У меня есть код C для шифрования текста:
ngx_int_t
ngx_http_encrypted_session_3des_mac_encrypt (ngx_pool_t * pool,
ngx_log_t * log,
const u_char * iv, size_t iv_len,
const u_char * key,
size_t key_len,
const u_char * in, size_t in_len,
ngx_uint_t expires,
u_char ** dst, size_t * dst_len)
{
EVP_CIPHER_CTX ctx;
const EVP_CIPHER *cipher;
u_char *p, *data;
int ret;
size_t block_size, buf_size, data_size;
int len;
uint64_t expires_time;
time_t now;
if (key_len != ngx_http_encrypted_session_key_length) {
return NGX_ERROR;
}
EVP_CIPHER_CTX_init (&ctx);
cipher = EVP_aes_256_cbc ();
block_size = EVP_CIPHER_block_size (cipher);
data_size = in_len + sizeof (expires_time);
buf_size = MD5_DIGEST_LENGTH /* for the digest */
+ (data_size + block_size - 1) /* for EVP_EncryptUpdate */
+block_size /* for EVP_EncryptFinal */
;
p = ngx_palloc (pool, buf_size + data_size);
if (p == NULL) {
return NGX_ERROR;
}
*dst = p;
data = p + buf_size;
ngx_memcpy (data, in, in_len);
if (expires == 0) {
expires_time = 0;
} else {
now = time (NULL);
if (now == -1) {
goto evp_error;
}
expires_time = (uint64_t) now + (uint64_t) expires;
}
expires_time = ngx_http_encrypted_session_htonll (expires_time);
ngx_memcpy (data + in_len, (u_char *) & expires_time,
sizeof (expires_time));
MD5 (data, data_size, p);
p += MD5_DIGEST_LENGTH;
ret = EVP_EncryptInit (&ctx, cipher, key, iv);
if (!ret) {
goto evp_error;
}
/* encrypt the raw input data */
ret = EVP_EncryptUpdate (&ctx, p, &len, data, data_size);
if (!ret) {
goto evp_error;
}
p += len;
ret = EVP_EncryptFinal (&ctx, p, &len);
if (!ret) {
return NGX_ERROR;
}
/* XXX we should still explicitly release the ctx
* or we'll leak memory here */
EVP_CIPHER_CTX_cleanup (&ctx);
p += len;
*dst_len = p - *dst;
if (*dst_len > buf_size) {
ngx_log_error (NGX_LOG_ERR, log, 0,
"encrypted_session: 3des_mac_encrypt: buffer error");
return NGX_ERROR;
}
return NGX_OK;
evp_error:
EVP_CIPHER_CTX_cleanup (&ctx);
return NGX_ERROR;
}
Но я хочу перевести эту логику в Perl.Почему в этом коде используется хеширование MD5?Какой модуль Perl мне следует использовать?