我有一个加密的 NSData 变量,它已经在 Objective-C 中进行了 Base64 编码,并且正在通过 POST 传递给 PHP 脚本。我正在尝试解密此字符串,但不断收到 HMAC 不匹配错误。这是我的PHP代码:
// back to binary
$bin_data = mb_convert_encoding($username_encrypted, "UTF-8", "BASE64");
// extract salt
$salt = substr($bin_data, 2, 8);
// extract HMAC salt
$hmac_salt = substr($bin_data, 10, 8);
// extract IV
$iv = substr($bin_data, 18, 16);
// extract data
$data = substr($bin_data, 34, strlen($bin_data) - 34 - 32);
// extract HMAC
$hmac = substr($bin_data, strlen($bin_data) - 32);
// make HMAC key
$hmac_key = pbkdf2('SHA1', $password, $hmac_salt, 10000, 32, true);
// make HMAC hash
$hmac_hash = hash_hmac('sha256', $data, $hmac_key, true);
// check if HMAC hash matches HMAC
if($hmac_hash != $hmac)
exit("Error HMAC mismatch");
// make data key
$key = pbkdf2('SHA1', $password, $salt, 10000, 32, true);
// decrypt
$ret = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, $data, MCRYPT_MODE_CBC, $iv);
echo trim(preg_replace('/[\x00-\x08\x0B\x0C\x0E-\x1F\x80-\xFF]/u', '', $ret));
function pbkdf2($algorithm, $password, $salt, $count, $key_length, $raw_output = false)
{
$algorithm = strtolower($algorithm);
if(!in_array($algorithm, hash_algos(), true))
die('PBKDF2 ERROR: Invalid hash algorithm.');
if($count <= 0 || $key_length <= 0)
die('PBKDF2 ERROR: Invalid parameters.');
$hash_length = strlen(hash($algorithm, "", true));
$block_count = ceil($key_length / $hash_length);
$output = "";
for($i = 1; $i <= $block_count; $i++) {
// $i encoded as 4 bytes, big endian.
$last = $salt . pack("N", $i);
// first iteration
$last = $xorsum = hash_hmac($algorithm, $last, $password, true);
// perform the other $count - 1 iterations
for ($j = 1; $j < $count; $j++) {
$xorsum ^= ($last = hash_hmac($algorithm, $last, $password, true));
}
$output .= $xorsum;
}
if($raw_output)
return substr($output, 0, $key_length);
else
return bin2hex(substr($output, 0, $key_length));
}
这是我的 iOS 代码:
NSData *plain_data = [plain_string dataUsingEncoding:NSUTF8StringEncoding];
NSError *error_encryption = nil;
NSData *encrypted_data = [RNOpenSSLEncryptor encryptData:plain_data
withSettings:kRNCryptorAES256Settings
password:key
error:&error_encryption];
NSString *test_variable = [encrypted_data base64Encoding];
知道有什么问题吗?