| /* |
| * Copyright 2014 The Android Open Source Project |
| * |
| * 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. |
| */ |
| |
| #ifndef SYSTEM_KEYMASTER_AES_OPERATION_H_ |
| #define SYSTEM_KEYMASTER_AES_OPERATION_H_ |
| |
| #include <openssl/evp.h> |
| |
| #include "ocb_utils.h" |
| #include "operation.h" |
| |
| namespace keymaster { |
| |
| /** |
| * Abstract base for AES operation factories. This class does all of the work to create |
| * AES operations. |
| */ |
| class AesOperationFactory : public OperationFactory { |
| public: |
| KeyType registry_key() const override { return KeyType(KM_ALGORITHM_AES, purpose()); } |
| |
| Operation* CreateOperation(const Key& key, const AuthorizationSet& begin_params, |
| keymaster_error_t* error) override; |
| const keymaster_block_mode_t* SupportedBlockModes(size_t* block_mode_count) const override; |
| const keymaster_padding_t* SupportedPaddingModes(size_t* padding_count) const override; |
| |
| virtual keymaster_purpose_t purpose() const = 0; |
| }; |
| |
| /** |
| * Concrete factory for AES encryption operations. |
| */ |
| class AesEncryptionOperationFactory : public AesOperationFactory { |
| keymaster_purpose_t purpose() const override { return KM_PURPOSE_ENCRYPT; } |
| }; |
| |
| /** |
| * Concrete factory for AES decryption operations. |
| */ |
| class AesDecryptionOperationFactory : public AesOperationFactory { |
| keymaster_purpose_t purpose() const override { return KM_PURPOSE_DECRYPT; } |
| }; |
| |
| static const size_t MAX_EVP_KEY_SIZE = 32; |
| |
| class AesEvpOperation : public Operation { |
| public: |
| AesEvpOperation(keymaster_purpose_t purpose, keymaster_block_mode_t block_mode, |
| keymaster_padding_t padding, bool caller_iv, size_t tag_length, |
| const uint8_t* key, size_t key_size); |
| ~AesEvpOperation(); |
| |
| keymaster_error_t Begin(const AuthorizationSet& input_params, |
| AuthorizationSet* output_params) override; |
| keymaster_error_t Update(const AuthorizationSet& additional_params, const Buffer& input, |
| AuthorizationSet* output_params, Buffer* output, |
| size_t* input_consumed) override; |
| keymaster_error_t Finish(const AuthorizationSet& additional_params, const Buffer& signature, |
| AuthorizationSet* output_params, Buffer* output) override; |
| keymaster_error_t Abort() override; |
| |
| virtual int evp_encrypt_mode() = 0; |
| |
| protected: |
| bool need_iv() const; |
| keymaster_error_t InitializeCipher(); |
| keymaster_error_t GetIv(const AuthorizationSet& input_params); |
| bool HandleAad(const AuthorizationSet& input_params, const Buffer& input, |
| keymaster_error_t* error); |
| bool ProcessAadBlocks(const uint8_t* data, size_t blocks, keymaster_error_t* error); |
| void FillBufferedAadBlock(keymaster_blob_t* aad); |
| bool ProcessBufferedAadBlock(keymaster_error_t* error); |
| bool InternalUpdate(const uint8_t* input, size_t input_length, Buffer* output, |
| keymaster_error_t* error); |
| |
| const keymaster_block_mode_t block_mode_; |
| EVP_CIPHER_CTX ctx_; |
| UniquePtr<uint8_t[]> iv_; |
| size_t iv_length_; |
| const bool caller_iv_; |
| size_t tag_length_; |
| UniquePtr<uint8_t[]> aad_block_buf_; |
| size_t aad_block_buf_length_; |
| |
| private: |
| bool data_started_; |
| const size_t key_size_; |
| const keymaster_padding_t padding_; |
| uint8_t key_[MAX_EVP_KEY_SIZE]; |
| }; |
| |
| class AesEvpEncryptOperation : public AesEvpOperation { |
| public: |
| AesEvpEncryptOperation(keymaster_block_mode_t block_mode, keymaster_padding_t padding, |
| bool caller_iv, size_t tag_length, const uint8_t* key, size_t key_size) |
| : AesEvpOperation(KM_PURPOSE_ENCRYPT, block_mode, padding, caller_iv, tag_length, key, |
| key_size) {} |
| |
| keymaster_error_t Begin(const AuthorizationSet& input_params, |
| AuthorizationSet* output_params) override; |
| keymaster_error_t Finish(const AuthorizationSet& additional_params, const Buffer& signature, |
| AuthorizationSet* output_params, Buffer* output) override; |
| |
| int evp_encrypt_mode() override { return 1; } |
| |
| private: |
| keymaster_error_t GenerateIv(); |
| }; |
| |
| class AesEvpDecryptOperation : public AesEvpOperation { |
| public: |
| AesEvpDecryptOperation(keymaster_block_mode_t block_mode, keymaster_padding_t padding, |
| size_t tag_length, const uint8_t* key, size_t key_size) |
| : AesEvpOperation(KM_PURPOSE_DECRYPT, block_mode, padding, |
| false /* caller_iv -- don't care */, tag_length, key, key_size) {} |
| |
| keymaster_error_t Begin(const AuthorizationSet& input_params, |
| AuthorizationSet* output_params) override; |
| keymaster_error_t Update(const AuthorizationSet& additional_params, const Buffer& input, |
| AuthorizationSet* output_params, Buffer* output, |
| size_t* input_consumed) override; |
| keymaster_error_t Finish(const AuthorizationSet& additional_params, const Buffer& signature, |
| AuthorizationSet* output_params, Buffer* output) override; |
| |
| int evp_encrypt_mode() override { return 0; } |
| |
| private: |
| size_t tag_buf_unused() { return tag_length_ - tag_buf_length_; } |
| |
| keymaster_error_t ProcessAllButTagLengthBytes(const Buffer& input, Buffer* output); |
| bool ProcessTagBufContentsAsData(size_t to_process, Buffer* output, keymaster_error_t* error); |
| void BufferCandidateTagData(const uint8_t* data, size_t data_length); |
| |
| UniquePtr<uint8_t[]> tag_buf_; |
| size_t tag_buf_length_; |
| }; |
| |
| } // namespace keymaster |
| |
| #endif // SYSTEM_KEYMASTER_AES_OPERATION_H_ |