头文件crypto_util.h
#pragma once#include <string>namespace hsm{namespace mgmt{void get_md5_digest(const std::string &data,uint8_t result[16]);std::string aes_encrypt_to_string(const std::string &string,const std::string &password);std::string aes_decrypt_from_string(const std::string &string,const std::string &password);}//namespace mgmt
}//namespace hsm
代码实现crypto_util.cpp
#include "../util/crypto_util.h"#include <cstring>
#include <memory>#include <openssl/aes.h>
#include <openssl/md5.h>namespace hsm{namespace mgmt{void get_md5_digest(const std::string &data,uint8_t result[16]){MD5_CTX md5_ctx{};MD5_Init(&md5_ctx);MD5_Update(&md5_ctx,data.c_str(),data.length());MD5_Final(result,&md5_ctx);}
/*** @brief generate a valid aes key from input password** @note AES only support keys with length 128/192/256bits* @note this implementation use md5 as a method to fix the password*/std::unique_ptr<AES_KEY> get_aes_key(const std::string &password,int flag){auto aes_key = std::make_unique<AES_KEY>();uint8_t data[16]{};get_md5_digest(password,data);if (flag == AES_ENCRYPT){AES_set_encrypt_key(data,sizeof(data)*8,aes_key.get());} else if (flag == AES_DECRYPT){AES_set_decrypt_key(data,sizeof(data)*8,aes_key.get());}return aes_key;}std::string aes_encrypt_to_string(const std::string &data,const std::string &password){auto aes_key = get_aes_key(password,AES_ENCRYPT);std::string result(data.length(),'0');auto input_offset = reinterpret_cast<const uint8_t *>(data.c_str());auto output_offset = reinterpret_cast<uint8_t *>(&result[0]);//encrypt blocksfor (size_t i = 0; i < data.length() / AES_BLOCK_SIZE ; ++i) {AES_encrypt(input_offset,output_offset,aes_key.get());input_offset += AES_BLOCK_SIZE;output_offset += AES_BLOCK_SIZE;}//write rest od data to fileauto rest_input_length = data.length() % AES_BLOCK_SIZE;if (rest_input_length > 0 ){std::memcpy(output_offset,input_offset,rest_input_length + 1);}return result;}std::string aes_decrypt_from_string(const std::string &enc_data,const std::string &password){auto aes_key = get_aes_key(password,AES_DECRYPT);std::string result(enc_data.length(),'0');auto input_offset = reinterpret_cast<const uint8_t *>(enc_data.c_str());auto output_offset = reinterpret_cast<uint8_t *>(&result[0]);//decrypt blocksfor (size_t i = 0;i < enc_data.length() / AES_BLOCK_SIZE;i++){AES_decrypt(input_offset,output_offset,aes_key.get());input_offset += AES_BLOCK_SIZE;output_offset += AES_BLOCK_SIZE;}//decrypt rest of dataauto rest_input_length = enc_data.length() % AES_BLOCK_SIZE;if (rest_input_length > 0 ){std::memcpy(output_offset,input_offset,rest_input_length + 1);}return result;}}//namespace mgmt
}//namespace hsm
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