AES CTR128

[Mohamed Amine Ourmech]

  Good morning,
I want to test the AES CTR128 encryption of openSSL but infortunately i
could not find one. I have tested one but still i got errors in the output
of the program. here is the code i tested (i found it on the internet), plz
can anyone provide a really simple test program for the counter mode of AES
in openSSL, or simply see what s the problem in that source code. Thank you
very much for consideration.

#include <stdio.h>
#include <string.h>
#include < openssl
<http://osdir.com/ml/encryption.openssl.devel/2002-07/msg00358.html#>/aes.h>


#define KEY_LENGTH 16
#define TEXT_LENGTH 36
#define COUNTER_LENGTH 16

void mirror(const unsigned char *in, unsigned char *out,
            const unsigned long length, const AES_KEY *key,
            unsigned char *counter, unsigned int *num) {

        unsigned int n;
        unsigned long l=length;
        unsigned char tmp[AES_BLOCK_SIZE];

        memset(tmp, 0xFF, AES_BLOCK_SIZE);
}

int main(void)
{
        unsigned char key[KEY_LENGTH + 1] = "9dfe5ea4c3f84ae3";
        unsigned char plaintext1[(TEXT_LENGTH / 2) + 1] =
"123456789012345678";
        unsigned char plaintext2[(TEXT_LENGTH / 2) + 1] =
"876543210987654321";
        unsigned char ciphertext[TEXT_LENGTH + 1];
        unsigned char plaintext[TEXT_LENGTH + 1];
        unsigned char ecounter[COUNTER_LENGTH + 1] = "6543210987654321";
        unsigned char dcounter[COUNTER_LENGTH + 1] = "6543210987654321";
        AES_KEY k;
        int num;
        int retval;


        retval = AES_set_encrypt_key(key, strlen(key) * 8, &k);
        if (retval < 0) {
                printf("couldn't set encrypt key: %d\n", retval);
                return -1;
        }

        num = 0;
        AES_ctr128_encrypt(plaintext1, ciphertext, strlen(plaintext1),
                           &k, ecounter, &num);

        mirror(NULL, NULL, 0, NULL, NULL, NULL);

        AES_ctr128_encrypt(plaintext2, ciphertext + strlen(plaintext1),
                           strlen(plaintext2), &k, ecounter, &num);

        num = 0;
        AES_ctr128_encrypt(ciphertext, plaintext,
                           strlen(plaintext1) + strlen(plaintext2),
                           &k, dcounter, &num);

        retval = strncmp(plaintext, plaintext1, strlen(plaintext1));
        if (retval != 0) {
                printf("error\n");
                return -1;
        }
        retval = strncmp(plaintext + strlen(plaintext1), plaintext2,
                         strlen(plaintext2));
        if (retval != 0) {
                printf("error\n");
                return -1;
        }

        printf("success\n");

        return 0;
}