问题
I'm using Rijndael Algorithm to encrypt strings (user passwords), but when I decrypt them, it returns me "System.SecureString", and not my decrypted password.
I'm using this basic code:
public static string DecryptString(string cipherText, string password)
{
byte[] key, iv;
Rfc2898DeriveBytes rfcDb = new Rfc2898DeriveBytes(password, Encoding.UTF8.GetBytes(password));
key = rfcDb.GetBytes(16);
iv = rfcDb.GetBytes(16);
byte[] cipheredData = Convert.FromBase64String(cipherText);
RijndaelManaged rijndael = new RijndaelManaged();
rijndael.Mode = CipherMode.CBC;
ICryptoTransform decryptor = rijndael.CreateDecryptor(key, iv);
MemoryStream ms = new MemoryStream(cipheredData);
CryptoStream cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read);
byte[] plainTextData = new byte[cipheredData.Length];
int decryptedByteCount = cs.Read(plainTextData, 0, plainTextData.Length);
ms.Close();
cs.Close();
return Encoding.UTF8.GetString(plainTextData, 0, decryptedByteCount);
}
The real problem is that it's sending me back "System.SecureString", and I can't do anything.
I think it comes from the conversion at the end but I really don't know how to change that (it seems good btw)
return Encoding.UTF8.GetString(plainTextData, 0, decryptedByteCount);
So if you have an idea or a working code sample, I'm interested.
Have a nice day
回答1:
I have implemented rijndael in the past, and here is my version if this is any help:
private static string Encrypt(string plainText, string passPhrase, string saltValue, string hashAlgorithm, int passwordIterations, string initVector, int keySize)
{
// Convert strings into byte arrays.
// Let us assume that strings only contain ASCII codes.
// If strings include Unicode characters, use Unicode, UTF7, or UTF8
// encoding.
var initVectorBytes = Encoding.ASCII.GetBytes(initVector);
var saltValueBytes = Encoding.ASCII.GetBytes(saltValue);
// Convert our plaintext into a byte array.
// Let us assume that plaintext contains UTF8-encoded characters.
var plainTextBytes = Encoding.UTF8.GetBytes(plainText);
// First, we must create a password, from which the key will be derived.
// This password will be generated from the specified passphrase and
// salt value. The password will be created using the specified hash
// algorithm. Password creation can be done in several iterations.
var password = new PasswordDeriveBytes(passPhrase, saltValueBytes, hashAlgorithm, passwordIterations);
// Use the password to generate pseudo-random bytes for the encryption
// key. Specify the size of the key in bytes (instead of bits).
var keyBytes = password.GetBytes(keySize / 8);
// Create uninitialized Rijndael encryption object.
// It is reasonable to set encryption mode to Cipher Block Chaining
// (CBC). Use default options for other symmetric key parameters.
var symmetricKey = new RijndaelManaged { Mode = CipherMode.CBC };
// Generate encryptor from the existing key bytes and initialization
// vector. Key size will be defined based on the number of the key
// bytes.
var encryptor = symmetricKey.CreateEncryptor(keyBytes, initVectorBytes);
// Define memory stream which will be used to hold encrypted data.
var memoryStream = new MemoryStream();
// Define cryptographic stream (always use Write mode for encryption).
var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write);
// Start encrypting.
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
// Finish encrypting.
cryptoStream.FlushFinalBlock();
// Convert our encrypted data from a memory stream into a byte array.
var cipherTextBytes = memoryStream.ToArray();
// Close both streams.
memoryStream.Close();
cryptoStream.Close();
// Convert encrypted data into a base64-encoded string.
var cipherText = Convert.ToBase64String(cipherTextBytes);
// Return encrypted string.
return cipherText;
}
private static string Decrypt(string cipherText, string passPhrase, string saltValue, string hashAlgorithm, int passwordIterations, string initVector, int keySize)
{
// Convert strings defining encryption key characteristics into byte
// arrays. Let us assume that strings only contain ASCII codes.
// If strings include Unicode characters, use Unicode, UTF7, or UTF8
// encoding.
var initVectorBytes = Encoding.ASCII.GetBytes(initVector);
var saltValueBytes = Encoding.ASCII.GetBytes(saltValue);
// Convert our ciphertext into a byte array.
var cipherTextBytes = Convert.FromBase64String(cipherText);
// First, we must create a password, from which the key will be
// derived. This password will be generated from the specified
// passphrase and salt value. The password will be created using
// the specified hash algorithm. Password creation can be done in
// several iterations.
var password = new PasswordDeriveBytes(passPhrase, saltValueBytes, hashAlgorithm, passwordIterations);
// Use the password to generate pseudo-random bytes for the encryption
// key. Specify the size of the key in bytes (instead of bits).
var keyBytes = password.GetBytes(keySize / 8);
// Create uninitialized Rijndael encryption object.
// It is reasonable to set encryption mode to Cipher Block Chaining
// (CBC). Use default options for other symmetric key parameters.
var symmetricKey = new RijndaelManaged { Mode = CipherMode.CBC };
// Generate decryptor from the existing key bytes and initialization
// vector. Key size will be defined based on the number of the key
// bytes.
var decryptor = symmetricKey.CreateDecryptor(keyBytes, initVectorBytes);
// Define memory stream which will be used to hold encrypted data.
var memoryStream = new MemoryStream(cipherTextBytes);
// Define cryptographic stream (always use Read mode for encryption).
var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);
// Since at this point we don't know what the size of decrypted data
// will be, allocate the buffer long enough to hold ciphertext;
// plaintext is never longer than ciphertext.
var plainTextBytes = new byte[cipherTextBytes.Length];
// Start decrypting.
var decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
// Close both streams.
memoryStream.Close();
cryptoStream.Close();
// Convert decrypted data into a string.
// Let us assume that the original plaintext string was UTF8-encoded.
var plainText = Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
// Return decrypted string.
return plainText;
}
public static string EncryptData(string encryptText, string passPhrase, string saltValue, string hashAlgorithm, int passwordIterations, string initVector, int keySize)
{
return Encrypt(encryptText, passPhrase, saltValue, hashAlgorithm, passwordIterations, initVector, keySize);
}
public static string DecryptData(string decryptText, string passPhrase, string saltValue, string hashAlgorithm, int passwordIterations, string initVector, int keySize)
{
return Decrypt(decryptText, passPhrase, saltValue, hashAlgorithm, passwordIterations, initVector, keySize);
}
I then had some public methods that call into the above methods...
public static string EncryptData(string encryptText)
{
return EncryptionHelper.EncryptData(encryptText, ConfigHelper.PassPhrase, ConfigHelper.SaltValue, ConfigHelper.HashAlgorithm, ConfigHelper.PasswordIterations, ConfigHelper.InitVector, ConfigHelper.KeySize);
}
public static string DecryptData(string decryptText)
{
return EncryptionHelper.DecryptData(decryptText, ConfigHelper.PassPhrase, ConfigHelper.SaltValue, ConfigHelper.HashAlgorithm, ConfigHelper.PasswordIterations, ConfigHelper.InitVector, ConfigHelper.KeySize);
}
I then had these in a config file...
<add key="passPhrase" value=""/>
<add key="saltValue" value=""/>
<add key="hashAlgorithm" value="SHA1"/>
<add key="passwordIterations" value="5"/>
<add key="initVector" value=""/>
<add key="keySize" value="256"/>
来源：https://stackoverflow.com/questions/17876782/decrypt-string-with-rijndael-return-system-securestring-as-a-string-but-not