context_ = NULL;
}
bool consume(const unsigned char* data, unsigned int size) override {
return ConsumeWithStatus(data, size).IsSuccess();
}
Status ConsumeWithStatus(const unsigned char* data, unsigned int size) {
// Initialize everything if the object hasn't been initialized yet.
if (!hash_context_) {
Status error = Init();
if (!error.IsSuccess())
return error;
}
HASH_Update(hash_context_, data, size);
return Status::Success();
}
bool finish(unsigned char*& result_data,
unsigned int& result_data_size) override {
Status error = FinishInternal(result_, &result_data_size);
if (!error.IsSuccess())
return false;
result_data = result_;
return true;
}
Status FinishWithVectorAndStatus(std::vector<uint8_t>* result) {
if (!hash_context_)
return Status::ErrorUnexpected();
unsigned int result_length = HASH_ResultLenContext(hash_context_);
result->resize(result_length);
unsigned char* digest = vector_as_array(result);
unsigned int digest_size; // ignored
return FinishInternal(digest, &digest_size);
}
private:
Status Init() {
HASH_HashType hash_type = WebCryptoAlgorithmToNSSHashType(algorithm_id_);
if (hash_type == HASH_AlgNULL)
return Status::ErrorUnsupported();
hash_context_ = HASH_Create(hash_type);
if (!hash_context_)
return Status::OperationError();
HASH_Begin(hash_context_);
return Status::Success();
}
Status FinishInternal(unsigned char* result, unsigned int* result_size) {
if (!hash_context_) {
Status error = Init();
if (!error.IsSuccess())
return error;
}
unsigned int hash_result_length = HASH_ResultLenContext(hash_context_);
DCHECK_LE(hash_result_length, static_cast<size_t>(HASH_LENGTH_MAX));
HASH_End(hash_context_, result, result_size, hash_result_length);
if (*result_size != hash_result_length)
return Status::ErrorUnexpected();
return Status::Success();
}
HASHContext* hash_context_;
blink::WebCryptoAlgorithmId algorithm_id_;
unsigned char result_[HASH_LENGTH_MAX];
};
class ShaImplementation : public AlgorithmImplementation {
public:
Status Digest(const blink::WebCryptoAlgorithm& algorithm,
const CryptoData& data,
std::vector<uint8_t>* buffer) const override {
DigestorNSS digestor(algorithm.id());
Status error = digestor.ConsumeWithStatus(data.bytes(), data.byte_length());
// http://crbug.com/366427: the spec does not define any other failures for
// digest, so none of the subsequent errors are spec compliant.
if (!error.IsSuccess())
return error;
return digestor.FinishWithVectorAndStatus(buffer);
}
};
} // namespace
AlgorithmImplementation* CreatePlatformShaImplementation() {
return new ShaImplementation();
}
scoped_ptr<blink::WebCryptoDigestor> CreatePlatformDigestor(
blink::WebCryptoAlgorithmId algorithm) {
return scoped_ptr<blink::WebCryptoDigestor>(new DigestorNSS(algorithm));
}
} // namespace webcrypto
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