rsa对称加密C++实现

#include <openssl/err.h> #include <openssl/pem.h> #include <openssl/rsa.h> #include "openssl/sha.h" #include "openssl/sha.h" #include <cstring> #include "rsa_codec.h" using namespace std; using namespace unp::crypto; const char* CRSACodec::GetErrMsg(){ return m_sErrMsg.c_str(); } int CRSACodec::Pubilc_Decode ( const std::string& sKeyFileName, const std::string& sSrcData, std::string& sResult, int iPadding ) { FILE* pFile = NULL; RSA* pRsa = NULL; unsigned char* pSigbuf = NULL; sResult = ""; bool bIfSuccess = false; do { char szErrMsg[1024] = {0}; // 检查密钥文件是否存在 pFile = fopen(sKeyFileName.c_str(), "r"); if(pFile == NULL){ snprintf(szErrMsg, sizeof(szErrMsg), "Key File[%s] Not Exist!!!", sKeyFileName.c_str() ); m_sErrMsg = szErrMsg; break; } // 取出密钥 pRsa = PEM_read_RSA_PUBKEY(pFile, NULL, NULL, NULL); if (pRsa == NULL){ m_sErrMsg = "PEM_read_RSA_PUBKEY FAIL:Key is NULL!!!"; break; } int iSiglen = RSA_size(pRsa); pSigbuf = (unsigned char *) malloc (iSiglen + 1); int iRet = RSA_public_decrypt(sSrcData.size(), (unsigned char *)sSrcData.c_str(), pSigbuf, pRsa, iPadding); if (iRet <= 0){ // 解密失败 ERR_load_ERR_strings(); ERR_load_crypto_strings(); unsigned long ulErr = ERR_get_error(); char szRSAErrMsg[1024] = {0}; char *pTmp = NULL; pTmp = ERR_error_string(ulErr,szRSAErrMsg); snprintf(szErrMsg, sizeof(szErrMsg), "RSA_public_decrypt FAIL!!!iRet:[%d],errMsg:[%s]", iRet,szRSAErrMsg ); m_sErrMsg = szErrMsg; break; } // 解密成功，赋值 sResult = std::string((char*)pSigbuf,iRet); bIfSuccess = true; }while(0); if(pFile != NULL){ fclose(pFile); pFile = NULL; } if(pSigbuf != NULL){ free(pSigbuf); pSigbuf = NULL; } if(pRsa != NULL){ RSA_free(pRsa); pRsa = NULL; } if(!bIfSuccess){ return -1; } return 0; } int CRSACodec::Private_Encode ( const std::string& sKeyFileName, const std::string& sSrcData, std::string& sResult, int iPadding ) { FILE* pFile = NULL; RSA* pRsa = NULL; unsigned char* pSigbuf = NULL; sResult = ""; bool bIfSuccess = false; do { char szErrMsg[1024] = {0}; // 检查密钥文件是否存在 pFile = fopen(sKeyFileName.c_str(), "r"); if(pFile == NULL) { snprintf(szErrMsg, sizeof(szErrMsg), "Key File[%s] Not Exist!!!", sKeyFileName.c_str() ); m_sErrMsg = szErrMsg; break; } // 取出密钥 -----BEGIN RSA PRIVATE KEY----- pRsa = PEM_read_RSAPrivateKey(pFile, NULL, NULL, NULL); if (pRsa == NULL) { m_sErrMsg = "PEM_read_RSAPrivateKey FAIL:Key is NULL!!!"; break; } int iSiglen = RSA_size(pRsa); pSigbuf = (unsigned char *) malloc (iSiglen + 1); int iRet = RSA_private_encrypt(sSrcData.size(), (unsigned char *)sSrcData.c_str(), pSigbuf, pRsa, iPadding); if(iRet <= 0) { // 加密失败 ERR_load_ERR_strings(); ERR_load_crypto_strings(); unsigned long ulErr = ERR_get_error(); char szRSAErrMsg[1024] = {0}; char *pTmp = NULL; pTmp = ERR_error_string(ulErr,szRSAErrMsg); snprintf(szErrMsg, sizeof(szErrMsg), "RSA_private_encrypt FAIL!!!iRet:[%d],errMsg:[%s]", iRet, szRSAErrMsg ); m_sErrMsg = szErrMsg; break; } // 加密成功，赋值 sResult = std::string((char*)pSigbuf, iRet); bIfSuccess = true; } while(0); if(pFile != NULL) { fclose(pFile); pFile = NULL; } if(pSigbuf != NULL) { free(pSigbuf); pSigbuf = NULL; } if(pRsa != NULL) { RSA_free(pRsa); pRsa = NULL; } if(!bIfSuccess) { return -1; } return 0; } // ---- sha256摘要哈希 ---- // void CRSACodec::sha256 ( const std::string &srcStr, std::string &encodedStr, std::string &encodedHexStr ) { // 调用sha256哈希 unsigned char mdStr[33] = {0}; SHA256((const unsigned char *)srcStr.c_str(), srcStr.length(), mdStr); // 哈希后的字符串 encodedStr = std::string((const char *)mdStr); // 哈希后的十六进制串 64字节 char buf[65] = {0}; char tmp[3] = {0}; for (int i = 0; i < 32; i++) { sprintf(tmp, "%02x", mdStr[i]); strcat(buf, tmp); } buf[64] = '\0'; // 后面都是0，从64字节截断 encodedHexStr = std::string(buf); }