[转贴]C++调用openssl 的AES加密例子
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <openssl/aes.h>
//g++ -g -o -Wall -m64 AesTest AesTest.cpp -lssl -lcrypto
//g++ -g -o -Wall AesTest AesTest.cpp -lssl -lcrypto
int main(int argc, char **argv)
{//由于与直接对接用的char，那么加解密要强制转换
char Source[1024];
char *InputData=NULL;
char *EncryptData=NULL;
char *DecryptData=NULL;
unsigned char Key[AES_BLOCK_SIZE+1]; //建议用unsigned char
unsigned char ivec[AES_BLOCK_SIZE]; //建议用unsigned char
AES_KEY AesKey;
int DataLen=0,SetDataLen=0, i;
memset(Source, 0x00, sizeof(Source));
strcpy(Source, "1234567890abcde"); //要加密的数据
DataLen = strlen(Source);
memset(Key, 0x00, sizeof(Key));
memcpy(Key, "0123456789abcdef", AES_BLOCK_SIZE);
// set the encryption length
SetDataLen = 0;
if ((DataLen%AES_BLOCK_SIZE) == 0)
{
SetDataLen = DataLen;
}
else
{
SetDataLen = ((DataLen/AES_BLOCK_SIZE)+1) * AES_BLOCK_SIZE;
}
printf("SetDataLen:%d...\n", SetDataLen); //取16的倍数
InputData = (char *)calloc(SetDataLen+1, sizeof(char));
if(InputData == NULL) //注意要SetDataLen+1
{
fprintf(stderr, "Unable to allocate memory for InputData\n");
exit(-1);
}
memcpy(InputData, Source, DataLen);
EncryptData = (char *)calloc(SetDataLen+1, sizeof(char));
if(EncryptData == NULL) //注意要SetDataLen+1
{
fprintf(stderr, "Unable to allocate memory for EncryptData\n");
exit(-1);
}
DecryptData = (char *)calloc(SetDataLen+1, sizeof(char));
if(DecryptData == NULL) //注意要SetDataLen+1
{
fprintf(stderr, "Unable to allocate memory for DecryptData\n");
exit(-1);
}
memset(&AesKey, 0x00, sizeof(AES_KEY));
if(AES_set_encrypt_key(Key, 128, &AesKey) < 0)
{//设置加密密钥
fprintf(stderr, "Unable to set encryption key in AES...\n");
exit(-1);
}
for(i=0; i<AES_BLOCK_SIZE; i++)
{//必须要有
ivec[i] = 0;
}
//加密
AES_cbc_encrypt((unsigned char *)InputData, (unsigned char *)EncryptData,
SetDataLen, &AesKey, ivec, AES_ENCRYPT);
memset(&AesKey, 0x00, sizeof(AES_KEY));
if(AES_set_decrypt_key(Key, 128, &AesKey) < 0)
{//设置解密密钥
fprintf(stderr, "Unable to set encryption key in AES...\n");
exit(-1);
}
for(i=0; i<AES_BLOCK_SIZE; i++)
{//必须要有
ivec[i] = 0;
}
//解密
AES_cbc_encrypt((unsigned char *)EncryptData, (unsigned char *)DecryptData,
SetDataLen, &AesKey, ivec, AES_DECRYPT);
printf("DecryptData:%s...\n", (char *)DecryptData);
if(InputData != NULL)
{
free(InputData);
InputData = NULL;
}
if(EncryptData != NULL)
{
free(EncryptData);
EncryptData = NULL;
}
if(DecryptData != NULL)
{
free(DecryptData);
DecryptData = NULL;
}
exit(0);
}
OpenSSL支持多种不同的加密算法
加密：
AES, Blowfish, Camellia, SEED, CAST-128, DES, IDEA, RC2, RC4, RC5, Triple DES, GOST 28147-89[4]
散列函数：
MD5, MD2, SHA-1, SHA-2, RIPEMD-160, MDC-2, GOST R 34.11-94[4]
公开密钥加密：
RSA, DSA, Diffie–Hellman key exchange, Elliptic curve, GOST R 34.10-2001[4]