/* * Copyright (C) 2020 Sony Interactive Entertainment Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF * THE POSSIBILITY OF SUCH DAMAGE. */ #include "config.h" #include "CryptoAlgorithmAES_GCM.h" #if ENABLE(WEB_CRYPTO) #include "CryptoAlgorithmAesGcmParams.h" #include "CryptoKeyAES.h" #include "OpenSSLCryptoUniquePtr.h" #include namespace WebCore { static const EVP_CIPHER* aesAlgorithm(size_t keySize) { if (keySize * 8 == 128) return EVP_aes_128_gcm(); if (keySize * 8 == 192) return EVP_aes_192_gcm(); if (keySize * 8 == 256) return EVP_aes_256_gcm(); return nullptr; } static std::optional> cryptEncrypt(const Vector& key, const Vector& iv, const Vector& plainText, const Vector& additionalData, uint8_t tagLength) { const EVP_CIPHER* algorithm = aesAlgorithm(key.size()); if (!algorithm) return std::nullopt; EvpCipherCtxPtr ctx; int len; Vector cipherText(plainText.size() + tagLength); size_t tagOffset = plainText.size(); // Create and initialize the context if (!(ctx = EvpCipherCtxPtr(EVP_CIPHER_CTX_new()))) return std::nullopt; // Disable padding if (1 != EVP_CIPHER_CTX_set_padding(ctx.get(), 0)) return std::nullopt; // Initialize the encryption operation if (1 != EVP_EncryptInit_ex(ctx.get(), algorithm, nullptr, nullptr, nullptr)) return std::nullopt; // Set IV length if (1 != EVP_CIPHER_CTX_ctrl(ctx.get(), EVP_CTRL_GCM_SET_IVLEN, iv.size(), nullptr)) return std::nullopt; // Initialize key and IV if (1 != EVP_EncryptInit_ex(ctx.get(), nullptr, nullptr, key.data(), iv.data())) return std::nullopt; // Provide any AAD data if (additionalData.size() > 0) { if (1 != EVP_EncryptUpdate(ctx.get(), nullptr, &len, additionalData.data(), additionalData.size())) return std::nullopt; } // Provide the message to be encrypted, and obtain the encrypted output if (1 != EVP_EncryptUpdate(ctx.get(), cipherText.data(), &len, plainText.data(), plainText.size())) return std::nullopt; // Finalize the encryption. Normally ciphertext bytes may be written at // this stage, but this does not occur in GCM mode if (1 != EVP_EncryptFinal_ex(ctx.get(), cipherText.data() + len, &len)) return std::nullopt; // Get the tag if (1 != EVP_CIPHER_CTX_ctrl(ctx.get(), EVP_CTRL_GCM_GET_TAG, tagLength, cipherText.data() + tagOffset)) return std::nullopt; return cipherText; } static std::optional> cryptDecrypt(const Vector& key, const Vector& iv, const Vector& cipherText, const Vector& additionalData, uint8_t tagLength) { const EVP_CIPHER* algorithm = aesAlgorithm(key.size()); if (!algorithm) return std::nullopt; EvpCipherCtxPtr ctx; int len; int plainTextLen; int cipherTextLen = cipherText.size() - tagLength; Vector plainText(cipherText.size()); Vector tag { cipherText.data() + cipherTextLen, tagLength }; // Create and initialize the context if (!(ctx = EvpCipherCtxPtr(EVP_CIPHER_CTX_new()))) return std::nullopt; // Disable padding if (1 != EVP_CIPHER_CTX_set_padding(ctx.get(), 0)) return std::nullopt; // Initialize the encryption operation if (1 != EVP_DecryptInit_ex(ctx.get(), algorithm, nullptr, nullptr, nullptr)) return std::nullopt; // Set IV length if (1 != EVP_CIPHER_CTX_ctrl(ctx.get(), EVP_CTRL_GCM_SET_IVLEN, iv.size(), nullptr)) return std::nullopt; // Initialize key and IV if (1 != EVP_DecryptInit_ex(ctx.get(), nullptr, nullptr, key.data(), iv.data())) return std::nullopt; // Provide any AAD data if (additionalData.size() > 0) { if (1 != EVP_DecryptUpdate(ctx.get(), nullptr, &len, additionalData.data(), additionalData.size())) return std::nullopt; } // Set expected tag value if (1 != EVP_CIPHER_CTX_ctrl(ctx.get(), EVP_CTRL_GCM_SET_TAG, tag.size(), tag.data())) return std::nullopt; // Provide the message to be encrypted, and obtain the encrypted output if (1 != EVP_DecryptUpdate(ctx.get(), plainText.data(), &len, cipherText.data(), cipherTextLen)) return std::nullopt; plainTextLen = len; // Finalize the decryption if (1 != EVP_DecryptFinal_ex(ctx.get(), plainText.data() + len, &len)) return std::nullopt; plainTextLen += len; plainText.shrink(plainTextLen); return plainText; } ExceptionOr> CryptoAlgorithmAES_GCM::platformEncrypt(const CryptoAlgorithmAesGcmParams& parameters, const CryptoKeyAES& key, const Vector& plainText) { auto output = cryptEncrypt(key.key(), parameters.ivVector(), plainText, parameters.additionalDataVector(), parameters.tagLength.value_or(0) / 8); if (!output) return Exception { OperationError }; return WTFMove(*output); } ExceptionOr> CryptoAlgorithmAES_GCM::platformDecrypt(const CryptoAlgorithmAesGcmParams& parameters, const CryptoKeyAES& key, const Vector& cipherText) { auto output = cryptDecrypt(key.key(), parameters.ivVector(), cipherText, parameters.additionalDataVector(), parameters.tagLength.value_or(0) / 8); if (!output) return Exception { OperationError }; return WTFMove(*output); } } // namespace WebCore #endif // ENABLE(WEB_CRYPTO)