C与C#通讯加密之C语言DES的cbc pkcs7的实现
/*
功能：用mode = cbc , padding = pkcs7 来加密 如果to == NULL, 则返回加密后数据的长度 书写：evlon ,QQ:273352165
*/
int des_ecb_pkcs7_encrypt(uchar* from, int nLength, uchar * to, uchar key[]){
int nSize = nLength % 8 ?(nLength + 7) / 8 * 8 : nLength + 8; if(to == NULL)
{
//计算长度 return nSize;
} else { deskey(key,EN0); uchar endBuf[8]; int i=0; for(; i < nSize; i+=8) { uchar* ps = NULL,* pd = NULL; if(nLength - i >= 8) { ps = from + i; pd = to + i; } else { memset(&endBuf, i + 8 - nLength, sizeof(endBuf)); memcpy(&endBuf,from + i,nLength - i); ps = endBuf; pd = to + i; } des(ps,pd); } return i; }}int des_ecb_pkcs7_decrypt(uchar* from, int nLength, uchar * to, uchar key[]){ if(nLength % 8) return 0; //数据不正确 deskey(key,DE1); int i = 0; for(; i < nLength; i+=8) { if(nLength - i > 8) { des(from + i,to + i); } else { uchar endBuf[8]; des(from + i,endBuf); //去除数据尾 uchar chEnd = endBuf[7]; if(chEnd > 0 && chEnd < 9) { //有可能是填充字符,去除掉 for(int j = 7; j >= 8 - chEnd; --j) { if(endBuf[j] != chEnd) return 0; } memcpy(to + i, endBuf, 8 - chEnd); return i + 8 - chEnd; } else { return 0; } } } return 0;}/* 功能：用mode = cbc , padding = pkcs7 来加密 如果to == NULL, 则返回加密后数据的长度 书写：evlon ,QQ:273352165*/int des_cbc_pkcs7_encrypt(uchar* from, int nLength, uchar * to, uchar key[],uchar iv[]){ int nSize = nLength % 8 ?(nLength + 7) / 8 * 8 : nLength + 8; if(to == NULL) { //计算长度 return nSize; } else { deskey(key,EN0); uchar* fromBackup = from; from = (uchar*)malloc(nSize); //申请内存 memcpy(from,fromBackup,nLength); memset(from + nLength, nSize - nLength,nSize - nLength); uchar preEnc[8]; memcpy(preEnc,iv,8); //加密块 int i=0; for(; i < nSize; i+=8) { uchar* ps = from + i; uchar* pd = to + i; //XOR for(int j = 0; j < 8; ++j) { ps[j] ^= preEnc[j]; } des(ps,pd); //保存前一个输出 memcpy(preEnc, pd,8); } free(from); //memcpy(to + i,preEnc,8); return i; }}int des_cbc_pkcs7_decrypt(uchar* from, int nLength, uchar * to, uchar key[], uchar iv[]){ if(nLength % 8) return 0; //数据不正确 uchar* toBackup = to; to = (uchar*)malloc(nLength); //申请内存 //XOR uchar preEnc[8]; memcpy(preEnc,iv,8); deskey(key,DE1); int i = 0; for(; i < nLength; i+=8) { uchar* ps = from + i; uchar* pd = to + i; des(ps,pd); //XOR for(int j = 0; j < 8; ++j) { pd[j] ^= preEnc[j]; } //保存前一个输出 memcpy(preEnc, ps,8); } //去除数据尾 uchar chEnd = to[nLength - 1]; if(chEnd > 0 && chEnd < 9) { //有可能是填充字符,去除掉 for(int j = nLength - 1; j >= nLength - chEnd; --j) { if(to[j] != chEnd) return 0; } int nSize =nLength - chEnd; memcpy(toBackup, to, nSize); free(to); return nSize; } else { //数据格式不正确 free(to);return 0; } return 0;}
测试代码如下：
//把字节数组转换成字串int Byte2String(uchar* bytes, int nLength, char* pszout){ if(!pszout) { return nLength * 3; } else { for (int i = 0; i < nLength; ++i) { //sb.AppendFormat("{0} ", b.ToString("X2")); sprintf(pszout + i * 3,"%2X ",bytes[i]); } *(pszout + nLength * 3 -1) = '\0'; return nLength * 3; }}////////////////////////////////////////////////////////// 测试代码 ////////////////////////////////////////////////////////////void cbcDesTest1(){ uchar key[8] = {1,2,3,4,5,6,7,8}; uchar iv[8] = {1,2,3,4,5,6,7,8}; uchar text[25] = "123456789abcdef中国人ok"; uchar *output = NULL; uchar text2[sizeof(text)]; memset(&text2,0,sizeof(text2)); int nLength = des_cbc_pkcs7_encrypt(text,24,NULL,key,iv); output = new uchar[nLength]; memset(output,0,nLength); des_cbc_pkcs7_encrypt(text,24,output,key,iv); des_cbc_pkcs7_decrypt(output,24,text2,key,iv); delete[] output; output = NULL;}void cbcDesTest2(){ char szPrint[1024]; uchar key[8] = {1,2,3,4,5,6,7,8}; uchar iv[8] = {1,2,3,4,5,6,7,8}; StringPack pack; pack.OpCode = 2; pack.CharEnd = '8'; strcpy(pack.Name, "123456789abcdef中国人ok"); uchar* pPack = (uchar*)&pack; //计算数据长度 int nLength = des_cbc_pkcs7_encrypt(pPack,sizeof(StringPack),NULL,key,iv); uchar* output = new uchar[nLength]; memset(output,0,nLength); //打印出来 Byte2String(pPack,sizeof(StringPack),szPrint); printf("%s\n",szPrint); //加密 des_cbc_pkcs7_encrypt(pPack,sizeof(StringPack),output,key,iv); //打印出来 Byte2String(output,nLength,szPrint); printf("%s\n",szPrint); //检验一下加密结果,现在解密 uchar *packData = new uchar[nLength]; memset(packData,0,nLength); des_cbc_pkcs7_decrypt(output,nLength,packData,key,iv); //好了,我们看一下结果吧 StringPack* pack2 = (StringPack*)packData; //清理内存 delete[] packData; output = NULL; delete[] output; output = NULL;}void cbcDesTest3(){ uchar key[8] = {1,2,3,4,5,6,7,8}; uchar iv[8] = {1,2,3,4,5,6,7,8}; // 7 位长 { uchar text[] = {0xF0, 0xA5, 0xED, 0x9F, 0x83, 0x8A, 0xE0}; uchar output[1024] = {0}; uchar text2[1024] = {0}; int nRet = des_cbc_pkcs7_encrypt(text,sizeof(text),output,key,iv); char szPrint[1024]; //打印出来 Byte2String(output,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); nRet = des_cbc_pkcs7_decrypt(output,nRet,text2,key,iv); //打印出来 Byte2String(text2,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); } // 8 位长 { uchar text[] = {0xF0, 0xA5, 0xED, 0x9F, 0x83, 0x8A, 0xE0, 0xE2}; uchar output[1024] = {0}; uchar text2[1024] = {0}; int nRet = des_cbc_pkcs7_encrypt(text,sizeof(text),output,key,iv); char szPrint[1024]; //打印出来 Byte2String(output,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); nRet = des_cbc_pkcs7_decrypt(output,nRet,text2,key,iv); //打印出来 Byte2String(text2,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); } // 9 位长 { uchar text[] = {0xF0, 0xA5, 0xED, 0x9F, 0x83, 0x8A, 0xE0, 0xE2,0xF0}; uchar output[1024] = {0}; uchar text2[1024] = {0}; int nRet = des_cbc_pkcs7_encrypt(text,sizeof(text),output,key,iv); char szPrint[1024]; //打印出来 Byte2String(output,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); nRet = des_cbc_pkcs7_decrypt(output,nRet,text2,key,iv); //打印出来 Byte2String(text2,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); } // N 位长 { uchar text[] = {0xF0, 0xA5, 0xED, 0x9F, 0x83, 0x8A, 0xE0, 0xE2,0xF0, 0xA5, 0xED, 0x9F, 0xA5, 0xED, 0x9F, 0xA5, 0xED, 0x9F}; uchar output[1024] = {0}; uchar text2[1024] = {0}; int nRet = des_cbc_pkcs7_encrypt(text,sizeof(text),output,key,iv); char szPrint[1024]; //打印出来 Byte2String(output,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); nRet = des_cbc_pkcs7_decrypt(output,nRet,text2,key,iv); //打印出来 Byte2String(text2,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); }}void ecbDesTest1(){ uchar key[8] = {1,2,3,4,5,6,7,8}; // 7 位长 { uchar text[] = {0xF0, 0xA5, 0xED, 0x9F, 0x83, 0x8A, 0xE0}; uchar output[1024] = {0}; uchar text2[1024] = {0}; int nRet = des_ecb_pkcs7_encrypt(text,sizeof(text),output,key); char szPrint[1024]; //打印出来 Byte2String(output,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); nRet = des_ecb_pkcs7_decrypt(output,nRet,text2,key); //打印出来 Byte2String(text2,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); } // 8 位长 { uchar text[] = {0xF0, 0xA5, 0xED, 0x9F, 0x83, 0x8A, 0xE0, 0xE2}; uchar output[1024] = {0}; uchar text2[1024] = {0}; int nRet = des_ecb_pkcs7_encrypt(text,sizeof(text),output,key); char szPrint[1024]; //打印出来 Byte2String(output,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); nRet = des_ecb_pkcs7_decrypt(output,nRet,text2,key); //打印出来 Byte2String(text2,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); } // 9 位长 { uchar text[] = {0xF0, 0xA5, 0xED, 0x9F, 0x83, 0x8A, 0xE0, 0xE2,0xF0}; uchar output[1024] = {0}; uchar text2[1024] = {0}; int nRet = des_ecb_pkcs7_encrypt(text,sizeof(text),output,key); char szPrint[1024]; //打印出来 Byte2String(output,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); nRet = des_ecb_pkcs7_decrypt(output,nRet,text2,key); //打印出来 Byte2String(text2,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); } // N 位长 { uchar text[] = {0xF0, 0xA5, 0xED, 0x9F, 0x83, 0x8A, 0xE0, 0xE2,0xF0, 0xA5, 0xED, 0x9F, 0xA5, 0xED, 0x9F, 0xA5, 0xED, 0x9F}; uchar output[1024] = {0}; uchar text2[1024] = {0}; int nRet = des_ecb_pkcs7_encrypt(text,sizeof(text),output,key); char szPrint[1024]; //打印出来 Byte2String(output,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); nRet = des_ecb_pkcs7_decrypt(output,nRet,text2,key); //打印出来 Byte2String(text2,nRet,szPrint); printf("(%d)\n%s\n",nRet,szPrint); }}int _tmain(int argc, _TCHAR* argv[]){ ecbDesTest1(); cbcDesTest1(); cbcDesTest2(); cbcDesTest3(); getchar(); return 0;}
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