[英]Refactor JavaScript decryption into C# - AES 128
I need to take working JavaScript that decrypts a message and convert it into C#.我需要使用 JavaScript 来解密消息并将其转换为 C#。 I have the decryption information (the "decrypt" variable below) which looks like:
AES-128:<salt>:<iv>:<key>
.我有解密信息(下面的“解密”变量),如下所示:
AES-128:<salt>:<iv>:<key>
。 Here's the JavaScript:这是 JavaScript:
function decodeString(message, decrypt) {
var parts = decrypt.split(':', 4);
var salt = CryptoJS.enc.Hex.parse(parts[1]);
var iv = CryptoJS.enc.Hex.parse(parts[2]);
var key = CryptoJS.PBKDF2(parts[3], salt, { keySize: 128/32, iterations: 100 });
try {
message = message.replace(/\s+/g, '');
var d = CryptoJS.AES.decrypt(message, key, { iv: iv, mode: CryptoJS.mode.CBC, padding: CryptoJS.pad.Pkcs7 });
message = d.toString(CryptoJS.enc.Utf8);
} catch (e) {
console.error("Encountered a problem decrypting and encrypted page!");
console.log(e);
}
return(message);
}
Here's what I have in C#, but I get an exception on the CreateDecryptor call.这是我在 C# 中的内容,但在 CreateDecryptor 调用中出现异常。
using System.Security.Cryptography;
private string DecodeString(string message, string decrypt)
{
string[] parts = decrypt.ToString().Split(':');
byte[] salt = Encoding.UTF8.GetBytes(parts[1]);
byte[] iv = Encoding.UTF8.GetBytes(parts[2]);
var pbkdf2 = new Rfc2898DeriveBytes(parts[3], salt, 100);
int numKeyBytes = 128; // Not sure this is correct
byte[] key = pbkdf2.GetBytes(numKeyBytes);
string plainText = null;
using (AesManaged aes = new AesManaged())
{
aes.KeySize = numKeyBytes; // Not sure if this is correct
aes.BlockSize = 128; // Defaults to 128, but not sure this is correct
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.PKCS7;
try
{
// The below line has the following exception:
// The specified key is not a valid size for this algorithm.
// Parameter name: key
using (var decrypter = aes.CreateDecryptor(key, iv))
using (var plainTextStream = new MemoryStream())
{
using (var decrypterStream = new CryptoStream(plainTextStream, decrypter, CryptoStreamMode.Write))
using (var binaryWriter = new BinaryWriter(decrypterStream))
{
string encryptedText = Regex.Replace(message, @"\s+", "");
binaryWriter.Write(encryptedText);
}
byte[] plainTextBytes = plainTextStream.ToArray();
plainText = Encoding.UTF8.GetString(plainTextBytes);
}
}
catch (Exception ex)
{
log.Error("Unable to decrypt message.", ex);
}
return plainText;
}
}
Any suggestions would be appreciated!任何建议,将不胜感激!
In the C# code there are the following issues:在 C# 代码中存在以下问题:
numKeyBytes
specifies the key size in bytes and is therefore 16 (and not 128) for AES-128. numKeyBytes
以字节为单位指定密钥大小,因此对于 AES-128 为 16(而不是 128)。aes.KeySize
specifies the key size in bits and is therefore numKeyBytes * 8
(and not numKeyBytes
), but can alternatively be omitted. aes.KeySize
以位为单位指定密钥大小,因此是numKeyBytes * 8
(而不是numKeyBytes
),但也可以省略。aes.BlockSize
, aes.Mode
and aes.Padding
the default values are used (128, CBC, PKCS7), so they do not need to be specified explicitly.aes.BlockSize
、 aes.Mode
和aes.Padding
使用默认值(128、CBC、PKCS7),因此不需要明确指定它们。encryptedText
must be Base64 decoded. encryptedText
必须经过 Base64 解码。 A possible implementation is:一个可能的实现是:
private string Decrypt(string message, string decrypt)
{
string[] parts = decrypt.ToString().Split(':');
byte[] salt = StringToByteArray(parts[1]); // Hex decode salt
byte[] iv = StringToByteArray(parts[2]); // Hex dedoce IV
var pbkdf2 = new Rfc2898DeriveBytes(parts[3], salt, 100);
int numKeyBytes = 16; // AES-128 key size in bytes: 16
byte[] key = pbkdf2.GetBytes(numKeyBytes);
string plainText = null;
using (AesManaged aes = new AesManaged())
{
aes.KeySize = 192;
try
{
string encryptedText = Regex.Replace(message, @"\s+", "");
using (var decrypter = aes.CreateDecryptor(key, iv))
using (MemoryStream msDecrypt = new MemoryStream(Convert.FromBase64String(encryptedText))) // Base64 decode ciphertext
{
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decrypter, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
{
plainText = srDecrypt.ReadToEnd();
}
}
}
}
catch (Exception ex)
{
Console.WriteLine("Unable to decrypt message.", ex);
}
return plainText;
}
}
where StringToByteArray()
is from here . StringToByteArray()
来自这里。
I changed the Stream part to be analogous to this example , but the original implementation works as well, so this change is optional.我将 Stream 部分更改为与此示例类似,但原始实现也可以,因此此更改是可选的。
Test: Both codes return for the data测试:两个代码都返回数据
message = "YhyXEjjNAnRUUONwVzlha59tRoWkeEwTkOtSKOicRd/iBKkGgIp+DeWmvEXxAU53";
decrypt = "AES-128:30313233343536373839303132333435:35343332313039383736353433323130:my passphrase";
the plaintext:明文:
The quick brown fox jumps over the lazy dog
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.