static unsigned
cipher_iv_size(PX_Cipher * c)
{
MCRYPT ctx = (MCRYPT) c->ptr;
return mcrypt_enc_mode_has_iv(ctx)
? mcrypt_enc_get_iv_size(ctx) : 0;
}
static Variant php_mcrypt_do_crypt(CStrRef cipher, CStrRef key, CStrRef data,
CStrRef mode, CStrRef iv, bool dencrypt) {
MCRYPT td = mcrypt_module_open((char*)cipher.data(),
(char*)MCG(algorithms_dir).data(),
(char*)mode.data(),
(char*)MCG(modes_dir).data());
if (td == MCRYPT_FAILED) {
raise_warning(MCRYPT_OPEN_MODULE_FAILED);
return false;
}
/* Checking for key-length */
int max_key_length = mcrypt_enc_get_key_size(td);
if (key.size() > max_key_length) {
raise_warning("Size of key is too large for this algorithm");
}
int count;
int *key_length_sizes = mcrypt_enc_get_supported_key_sizes(td, &count);
int use_key_length;
char *key_s = NULL;
if (count == 0 && key_length_sizes == NULL) { // all lengths 1 - k_l_s = OK
use_key_length = key.size();
key_s = (char*)malloc(use_key_length);
memcpy(key_s, key.data(), use_key_length);
} else if (count == 1) { /* only m_k_l = OK */
key_s = (char*)malloc(key_length_sizes[0]);
memset(key_s, 0, key_length_sizes[0]);
memcpy(key_s, key.data(), MIN(key.size(), key_length_sizes[0]));
use_key_length = key_length_sizes[0];
} else { /* dertermine smallest supported key > length of requested key */
use_key_length = max_key_length; /* start with max key length */
for (int i = 0; i < count; i++) {
if (key_length_sizes[i] >= key.size() &&
key_length_sizes[i] < use_key_length) {
use_key_length = key_length_sizes[i];
}
}
key_s = (char*)malloc(use_key_length);
memset(key_s, 0, use_key_length);
memcpy(key_s, key.data(), MIN(key.size(), use_key_length));
}
mcrypt_free(key_length_sizes);
/* Check IV */
char *iv_s = NULL;
int iv_size = mcrypt_enc_get_iv_size(td);
/* IV is required */
if (mcrypt_enc_mode_has_iv(td) == 1) {
if (!iv.empty()) {
if (iv_size != iv.size()) {
raise_warning("The IV parameter must be as long as the blocksize");
} else {
iv_s = (char*)malloc(iv_size + 1);
memcpy(iv_s, iv.data(), iv_size);
}
} else {
raise_warning("Attempt to use an empty IV, which is NOT recommended");
iv_s = (char*)malloc(iv_size + 1);
memset(iv_s, 0, iv_size + 1);
}
}
int block_size;
unsigned long int data_size;
String s;
char *data_s;
/* Check blocksize */
if (mcrypt_enc_is_block_mode(td) == 1) { /* It's a block algorithm */
block_size = mcrypt_enc_get_block_size(td);
data_size = (((data.size() - 1) / block_size) + 1) * block_size;
s = String(data_size, ReserveString);
data_s = (char*)s.mutableSlice().ptr;
memset(data_s, 0, data_size);
memcpy(data_s, data.data(), data.size());
} else { /* It's not a block algorithm */
data_size = data.size();
s = String(data_size, ReserveString);
data_s = (char*)s.mutableSlice().ptr;
memcpy(data_s, data.data(), data.size());
}
if (mcrypt_generic_init(td, key_s, use_key_length, iv_s) < 0) {
raise_warning("Mcrypt initialisation failed");
return false;
}
if (dencrypt) {
mdecrypt_generic(td, data_s, data_size);
} else {
mcrypt_generic(td, data_s, data_size);
}
/* freeing vars */
mcrypt_generic_end(td);
if (key_s != NULL) {
free(key_s);
}
if (iv_s != NULL) {
free(iv_s);
}
return s.setSize(data_size);
}
