| // Copyright 2015 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 <stdint.h> |
| |
| #include <memory> |
| |
| #include "base/logging.h" |
| #include "components/webcrypto/algorithm_implementation.h" |
| #include "components/webcrypto/algorithms/secret_key_util.h" |
| #include "components/webcrypto/algorithms/util.h" |
| #include "components/webcrypto/blink_key_handle.h" |
| #include "components/webcrypto/crypto_data.h" |
| #include "components/webcrypto/status.h" |
| #include "crypto/openssl_util.h" |
| #include "third_party/blink/public/platform/web_crypto_algorithm_params.h" |
| #include "third_party/blink/public/platform/web_crypto_key_algorithm.h" |
| #include "third_party/boringssl/src/include/openssl/err.h" |
| #include "third_party/boringssl/src/include/openssl/hkdf.h" |
| |
| namespace webcrypto { |
| |
| namespace { |
| |
| const blink::WebCryptoKeyUsageMask kValidUsages = |
| blink::kWebCryptoKeyUsageDeriveKey | blink::kWebCryptoKeyUsageDeriveBits; |
| |
| class HkdfImplementation : public AlgorithmImplementation { |
| public: |
| HkdfImplementation() {} |
| |
| Status ImportKey(blink::WebCryptoKeyFormat format, |
| const CryptoData& key_data, |
| const blink::WebCryptoAlgorithm& algorithm, |
| bool extractable, |
| blink::WebCryptoKeyUsageMask usages, |
| blink::WebCryptoKey* key) const override { |
| switch (format) { |
| case blink::kWebCryptoKeyFormatRaw: |
| return ImportKeyRaw(key_data, algorithm, extractable, usages, key); |
| default: |
| return Status::ErrorUnsupportedImportKeyFormat(); |
| } |
| } |
| |
| Status ImportKeyRaw(const CryptoData& key_data, |
| const blink::WebCryptoAlgorithm& algorithm, |
| bool extractable, |
| blink::WebCryptoKeyUsageMask usages, |
| blink::WebCryptoKey* key) const { |
| Status status = CheckKeyCreationUsages(kValidUsages, usages); |
| if (status.IsError()) |
| return status; |
| |
| if (extractable) |
| return Status::ErrorImportExtractableKdfKey(); |
| |
| return CreateWebCryptoSecretKey( |
| key_data, |
| blink::WebCryptoKeyAlgorithm::CreateWithoutParams( |
| blink::kWebCryptoAlgorithmIdHkdf), |
| extractable, usages, key); |
| } |
| |
| Status DeriveBits(const blink::WebCryptoAlgorithm& algorithm, |
| const blink::WebCryptoKey& base_key, |
| bool has_optional_length_bits, |
| unsigned int optional_length_bits, |
| std::vector<uint8_t>* derived_bytes) const override { |
| crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE); |
| if (!has_optional_length_bits) |
| return Status::ErrorHkdfDeriveBitsLengthNotSpecified(); |
| |
| if (optional_length_bits % 8) |
| return Status::ErrorHkdfLengthNotWholeByte(); |
| |
| const blink::WebCryptoHkdfParams* params = algorithm.HkdfParams(); |
| |
| const EVP_MD* digest_algorithm = GetDigest(params->GetHash()); |
| if (!digest_algorithm) |
| return Status::ErrorUnsupported(); |
| |
| // Size output to fit length |
| unsigned int derived_bytes_len = optional_length_bits / 8; |
| derived_bytes->resize(derived_bytes_len); |
| |
| // Algorithm dispatch checks that the algorithm in |base_key| matches |
| // |algorithm|. |
| const std::vector<uint8_t>& raw_key = GetSymmetricKeyData(base_key); |
| if (!HKDF(derived_bytes->data(), derived_bytes_len, digest_algorithm, |
| raw_key.data(), raw_key.size(), params->Salt().Data(), |
| params->Salt().size(), params->Info().Data(), |
| params->Info().size())) { |
| uint32_t error = ERR_get_error(); |
| if (ERR_GET_LIB(error) == ERR_LIB_HKDF && |
| ERR_GET_REASON(error) == HKDF_R_OUTPUT_TOO_LARGE) { |
| return Status::ErrorHkdfLengthTooLong(); |
| } |
| return Status::OperationError(); |
| } |
| |
| return Status::Success(); |
| } |
| |
| Status DeserializeKeyForClone(const blink::WebCryptoKeyAlgorithm& algorithm, |
| blink::WebCryptoKeyType type, |
| bool extractable, |
| blink::WebCryptoKeyUsageMask usages, |
| const CryptoData& key_data, |
| blink::WebCryptoKey* key) const override { |
| if (algorithm.ParamsType() != blink::kWebCryptoKeyAlgorithmParamsTypeNone || |
| type != blink::kWebCryptoKeyTypeSecret) |
| return Status::ErrorUnexpected(); |
| |
| // NOTE: Unlike ImportKeyRaw(), this does not enforce extractable==false. |
| // This is intentional. Although keys cannot currently be created with |
| // extractable==true, earlier implementations permitted this, so |
| // de-serialization by structured clone should not reject them. |
| return CreateWebCryptoSecretKey(key_data, algorithm, extractable, usages, |
| key); |
| } |
| |
| Status GetKeyLength(const blink::WebCryptoAlgorithm& key_length_algorithm, |
| bool* has_length_bits, |
| unsigned int* length_bits) const override { |
| *has_length_bits = false; |
| return Status::Success(); |
| } |
| }; |
| |
| } // namespace |
| |
| std::unique_ptr<AlgorithmImplementation> CreateHkdfImplementation() { |
| return std::make_unique<HkdfImplementation>(); |
| } |
| |
| } // namespace webcrypto |