Agfdhyk

I'm trying to encrypt "customer" information before writing that information to a file using the OpenSSL CBC-Mode for C.

When I try to encrypt the text it doesn't create an encrypted output it also appears to corrupt the given IV
It goes as follows

BANK: create-user bob 1234 1

PLAINTEXT: bob

IV: 9289437166649966

ENCRYPTION OF NAME OUTPUT:

0010 - <SPACES/NULS>        <-- encrypting name outputs nothing

PLAINTEXT: 1234

IV: ��=H�W��I��%%��� <-- IV becomes unusable afterwards

ENCRYPTION OF PIN OUTPUT:

0010 - <SPACES/NULS>        <-- Still no encryption output

The corrupted IV is always the same regardless of inputted IV

My code for generating the encryption is this:

unsigned char *cipher_name, *cipher_pin, IV[16], *IV_cpy*plaintext_n, *plaintext_p;

cipher_name = (unsigned char *) calloc(1000, sizeof(unsigned char));

cipher_pin = (unsigned char *) calloc(1000, sizeof(unsigned char));

plaintext_n = (unsigned char *) calloc(1000, sizeof(unsigned char));

plaintext_p = (unsigned char *) calloc(1000, sizeof(unsigned char));

int cipher_len;

.

.

.

rand_gen(IV);

IV_cpy = (unsigned char *)malloc(strlen((char *)IV));

memcpy(IV_cpy, IV, strlen((char *)(IV)));



strcpy((char *)plaintext_n,cmd[1]);

cipher_len = encrypt(plaintext_n, strlen((char *) plaintext_n), IV,cipher_name);

BIO_dump_fp (stdout, (const char *)cipher_name, cipher_len);

strcpy((char *)plaintext_p, cmd[2]);

memcpy(IV_cpy, IV, strlen((char *)(IV)));

cipher_len = encrypt(plaintext_p, strlen((char *) plaintext_p), IV, cipher_pin);

BIO_dump_fp (stdout, (const char *)cipher_pin, cipher_len);

I omitted the print statements to help readability.

The code that generates the IV is:

void rand_gen(unsigned char *ret_val) {

    int i, random;

    char rand_int[2];

    ret_val[0] = '';

    srand(time(0));

    for(i = 0; i < 16; i++) {

            random = rand() % 10;

            if(random == 0) {

                    random = 1;

            }

            sprintf(rand_int, "%d", random);

            strcat((char *)ret_val, rand_int);

    }

}

The code for the encrypt function is

int encrypt(unsigned char *plaintext, int plaintext_len, unsigned char

*ciphertext, unsigned char *IV) {

    EVP_CIPHER_CTX *ctx;

    int len;

    int ciphertext_len;

    if(!(ctx = EVP_CIPHER_CTX_new())) handleErrors();

    if(1 != EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, key, IV)) handleErrors();

    if(1 != EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len)) handleErrors();

    ciphertext_len = len;

    if(1 != EVP_EncryptFinal_ex(ctx, ciphertext + len, &len)) handleErrors(); 

    ciphertext_len += len;

    EVP_CIPHER_CTX_free(ctx);

    return ciphertext_len;

}

The key is available elsewhere which is why it's not in the function args

What is being output by encrypt:

0010 - <SPACES/NULS>

What encrypt is supposed to be outputting:

0000 - c7 2b 0a 46 7f 8e 2f e1-7d e6 a3 20 99 c2 7d 2b   .+.F../.}.. ..}+