使用openssl C进行AES（AES-ige-128、AES-ige-192、AES-ege-256）加密/解密

Question

最近，我终于（在stackoverflow的用户@WhozCraig的帮助下）开始在CBC模式下使用AES。现在，我想用AES IGE做同样的事情。我看了openssl-1.0.1e/test/igetest. c并尝试构建自己的测试。但是，我再次遇到了输入和输出大小合适的问题。其他一切都很好，因为我从以前的代码中复制了它：AES（aes-cbc-128、aes-cbc-192、aes-cbc-256）使用openssl C进行加密/解密。

现在，当我传递一个长度小于32的输入时，它会说:

Give a key length [only 128 or 192 or 256!]:
256
Give an input's length:
3
aes_ige.c(88): OpenSSL internal error, assertion failed: (length%AES_BLOCK_SIZE) == 0
 (core dumped)

但是当长度大于32时，我也不太确定它是否都没问题：

Give a key length [only 128 or 192 or 256!]:
256
Give an input's length:
48
original:       58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 
encrypt:        A4 1F C4 E8 42 5E E5 62 1A B6 C1 47 D2 2F 8D 98 D0 0B 32 77 4E 36 84 25 15 5B BA 60 EA A9 64 D2 53 D1 98 78 83 21 90 90 74 44 C7 AA 3E AD 9B 26 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
decrypt:        58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 

这是代码：

    #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);

    const size_t ivsize = AES_BLOCK_SIZE*2;

    /* init vector */
    unsigned char iv_enc[ivsize], iv_dec[ivsize];
    RAND_bytes(iv_enc, ivsize);
    memcpy(iv_dec, iv_enc, ivsize);

    // buffers for encryption and decryption
    const size_t encslength = (inputslength/AES_BLOCK_SIZE + 1) * AES_BLOCK_SIZE;//((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));

    AES_KEY enc_key, dec_key;
    AES_set_encrypt_key(aes_key, keylength, &enc_key);
    AES_set_decrypt_key(aes_key, keylength, &dec_key);

    AES_ige_encrypt(aes_input, enc_out, inputslength, &enc_key, iv_enc, AES_ENCRYPT);

    AES_ige_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;
}

终于！成功了（希望如此）。但如果有人能说，下面的代码是100%好的，我会非常感激；）

#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 = 256;
    //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);

    const size_t ivsize = AES_BLOCK_SIZE*2;
    /* init vector */
    unsigned char iv_enc[ivsize], iv_dec[ivsize];
    RAND_bytes(iv_enc, ivsize);
    memcpy(iv_dec, iv_enc, ivsize);

    // 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_ige_encrypt(aes_input, enc_out, encslength, &enc_key, iv_enc, AES_ENCRYPT);

    AES_set_decrypt_key(aes_key, keylength, &dec_key);
    AES_ige_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;
}

我只改变了这个:

AES_ige_encrypt（aes_input，enc_out，输入长度，，

进入那个：

AES_ige_encrypt（AES_input，enc_out，**encslength**，

正确吗？

编辑2号;)

好的，伙计们，做了另一个例子，根据你们的建议在输入中添加了一些填充。希望现在可以了吗？

#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 = 256;
    //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);

    const size_t ivsize = AES_BLOCK_SIZE*2;
    /* init vector */
    unsigned char iv_enc[ivsize], iv_dec[ivsize];
    RAND_bytes(iv_enc, ivsize);
    memcpy(iv_dec, iv_enc, ivsize);

    // buffers for encryption and decryption
    const size_t encslength = ((inputslength + AES_BLOCK_SIZE) / AES_BLOCK_SIZE) * AES_BLOCK_SIZE;

    unsigned char paddedinput[encslength];
    memset(paddedinput, 0, encslength);
    memcpy(paddedinput, aes_input, inputslength);

    unsigned char enc_out[encslength];
    unsigned char dec_out[inputslength];
    memset(enc_out, 0, sizeof(enc_out));
    memset(dec_out, 0, sizeof(dec_out));

    AES_KEY enc_key, dec_key;
    AES_set_encrypt_key(aes_key, keylength, &enc_key);
    AES_ige_encrypt(paddedinput, enc_out, encslength, &enc_key, iv_enc, AES_ENCRYPT);

    AES_set_decrypt_key(aes_key, keylength, &dec_key);
    AES_ige_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;
}




Answer 1

匿名用户

错误消息说明了一切。

aes_ige.c(88): OpenSSL internal error, assertion failed: (length%AES_BLOCK_SIZE) == 0

这基本上是一个运行时检查（断言），由于向AES_ige.c第88行的源代码中存在的函数AES_ige_encrypt（）提供的输入无效而失败。

OPENSSL_assert((length%AES_BLOCK_SIZE) == 0);

断言基本上检查长度（传递给函数的第三个参数）是否是AES_BLOCK_SIZE的整数倍。如果是，则继续执行，否则程序将停止并输出有关断言失败的警告。

> < li>

因此，请确保传送到< code>AES_ige_encrypt()的数据大小是< code>AES_BLOCK_SIZE的倍数。

如果数据大小不是整数倍，则向其追加< code>NUL字节，使总大小成为< code>AES_BLOCK_SIZE的最近倍数。

此外，始终将整数多重AES_BLOCK_SIZE值作为长度参数传递给AES_ige_encrypt（）。