在C＃中使用AESencryption

我似乎无法find使用AES 128位encryption的一个很好的干净的例子。

有没有人有一些示例代码？

Answer 1

如果您只想使用内置的encryption提供程序RijndaelManaged，请参阅以下帮助文章（它也有一个简单的代码示例）：

http://msdn.microsoft.com/en-us/library/system.security.cryptography.rijndaelmanaged.aspx

而且万一你急需样品，这里就是剽窃的荣耀：

using System; using System.IO; using System.Security.Cryptography; namespace RijndaelManaged_Example { class RijndaelExample { public static void Main() { try { string original = "Here is some data to encrypt!"; // Create a new instance of the RijndaelManaged // class. This generates a new key and initialization // vector (IV). using (RijndaelManaged myRijndael = new RijndaelManaged()) { myRijndael.GenerateKey(); myRijndael.GenerateIV(); // Encrypt the string to an array of bytes. byte[] encrypted = EncryptStringToBytes(original, myRijndael.Key, myRijndael.IV); // Decrypt the bytes to a string. string roundtrip = DecryptStringFromBytes(encrypted, myRijndael.Key, myRijndael.IV); //Display the original data and the decrypted data. Console.WriteLine("Original: {0}", original); Console.WriteLine("Round Trip: {0}", roundtrip); } } catch (Exception e) { Console.WriteLine("Error: {0}", e.Message); } } static byte[] EncryptStringToBytes(string plainText, byte[] Key, byte[] IV) { // Check arguments. if (plainText == null || plainText.Length <= 0) throw new ArgumentNullException("plainText"); if (Key == null || Key.Length <= 0) throw new ArgumentNullException("Key"); if (IV == null || IV.Length <= 0) throw new ArgumentNullException("IV"); byte[] encrypted; // Create an RijndaelManaged object // with the specified key and IV. using (RijndaelManaged rijAlg = new RijndaelManaged()) { rijAlg.Key = Key; rijAlg.IV = IV; // Create a decryptor to perform the stream transform. ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV); // Create the streams used for encryption. using (MemoryStream msEncrypt = new MemoryStream()) { using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)) { using (StreamWriter swEncrypt = new StreamWriter(csEncrypt)) { //Write all data to the stream. swEncrypt.Write(plainText); } encrypted = msEncrypt.ToArray(); } } } // Return the encrypted bytes from the memory stream. return encrypted; } static string DecryptStringFromBytes(byte[] cipherText, byte[] Key, byte[] IV) { // Check arguments. if (cipherText == null || cipherText.Length <= 0) throw new ArgumentNullException("cipherText"); if (Key == null || Key.Length <= 0) throw new ArgumentNullException("Key"); if (IV == null || IV.Length <= 0) throw new ArgumentNullException("IV"); // Declare the string used to hold // the decrypted text. string plaintext = null; // Create an RijndaelManaged object // with the specified key and IV. using (RijndaelManaged rijAlg = new RijndaelManaged()) { rijAlg.Key = Key; rijAlg.IV = IV; // Create a decrytor to perform the stream transform. ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV); // Create the streams used for decryption. using (MemoryStream msDecrypt = new MemoryStream(cipherText)) { using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)) { using (StreamReader srDecrypt = new StreamReader(csDecrypt)) { // Read the decrypted bytes from the decrypting stream // and place them in a string. plaintext = srDecrypt.ReadToEnd(); } } } } return plaintext; } } } 

Answer 2

最近我不得不在自己的项目中再次遇到这个问题，并且想分享我一直使用的比较简单的代码，因为这个问题和一系列的答案不断出现在我的search中。

我不会考虑多长时间更新一下像Salt和Initialization Vector这样的安全问题 – 这是安全论坛的主题，有一些很好的资源可供您查看。 这只是一个在C＃中实现AesManaged的代码块。

 using System; using System.IO; using System.Security.Cryptography; using System.Text; namespace Your.Namespace.Security { public static class Cryptography { #region Settings private static int _iterations = 2; private static int _keySize = 256; private static string _hash = "SHA1"; private static string _salt = "aselrias38490a32"; // Random private static string _vector = "8947az34awl34kjq"; // Random #endregion public static string Encrypt(string value, string password) { return Encrypt<AesManaged>(value, password); } public static string Encrypt<T>(string value, string password) where T : SymmetricAlgorithm, new() { byte[] vectorBytes = GetBytes<ASCIIEncoding>(_vector); byte[] saltBytes = GetBytes<ASCIIEncoding>(_salt); byte[] valueBytes = GetBytes<UTF8Encoding>(value); byte[] encrypted; using (T cipher = new T()) { PasswordDeriveBytes _passwordBytes = new PasswordDeriveBytes(password, saltBytes, _hash, _iterations); byte[] keyBytes = _passwordBytes.GetBytes(_keySize / 8); cipher.Mode = CipherMode.CBC; using (ICryptoTransform encryptor = cipher.CreateEncryptor(keyBytes, vectorBytes)) { using (MemoryStream to = new MemoryStream()) { using (CryptoStream writer = new CryptoStream(to, encryptor, CryptoStreamMode.Write)) { writer.Write(valueBytes, 0, valueBytes.Length); writer.FlushFinalBlock(); encrypted = to.ToArray(); } } } cipher.Clear(); } return Convert.ToBase64String(encrypted); } public static string Decrypt(string value, string password) { return Decrypt<AesManaged>(value, password); } public static string Decrypt<T>(string value, string password) where T : SymmetricAlgorithm, new() { byte[] vectorBytes = GetBytes<ASCIIEncoding>(_vector); byte[] saltBytes = GetBytes<ASCIIEncoding>(_salt); byte[] valueBytes = Convert.FromBase64String(value); byte[] decrypted; int decryptedByteCount = 0; using (T cipher = new T()) { PasswordDeriveBytes _passwordBytes = new PasswordDeriveBytes(password, saltBytes, _hash, _iterations); byte[] keyBytes = _passwordBytes.GetBytes(_keySize / 8); cipher.Mode = CipherMode.CBC; try { using (ICryptoTransform decryptor = cipher.CreateDecryptor(keyBytes, vectorBytes)) { using (MemoryStream from = new MemoryStream(valueBytes)) { using (CryptoStream reader = new CryptoStream(from, decryptor, CryptoStreamMode.Read)) { decrypted = new byte[valueBytes.Length]; decryptedByteCount = reader.Read(decrypted, 0, decrypted.Length); } } } } catch (Exception ex) { return String.Empty; } cipher.Clear(); } return Encoding.UTF8.GetString(decrypted, 0, decryptedByteCount); } } } 

代码使用起来非常简单。 它从字面上只需要以下几点：

 string encrypted = Cryptography.Encrypt(data, "testpass"); string decrypted = Cryptography.Decrypt(encrypted, "testpass"); 

默认情况下，实现使用AesManaged – 但实际上也可以插入任何其他SymmetricAlgorithm 。 有关.NET 4.5的可用SymmetricAlgorithminheritance器的列表，请参见：

http://msdn.microsoft.com/en-us/library/system.security.cryptography.symmetricalgorithm.aspx

截至本文发稿时，目前的名单包括：

• AesManaged
• RijndaelManaged
• DESCryptoServiceProvider
• RC2CryptoServiceProvider
• TripleDESCryptoServiceProvider

要使用上面的代码使用RijndaelManaged ，作为示例，您可以使用：

 string encrypted = Cryptography.Encrypt<RijndaelManaged>(dataToEncrypt, password); string decrypted = Cryptography.Decrypt<RijndaelManaged>(encrypted, password); 

我希望这对那里的人有帮助。

Answer 3

看看这里的样品..

http://msdn.microsoft.com/en-us/library/system.security.cryptography.rijndaelmanaged(v=VS.100).aspx#Y2262

MSDN上的示例没有正常运行（发生错误），因为没有 Initial Vector（iv）和Key的 初始值 。 我添加2行代码，现在正常工作。

更多细节见下面：

 using System.Windows.Forms; using System; using System.Text; using System.IO; using System.Security.Cryptography; namespace AES_TESTER { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { try { string original = "Here is some data to encrypt!"; MessageBox.Show("Original: " + original); // Create a new instance of the RijndaelManaged // class. This generates a new key and initialization // vector (IV). using (RijndaelManaged myRijndael = new RijndaelManaged()) { myRijndael.GenerateKey(); myRijndael.GenerateIV(); // Encrypt the string to an array of bytes. byte[] encrypted = EncryptStringToBytes(original, myRijndael.Key, myRijndael.IV); StringBuilder s = new StringBuilder(); foreach (byte item in encrypted) { s.Append(item.ToString("X2") + " "); } MessageBox.Show("Encrypted: " + s); // Decrypt the bytes to a string. string decrypted = DecryptStringFromBytes(encrypted, myRijndael.Key, myRijndael.IV); //Display the original data and the decrypted data. MessageBox.Show("Decrypted: " + decrypted); } } catch (Exception ex) { MessageBox.Show("Error: {0}", ex.Message); } } static byte[] EncryptStringToBytes(string plainText, byte[] Key, byte[] IV) { // Check arguments. if (plainText == null || plainText.Length <= 0) throw new ArgumentNullException("plainText"); if (Key == null || Key.Length <= 0) throw new ArgumentNullException("Key"); if (IV == null || IV.Length <= 0) throw new ArgumentNullException("Key"); byte[] encrypted; // Create an RijndaelManaged object // with the specified key and IV. using (RijndaelManaged rijAlg = new RijndaelManaged()) { rijAlg.Key = Key; rijAlg.IV = IV; rijAlg.Mode = CipherMode.CBC; rijAlg.Padding = PaddingMode.Zeros; // Create a decrytor to perform the stream transform. ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV); // Create the streams used for encryption. using (MemoryStream msEncrypt = new MemoryStream()) { using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)) { using (StreamWriter swEncrypt = new StreamWriter(csEncrypt)) { //Write all data to the stream. swEncrypt.Write(plainText); } encrypted = msEncrypt.ToArray(); } } } // Return the encrypted bytes from the memory stream. return encrypted; } static string DecryptStringFromBytes(byte[] cipherText, byte[] Key, byte[] IV) { // Check arguments. if (cipherText == null || cipherText.Length <= 0) throw new ArgumentNullException("cipherText"); if (Key == null || Key.Length <= 0) throw new ArgumentNullException("Key"); if (IV == null || IV.Length <= 0) throw new ArgumentNullException("Key"); // Declare the string used to hold // the decrypted text. string plaintext = null; // Create an RijndaelManaged object // with the specified key and IV. using (RijndaelManaged rijAlg = new RijndaelManaged()) { rijAlg.Key = Key; rijAlg.IV = IV; rijAlg.Mode = CipherMode.CBC; rijAlg.Padding = PaddingMode.Zeros; // Create a decrytor to perform the stream transform. ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV); // Create the streams used for decryption. using (MemoryStream msDecrypt = new MemoryStream(cipherText)) { using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)) { using (StreamReader srDecrypt = new StreamReader(csDecrypt)) { // Read the decrypted bytes from the decrypting stream // and place them in a string. plaintext = srDecrypt.ReadToEnd(); } } } } return plaintext; } } } 

Answer 4

使用AES或实施AES？ 要使用AES，有System.Security.Cryptography.RijndaelManaged类。

Answer 5

有关除AESencryption外还要执行密钥派生的更完整示例，请参阅Getting AESencryption中发布的答案和链接， 以便跨Javascript和C＃使用 。

编辑
一个侧面说明： JavaScriptencryption被认为是有害的。 值得一读。

Answer 6

 //Code to encrypt Data : public byte[] encryptdata(byte[] bytearraytoencrypt, string key, string iv) { AesCryptoServiceProvider dataencrypt = new AesCryptoServiceProvider(); //Block size : Gets or sets the block size, in bits, of the cryptographic operation. dataencrypt.BlockSize = 128; //KeySize: Gets or sets the size, in bits, of the secret key dataencrypt.KeySize = 128; //Key: Gets or sets the symmetric key that is used for encryption and decryption. dataencrypt.Key = System.Text.Encoding.UTF8.GetBytes(key); //IV : Gets or sets the initialization vector (IV) for the symmetric algorithm dataencrypt.IV = System.Text.Encoding.UTF8.GetBytes(iv); //Padding: Gets or sets the padding mode used in the symmetric algorithm dataencrypt.Padding = PaddingMode.PKCS7; //Mode: Gets or sets the mode for operation of the symmetric algorithm dataencrypt.Mode = CipherMode.CBC; //Creates a symmetric AES encryptor object using the current key and initialization vector (IV). ICryptoTransform crypto1 = dataencrypt.CreateEncryptor(dataencrypt.Key, dataencrypt.IV); //TransformFinalBlock is a special function for transforming the last block or a partial block in the stream. //It returns a new array that contains the remaining transformed bytes. A new array is returned, because the amount of //information returned at the end might be larger than a single block when padding is added. byte[] encrypteddata = crypto1.TransformFinalBlock(bytearraytoencrypt, 0, bytearraytoencrypt.Length); crypto1.Dispose(); //return the encrypted data return encrypteddata; } //code to decrypt data private byte[] decryptdata(byte[] bytearraytodecrypt, string key, string iv) { AesCryptoServiceProvider keydecrypt = new AesCryptoServiceProvider(); keydecrypt.BlockSize = 128; keydecrypt.KeySize = 128; keydecrypt.Key = System.Text.Encoding.UTF8.GetBytes(key); keydecrypt.IV = System.Text.Encoding.UTF8.GetBytes(iv); keydecrypt.Padding = PaddingMode.PKCS7; keydecrypt.Mode = CipherMode.CBC; ICryptoTransform crypto1 = keydecrypt.CreateDecryptor(keydecrypt.Key, keydecrypt.IV); byte[] returnbytearray = crypto1.TransformFinalBlock(bytearraytodecrypt, 0, bytearraytodecrypt.Length); crypto1.Dispose(); return returnbytearray; } 

Answer 7

试试这个代码，也许有用。
1.创build新的C＃项目并将下面的代码添加到Form1中：

 using System; using System.Windows.Forms; using System.Security.Cryptography; namespace ExampleCrypto { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { string strOriginalData = string.Empty; string strEncryptedData = string.Empty; string strDecryptedData = string.Empty; strOriginalData = "this is original data 1234567890"; // your original data in here MessageBox.Show("ORIGINAL DATA:\r\n" + strOriginalData); clsCrypto aes = new clsCrypto(); aes.IV = "this is your IV"; // your IV aes.KEY = "this is your KEY"; // your KEY strEncryptedData = aes.Encrypt(strOriginalData, CipherMode.CBC); // your cipher mode MessageBox.Show("ENCRYPTED DATA:\r\n" + strEncryptedData); strDecryptedData = aes.Decrypt(strEncryptedData, CipherMode.CBC); MessageBox.Show("DECRYPTED DATA:\r\n" + strDecryptedData); } } } 

2.创buildclsCrypto.cs并复制粘贴在代码中，然后运行你的代码。 我用MD5生成了AES的初始向量（IV）和KEY。

 using System; using System.Security.Cryptography; using System.Text; using System.Windows.Forms; using System.IO; using System.Runtime.Remoting.Metadata.W3cXsd2001; namespace ExampleCrypto { public class clsCrypto { private string _KEY = string.Empty; protected internal string KEY { get { return _KEY; } set { if (!string.IsNullOrEmpty(value)) { _KEY = value; } } } private string _IV = string.Empty; protected internal string IV { get { return _IV; } set { if (!string.IsNullOrEmpty(value)) { _IV = value; } } } private string CalcMD5(string strInput) { string strOutput = string.Empty; if (!string.IsNullOrEmpty(strInput)) { try { StringBuilder strHex = new StringBuilder(); using (MD5 md5 = MD5.Create()) { byte[] bytArText = Encoding.Default.GetBytes(strInput); byte[] bytArHash = md5.ComputeHash(bytArText); for (int i = 0; i < bytArHash.Length; i++) { strHex.Append(bytArHash[i].ToString("X2")); } strOutput = strHex.ToString(); } } catch (Exception ex) { MessageBox.Show(ex.Message); } } return strOutput; } private byte[] GetBytesFromHexString(string strInput) { byte[] bytArOutput = new byte[] { }; if ((!string.IsNullOrEmpty(strInput)) && strInput.Length % 2 == 0) { SoapHexBinary hexBinary = null; try { hexBinary = SoapHexBinary.Parse(strInput); } catch (Exception ex) { MessageBox.Show(ex.Message); } bytArOutput = hexBinary.Value; } return bytArOutput; } private byte[] GenerateIV() { byte[] bytArOutput = new byte[] { }; try { string strIV = CalcMD5(IV); bytArOutput = GetBytesFromHexString(strIV); } catch (Exception ex) { MessageBox.Show(ex.Message); } return bytArOutput; } private byte[] GenerateKey() { byte[] bytArOutput = new byte[] { }; try { string strKey = CalcMD5(KEY); bytArOutput = GetBytesFromHexString(strKey); } catch (Exception ex) { MessageBox.Show(ex.Message); } return bytArOutput; } protected internal string Encrypt(string strInput, CipherMode cipherMode) { string strOutput = string.Empty; if (!string.IsNullOrEmpty(strInput)) { try { byte[] bytePlainText = Encoding.Default.GetBytes(strInput); using (RijndaelManaged rijManaged = new RijndaelManaged()) { rijManaged.Mode = cipherMode; rijManaged.BlockSize = 128; rijManaged.KeySize = 128; rijManaged.IV = GenerateIV(); rijManaged.Key = GenerateKey(); rijManaged.Padding = PaddingMode.Zeros; ICryptoTransform icpoTransform = rijManaged.CreateEncryptor(rijManaged.Key, rijManaged.IV); using (MemoryStream memStream = new MemoryStream()) { using (CryptoStream cpoStream = new CryptoStream(memStream, icpoTransform, CryptoStreamMode.Write)) { cpoStream.Write(bytePlainText, 0, bytePlainText.Length); cpoStream.FlushFinalBlock(); } strOutput = Encoding.Default.GetString(memStream.ToArray()); } } } catch (Exception ex) { MessageBox.Show(ex.Message); } } return strOutput; } protected internal string Decrypt(string strInput, CipherMode cipherMode) { string strOutput = string.Empty; if (!string.IsNullOrEmpty(strInput)) { try { byte[] byteCipherText = Encoding.Default.GetBytes(strInput); byte[] byteBuffer = new byte[strInput.Length]; using (RijndaelManaged rijManaged = new RijndaelManaged()) { rijManaged.Mode = cipherMode; rijManaged.BlockSize = 128; rijManaged.KeySize = 128; rijManaged.IV = GenerateIV(); rijManaged.Key = GenerateKey(); rijManaged.Padding = PaddingMode.Zeros; ICryptoTransform icpoTransform = rijManaged.CreateDecryptor(rijManaged.Key, rijManaged.IV); using (MemoryStream memStream = new MemoryStream(byteCipherText)) { using (CryptoStream cpoStream = new CryptoStream(memStream, icpoTransform, CryptoStreamMode.Read)) { cpoStream.Read(byteBuffer, 0, byteBuffer.Length); } strOutput = Encoding.Default.GetString(byteBuffer); } } } catch (Exception ex) { MessageBox.Show(ex.Message); } } return strOutput; } } } 

Answer 8

http://www.codeproject.com/Articles/769741/Csharp-AES-bits-Encryption-Library-with-Salt

 using System.Security.Cryptography; using System.IO; 

 public byte[] AES_Encrypt(byte[] bytesToBeEncrypted, byte[] passwordBytes) { byte[] encryptedBytes = null; byte[] saltBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 }; using (MemoryStream ms = new MemoryStream()) { using (RijndaelManaged AES = new RijndaelManaged()) { AES.KeySize = 256; AES.BlockSize = 128; var key = new Rfc2898DeriveBytes(passwordBytes, saltBytes, 1000); AES.Key = key.GetBytes(AES.KeySize / 8); AES.IV = key.GetBytes(AES.BlockSize / 8); AES.Mode = CipherMode.CBC; using (var cs = new CryptoStream(ms, AES.CreateEncryptor(), CryptoStreamMode.Write)) { cs.Write(bytesToBeEncrypted, 0, bytesToBeEncrypted.Length); cs.Close(); } encryptedBytes = ms.ToArray(); } } return encryptedBytes; } public byte[] AES_Decrypt(byte[] bytesToBeDecrypted, byte[] passwordBytes) { byte[] decryptedBytes = null; byte[] saltBytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 }; using (MemoryStream ms = new MemoryStream()) { using (RijndaelManaged AES = new RijndaelManaged()) { AES.KeySize = 256; AES.BlockSize = 128; var key = new Rfc2898DeriveBytes(passwordBytes, saltBytes, 1000); AES.Key = key.GetBytes(AES.KeySize / 8); AES.IV = key.GetBytes(AES.BlockSize / 8); AES.Mode = CipherMode.CBC; using (var cs = new CryptoStream(ms, AES.CreateDecryptor(), CryptoStreamMode.Write)) { cs.Write(bytesToBeDecrypted, 0, bytesToBeDecrypted.Length); cs.Close(); } decryptedBytes = ms.ToArray(); } } return decryptedBytes; } 

Answer 9

您可以使用密钥从文本框中的密钥…使用此代码，您可以encryption/解密文本，图片，文字文件，PDF ….

  public class Rijndael { private byte[] key; private readonly byte[] vector = { 255, 64, 191, 111, 23, 3, 113, 119, 231, 121, 252, 112, 79, 32, 114, 156 }; ICryptoTransform EnkValue, DekValue; public Rijndael(byte[] key) { this.key = key; RijndaelManaged rm = new RijndaelManaged(); rm.Padding = PaddingMode.PKCS7; EnkValue = rm.CreateEncryptor(key, vector); DekValue = rm.CreateDecryptor(key, vector); } public byte[] Encrypt(byte[] byte) { byte[] enkByte= byte; byte[] enkNewByte; using (MemoryStream ms = new MemoryStream()) { using (CryptoStream cs = new CryptoStream(ms, EnkValue, CryptoStreamMode.Write)) { cs.Write(enkByte, 0, enkByte.Length); cs.FlushFinalBlock(); ms.Position = 0; enkNewByte= new byte[ms.Length]; ms.Read(enkNewByte, 0, enkNewByte.Length); } } return enkNeyByte; } public byte[] Dekrypt(byte[] enkByte) { byte[] dekByte; using (MemoryStream ms = new MemoryStream()) { using (CryptoStream cs = new CryptoStream(ms, DekValue, CryptoStreamMode.Write)) { cs.Write(enkByte, 0, enkByte.Length); cs.FlushFinalBlock(); ms.Position = 0; dekByte= new byte[ms.Length]; ms.Read(dekByte, 0, dekByte.Length); } } return dekByte; } } 

将密码从文本框转换为字节数组…

 private byte[] ConvertPasswordToByte(string password) { byte[] key = new byte[32]; for (int i = 0; i < passwprd.Length; i++) { key[i] = Convert.ToByte(passwprd[i]); } return key; } 

Answer 10

这里是一个整洁干净的代码，用于理解在C＃调用encryption函数中实现的AES 256algorithm，如encryptedstring = cryptObj.Encrypt(username, "AGARAMUDHALA", "EZHUTHELLAM", "SHA1", 3, "@1B2c3D4e5F6g7H8", 256);

 public class Crypt { public string Encrypt(string passtext, string passPhrase, string saltV, string hashstring, int Iterations, string initVect, int keysize) { string functionReturnValue = null; // 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. byte[] initVectorBytes = null; initVectorBytes = Encoding.ASCII.GetBytes(initVect); byte[] saltValueBytes = null; saltValueBytes = Encoding.ASCII.GetBytes(saltV); // Convert our plaintext into a byte array. // Let us assume that plaintext contains UTF8-encoded characters. byte[] plainTextBytes = null; plainTextBytes = Encoding.UTF8.GetBytes(passtext); // 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. PasswordDeriveBytes password = default(PasswordDeriveBytes); password = new PasswordDeriveBytes(passPhrase, saltValueBytes, hashstring, Iterations); // Use the password to generate pseudo-random bytes for the encryption // key. Specify the size of the key in bytes (instead of bits). byte[] keyBytes = null; keyBytes = password.GetBytes(keysize/8); // Create uninitialized Rijndael encryption object. RijndaelManaged symmetricKey = default(RijndaelManaged); symmetricKey = new RijndaelManaged(); // It is reasonable to set encryption mode to Cipher Block Chaining // (CBC). Use default options for other symmetric key parameters. symmetricKey.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. ICryptoTransform encryptor = default(ICryptoTransform); encryptor = symmetricKey.CreateEncryptor(keyBytes, initVectorBytes); // Define memory stream which will be used to hold encrypted data. MemoryStream memoryStream = default(MemoryStream); memoryStream = new MemoryStream(); // Define cryptographic stream (always use Write mode for encryption). CryptoStream cryptoStream = default(CryptoStream); 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. byte[] cipherTextBytes = null; cipherTextBytes = memoryStream.ToArray(); // Close both streams. memoryStream.Close(); cryptoStream.Close(); // Convert encrypted data into a base64-encoded string. string cipherText = null; cipherText = Convert.ToBase64String(cipherTextBytes); functionReturnValue = cipherText; return functionReturnValue; } public string Decrypt(string cipherText, string passPhrase, string saltValue, string hashAlgorithm, int passwordIterations, string initVector, int keySize) { string functionReturnValue = null; // 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. byte[] initVectorBytes = null; initVectorBytes = Encoding.ASCII.GetBytes(initVector); byte[] saltValueBytes = null; saltValueBytes = Encoding.ASCII.GetBytes(saltValue); // Convert our ciphertext into a byte array. byte[] cipherTextBytes = null; 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. PasswordDeriveBytes password = default(PasswordDeriveBytes); 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). byte[] keyBytes = null; keyBytes = password.GetBytes(keySize / 8); // Create uninitialized Rijndael encryption object. RijndaelManaged symmetricKey = default(RijndaelManaged); symmetricKey = new RijndaelManaged(); // It is reasonable to set encryption mode to Cipher Block Chaining // (CBC). Use default options for other symmetric key parameters. symmetricKey.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. ICryptoTransform decryptor = default(ICryptoTransform); decryptor = symmetricKey.CreateDecryptor(keyBytes, initVectorBytes); // Define memory stream which will be used to hold encrypted data. MemoryStream memoryStream = default(MemoryStream); memoryStream = new MemoryStream(cipherTextBytes); // Define memory stream which will be used to hold encrypted data. CryptoStream cryptoStream = default(CryptoStream); 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. byte[] plainTextBytes = null; plainTextBytes = new byte[cipherTextBytes.Length + 1]; // Start decrypting. int decryptedByteCount = 0; 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. string plainText = null; plainText = Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount); // Return decrypted string. functionReturnValue = plainText; return functionReturnValue; } }