I'm trying to decrypt passwords that were stored in a database from a standard SqlMembershipProvider. In order to do this, I hacked together following console app:
static void Main(string[] args)
{
const string encryptedPassword = @"wGZmgyql4prPIr7t1uaxa+RBRJC51qOPBO5ZkSskUtUCY1aBpqNifQGknEfWzky4";
const string iv = @"Jc0RhfDog8SKvtF9aI+Zmw==";
var password = Decrypt(encryptedPassword, iv);
Console.WriteLine(password);
Console.ReadKey();
}
public static string Decrypt(string toDecrypt, string iv)
{
var ivBytes = Convert.FromBase64String(iv);
const string decryptKey = "DECRYPTION_KEY_HERE";
开发者_如何学编程 var keyArray = StringToByteArray(decryptKey);
var toEncryptArray = Convert.FromBase64String(toDecrypt);
var rDel = new AesCryptoServiceProvider() { Key = keyArray, IV = ivBytes};
var cTransform = rDel.CreateDecryptor();
var resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
return Encoding.UTF8.GetString(resultArray);
}
public static byte[] StringToByteArray(String hex)
{
var numberChars = hex.Length;
var bytes = new byte[numberChars / 2];
for (var i = 0; i < numberChars; i += 2)
bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
return bytes;
}
This does indeed decrypt the text, however instead of the resulting text being something like "Password1", it's "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0P\0a\0s\0s\0w\0o\0r\0d\01\0" which writes to the console as a bunch of spaces, then "P a s s w o r d 1". Any ideas what I'm doing wrong?
I suspect that part of the problem might be that the original password was encoded as UTF-16 before encryption, and you're decoding it as UTF-8. Try changing the final line of your Decrypt
method:
return Encoding.Unicode.GetString(resultArray);
That doesn't explain all those spurious leading zeros though. Very strange...
EDIT...
Actually, I seem to remember that SqlMembershipProvider
prefixes the password bytes with a 16-byte salt before encryption, in which case you'll probably be able to get away with something like this:
return Encoding.Unicode.GetString(resultArray, 16, resultArray.Length - 16);
But that still doesn't explain why those 16 bytes are all zeros rather than a bunch of random values...
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