使用OpenSSL库的AES加解密

jopen 6年前

AesTest.cpp

#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);  }

Makefile

PROC_INC1=/usr/include    INC_DIR=-I$(PROC_INC1)    LIB_DIR=     #-lssl -lcrypto,是openssl的两个库  All_LIB=-lssl -lcrypto      CC=g++    default: AesTest    AesTest:AesTest.o   $(CC) -o $@ $^ $(INC_DIR) $(LIB_DIR) $(All_LIB)    .cpp.o:   $(CC) -c -g -Wall -D_GNU_SOURCE $(INC_DIR) $<    clean:   rm -f *.o AesTest
附: 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]