| // Copyright 2022 Google LLC |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // |
| //////////////////////////////////////////////////////////////////////////////// |
| |
| #include "tink/mac/aes_cmac_parameters.h" |
| |
| #include <cstdlib> |
| #include <iostream> |
| #include <memory> |
| #include <ostream> |
| #include <set> |
| |
| #include "tink/crypto_format.h" |
| #include "tink/util/status.h" |
| #include "tink/util/statusor.h" |
| |
| namespace crypto { |
| namespace tink { |
| |
| util::StatusOr<AesCmacParameters> AesCmacParameters::Create( |
| int cryptographic_tag_size_in_bytes, Variant variant) { |
| if (cryptographic_tag_size_in_bytes < 10) { |
| return util::Status( |
| absl::StatusCode::kInvalidArgument, |
| absl::StrCat("Tag size should be at least 10 bytes, got ", |
| cryptographic_tag_size_in_bytes, " bytes.")); |
| } |
| if (cryptographic_tag_size_in_bytes > 16) { |
| return util::Status( |
| absl::StatusCode::kInvalidArgument, |
| absl::StrCat("Tag size should not exceed 16 bytes, got ", |
| cryptographic_tag_size_in_bytes, " bytes.")); |
| } |
| static const std::set<Variant>* supported_variants = |
| new std::set<Variant>({Variant::kTink, Variant::kCrunchy, |
| Variant::kLegacy, Variant::kNoPrefix}); |
| if (supported_variants->find(variant) == supported_variants->end()) { |
| return util::Status( |
| absl::StatusCode::kInvalidArgument, |
| "Cannot create AES-CMAC parameters with unknown variant."); |
| } |
| return AesCmacParameters(cryptographic_tag_size_in_bytes, variant); |
| } |
| |
| int AesCmacParameters::TotalTagSizeInBytes() const { |
| switch (variant_) { |
| case Variant::kTink: |
| case Variant::kCrunchy: |
| case Variant::kLegacy: |
| return CryptographicTagSizeInBytes() + CryptoFormat::kNonRawPrefixSize; |
| case Variant::kNoPrefix: |
| return CryptographicTagSizeInBytes(); |
| default: |
| // Parameters objects with unknown variants should never be created. |
| std::cerr << "AES-CMAC parameters has an unknown variant." << std::endl; |
| std::exit(1); |
| } |
| } |
| |
| bool AesCmacParameters::operator==(const Parameters& other) const { |
| const AesCmacParameters* that = |
| dynamic_cast<const AesCmacParameters*>(&other); |
| if (that == nullptr) { |
| return false; |
| } |
| return cryptographic_tag_size_in_bytes_ == |
| that->cryptographic_tag_size_in_bytes_ && |
| variant_ == that->variant_; |
| } |
| |
| } // namespace tink |
| } // namespace crypto |