Clean up do_crypt code

Avoid unnecessary alloc/copy/free cycles and clean up structure in
general. Add a few extra checks for the key length.
This commit is contained in:
Nikita Popov 2014-03-02 00:42:13 +01:00
parent a861a3a93d
commit 32333abe3e

View file

@ -658,7 +658,7 @@ PHP_FUNCTION(mcrypt_generic)
char *data;
int data_len;
php_mcrypt *pm;
unsigned char* data_s;
char* data_s;
int block_size, data_size;
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "rs", &mcryptind, &data, &data_len) == FAILURE) {
@ -1165,14 +1165,43 @@ PHP_FUNCTION(mcrypt_get_cipher_name)
}
/* }}} */
static void php_mcrypt_do_crypt(char* cipher, const char *key, int key_len, const char *data, int data_len, char *mode, const char *iv, int iv_len, int argc, int dencrypt, zval* return_value TSRMLS_DC) /* {{{ */
static zend_bool php_mcrypt_is_valid_key_size(MCRYPT td, int key_len) /* {{{ */
{
if (key_len <= 0) {
return 0;
}
if (key_len > mcrypt_enc_get_key_size(td)) {
return 0;
}
{
int count, i;
int *key_sizes = mcrypt_enc_get_supported_key_sizes(td, &count);
if (!key_sizes) {
/* All key sizes are valid */
return 1;
}
for (i = 0; i < count; i++) {
if (key_sizes[i] == key_len) {
mcrypt_free(key_sizes);
return 1;
}
}
mcrypt_free(key_sizes);
return 0;
}
}
/* }}} */
static void php_mcrypt_do_crypt(char* cipher, const char *key, int key_len, const char *data, int data_len, char *mode, const char *iv, int iv_len, int dencrypt, zval* return_value TSRMLS_DC) /* {{{ */
{
char *cipher_dir_string;
char *module_dir_string;
int block_size, use_key_length, i, count, iv_size;
unsigned long int data_size;
int *key_length_sizes;
char *key_s = NULL, *iv_s;
char *data_s;
MCRYPT td;
@ -1183,88 +1212,55 @@ static void php_mcrypt_do_crypt(char* cipher, const char *key, int key_len, cons
php_error_docref(NULL TSRMLS_CC, E_WARNING, MCRYPT_OPEN_MODULE_FAILED);
RETURN_FALSE;
}
/* Checking for key-length */
key_length_sizes = mcrypt_enc_get_supported_key_sizes(td, &count);
if (count == 0 && key_length_sizes == NULL) { /* all lengths 1 - k_l_s = OK */
use_key_length = key_len;
key_s = emalloc(use_key_length);
memset(key_s, 0, use_key_length);
memcpy(key_s, key, use_key_length);
} else {
for (i = 0; i < count; i++) {
if (key_length_sizes[i] == key_len) {
use_key_length = key_len;
key_s = emalloc(use_key_length);
memcpy(key_s, key, use_key_length);
break;
}
}
if (!key_s) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "Key of length %d not supported by this algorithm", key_len);
mcrypt_free(key_length_sizes);
RETURN_FALSE;
}
/* Checking for key-length */
if (!php_mcrypt_is_valid_key_size(td, key_len)) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "Key of length %d not supported by this algorithm", key_len);
RETURN_FALSE;
}
mcrypt_free (key_length_sizes);
/* Check IV */
iv_s = NULL;
iv_size = mcrypt_enc_get_iv_size (td);
/* IV is required */
if (mcrypt_enc_mode_has_iv(td) == 1) {
if (argc == 5) {
if (iv_size != iv_len) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, MCRYPT_IV_WRONG_SIZE);
efree(key_s);
RETURN_FALSE;
} else {
iv_s = emalloc(iv_size + 1);
memcpy(iv_s, iv, iv_size);
}
} else if (argc == 4) {
if (!iv) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "Encryption mode requires an initialization vector");
efree(key_s);
RETURN_FALSE;
}
if (iv_len != mcrypt_enc_get_iv_size(td)) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, MCRYPT_IV_WRONG_SIZE);
RETURN_FALSE;
}
}
/* Check blocksize */
if (mcrypt_enc_is_block_mode(td) == 1) { /* It's a block algorithm */
block_size = mcrypt_enc_get_block_size(td);
int block_size = mcrypt_enc_get_block_size(td);
data_size = (((data_len - 1) / block_size) + 1) * block_size;
data_s = emalloc(data_size);
data_s = emalloc(data_size + 1);
memset(data_s, 0, data_size);
memcpy(data_s, data, data_len);
} else { /* It's not a block algorithm */
data_size = data_len;
data_s = emalloc(data_size);
memset(data_s, 0, data_size);
data_s = emalloc(data_size + 1);
memcpy(data_s, data, data_len);
}
if (mcrypt_generic_init(td, key_s, use_key_length, iv_s) < 0) {
if (mcrypt_generic_init(td, (void *) key, key_len, (void *) iv) < 0) {
php_error_docref(NULL TSRMLS_CC, E_RECOVERABLE_ERROR, "Mcrypt initialisation failed");
RETURN_FALSE;
}
if (dencrypt == MCRYPT_ENCRYPT) {
mcrypt_generic(td, data_s, data_size);
} else {
mdecrypt_generic(td, data_s, data_size);
}
RETVAL_STRINGL(data_s, data_size, 1);
data_s[data_size] = 0;
RETVAL_STRINGL(data_s, data_size, 0);
/* freeing vars */
mcrypt_generic_end(td);
if (key_s != NULL) {
efree (key_s);
}
if (iv_s != NULL) {
efree (iv_s);
}
efree (data_s);
}
/* }}} */
@ -1280,7 +1276,7 @@ PHP_FUNCTION(mcrypt_encrypt)
convert_to_string_ex(mode);
php_mcrypt_do_crypt(cipher, key, key_len, data, data_len, Z_STRVAL_PP(mode), iv, iv_len, ZEND_NUM_ARGS(), MCRYPT_ENCRYPT, return_value TSRMLS_CC);
php_mcrypt_do_crypt(cipher, key, key_len, data, data_len, Z_STRVAL_PP(mode), iv, iv_len, MCRYPT_ENCRYPT, return_value TSRMLS_CC);
}
/* }}} */
@ -1296,7 +1292,7 @@ PHP_FUNCTION(mcrypt_decrypt)
convert_to_string_ex(mode);
php_mcrypt_do_crypt(cipher, key, key_len, data, data_len, Z_STRVAL_PP(mode), iv, iv_len, ZEND_NUM_ARGS(), MCRYPT_DECRYPT, return_value TSRMLS_CC);
php_mcrypt_do_crypt(cipher, key, key_len, data, data_len, Z_STRVAL_PP(mode), iv, iv_len, MCRYPT_DECRYPT, return_value TSRMLS_CC);
}
/* }}} */
@ -1312,7 +1308,7 @@ PHP_FUNCTION(mcrypt_ecb)
convert_to_long_ex(mode);
php_mcrypt_do_crypt(cipher, key, key_len, data, data_len, "ecb", iv, iv_len, ZEND_NUM_ARGS(), Z_LVAL_PP(mode), return_value TSRMLS_CC);
php_mcrypt_do_crypt(cipher, key, key_len, data, data_len, "ecb", iv, iv_len, Z_LVAL_PP(mode), return_value TSRMLS_CC);
}
/* }}} */
@ -1328,7 +1324,7 @@ PHP_FUNCTION(mcrypt_cbc)
convert_to_long_ex(mode);
php_mcrypt_do_crypt(cipher, key, key_len, data, data_len, "cbc", iv, iv_len, ZEND_NUM_ARGS(), Z_LVAL_PP(mode), return_value TSRMLS_CC);
php_mcrypt_do_crypt(cipher, key, key_len, data, data_len, "cbc", iv, iv_len, Z_LVAL_PP(mode), return_value TSRMLS_CC);
}
/* }}} */
@ -1344,7 +1340,7 @@ PHP_FUNCTION(mcrypt_cfb)
convert_to_long_ex(mode);
php_mcrypt_do_crypt(cipher, key, key_len, data, data_len, "cfb", iv, iv_len, ZEND_NUM_ARGS(), Z_LVAL_PP(mode), return_value TSRMLS_CC);
php_mcrypt_do_crypt(cipher, key, key_len, data, data_len, "cfb", iv, iv_len, Z_LVAL_PP(mode), return_value TSRMLS_CC);
}
/* }}} */
@ -1360,7 +1356,7 @@ PHP_FUNCTION(mcrypt_ofb)
convert_to_long_ex(mode);
php_mcrypt_do_crypt(cipher, key, key_len, data, data_len, "ofb", iv, iv_len, ZEND_NUM_ARGS(), Z_LVAL_PP(mode), return_value TSRMLS_CC);
php_mcrypt_do_crypt(cipher, key, key_len, data, data_len, "ofb", iv, iv_len, Z_LVAL_PP(mode), return_value TSRMLS_CC);
}
/* }}} */