微信小程序数据解密组件demo-C++版本

#include "WXBizDataCrypt.h" #include <string.h> #include <stdlib.h> #include <arpa/inet.h> #include <string> #include <vector> #include <algorithm> #include <iostream> #include "openssl/aes.h" #include "openssl/sha.h" #include "openssl/evp.h" #include "rapidjson/document.h" #define FREE_PTR(ptr) \ if (NULL != (ptr)) {\ free (ptr);\ (ptr) = NULL;\ } #define DELETE_PTR(ptr) \ if (NULL != (ptr)) {\ delete (ptr);\ (ptr) = NULL;\ } namespace WxBizDataSecure{ int WXBizDataCrypt :: DecryptData( const std::string &sEncryptedData, const std::string &sIv, std::string &sData) { std::string result; //1.decode base64 for sessionkey , iv and encryptedData std::string sAesData; if(0 != DecodeBase64( sEncryptedData, sAesData )) { return WXBizDataCrypt_DecodeBase64_Error; } std::string sAesKey; if(0 != DecodeBase64(m_sSessionkey,sAesKey)) { return WXBizDataCrypt_IllegalAesKey; } std::string sAesIv; if(0 != DecodeBase64(sIv, sAesIv)) { return WXBizDataCrypt_IllegalIv; } //2.decode aes if(0 != AES_CBCDecrypt(sAesData, sAesKey, sAesIv, &result)) { return WXBizDataCrypt_IllegalBuffer; } // 3. check appid rapidjson::Document tJsonDoc; if( tJsonDoc.Parse < 0 > ( result.c_str() ).HasParseError() || tJsonDoc.IsObject() == false ) { return WXBizDataCrypt_IllegalBuffer; } if( tJsonDoc.HasMember( "watermark" ) == false || tJsonDoc["watermark"].IsObject() == false ) { return WXBizDataCrypt_IllegalBuffer; } rapidjson::Value & tWaterMarkDoc = tJsonDoc["watermark"]; if( tWaterMarkDoc.HasMember( "appid" ) == false || tWaterMarkDoc["appid"].IsString() == false ) { return WXBizDataCrypt_IllegalBuffer; } if( tWaterMarkDoc["appid"].GetString() != m_sAppid ) { return WXBizDataCrypt_IllegalBuffer; } sData = result; return WXBizDataCrypt_OK; } int WXBizDataCrypt::AES_CBCDecrypt( const std::string & objSource, const std::string & objKey, const std::string & sIv, std::string * poResult ) { return AES_CBCDecrypt( objSource.data(), objSource.size(), objKey.data(), objKey.size(), sIv.c_str(), sIv.size(), poResult ); } int WXBizDataCrypt::AES_CBCDecrypt( const char * sSource, const uint32_t iSize, const char * sKey, uint32_t iKeySize, const char * sIv, uint32_t iIvSize, std::string * poResult ) { if ( !sSource || !sKey || iSize < kAesKeySize || iSize % kAesKeySize != 0 || !poResult) { return -1; } poResult->clear(); unsigned char * out = (unsigned char*)malloc( iSize ); if(NULL == out) { return -1; } unsigned char key[ kAesKeySize ] = { 0 }; unsigned char iv[ kAesIVSize ] = {0} ; memcpy( key, sKey, iKeySize > kAesKeySize ? kAesKeySize : iKeySize ); memcpy(iv, sIv, iIvSize > kAesIVSize ? kAesIVSize : iIvSize ); int iReturnValue = 0; AES_KEY aesKey; AES_set_decrypt_key( key, 8 * kAesKeySize, &aesKey ); AES_cbc_encrypt( (unsigned char *)sSource, out, iSize, &aesKey, iv ,AES_DECRYPT); if( out[iSize-1] > 0 && out[iSize-1] <= kAesKeySize && (iSize - out[iSize-1]) > 0 ) { poResult->append( (char *)out , iSize - out[iSize-1] ); } else { iReturnValue = -1; } FREE_PTR(out); return iReturnValue; } int WXBizDataCrypt::DecodeBase64(const std::string sSrc, std::string & sTarget) { if(0 == sSrc.size() || kMaxBase64Size < sSrc.size()) { return -1; } //计算末尾=号个数 int iEqualNum = 0; for(int n= sSrc.size() - 1; n>=0; --n) { if(sSrc.c_str()[n] == '=') { iEqualNum++; } else { break; } } int iOutBufSize = sSrc.size(); char * pcOutBuf = (char*)malloc( iOutBufSize); if(NULL == pcOutBuf) { return -1; } int iRet = 0; int iTargetSize = 0; iTargetSize = EVP_DecodeBlock((unsigned char*)pcOutBuf, (const unsigned char*)sSrc.c_str(), sSrc.size()); if(iTargetSize > iEqualNum && iTargetSize < iOutBufSize) { sTarget.assign(pcOutBuf, iTargetSize - iEqualNum); } else { iRet = -1; } FREE_PTR(pcOutBuf); return iRet; } }