找到了一个如何在http://www.obviex.com/samples/Encryption.aspx
上实现Rijndael的示例此代码对于生产系统是否足够安全？
using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;
该类使用对称密钥算法（Rijndael / AES）来加密和 解密数据。只要加密和解密例程使用相同的 生成密钥的参数，密钥保证是相同的。 该类使用具有重复代码的静态函数，以使其更容易 演示加密和解密逻辑。在现实生活中， 这可能不是处理加密的最有效方式，因此 - 如此 你觉得它很舒服 - 你可能想重新设计这个课程。
public class RijndaelSimple
{
/// <summary>
/// Encrypts specified plaintext using Rijndael symmetric key algorithm
/// and returns a base64-encoded result.
/// </summary>
/// <param name="plainText">
/// Plaintext value to be encrypted.
/// </param>
/// <param name="passPhrase">
/// Passphrase from which a pseudo-random password will be derived. The
/// derived password will be used to generate the encryption key.
/// Passphrase can be any string. In this example we assume that this
/// passphrase is an ASCII string.
/// </param>
/// <param name="saltValue">
/// Salt value used along with passphrase to generate password. Salt can
/// be any string. In this example we assume that salt is an ASCII string.
/// </param>
/// <param name="hashAlgorithm">
/// Hash algorithm used to generate password. Allowed values are: "MD5" and
/// "SHA1". SHA1 hashes are a bit slower, but more secure than MD5 hashes.
/// </param>
/// <param name="passwordIterations">
/// Number of iterations used to generate password. One or two iterations
/// should be enough.
/// </param>
/// <param name="initVector">
/// Initialization vector (or IV). This value is required to encrypt the
/// first block of plaintext data. For RijndaelManaged class IV must be
/// exactly 16 ASCII characters long.
/// </param>
/// <param name="keySize">
/// Size of encryption key in bits. Allowed values are: 128, 192, and 256.
/// Longer keys are more secure than shorter keys.
/// </param>
/// <returns>
/// Encrypted value formatted as a base64-encoded string.
/// </returns>
public 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.
byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector);
byte[] saltValueBytes = Encoding.ASCII.GetBytes(saltValue);
// Convert our plaintext into a byte array.
// Let us assume that plaintext contains UTF8-encoded characters.
byte[] 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.
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 = password.GetBytes(keySize / 8);
// Create uninitialized Rijndael encryption object.
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 = symmetricKey.CreateEncryptor(
keyBytes,
initVectorBytes);
// Define memory stream which will be used to hold encrypted data.
MemoryStream memoryStream = new MemoryStream();
// Define cryptographic stream (always use Write mode for encryption).
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 = memoryStream.ToArray();
// Close both streams.
memoryStream.Close();
cryptoStream.Close();
// Convert encrypted data into a base64-encoded string.
string cipherText = Convert.ToBase64String(cipherTextBytes);
// Return encrypted string.
return cipherText;
}
/// <summary>
/// Decrypts specified ciphertext using Rijndael symmetric key algorithm.
/// </summary>
/// <param name="cipherText">
/// Base64-formatted ciphertext value.
/// </param>
/// <param name="passPhrase">
/// Passphrase from which a pseudo-random password will be derived. The
/// derived password will be used to generate the encryption key.
/// Passphrase can be any string. In this example we assume that this
/// passphrase is an ASCII string.
/// </param>
/// <param name="saltValue">
/// Salt value used along with passphrase to generate password. Salt can
/// be any string. In this example we assume that salt is an ASCII string.
/// </param>
/// <param name="hashAlgorithm">
/// Hash algorithm used to generate password. Allowed values are: "MD5" and
/// "SHA1". SHA1 hashes are a bit slower, but more secure than MD5 hashes.
/// </param>
/// <param name="passwordIterations">
/// Number of iterations used to generate password. One or two iterations
/// should be enough.
/// </param>
/// <param name="initVector">
/// Initialization vector (or IV). This value is required to encrypt the
/// first block of plaintext data. For RijndaelManaged class IV must be
/// exactly 16 ASCII characters long.
/// </param>
/// <param name="keySize">
/// Size of encryption key in bits. Allowed values are: 128, 192, and 256.
/// Longer keys are more secure than shorter keys.
/// </param>
/// <returns>
/// Decrypted string value.
/// </returns>
/// <remarks>
/// Most of the logic in this function is similar to the Encrypt
/// logic. In order for decryption to work, all parameters of this function
/// - except cipherText value - must match the corresponding parameters of
/// the Encrypt function which was called to generate the
/// ciphertext.
/// </remarks>
public 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.
byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector);
byte[] saltValueBytes = Encoding.ASCII.GetBytes(saltValue);
// Convert our ciphertext into a byte array.
byte[] 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 = 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 = password.GetBytes(keySize / 8);
// Create uninitialized Rijndael encryption object.
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 = symmetricKey.CreateDecryptor(
keyBytes,
initVectorBytes);
// Define memory stream which will be used to hold encrypted data.
MemoryStream memoryStream = new MemoryStream(cipherTextBytes);
// Define cryptographic stream (always use Read mode for encryption).
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 = new byte[cipherTextBytes.Length];
// Start decrypting.
int 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 = Encoding.UTF8.GetString(plainTextBytes,
0,
decryptedByteCount);
// Return decrypted string.
return plainText;
}
}
/// <summary>
/// Illustrates the use of RijndaelSimple class to encrypt and decrypt data.
/// </summary>
public class RijndaelSimpleTest
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main(string[] args)
{
string plainText = "Hello, World!"; // original plaintext
string passPhrase = "Pas5pr@se"; // can be any string
string saltValue = "s@1tValue"; // can be any string
string hashAlgorithm = "SHA1"; // can be "MD5"
int passwordIterations = 2; // can be any number
string initVector = "@1B2c3D4e5F6g7H8"; // must be 16 bytes
int keySize = 256; // can be 192 or 128
Console.WriteLine(String.Format("Plaintext : {0}", plainText));
string cipherText = RijndaelSimple.Encrypt(plainText,
passPhrase,
saltValue,
hashAlgorithm,
passwordIterations,
initVector,
keySize);
Console.WriteLine(String.Format("Encrypted : {0}", cipherText));
plainText = RijndaelSimple.Decrypt(cipherText,
passPhrase,
saltValue,
hashAlgorithm,
passwordIterations,
initVector,
keySize);
Console.WriteLine(String.Format("Decrypted : {0}", plainText));
}
}
答案 0 :(得分：2)
不。
如果不理解字符串和八位字符串之间的区别，就会出现明显的错误。对于盐，这可能是可以原谅的，但对于IV来说肯定不是这样。
此外，它使用PasswordDeriveBytes的Microsoft专有扩展PKCS＃5 PBKDF1实现，而不是Rfc2898DeriveBytes中定义的PBKDF2。对于超过20个字节长的任何字节（这是SHA-1输出大小，以及PBKDF1的定义输出大小），此实现不安全 - 它可能在输出中重复字节。任何超过20个字节的输出都不会在其他框架上重现。即使是Mono也指定了“不会修复”。
初始化向量应由安全随机数生成器生成，而不是作为参数传递。
CBC模式可以是安全的，但它不提供完整性保护，因此在通过传输协议使用时（通常）不安全。
此列表可能并非详尽无遗。