1*e7b1675dSTing-Kang Chang // Copyright 2021 Google LLC 2*e7b1675dSTing-Kang Chang // 3*e7b1675dSTing-Kang Chang // Licensed under the Apache License, Version 2.0 (the "License"); 4*e7b1675dSTing-Kang Chang // you may not use this file except in compliance with the License. 5*e7b1675dSTing-Kang Chang // You may obtain a copy of the License at 6*e7b1675dSTing-Kang Chang // 7*e7b1675dSTing-Kang Chang // http://www.apache.org/licenses/LICENSE-2.0 8*e7b1675dSTing-Kang Chang // 9*e7b1675dSTing-Kang Chang // Unless required by applicable law or agreed to in writing, software 10*e7b1675dSTing-Kang Chang // distributed under the License is distributed on an "AS IS" BASIS, 11*e7b1675dSTing-Kang Chang // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12*e7b1675dSTing-Kang Chang // See the License for the specific language governing permissions and 13*e7b1675dSTing-Kang Chang // limitations under the License. 14*e7b1675dSTing-Kang Chang // 15*e7b1675dSTing-Kang Chang /////////////////////////////////////////////////////////////////////////////// 16*e7b1675dSTing-Kang Chang #ifndef TINK_INTERNAL_AES_UTIL_H_ 17*e7b1675dSTing-Kang Chang #define TINK_INTERNAL_AES_UTIL_H_ 18*e7b1675dSTing-Kang Chang 19*e7b1675dSTing-Kang Chang #include <cstdint> 20*e7b1675dSTing-Kang Chang #include <memory> 21*e7b1675dSTing-Kang Chang 22*e7b1675dSTing-Kang Chang #include "absl/strings/string_view.h" 23*e7b1675dSTing-Kang Chang #include "absl/types/span.h" 24*e7b1675dSTing-Kang Chang #include "openssl/aes.h" 25*e7b1675dSTing-Kang Chang #include "tink/util/secret_data.h" 26*e7b1675dSTing-Kang Chang #include "tink/util/status.h" 27*e7b1675dSTing-Kang Chang #include "tink/util/statusor.h" 28*e7b1675dSTing-Kang Chang 29*e7b1675dSTing-Kang Chang namespace crypto { 30*e7b1675dSTing-Kang Chang namespace tink { 31*e7b1675dSTing-Kang Chang namespace internal { 32*e7b1675dSTing-Kang Chang 33*e7b1675dSTing-Kang Chang // AES block size in bytes. AesBlockSize()34*e7b1675dSTing-Kang Changconstexpr int AesBlockSize() { return 16; } 35*e7b1675dSTing-Kang Chang 36*e7b1675dSTing-Kang Chang // Wrapper for BoringSSL/OpenSSL low-level functions that encrypt/decrypt (same 37*e7b1675dSTing-Kang Chang // operation in CTR mode) `data`, with IV `iv` and key `key`. The result is 38*e7b1675dSTing-Kang Chang // written to `out`. `out` may fully overlap with `data`; partial overlaps will 39*e7b1675dSTing-Kang Chang // result in an kInvalidArgument error. `iv` is incremented of the number of 40*e7b1675dSTing-Kang Chang // blocks that were encrypted/decrypted. 41*e7b1675dSTing-Kang Chang crypto::tink::util::Status AesCtr128Crypt(absl::string_view data, 42*e7b1675dSTing-Kang Chang uint8_t iv[AesBlockSize()], 43*e7b1675dSTing-Kang Chang const AES_KEY* key, 44*e7b1675dSTing-Kang Chang absl::Span<char> out); 45*e7b1675dSTing-Kang Chang 46*e7b1675dSTing-Kang Chang // Returns a pointer to an AES-CTR EVP_CIPHER for the given key size 47*e7b1675dSTing-Kang Chang // `key_size_in_bytes`. 48*e7b1675dSTing-Kang Chang util::StatusOr<const EVP_CIPHER*> GetAesCtrCipherForKeySize( 49*e7b1675dSTing-Kang Chang uint32_t key_size_in_bytes); 50*e7b1675dSTing-Kang Chang 51*e7b1675dSTing-Kang Chang // Returns a pointer to an AES-CBC EVP_CIPHER for the given key size 52*e7b1675dSTing-Kang Chang // `key_size_in_bytes`. 53*e7b1675dSTing-Kang Chang util::StatusOr<const EVP_CIPHER*> GetAesCbcCipherForKeySize( 54*e7b1675dSTing-Kang Chang uint32_t key_size_in_bytes); 55*e7b1675dSTing-Kang Chang 56*e7b1675dSTing-Kang Chang } // namespace internal 57*e7b1675dSTing-Kang Chang } // namespace tink 58*e7b1675dSTing-Kang Chang } // namespace crypto 59*e7b1675dSTing-Kang Chang 60*e7b1675dSTing-Kang Chang #endif // TINK_INTERNAL_AES_UTIL_H_ 61