使用openssl C进行AES（AES-cbc-128、AES-cbc-192、AES-cbc-256）加密/解密
我只想用这3种模式测试openSSL中的AES：128192和256密钥长度，但我解密的文本与我的输入不同，我不知道为什么。此外，当我传递一个巨大的输入长度（比如1024字节）时，我的程序显示使用openssl C进行AES（AES-cbc-128、AES-cbc-192、AES-cbc-256）加密/解密,c,openssl,aes,C,Openssl,Aes,我只想用这3种模式测试openSSL中的AES：128192和256密钥长度，但我解密的文本与我的输入不同，我不知道为什么。此外，当我传递一个巨大的输入长度（比如1024字节）时，我的程序显示核心转储。。。我的意见总是一样的，但这并不重要，至少现在是这样。代码如下： #include <stdio.h> #include <stdlib.h> #include <string.h> #include <openssl/aes.h> int mai
核心转储#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/aes.h>
int main(int argc, char **argv)
{
int i;
int keylength;
printf("Give a key length [only 128 or 192 or 256!]:\n");
scanf("%d", &keylength);
/* generate a key with a given length */
unsigned char aes_key[keylength];
memset(aes_key, 0, sizeof(aes_key));
if (!RAND_bytes(aes_key, keylength))
{
exit(-1);
}
aes_key[keylength-1] = '\0';
int inputslength;
printf("Give an input's length:\n");
scanf("%d", &inputslength);
/* generate input with a given length */
unsigned char aes_input[inputslength+1];
memset(aes_input, '0', sizeof(aes_input));
aes_input[inputslength] = '\0';
/*printf("original:\t");
for(i=0; i<inputslength; i++)
{
printf("%c ", aes_input[i]);
}
printf("\n");*/
/* init vector */
unsigned char iv[AES_BLOCK_SIZE];
if (!RAND_bytes(iv, AES_BLOCK_SIZE))
{
exit(-1);
}
//printf("AES_BLOCK_SIZE = %d\n", AES_BLOCK_SIZE); // aes block size is 16 bytes = 128 bits
AES_KEY enc_key, dec_key;
unsigned char enc_out[AES_BLOCK_SIZE];
unsigned char dec_out[AES_BLOCK_SIZE];
// so i can do with this aes-cbc-128 aes-cbc-192 aes-cbc-256
AES_set_encrypt_key(aes_key, keylength, &enc_key);
AES_cbc_encrypt(aes_input, enc_out, inputslength, &enc_key, iv, AES_ENCRYPT);
AES_set_decrypt_key(aes_key, keylength, &dec_key);
AES_decrypt(enc_out, dec_out, &dec_key);
printf("original:\t");
for(i=0;*(aes_input+i)!=0x00;i++)
printf("%X ",*(aes_input+i));
printf("\nencrypted:\t");
for(i=0;*(enc_out+i)!=0x00;i++)
printf("%X ",*(enc_out+i));
printf("\ndecrypted:\t");
for(i=0;*(dec_out+i)!=0x00;i++)
printf("%X ",*(dec_out+i));
printf("\n");
/*printf("\n\noriginal:\t");
for(i=0; i<inputslength; i++)
{
printf("%x ", dec_out[i]);
}
printf("\n");*/
return 0;
}
那么，输出口的大小和iv的大小是否可能存在问题？它们应该有多大的尺寸（适用于AES-CBC-128、AES-CBC-192、AES-CBC-256）？看看您的代码的这个修改版本。注意以下几点：
AES\u cbc\u encrypt（）#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/aes.h>
#include <openssl/rand.h>
// a simple hex-print routine. could be modified to print 16 bytes-per-line
static void hex_print(const void* pv, size_t len)
{
const unsigned char * p = (const unsigned char*)pv;
if (NULL == pv)
printf("NULL");
else
{
size_t i = 0;
for (; i<len;++i)
printf("%02X ", *p++);
}
printf("\n");
}
// main entrypoint
int main(int argc, char **argv)
{
int keylength;
printf("Give a key length [only 128 or 192 or 256!]:\n");
scanf("%d", &keylength);
/* generate a key with a given length */
unsigned char aes_key[keylength/8];
memset(aes_key, 0, keylength/8);
if (!RAND_bytes(aes_key, keylength/8))
exit(-1);
size_t inputslength = 0;
printf("Give an input's length:\n");
scanf("%lu", &inputslength);
/* generate input with a given length */
unsigned char aes_input[inputslength];
memset(aes_input, 'X', inputslength);
/* init vector */
unsigned char iv_enc[AES_BLOCK_SIZE], iv_dec[AES_BLOCK_SIZE];
RAND_bytes(iv_enc, AES_BLOCK_SIZE);
memcpy(iv_dec, iv_enc, AES_BLOCK_SIZE);
// buffers for encryption and decryption
const size_t encslength = ((inputslength + AES_BLOCK_SIZE) / AES_BLOCK_SIZE) * AES_BLOCK_SIZE;
unsigned char enc_out[encslength];
unsigned char dec_out[inputslength];
memset(enc_out, 0, sizeof(enc_out));
memset(dec_out, 0, sizeof(dec_out));
// so i can do with this aes-cbc-128 aes-cbc-192 aes-cbc-256
AES_KEY enc_key, dec_key;
AES_set_encrypt_key(aes_key, keylength, &enc_key);
AES_cbc_encrypt(aes_input, enc_out, inputslength, &enc_key, iv_enc, AES_ENCRYPT);
AES_set_decrypt_key(aes_key, keylength, &dec_key);
AES_cbc_encrypt(enc_out, dec_out, encslength, &dec_key, iv_dec, AES_DECRYPT);
printf("original:\t");
hex_print(aes_input, sizeof(aes_input));
printf("encrypt:\t");
hex_print(enc_out, sizeof(enc_out));
printf("decrypt:\t");
hex_print(dec_out, sizeof(dec_out));
return 0;
}
Give a key length [only 128 or 192 or 256!]:
128
Give an input's length:
10
original: 58 58 58 58 58 58 58 58 58 58
encrypt: A9 66 C5 24 A4 02 AB 96 08 65 F7 22 A5 FB BE 26
decrypt: 58 58 58 58 58 58 58 58 58 58
Give a key length [only 128 or 192 or 256!]:
128
Give an input's length:
10
original: 58 58 58 58 58 58 58 58 58 58
encrypt: C2 47 6D B1 A1 68 29 53 55 74 C5 CC 3F 27 0A 3F
decrypt: 58 58 58 58 58 58 58 58 58 58
我真诚地希望这能有所帮助。@WhozCraig:非常感谢您的帮助！它向我解释了很多！但还有一个问题。我将静态数组更改为动态数组。当我这样做时，出现了一些错误。但只有当我提供了大量输入时才会出现错误，请查看valgrind输出：。错误仅在我传递大量输入时发生，当我通过一个小尺寸的（如你的例子中的10）就可以了。其他一切都很好地工作
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/aes.h>
#include <openssl/rand.h>
// a simple hex-print routine. could be modified to print 16 bytes-per-line
static void hex_print(const void* pv, size_t len)
{
const unsigned char * p = (const unsigned char*)pv;
if (NULL == pv)
printf("NULL");
else
{
size_t i = 0;
for (; i<len;++i)
printf("%02X ", *p++);
}
printf("\n");
}
// main entrypoint
int main(int argc, char **argv)
{
size_t inputslength = 0;
printf("Give an input's length:\n");
scanf("%lu", &inputslength);
int keylength;
printf("Give a key length [only 128 or 192 or 256!]:\n");
scanf("%d", &keylength);
// generate a key with a given length
unsigned char *aes_key = (unsigned char*)malloc(sizeof(unsigned char) * (keylength/8));
memset(aes_key, 0, keylength/8);
RAND_bytes(aes_key, keylength/8);
// generate input with a given length
unsigned char *aes_input = (unsigned char*)malloc(sizeof(unsigned char) * (inputslength));
memset(aes_input, 'X', sizeof(aes_input));
// init vectors
unsigned char *iv_enc = (unsigned char*)malloc(sizeof(unsigned char) * (AES_BLOCK_SIZE));
unsigned char *iv_dec = (unsigned char*)malloc(sizeof(unsigned char) * (AES_BLOCK_SIZE));
// iv_dec == iv_enc
RAND_bytes(iv_enc, AES_BLOCK_SIZE);
memcpy(iv_dec, iv_enc, AES_BLOCK_SIZE);
// buffers for encryption and decryption
const size_t length = (((inputslength + AES_BLOCK_SIZE) / AES_BLOCK_SIZE) * AES_BLOCK_SIZE);
unsigned char *enc_out = (unsigned char*)malloc(sizeof(unsigned char) * (length));
unsigned char *dec_out = (unsigned char*)malloc(sizeof(unsigned char) * (inputslength));
// so i can do with this aes-cbc-128 aes-cbc-192 aes-cbc-256
AES_KEY encKey, decKey;
AES_set_encrypt_key(aes_key, keylength, &encKey);
AES_cbc_encrypt(aes_input, enc_out, inputslength, &encKey, iv_enc, AES_ENCRYPT);
AES_set_decrypt_key(aes_key, keylength, &decKey);
AES_cbc_encrypt(enc_out, dec_out, length, &decKey, iv_dec, AES_DECRYPT);
printf("original:\t");
hex_print(aes_input, sizeof(aes_input));
printf("encrypt:\t");
hex_print(enc_out, sizeof(enc_out));
printf("decrypt:\t");
hex_print(dec_out, sizeof(dec_out));
free(aes_key);
aes_key = NULL;
free(aes_input);
aes_input = NULL;
free(iv_enc);
iv_enc = NULL;
free(iv_dec);
iv_dec = NULL;
free(enc_out);
enc_out = NULL;
free(dec_out);
dec_out = NULL;
return 0;
}
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//一个简单的十六进制打印例程。可以修改为每行打印16字节
静态无效十六进制打印（常量无效*pv，尺寸长度）
{
常量无符号字符*p=（常量无符号字符*）pv；
如果（NULL==pv）
printf（“空”）；
其他的
{
尺寸i=0；
对于（；IsIdefine:您的AES密钥不需要以null结尾。这是一个随机的字节块；仅此而已。它没有任何null项，因此AES_key[keylength-1]='\0'
是无意义的（除非它总是将密钥的最后一个字节（顺便说一句，它比需要的字节大8倍）设置为零）@WhozCraig：谢谢，很高兴知道这一点。主要问题是什么，你有什么想法吗？很多。加密和解密的缓冲区大小远远不够大。你需要一个通用的十六进制打印函数，而不是试图把这些东西当作字符数据。它是二进制的。现在就形成一个正式的答案，但从那里开始寻找。你应该uld不能使用AES\u encrypt
和friends。您应该使用EVP\u*
函数。请参阅OpenSSL wiki上的。事实上，您可能应该使用经过身份验证的加密，因为它提供机密性和真实性。请参阅OpenSSL wiki上的。很抱歉打扰您，您是对的，现在一切都很好：）我认为这段代码是错误的。我的测试用例：keylen=128，inputlen=100。你应该再测试一次。@g10guang如果你能描述你认为它应该做什么，它实际上在做什么，以及它们之间的区别，我会感兴趣的是你为什么认为它是错误的。它不是。它正是我想要做的：生成一个随机键，一个随机键四、 加密由'X'
字符填充的恒定数据块，解密相同的数据，并演示原始数据、加密数据和解密数据（其中原始数据和解密数据最好相同，并且它们是相同的），使用十六进制转储进行输出。它可能没有执行您认为的操作，这可能就是断开连接的地方。请再次查看。sizeof（）
当与指针而不是固定或可变数组一起使用时，具有全新的含义。它成为指针的大小，而不是分配给它的数据的大小。您所有的大小都应该是变量；而不是sizeof（某物）
。解决了这个问题，我打赌您最后的问题将消失。（旁注：不要抛出malloc（）在常规C编程时，它会引起非常微妙的问题，尤其是对于可移植性。C++需要它，但是，首先，不应该在C++中使用<代码> MalCube（）/<代码>。“我的GCC告诉我，-<代码> MalOC/<代码>返回空，我在用C++编写的时候，我使用<代码>新< /COD>和<代码>删除< /代码>，我知道我不应该在C++中使用<代码> MalOC/<代码>；在C编程中有可能存在的缺陷。显然，C++是必需的，但是正如你所说的，你使用<代码>新< /COD>和<代码>删除< /C> >查找“MulcC[C]”。在这个网站上。这是一个相当有争议的问题。除此之外，非常高兴您已经启动并运行。感谢您的实施！！@Puffin这是不正确的。必须有足够的空间容纳一整块填充。PKCS#5填充就是这样工作的。任何“有效”的东西都可以对于您来说，如果不考虑这种情况，那么这样做只是因为加密的明文不是AES块大小（16字节）的精确倍数，因此当这种情况最终出现时，它是一个滴答作响的定时炸弹。具体来说，描述遇到精确块大小倍数时会发生什么的段落。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/aes.h>
#include <openssl/rand.h>
// a simple hex-print routine. could be modified to print 16 bytes-per-line
static void hex_print(const void* pv, size_t len)
{
const unsigned char * p = (const unsigned char*)pv;
if (NULL == pv)
printf("NULL");
else
{
size_t i = 0;
for (; i<len;++i)
printf("%02X ", *p++);
}
printf("\n");
}
// main entrypoint
int main(int argc, char **argv)
{
size_t inputslength = 0;
printf("Give an input's length:\n");
scanf("%lu", &inputslength);
int keylength;
printf("Give a key length [only 128 or 192 or 256!]:\n");
scanf("%d", &keylength);
// generate a key with a given length
unsigned char *aes_key = (unsigned char*)malloc(sizeof(unsigned char) * (keylength/8));
memset(aes_key, 0, keylength/8);
RAND_bytes(aes_key, keylength/8);
// generate input with a given length
unsigned char *aes_input = (unsigned char*)malloc(sizeof(unsigned char) * (inputslength));
memset(aes_input, 'X', sizeof(aes_input));
// init vectors
unsigned char *iv_enc = (unsigned char*)malloc(sizeof(unsigned char) * (AES_BLOCK_SIZE));
unsigned char *iv_dec = (unsigned char*)malloc(sizeof(unsigned char) * (AES_BLOCK_SIZE));
// iv_dec == iv_enc
RAND_bytes(iv_enc, AES_BLOCK_SIZE);
memcpy(iv_dec, iv_enc, AES_BLOCK_SIZE);
// buffers for encryption and decryption
const size_t length = (((inputslength + AES_BLOCK_SIZE) / AES_BLOCK_SIZE) * AES_BLOCK_SIZE);
unsigned char *enc_out = (unsigned char*)malloc(sizeof(unsigned char) * (length));
unsigned char *dec_out = (unsigned char*)malloc(sizeof(unsigned char) * (inputslength));
// so i can do with this aes-cbc-128 aes-cbc-192 aes-cbc-256
AES_KEY encKey, decKey;
AES_set_encrypt_key(aes_key, keylength, &encKey);
AES_cbc_encrypt(aes_input, enc_out, inputslength, &encKey, iv_enc, AES_ENCRYPT);
AES_set_decrypt_key(aes_key, keylength, &decKey);
AES_cbc_encrypt(enc_out, dec_out, length, &decKey, iv_dec, AES_DECRYPT);
printf("original:\t");
hex_print(aes_input, sizeof(aes_input));
printf("encrypt:\t");
hex_print(enc_out, sizeof(enc_out));
printf("decrypt:\t");
hex_print(dec_out, sizeof(dec_out));
free(aes_key);
aes_key = NULL;
free(aes_input);
aes_input = NULL;
free(iv_enc);
iv_enc = NULL;
free(iv_dec);
iv_dec = NULL;
free(enc_out);
enc_out = NULL;
free(dec_out);
dec_out = NULL;
return 0;
}
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/aes.h>
#include <openssl/rand.h>
// a simple hex-print routine. could be modified to print 16 bytes-per-line
static void hex_print(const void* pv, size_t len)
{
const unsigned char * p = (const unsigned char*)pv;
if (NULL == pv)
printf("NULL");
else
{
size_t i = 0;
for (; i<len;++i)
printf("%02X ", *p++);
}
printf("\n");
}
// main entrypoint
int main(int argc, char **argv)
{
int keylength;
printf("Give a key length [only 128 or 192 or 256!]:\n");
scanf("%d", &keylength);
/* generate a key with a given length */
unsigned char *aes_key = (unsigned char*)malloc(sizeof(unsigned char) * (keylength/8));
memset(aes_key, 0, keylength/8);
if (!RAND_bytes(aes_key, keylength/8))
exit(-1);
size_t inputslength = 0;
printf("Give an input's length:\n");
scanf("%lu", &inputslength);
/* generate input with a given length */
unsigned char *aes_input = (unsigned char*)malloc(sizeof(unsigned char) *inputslength);
memset(aes_input, 'X', inputslength);
/* init vector */
unsigned char *iv_enc = (unsigned char*)malloc(sizeof(unsigned char) *AES_BLOCK_SIZE), *iv_dec = (unsigned char*)malloc(sizeof(unsigned char) *AES_BLOCK_SIZE);
RAND_bytes(iv_enc, AES_BLOCK_SIZE);
memcpy(iv_dec, iv_enc, AES_BLOCK_SIZE);
// buffers for encryption and decryption
const size_t encslength = ((inputslength + AES_BLOCK_SIZE) / AES_BLOCK_SIZE) * AES_BLOCK_SIZE;
unsigned char *enc_out = (unsigned char*)malloc(sizeof(unsigned char) *encslength);
unsigned char *dec_out = (unsigned char*)malloc(sizeof(unsigned char) *inputslength);
memset(enc_out, 0, sizeof(enc_out));
memset(dec_out, 0, sizeof(dec_out));
// so i can do with this aes-cbc-128 aes-cbc-192 aes-cbc-256
AES_KEY enc_key, dec_key;
AES_set_encrypt_key(aes_key, keylength, &enc_key);
AES_cbc_encrypt(aes_input, enc_out, inputslength, &enc_key, iv_enc, AES_ENCRYPT);
AES_set_decrypt_key(aes_key, keylength, &dec_key);
AES_cbc_encrypt(enc_out, dec_out, encslength, &dec_key, iv_dec, AES_DECRYPT);
printf("original:\t");
hex_print(aes_input, inputslength);
printf("encrypt:\t");
hex_print(enc_out, encslength);
printf("decrypt:\t");
hex_print(dec_out, inputslength);
// free memory here
return 0;
}