我正在使用一个外部 API，它返回一个 Blowfish 加密的 JSON 数组。首先，我尝试使用基于这篇文章的 BountyCaSTLe 包来实现 Blowfish 加密/解密方法c# Bouncy Castle Blowfish Decryption - Pad block corrupted .
internal class Program
{
private static void Main(string[] args)
{
string key = "KgKnVRujrgAv4XjD4bKCqdQVN5De0DCw8zpu1URnPw8="; // random
string content = "[{'id':1},{'id':2}]";
string encryptedContent = Encrypt(content, key);
string decryptedContent = Decrypt(encryptedContent, key);
/*
decryptedContent returns
[{'id':1},{'id':2}]\0\0\0\0\0
so I think this should be fine
*/
}
private static string Encrypt(string content, string encryptionKey)
{
byte[] contentBytes = Encoding.UTF8.GetBytes(content);
return SharedCode(
contentBytes,
encryptionKey,
true,
encryptedContentBytes => BitConverter
.ToString(encryptedContentBytes)
.Replace("-", ""));
}
private static string Decrypt(string encryptedContent, string decryptionKey)
{
byte[] contentBytes = Hex.Decode(encryptedContent);
return SharedCode(contentBytes, decryptionKey, false, decryptedContentBytes =>
{
string decryptedContentString = BitConverter
.ToString(decryptedContentBytes)
.Replace("-", "");
byte[] hexBytes = new byte[decryptedContentString.Length / 2];
for (int i = 0; i < hexBytes.Length; i++)
{
string currentHexString = decryptedContentString.Substring(i * 2, 2);
hexBytes[i] = Convert.ToByte(currentHexString, 16);
}
return Encoding.UTF8.GetString(hexBytes);
});
}
private static string SharedCode(byte[] contentBytes, string key, bool forceEncryption, Func<byte[], string> processor)
{
BlowfishEngine blowfishEngine = new BlowfishEngine();
PaddedBufferedBlockCipher paddedBufferedBlockCipher = new PaddedBufferedBlockCipher(blowfishEngine);
byte[] keyBytes = Encoding.UTF8.GetBytes(key);
KeyParameter keyParameter = new KeyParameter(keyBytes);
paddedBufferedBlockCipher.Init(forceEncryption, keyParameter);
int outputLength = paddedBufferedBlockCipher.GetOutputSize(contentBytes.Length);
byte[] outputBytes = new byte[outputLength];
int processedBytes = paddedBufferedBlockCipher.ProcessBytes(contentBytes, 0, contentBytes.Length, outputBytes, 0);
paddedBufferedBlockCipher.DoFinal(outputBytes, processedBytes);
return processor(outputBytes);
}
}
$-1$cb8ba9e30b19ff2a$d1157421764fe503d1fa9810fb9e6c3b424a1e8d014a321f5a2fb47ec6ebc8287d4d6236448d3623be42cf927fb883ca48810037c1a62bd229f937727c272c76420eb1f630bb2856c27d10c955220a1539f64e07c5708db90787ac470cad8372ea086501981c7a53ca69740c7ccfced856e234a6801efcf1f71178e75646441ba2716ea75a75ff3e6e002ba08ad18efeef95a909c9a5c68087cc63ed138a63c6788b9bbc43f3c04d2a496660f84ac98f011d3930c61ce9d5565131d2cba65db7c9bef824dd9a6594
我收到了一个解密 key 和这个 PHP 代码示例作为“文档”。响应本身包含三组
.
<?php
function decryptData(string $data, string $key): string{
$matches = [];
if(!preg_match('|^\$([^$]{2,4})\$([a-f0-9]{16,64})\$|i', $data, $matches)){
return '';
}
$data = (string) substr($data, strlen($matches[0]));
switch($matches[1]){
default:
return '';
case '-1':
$data = (string) hex2bin($data);
case '-1a':
$algo = 'blowfish';
return (string) openssl_decrypt($data, $algo, (string) base64_decode($key), OPENSSL_RAW_DATA, (string) hex2bin($matches[2]));
}
}
internal class Program
{
private static void Main(string[] args)
{
string key = "KgKnVRujrgAv4XjD4bKCqdQVN5De0DCw8zpu1URnPw8"; // this decryption key is not the correct one to use
string apiResponse = "$-1$cb8ba9e30b19ff2a$d1157421764fe503d1fa9810fb9e6c3b424a1e8d014a321f5a2fb47ec6ebc8287d4d6236448d3623be42cf927fb883ca48810037c1a62bd229f937727c272c76420eb1f630bb2856c27d10c955220a1539f64e07c5708db90787ac470cad8372ea086501981c7a53ca69740c7ccfced856e234a6801efcf1f71178e75646441ba2716ea75a75ff3e6e002ba08ad18efeef95a909c9a5c68087cc63ed138a63c6788b9bbc43f3c04d2a496660f84ac98f011d3930c61ce9d5565131d2cba65db7c9bef824dd9a6594";
Match matches = Regex.Match(apiResponse, @"^\$([^$]{2,4})\$([a-f0-9]{16,64})\$([a-f0-9]*)");
Group algorithm = matches.Groups[1];
Group salt = matches.Groups[2];
Group content = matches.Groups[3];
string encryptedContent = content.ToString();
string decryptedContent = Decrypt(encryptedContent, key);
}
private static string Decrypt(string encryptedContent, string decryptionKey)
{
byte[] contentBytes = Hex.Decode(encryptedContent);
BlowfishEngine blowfishEngine = new BlowfishEngine();
PaddedBufferedBlockCipher paddedBufferedBlockCipher = new PaddedBufferedBlockCipher(blowfishEngine);
byte[] keyBytes = Encoding.UTF8.GetBytes(decryptionKey);
KeyParameter keyParameter = new KeyParameter(keyBytes);
paddedBufferedBlockCipher.Init(false, keyParameter);
int outputLength = paddedBufferedBlockCipher.GetOutputSize(contentBytes.Length);
byte[] outputBytes = new byte[outputLength];
int processedBytes = paddedBufferedBlockCipher.ProcessBytes(contentBytes, 0, contentBytes.Length, outputBytes, 0);
paddedBufferedBlockCipher.DoFinal(outputBytes, processedBytes); // throws Org.BouncyCastle.Crypto.InvalidCipherTextException: 'pad block corrupted'
string decryptedContentString = BitConverter
.ToString(outputBytes)
.Replace("-", "");
byte[] hexBytes = new byte[decryptedContentString.Length / 2];
for (int i = 0; i < hexBytes.Length; i++)
{
string currentHexString = decryptedContentString.Substring(i * 2, 2);
hexBytes[i] = Convert.ToByte(currentHexString, 16);
}
return Encoding.UTF8.GetString(hexBytes);
}
}
paddedBufferedBlockCipher.DoFinal(outputBytes, processedBytes);
Org.BouncyCastle.Crypto.InvalidCipherTextException: 'pad block corrupted'
异常(exception)。有人知道如何解密这个 Api 响应吗？
最佳答案
PHP 代码首先将三部分分开。第二部分是 IV，它是十六进制解码的，因此大小为 8 个字节。第三部分是数据，由于第一部分中的 -1，首先对其进行十六进制解码，然后通过在 CBC 模式下应用 Blowfish 并使用 PKCS7 填充使用 key 和 IV 进行解密。
要检查 C# 实现，测试数据很有用:
MDEyMzQ1Njc4OTAxMjM0NTY3ODk=
$-1$cb8ba9e30b19ff2a$1cb8430f6b9c109e4334874408dbd26be36b0c9600383d63afd70669efcec38bea1290dfbe6b71519b1f48b514957845
decryptData()返回:The quick brown fox jumps over the lazy dog
这导致例如在下面的实现中:
private static void Main(string[] args)
{
//string key = "KgKnVRujrgAv4XjD4bKCqdQVN5De0DCw8zpu1URnPw8"; // this decryption key is not the correct one to use
//string apiResponse = "$-1$cb8ba9e30b19ff2a$d1157421764fe503d1fa9810fb9e6c3b424a1e8d014a321f5a2fb47ec6ebc8287d4d6236448d3623be42cf927fb883ca48810037c1a62bd229f937727c272c76420eb1f630bb2856c27d10c955220a1539f64e07c5708db90787ac470cad8372ea086501981c7a53ca69740c7ccfced856e234a6801efcf1f71178e75646441ba2716ea75a75ff3e6e002ba08ad18efeef95a909c9a5c68087cc63ed138a63c6788b9bbc43f3c04d2a496660f84ac98f011d3930c61ce9d5565131d2cba65db7c9bef824dd9a6594";
string key = "MDEyMzQ1Njc4OTAxMjM0NTY3ODk=";
string apiResponse = "$-1$cb8ba9e30b19ff2a$1cb8430f6b9c109e4334874408dbd26be36b0c9600383d63afd70669efcec38bea1290dfbe6b71519b1f48b514957845";
Match matches = Regex.Match(apiResponse, @"^\$([^$]{2,4})\$([a-f0-9]{16,64})\$([a-f0-9]*)");
Group algorithm = matches.Groups[1];
Group iv = matches.Groups[2]; // 2nd part is the IV
Group content = matches.Groups[3];
string decryptedContent = Decrypt(content.ToString(), key, iv.ToString()); // Pass additionally the IV
Console.WriteLine(decryptedContent);
}
private static string Decrypt(string encryptedContent, string decryptionKey, string iv)
{
byte[] contentBytes = Hex.Decode(encryptedContent);
byte[] keyBytes = Convert.FromBase64String(decryptionKey); // Base64 decode the key
KeyParameter keyParameter = new KeyParameter(keyBytes);
ParametersWithIV keyParamWithIv = new ParametersWithIV(keyParameter, Hex.Decode(iv)); // Consider the IV
BlowfishEngine blowfishEngine = new BlowfishEngine();
PaddedBufferedBlockCipher paddedBufferedBlockCipher = new PaddedBufferedBlockCipher(new CbcBlockCipher(blowfishEngine), new Pkcs7Padding()); // Consider CBC mode and PKCS7 padding
paddedBufferedBlockCipher.Init(false, keyParamWithIv);
int outputLength = paddedBufferedBlockCipher.GetOutputSize(contentBytes.Length);
byte[] outputBytes = new byte[outputLength];
int processedBytes = paddedBufferedBlockCipher.ProcessBytes(contentBytes, 0, contentBytes.Length, outputBytes, 0);
processedBytes += paddedBufferedBlockCipher.DoFinal(outputBytes, processedBytes);
return Encoding.UTF8.GetString(outputBytes, 0, processedBytes); // The quick brown fox jumps over the lazy dog
}
关于c# - 如何使用 BouncyCaSTLe Blowfish 实现解密数据？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/66370462/