Develop Reference

How can i encrypt by postgres and decrypt by c#?

I encrypt password in postgres
and i want to decrypt it in c#, but two ways can not matching
.How can i do that?
private static byte[] TruncateHash(string key, int length)
{
SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider();
// Hash the key.
byte[] keyBytes = System.Text.Encoding.Unicode.GetBytes(key);
byte[] hash = sha1.ComputeHash(keyBytes);
// Truncate or pad the hash.
Array.Resize(ref hash, length);
return hash;
}
public static string EncryptString(string plaintext, string Passphrase)
{
TripleDESCryptoServiceProvider tripleDes = new TripleDESCryptoServiceProvider();
// Initialize the crypto provider.
tripleDes.Key = TruncateHash(Passphrase, tripleDes.KeySize / 8);
tripleDes.IV = TruncateHash("", tripleDes.BlockSize / 8);
// Convert the plaintext string to a byte array.
byte[] plaintextBytes = System.Text.Encoding.Unicode.GetBytes(plaintext);
// Create the stream.
System.IO.MemoryStream ms = new System.IO.MemoryStream();
// Create the encoder to write to the stream.
CryptoStream encStream = new CryptoStream(ms, tripleDes.CreateEncryptor(), System.Security.Cryptography.CryptoStreamMode.Write);
// Use the crypto stream to write the byte array to the stream.
encStream.Write(plaintextBytes, 0, plaintextBytes.Length);
encStream.FlushFinalBlock();
// Convert the encrypted stream to a printable string.
return Convert.ToBase64String(ms.ToArray());
}
public static string DecryptString(string encryptedtext, string Passphrase)
{
TripleDESCryptoServiceProvider tripleDes = new TripleDESCryptoServiceProvider();
// Initialize the crypto provider.
tripleDes.Key = TruncateHash(Passphrase, tripleDes.KeySize / 8);
tripleDes.IV = TruncateHash("", tripleDes.BlockSize / 8);
// Convert the encrypted text string to a byte array.
byte[] encryptedBytes = Convert.FromBase64String(encryptedtext);
// Create the stream.
System.IO.MemoryStream ms = new System.IO.MemoryStream();
// Create the decoder to write to the stream.
CryptoStream decStream = new CryptoStream(ms, tripleDes.CreateDecryptor(), System.Security.Cryptography.CryptoStreamMode.Write);
// Use the crypto stream to write the byte array to the stream.
decStream.Write(encryptedBytes, 0, encryptedBytes.Length);
decStream.FlushFinalBlock();
// Convert the plaintext stream to a string.
return System.Text.Encoding.Unicode.GetString(ms.ToArray());
}
I found a way to encrypt in postgres using pgcrypto.
And below is encrypt and decrypt in postgres.
SELECT encode(encrypt_iv('ABCDE121212','Key123', '','3des'), 'base64');
select decrypt_iv(decode('jEI4V5q6h5/p12NRJm666g==','base64'),'Key123','','3des')
What's wrong in my code, c# and postgres can't not matching.
I want to keep c# code and change postgres code to matching

Source Url
Encrypt function:
public static String AES_encrypt(String input, string key, string Iv, int keyLength)
{
RijndaelManaged aes = new RijndaelManaged();
aes.KeySize = keyLength;
aes.BlockSize = 128;
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.PKCS7;
aes.Key = mkey(key,keyLength);
aes.IV = mkey(Iv,128);
var encrypt = aes.CreateEncryptor(aes.Key, aes.IV);
byte[] xBuff = null;
using (var ms = new MemoryStream())
{
using (var cs = new CryptoStream(ms, encrypt, CryptoStreamMode.Write))
{
byte[] xXml = Encoding.UTF8.GetBytes(input);
cs.Write(xXml, 0, xXml.Length);
cs.FlushFinalBlock();
}
xBuff = ms.ToArray();
}
return Convert.ToBase64String(xBuff,Base64FormattingOptions.None);
}
Decrypt function:
public static String AES_decrypt(String Input, string key, string Iv, int keyLength)
{
try
{
RijndaelManaged aes = new RijndaelManaged();
aes.KeySize = keyLength;
aes.BlockSize = 128;
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.PKCS7;
aes.Key = mkey(key,keyLength);
aes.IV = mkey(Iv,128);
var decrypt = aes.CreateDecryptor();
byte[] encryptedStr = Convert.FromBase64String(Input);
string Plain_Text;
using (var ms = new MemoryStream(encryptedStr))
{
using (var cs = new CryptoStream(ms, decrypt, CryptoStreamMode.Read))
{
using (StreamReader reader = new StreamReader(cs))
{
Plain_Text = reader.ReadToEnd();
}
}
}
return Plain_Text;
}
catch (Exception ex)
{
return null;
}
}
Helper function:
private static byte[] mkey(string skey, int keyLength)
{
int length = keyLength / 8;
byte[] key = Encoding.UTF8.GetBytes(skey);
byte[] k = GenerateEmptyArray(length);
for (int i = 0; i < key.Length; i++)
{
//k[i % 16] = (byte)(k[i % 16] ^ key[i]);
k[i] = key[i];
if(i == length-1)
break;
}
return k;
}
Variables:
input = "Hello World"
key = "NBJ42RKQ2vQoYFZO"
Iv = "j1C83921vHExVhVp"
keyLength = 128
Info about variables:
input - string that is not encrypted or encrypted. If it's encrypted it will be in Base64 format
key - Any Unicode character that will match the AES key size(in this example it's 128). I have written a function that will extract the specific length of characters and add them to a byte array
Code:
public static string PasswordFixer(string skey,int keyLength)
{
int length = keyLength / 8;
byte[] key = Encoding.UTF8.GetBytes(skey);
byte[] k = GenerateEmptyArray(length);
for (int i = 0; i < key.Length; i++)
{
k[i] = key[i];
if(i == length-1)
break;
}
return Encoding.UTF8.GetString(k);
}
Iv - it's always 128bit long meaning 16bytes. you can ignore Iv if you want, in PostgreSQL if you planing to use `encrypt` function then you can ignore the Iv by hard coding like this `aes.IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };`
keylength-
This is the AES key length in this example we use 128bit meaning 16 bytes. whatever the characters that you use as the Key need to match the length of 16 bytes.
PostgreSQL
The equivalent SQL statement for the encryption and decryption is this
encrypt_iv,decrypt_iv
select convert_from(decrypt_iv(decode(tbl1.encrypted,'base64')::bytea ,'NBJ42RKQ2vQoYFZO','j1C83921vHExVhVp', 'aes-cbc/pad:pkcs'), 'UTF-8') as decrypted,tbl1.encrypted from (select encode(encrypt_iv('Hello World', 'NBJ42RKQ2vQoYFZO','j1C83921vHExVhVp', 'aes-cbc/pad:pkcs'), 'base64') as encrypted) as tbl1
encrypt,decrypt
select convert_from(decrypt(decode(tbl1.encrypted,'base64')::bytea ,'NBJ42RKQ2vQoYFZO', 'aes-cbc/pad:pkcs'), 'UTF-8') as decrypted,tbl1.encrypted from (select encode(encrypt('Hello World', 'NBJ42RKQ2vQoYFZO', 'aes-cbc/pad:pkcs'), 'base64') as encrypted) as tbl1

AES Encryption Windows Phone 8.1

I need to do 128 bit AES encryption on an application in Windows Phone 8.1. I used the following code for Encrypting and Decrypting the data respectively:
private string GetEncryptedContent(string content)
{
byte[] keyMaterial = Encoding.UTF8.GetBytes(EncryptionKey);
byte[] data = Encoding.UTF8.GetBytes(content);
var provider = WinRTCrypto.SymmetricKeyAlgorithmProvider.OpenAlgorithm(SymmetricAlgorithm.AesCbcPkcs7);
var key = provider.CreateSymmetricKey(keyMaterial);
byte[] cipherText = WinRTCrypto.CryptographicEngine.Encrypt(key, data, null);
return Encoding.UTF8.GetString(cipherText, 0, cipherText.Length);
}
private string GetDecryptedContent(string content)
{
byte[] keyMaterial = Encoding.UTF8.GetBytes(EncryptionKey);
byte[] data = Encoding.UTF8.GetBytes(content);
var provider = WinRTCrypto.SymmetricKeyAlgorithmProvider.OpenAlgorithm(SymmetricAlgorithm.AesCbcPkcs7);
var key = provider.CreateSymmetricKey(keyMaterial);
byte[] cipherText = WinRTCrypto.CryptographicEngine.Decrypt(key, data, null);
return Encoding.UTF8.GetString(cipherText, 0, cipherText.Length);
}
But the encryption and decryption doesn't seem to be working properly. It is getting encrypted to some unicode characters and throwing a crash on decrypting:
Length is not a multiple of block size and no padding is
selected.\r\nParameter name: ciphertext
What am I doing wrong here? Can someone please help?
EDIT
After a lot more time with Google, I found the following methods for encryption and decryption, but they doesn't seem to work either.
public string GetEncryptedContent(string input, string pass)
{
SymmetricKeyAlgorithmProvider SAP = SymmetricKeyAlgorithmProvider.OpenAlgorithm(SymmetricAlgorithmNames.AesEcbPkcs7);
CryptographicKey AES;
HashAlgorithmProvider HAP = HashAlgorithmProvider.OpenAlgorithm(HashAlgorithmNames.Md5);
CryptographicHash Hash_AES = HAP.CreateHash();
string encrypted = "";
try
{
byte[] hash = new byte[32];
Hash_AES.Append(CryptographicBuffer.CreateFromByteArray(Encoding.UTF8.GetBytes(pass)));
byte[] temp;
CryptographicBuffer.CopyToByteArray(Hash_AES.GetValueAndReset(), out temp);
Array.Copy(temp, 0, hash, 0, 16);
Array.Copy(temp, 0, hash, 15, 16);
AES = SAP.CreateSymmetricKey(CryptographicBuffer.CreateFromByteArray(hash));
IBuffer Buffer = CryptographicBuffer.CreateFromByteArray(Encoding.UTF8.GetBytes(input));
encrypted = CryptographicBuffer.EncodeToBase64String(CryptographicEngine.Encrypt(AES, Buffer, null));
return encrypted;
}
catch (Exception ex)
{
return null;
}
}
public string GetDecryptedContent(string input, string pass)
{
SymmetricKeyAlgorithmProvider SAP = SymmetricKeyAlgorithmProvider.OpenAlgorithm(SymmetricAlgorithmNames.AesEcbPkcs7);
CryptographicKey AES;
HashAlgorithmProvider HAP = HashAlgorithmProvider.OpenAlgorithm(HashAlgorithmNames.Md5);
CryptographicHash Hash_AES = HAP.CreateHash();
string decrypted = "";
try
{
byte[] hash = new byte[32];
Hash_AES.Append(CryptographicBuffer.CreateFromByteArray(Encoding.UTF8.GetBytes(pass)));
byte[] temp;
CryptographicBuffer.CopyToByteArray(Hash_AES.GetValueAndReset(), out temp);
Array.Copy(temp, 0, hash, 0, 16);
Array.Copy(temp, 0, hash, 15, 16);
AES = SAP.CreateSymmetricKey(CryptographicBuffer.CreateFromByteArray(hash));
IBuffer Buffer = CryptographicBuffer.DecodeFromBase64String(input);
byte[] Decrypted;
CryptographicBuffer.CopyToByteArray(CryptographicEngine.Decrypt(AES, Buffer, null), out Decrypted);
decrypted = Encoding.UTF8.GetString(Decrypted, 0, Decrypted.Length);
return decrypted;
}
catch (Exception ex)
{
return null;
}
}
EDIT 2
Finally managed to get the encryption working properly, but the decryption is still not working presumably because the encoding I am passing is not the right one:
private string GetEncryptedContent(string content)
{
byte[] keyMaterial = Encoding.UTF8.GetBytes(EncryptionKey);
byte[] data = Encoding.UTF8.GetBytes(content);
byte[] iv = new byte[128 / 8]; // Adding this solved the encryption issue.
var provider = WinRTCrypto.SymmetricKeyAlgorithmProvider.OpenAlgorithm(SymmetricAlgorithm.AesCbcPkcs7);
var key = provider.CreateSymmetricKey(keyMaterial);
byte[] cipherText = WinRTCrypto.CryptographicEngine.Encrypt(key, data, iv);
return Convert.ToBase64String(cipherText);
}
private string GetDecryptedContent(string content)
{
byte[] keyMaterial = Encoding.UTF8.GetBytes(EncryptionKey);
byte[] data = Convert.FromBase64String(content); // Believe this is where the issue is, but not able to figure it out.
byte[] iv = new byte[128 / 8]; // Added this to make the decryption work the same way.
var provider = WinRTCrypto.SymmetricKeyAlgorithmProvider.OpenAlgorithm(SymmetricAlgorithm.AesCbcPkcs7);
var key = provider.CreateSymmetricKey(keyMaterial);
byte[] cipherText = WinRTCrypto.CryptographicEngine.Decrypt(key, data, iv);
return Convert.ToBase64String(cipherText);
}

I finally solved the problem. The problem was with the text encoding. Using the correct encoding solved the issue. The working code below:
public static string EncryptAES(string content, string password)
{
byte[] keyMaterial = Encoding.UTF8.GetBytes(password);
byte[] data = Encoding.UTF8.GetBytes(content);
byte[] iv = new byte[keyMaterial.Length];
var provider = WinRTCrypto.SymmetricKeyAlgorithmProvider.OpenAlgorithm(SymmetricAlgorithm.AesCbcPkcs7);
var key = provider.CreateSymmetricKey(keyMaterial);
byte[] cipherText = WinRTCrypto.CryptographicEngine.Encrypt(key, data, iv);
return Convert.ToBase64String(cipherText);
}
public static string DecryptAES(string content, string password)
{
byte[] keyMaterial = Encoding.UTF8.GetBytes(password);
byte[] data = Convert.FromBase64String(content);
byte[] iv = new byte[keyMaterial.Length];
var provider = WinRTCrypto.SymmetricKeyAlgorithmProvider.OpenAlgorithm(SymmetricAlgorithm.AesCbcPkcs7);
var key = provider.CreateSymmetricKey(keyMaterial);
byte[] cipherText = WinRTCrypto.CryptographicEngine.Decrypt(key, data, iv);
return Encoding.UTF8.GetString(cipherText, 0, cipherText.Length);
}
WinRTCrypto is available as part of PCLCrypto.

AES cbc padding encryption/decryption on cross platform (.net c# and codename one bouncy castle)

Encryption/Decryption won't work in cross platform.
I have used this link to encrypt/decrypt text using bouncy castle AES cipher within codename one.
AES Encryption/Decryption with Bouncycastle Example in J2ME
While from server side (.net) , i am using this link to implement same method.
http://zenu.wordpress.com/2011/09/21/aes-128bit-cross-platform-java-and-c-encryption-compatibility/
now i am not getting any error but encrypted from codename one will not getting fully decrypted on server side and vice a versa.
any one please help me out on this.
Code from Codename one:
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.CryptoException;
import org.bouncycastle.crypto.engines.AESEngine;
import org.bouncycastle.crypto.modes.CBCBlockCipher;
import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.params.ParametersWithIV;
import org.bouncycastle.util.encoders.Base64;
public class Test
{
private static PaddedBufferedBlockCipher cipher = null;
public static void main(String[] args)
{
try
{
byte key[] = "MAKV2SPBNI992122".getBytes("UTF-8");
byte[] iv = new byte[16];
PaddedBufferedBlockCipher cipher = new PaddedBufferedBlockCipher(
new CBCBlockCipher(
new AESEngine()) );
//Encryption
String plainText = "Hello How are you !2#&*()% 123456#";
byte[] plainData = plainText.getBytes("UTF-8");
KeyParameter keyParam = new KeyParameter(key);
CipherParameters ivAndKey = new ParametersWithIV(keyParam, iv);
cipher.init(true, ivAndKey);
byte[] ciptherBytes = cipherData(plainData); //48
String cipherText = new String(Base64.encode(ciptherBytes), "UTF-8");//FileUtil.getStringFromByteArray(Base64.encode(ciptherBytes));
System.out.println("encrypted >> "+cipherText);
//Decryption
byte[] cipherData = Base64.decode(cipherText);
ivAndKey = new ParametersWithIV(keyParam, iv);
cipher.init(false, ivAndKey);
plainText = new String(cipherData(cipherData), "UTF-8");//FileUtil.getStringFromByteArray(cipherData(cipherData));
System.out.println("decrypted >> "+plainText);
}
catch (Exception e)
{
e.printStackTrace();
}
}
private static byte[] cipherData(byte[] data)
throws CryptoException
{
int minSize = cipher.getOutputSize(data.length);
byte[] outBuf = new byte[minSize];
int length1 = cipher.processBytes(data, 0, data.length, outBuf, 0);
int length2 = cipher.doFinal(outBuf, length1);
int actualLength = length1 + length2;
byte[] result = new byte[actualLength];
System.arraycopy(outBuf, 0, result, 0, result.length);
return result;
}
Code from .net:
public static RijndaelManaged GetRijndaelManaged(String secretKey)
{
var keyBytes = new byte[16];
var secretKeyBytes = Encoding.UTF8.GetBytes(secretKey);
Array.Copy(secretKeyBytes, keyBytes, Math.Min(keyBytes.Length, secretKeyBytes.Length));
return new RijndaelManaged
{
Mode = CipherMode.CBC,
Padding = PaddingMode.PKCS7,
KeySize = 128,
BlockSize = 128,
Key = keyBytes,
IV = keyBytes
};
}
public static byte[] EncryptCBC(byte[] plainBytes, RijndaelManaged rijndaelManaged)
{
return rijndaelManaged.CreateEncryptor()
.TransformFinalBlock(plainBytes, 0, plainBytes.Length);
}
public static byte[] DecryptCBC(byte[] encryptedData, RijndaelManaged rijndaelManaged)
{
return rijndaelManaged.CreateDecryptor()
.TransformFinalBlock(encryptedData, 0, encryptedData.Length);
}
public static String EncryptCBCStr(String plainText, String key)
{
var plainBytes = Encoding.UTF8.GetBytes(plainText);
return Convert.ToBase64String(EncryptCBC(plainBytes, GetRijndaelManaged(key)));
}
public static String DecryptCBCStr(String encryptedText, String key)
{
var encryptedBytes = Convert.FromBase64String(encryptedText);
return Encoding.UTF8.GetString(DecryptCBC(encryptedBytes, GetRijndaelManaged(key)));
}
// call
var PlainText = "Hello How are you !2#&*()% 123456#";
var EncryptionKey = "MAKV2SPBNI992122";
var cypherCBC = EncryptCBCStr(PlainText, EncryptionKey);
var decryptCBC = DecryptCBCStr(cypherCBC, EncryptionKey);
Thanks in adv.

This issue has been fixed...it is just key/IV bytes issue.as in .net there is same key and IV when in java i have used different IV.
correction in java code:
instead of this
byte key[] = "MAKV2SPBNI992122".getBytes("UTF-8");
byte[] iv = new byte[16];
use this.
byte key[] = "MAKV2SPBNI992122".getBytes("UTF-8");
byte[] iv = "MAKV2SPBNI992122".getBytes("UTF-8");

3DES Decrypt in java a token encrypted in C#

I've searched a lot before asking, but none of the ideas I found work in my problem so here's my problem :
In C# the code (which I cannot change because it is from another application) for encryption is detailed after.
I have to decrypt the encrypted token in Java but nothing works so far, can anyone help ?
For 1. C# code :
static public string Encrypt3DES(string toEncrypt, string SecKey, string IV){
byte[] keyArray;
try
{
byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(SecKey));
hashmd5.Clear();
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
tdes.Key = keyArray;
tdes.Mode = CipherMode.CBC;
tdes.Padding = PaddingMode.PKCS7;
tdes.IV = UTF8Encoding.UTF8.GetBytes(IV);
ICryptoTransform cTransform = tdes.CreateEncryptor();
//transform the specified region of bytes array to resultArray
byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
tdes.Clear();
//Return the encrypted data into unreadable string format
return Convert.ToBase64String(resultArray, 0, resultArray.Length);
}
catch (Exception e) { return string.Empty; }
}
For 2 Java code that does not work :
public class TripleDesTest {
private KeySpec keySpec;
private SecretKey key;
private IvParameterSpec iv;
public TripleDesTest() {
String keyString = "THE_KEY";
String ivString = "THE_IV";
try {
final MessageDigest md = MessageDigest.getInstance("md5");
final byte[] digestOfPassword = md.digest(Base64.decodeBase64(keyString.getBytes("UTF-8")));
final byte[] keyBytes = Arrays.copyOf(digestOfPassword, 24);
for (int j = 0, k = 16; j < 8;) {
keyBytes[k++] = keyBytes[j++];
}
keySpec = new DESedeKeySpec(keyBytes);
key = SecretKeyFactory.getInstance("DESede").generateSecret(keySpec);
iv = new IvParameterSpec(ivString.getBytes("UTF-8"));
} catch (Exception e) {
e.printStackTrace();
}
}
public String decrypt(String value) {
try {
Cipher dcipher = Cipher.getInstance("DESede/CBC/PKCS5Padding", "SunJCE");
dcipher.init(Cipher.DECRYPT_MODE, key, iv);
if (value == null)
return null;
// Decode base64 to get bytes
byte[] dec = Base64.decodeBase64(value.getBytes("UTF-8"));
// Decrypt
byte[] utf8 = dcipher.doFinal(dec);
// Decode using UTF-8
return new String(utf8, "UTF-8");
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}

Here is the solution to the problem (I finally was able to solve this myself) :
In Java, replace
final byte[] digestOfPassword = md.digest(Base64.decodeBase64(keyString.getBytes("UTF-8")));`
with :
final byte[] digestOfPassword = md.digest(keyString.getBytes("UTF-8"));
Because on the C# side, no Base64 is used for the key :
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(SecKey));

what is algorithm hash with login control?

I use Login control and membership asp.net 4. and create user with passwrod = "12345678", my password hash in database is "h8A5hga0Cy93JsKxYnJl/U2AluU=" and passwordsalt is "UhVlqavmEX9CiKcUXkSwCw==".
Then I use this code for hash password in other project:
public string HashPassword(string pass, string salt)
{
byte[] bytes = Encoding.Unicode.GetBytes(pass);
byte[] src = Encoding.Unicode.GetBytes(salt);
byte[] dst = new byte[src.Length + bytes.Length];
Buffer.BlockCopy(src, 0, dst, 0, src.Length);
Buffer.BlockCopy(bytes, 0, dst, src.Length, bytes.Length);
HashAlgorithm algorithm = HashAlgorithm.Create("SHA1");
byte[] inArray = algorithm.ComputeHash(dst);
return Convert.ToBase64String(inArray);
}
private void button2_Click(object sender, EventArgs e)
{
textBox2.Text = HashPassword("12345678", "UhVlqavmEX9CiKcUXkSwCw==");
}
textBox2.Text = "YM/JNwFqlL+WA3SINQp48BIxZRI=". But textBox2.Text != my password hashed with login control in database. it is "h8A5hga0Cy93JsKxYnJl/U2AluU=".
Edit:
It is algorithm hash with login control?
public string EncodePassword(string pass, string salt)
{
byte[] bytes = Encoding.Unicode.GetBytes(pass);
byte[] src = Convert.FromBase64String(salt);
byte[] dst = new byte[src.Length + bytes.Length];
Buffer.BlockCopy(src, 0, dst, 0, src.Length);
Buffer.BlockCopy(bytes, 0, dst, src.Length, bytes.Length);
HashAlgorithm algorithm = HashAlgorithm.Create("SHA1");
byte[] inArray = algorithm.ComputeHash(dst);
return Convert.ToBase64String(inArray);
}

MD5 and SHA1 are not encryption algorithms. They are hashing algorithms.
It is a one way formula. Running MD5 or SHA1 on a particular string gives a hash that is always the same. It isn't possible to reverse the function to get back to the original string.
so, you can not decrypt.
if you want encrypt & decrypt, you can use below methods.
public class Encryption
{
private const string _defaultKey = "*3ld+43j";
public static string Encrypt(string toEncrypt, string key)
{
var des = new DESCryptoServiceProvider();
var ms = new MemoryStream();
VerifyKey(ref key);
des.Key = HashKey(key, des.KeySize / 8);
des.IV = HashKey(key, des.KeySize / 8);
byte[] inputBytes = Encoding.UTF8.GetBytes(toEncrypt);
var cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
cs.Write(inputBytes, 0, inputBytes.Length);
cs.FlushFinalBlock();
return HttpServerUtility.UrlTokenEncode(ms.ToArray());
}
public static string Decrypt(string toDecrypt, string key)
{
var des = new DESCryptoServiceProvider();
var ms = new MemoryStream();
VerifyKey(ref key);
des.Key = HashKey(key, des.KeySize / 8);
des.IV = HashKey(key, des.KeySize / 8);
byte[] inputBytes = HttpServerUtility.UrlTokenDecode(toDecrypt);
var cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
cs.Write(inputBytes, 0, inputBytes.Length);
cs.FlushFinalBlock();
var encoding = Encoding.UTF8;
return encoding.GetString(ms.ToArray());
}
/// <summary>
/// Make sure key is exactly 8 characters
/// </summary>
/// <param name="key"></param>
private static void VerifyKey(ref string key)
{
if (string.IsNullOrEmpty(key))
key = _defaultKey;
key = key.Length > 8 ? key.Substring(0, 8) : key;
if (key.Length < 8)
{
for (int i = key.Length; i < 8; i++)
{
key += _defaultKey[i];
}
}
}
private static byte[] HashKey(string key, int length)
{
var sha = new SHA1CryptoServiceProvider();
byte[] keyBytes = Encoding.UTF8.GetBytes(key);
byte[] hash = sha.ComputeHash(keyBytes);
byte[] truncateHash = new byte[length];
Array.Copy(hash, 0, truncateHash, 0, length);
return truncateHash;
}
}

try
private static string CreateSalt()
{
//Generate a cryptographic random number.
RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
byte[] buff = new byte[32];
rng.GetBytes(buff);
//Return a Base64 string representation of the random number.
return Convert.ToBase64String(buff);
}
private static string CreatePasswordHash(string pwd, string salt)
{
string saltAndPwd = String.Concat(pwd, salt);
string hashedPwd = FormsAuthentication.HashPasswordForStoringInConfigFile(saltAndPwd, "sha1");
return hashedPwd;
}

Login control doesn't encode or decode password. Instead, it is MembershipProvider's job.
Here is the Hash Algorithm used by new ASP.Net Universal Provider.
private static string GenerateSalt()
{
byte[] numArray = new byte[16];
(new RNGCryptoServiceProvider()).GetBytes(numArray);
string base64String = Convert.ToBase64String(numArray);
return base64String;
}
private string EncodePassword(string pass, int passwordFormat, string salt)
{
byte[] numArray;
byte[] numArray1;
string base64String;
bool length = passwordFormat != 0;
if (length)
{
byte[] bytes = Encoding.Unicode.GetBytes(pass);
byte[] numArray2 = Convert.FromBase64String(salt);
byte[] numArray3 = null;
HashAlgorithm hashAlgorithm = HashAlgorithm.Create(Membership.HashAlgorithmType);
if (hashAlgorithm as KeyedHashAlgorithm == null)
{
numArray1 = new byte[(int) numArray2.Length + (int) bytes.Length];
Buffer.BlockCopy(numArray2, 0, numArray1, 0, (int) numArray2.Length);
Buffer.BlockCopy(bytes, 0, numArray1, (int) numArray2.Length, (int) bytes.Length);
numArray3 = hashAlgorithm.ComputeHash(numArray1);
}
else
{
KeyedHashAlgorithm keyedHashAlgorithm = (KeyedHashAlgorithm) hashAlgorithm;
if (keyedHashAlgorithm.Key.Length != numArray2.Length)
{
if (keyedHashAlgorithm.Key.Length >= (int) numArray2.Length)
{
numArray = new byte[(int) keyedHashAlgorithm.Key.Length];
int num = 0;
while (true)
{
length = num < (int) numArray.Length;
if (!length)
{
break;
}
int num1 = Math.Min((int) numArray2.Length, (int) numArray.Length - num);
Buffer.BlockCopy(numArray2, 0, numArray, num, num1);
num = num + num1;
}
keyedHashAlgorithm.Key = numArray;
}
else
{
numArray = new byte[(int) keyedHashAlgorithm.Key.Length];
Buffer.BlockCopy(numArray2, 0, numArray, 0, (int) numArray.Length);
keyedHashAlgorithm.Key = numArray;
}
}
else
{
keyedHashAlgorithm.Key = numArray2;
}
numArray3 = keyedHashAlgorithm.ComputeHash(bytes);
}
base64String = Convert.ToBase64String(numArray3);
}
else
{
base64String = pass;
}
return base64String;
}