在C＃中满足以下内容的最现代（最佳）方式是什么？
string encryptedString = SomeStaticClass.Encrypt(sourceString);
string decryptedString = SomeStaticClass.Decrypt(encryptedString);
但最少涉及盐，钥匙，用字节[]等进行捣乱等。
谷歌搜索并对我所发现的内容感到困惑（你可以看到类似的SO Q列表，看这是一个有待提出的欺骗性问题）。
答案 0 :(得分：673)
更新23/2015年12月：由于这个答案似乎得到了很多赞成，我已经更新它以修复愚蠢的错误，并根据评论和反馈大致改进代码。有关具体改进的列表，请参阅帖子的结尾。
正如其他人所说，密码学并不简单，所以最好避免“滚动自己的”加密算法。
但是，您可以围绕类似内置RijndaelManaged加密类的内容“推出自己的”包装类。
Rijndael是当前Advanced Encryption Standard的算法名称，因此您肯定使用的算法可被视为“最佳实践”。
RijndaelManaged类确实通常要求你用字节数组，盐，键，初始化向量等来“捣乱”，但这正是你的“包装器”中可以有所抽象的那种细节。 “上课。
下面的类是我前一段时间写的一个，用于执行你所追求的事情，一个简单的单一方法调用，允许一些基于字符串的明文用基于字符串的密码加密，结果加密字符串也表示为字符串。当然，有一种等效方法可以用相同的密码解密加密的字符串。
与此代码的第一个版本不同，每次使用完全相同的salt和IV值时，这个较新的版本每次都会生成随机的salt和IV值。由于在给定字符串的加密和解密之间盐和IV必须相同，因此在加密时将盐和IV预先加密到密文，并再次从密码中提取以便执行解密。结果是用完全相同的密码加密完全相同的明文，每次都会产生完全不同的密文结果。
使用此功能的“优势”来自于使用RijndaelManaged类为您执行加密，以及使用System.Security.Cryptography命名空间的Rfc2898DeriveBytes函数来生成加密密钥使用标准和安全的算法（具体来说，PBKDF2）基于您提供的基于字符串的密码。 （注意，这是对第一个版本使用旧版PBKDF1算法的改进）。
最后，请注意，这仍然是未经身份验证的加密。仅加密仅提供隐私（即，第三方不知道消息），而经认证的加密旨在提供隐私和真实性（即，接收者知道消息是由发送者发送的）。
在不知道您的确切要求的情况下，很难说这里的代码是否足以满足您的需求，但是，它的制作是为了在实现的相对简单性与“质量”之间实现良好的平衡。例如，如果加密字符串的“接收者”直接从受信任的“发件人”接收字符串，则验证may not even be necessary。
如果您需要更复杂的内容并提供经过身份验证的加密，请查看this post以了解实施情况。
以下是代码：
using System;
using System.Text;
using System.Security.Cryptography;
using System.IO;
using System.Linq;
namespace EncryptStringSample
{
public static class StringCipher
{
// This constant is used to determine the keysize of the encryption algorithm in bits.
// We divide this by 8 within the code below to get the equivalent number of bytes.
private const int Keysize = 256;
// This constant determines the number of iterations for the password bytes generation function.
private const int DerivationIterations = 1000;
public static string Encrypt(string plainText, string passPhrase)
{
// Salt and IV is randomly generated each time, but is preprended to encrypted cipher text
// so that the same Salt and IV values can be used when decrypting.
var saltStringBytes = Generate256BitsOfRandomEntropy();
var ivStringBytes = Generate256BitsOfRandomEntropy();
var plainTextBytes = Encoding.UTF8.GetBytes(plainText);
using (var password = new Rfc2898DeriveBytes(passPhrase, saltStringBytes, DerivationIterations))
{
var keyBytes = password.GetBytes(Keysize / 8);
using (var symmetricKey = new RijndaelManaged())
{
symmetricKey.BlockSize = 256;
symmetricKey.Mode = CipherMode.CBC;
symmetricKey.Padding = PaddingMode.PKCS7;
using (var encryptor = symmetricKey.CreateEncryptor(keyBytes, ivStringBytes))
{
using (var memoryStream = new MemoryStream())
{
using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
// Create the final bytes as a concatenation of the random salt bytes, the random iv bytes and the cipher bytes.
var cipherTextBytes = saltStringBytes;
cipherTextBytes = cipherTextBytes.Concat(ivStringBytes).ToArray();
cipherTextBytes = cipherTextBytes.Concat(memoryStream.ToArray()).ToArray();
memoryStream.Close();
cryptoStream.Close();
return Convert.ToBase64String(cipherTextBytes);
}
}
}
}
}
}
public static string Decrypt(string cipherText, string passPhrase)
{
// Get the complete stream of bytes that represent:
// [32 bytes of Salt] + [32 bytes of IV] + [n bytes of CipherText]
var cipherTextBytesWithSaltAndIv = Convert.FromBase64String(cipherText);
// Get the saltbytes by extracting the first 32 bytes from the supplied cipherText bytes.
var saltStringBytes = cipherTextBytesWithSaltAndIv.Take(Keysize / 8).ToArray();
// Get the IV bytes by extracting the next 32 bytes from the supplied cipherText bytes.
var ivStringBytes = cipherTextBytesWithSaltAndIv.Skip(Keysize / 8).Take(Keysize / 8).ToArray();
// Get the actual cipher text bytes by removing the first 64 bytes from the cipherText string.
var cipherTextBytes = cipherTextBytesWithSaltAndIv.Skip((Keysize / 8) * 2).Take(cipherTextBytesWithSaltAndIv.Length - ((Keysize / 8) * 2)).ToArray();
using (var password = new Rfc2898DeriveBytes(passPhrase, saltStringBytes, DerivationIterations))
{
var keyBytes = password.GetBytes(Keysize / 8);
using (var symmetricKey = new RijndaelManaged())
{
symmetricKey.BlockSize = 256;
symmetricKey.Mode = CipherMode.CBC;
symmetricKey.Padding = PaddingMode.PKCS7;
using (var decryptor = symmetricKey.CreateDecryptor(keyBytes, ivStringBytes))
{
using (var memoryStream = new MemoryStream(cipherTextBytes))
{
using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
{
var plainTextBytes = new byte[cipherTextBytes.Length];
var decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
memoryStream.Close();
cryptoStream.Close();
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
}
}
}
}
}
}
private static byte[] Generate256BitsOfRandomEntropy()
{
var randomBytes = new byte[32]; // 32 Bytes will give us 256 bits.
using (var rngCsp = new RNGCryptoServiceProvider())
{
// Fill the array with cryptographically secure random bytes.
rngCsp.GetBytes(randomBytes);
}
return randomBytes;
}
}
}
上述类可以非常简单地使用类似于以下代码：
using System;
namespace EncryptStringSample
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Please enter a password to use:");
string password = Console.ReadLine();
Console.WriteLine("Please enter a string to encrypt:");
string plaintext = Console.ReadLine();
Console.WriteLine("");
Console.WriteLine("Your encrypted string is:");
string encryptedstring = StringCipher.Encrypt(plaintext, password);
Console.WriteLine(encryptedstring);
Console.WriteLine("");
Console.WriteLine("Your decrypted string is:");
string decryptedstring = StringCipher.Decrypt(encryptedstring, password);
Console.WriteLine(decryptedstring);
Console.WriteLine("");
Console.WriteLine("Press any key to exit...");
Console.ReadLine();
}
}
}
（您可以下载一个简单的VS2013示例解决方案（包括一些单元测试）here）。
2015年12月23日更新： 代码的具体改进列表如下：
答案 1 :(得分：76)
using System.IO;
using System.Text;
using System.Security.Cryptography;
public static class EncryptionHelper
{
public static string Encrypt(string clearText)
{
string EncryptionKey = "abc123";
byte[] clearBytes = Encoding.Unicode.GetBytes(clearText);
using (Aes encryptor = Aes.Create())
{
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(clearBytes, 0, clearBytes.Length);
cs.Close();
}
clearText = Convert.ToBase64String(ms.ToArray());
}
}
return clearText;
}
public static string Decrypt(string cipherText)
{
string EncryptionKey = "abc123";
cipherText = cipherText.Replace(" ", "+");
byte[] cipherBytes = Convert.FromBase64String(cipherText);
using (Aes encryptor = Aes.Create())
{
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Write))
{
cs.Write(cipherBytes, 0, cipherBytes.Length);
cs.Close();
}
cipherText = Encoding.Unicode.GetString(ms.ToArray());
}
}
return cipherText;
}
}
答案 2 :(得分：28)
试试这堂课：
public class DataEncryptor
{
TripleDESCryptoServiceProvider symm;
#region Factory
public DataEncryptor()
{
this.symm = new TripleDESCryptoServiceProvider();
this.symm.Padding = PaddingMode.PKCS7;
}
public DataEncryptor(TripleDESCryptoServiceProvider keys)
{
this.symm = keys;
}
public DataEncryptor(byte[] key, byte[] iv)
{
this.symm = new TripleDESCryptoServiceProvider();
this.symm.Padding = PaddingMode.PKCS7;
this.symm.Key = key;
this.symm.IV = iv;
}
#endregion
#region Properties
public TripleDESCryptoServiceProvider Algorithm
{
get { return symm; }
set { symm = value; }
}
public byte[] Key
{
get { return symm.Key; }
set { symm.Key = value; }
}
public byte[] IV
{
get { return symm.IV; }
set { symm.IV = value; }
}
#endregion
#region Crypto
public byte[] Encrypt(byte[] data) { return Encrypt(data, data.Length); }
public byte[] Encrypt(byte[] data, int length)
{
try
{
// Create a MemoryStream.
var ms = new MemoryStream();
// Create a CryptoStream using the MemoryStream
// and the passed key and initialization vector (IV).
var cs = new CryptoStream(ms,
symm.CreateEncryptor(symm.Key, symm.IV),
CryptoStreamMode.Write);
// Write the byte array to the crypto stream and flush it.
cs.Write(data, 0, length);
cs.FlushFinalBlock();
// Get an array of bytes from the
// MemoryStream that holds the
// encrypted data.
byte[] ret = ms.ToArray();
// Close the streams.
cs.Close();
ms.Close();
// Return the encrypted buffer.
return ret;
}
catch (CryptographicException ex)
{
Console.WriteLine("A cryptographic error occured: {0}", ex.Message);
}
return null;
}
public string EncryptString(string text)
{
return Convert.ToBase64String(Encrypt(Encoding.UTF8.GetBytes(text)));
}
public byte[] Decrypt(byte[] data) { return Decrypt(data, data.Length); }
public byte[] Decrypt(byte[] data, int length)
{
try
{
// Create a new MemoryStream using the passed
// array of encrypted data.
MemoryStream ms = new MemoryStream(data);
// Create a CryptoStream using the MemoryStream
// and the passed key and initialization vector (IV).
CryptoStream cs = new CryptoStream(ms,
symm.CreateDecryptor(symm.Key, symm.IV),
CryptoStreamMode.Read);
// Create buffer to hold the decrypted data.
byte[] result = new byte[length];
// Read the decrypted data out of the crypto stream
// and place it into the temporary buffer.
cs.Read(result, 0, result.Length);
return result;
}
catch (CryptographicException ex)
{
Console.WriteLine("A cryptographic error occured: {0}", ex.Message);
}
return null;
}
public string DecryptString(string data)
{
return Encoding.UTF8.GetString(Decrypt(Convert.FromBase64String(data))).TrimEnd('\0');
}
#endregion
}
并像这样使用它：
string message="A very secret message here.";
DataEncryptor keys=new DataEncryptor();
string encr=keys.EncryptString(message);
// later
string actual=keys.DecryptString(encr);
答案 3 :(得分：19)
如果您需要在内存中存储密码并希望加密，则应使用 SecureString ：
http://msdn.microsoft.com/en-us/library/system.security.securestring.aspx
对于更一般的用途，我会使用FIPS认可的算法，例如Advanced Encryption Standard，以前称为Rijndael。有关实现示例，请参阅此页面：
http://msdn.microsoft.com/en-us/library/system.security.cryptography.rijndael.aspx
答案 4 :(得分：14)
如果您的目标是不支持RijndaelManaged的ASP.NET Core，则可以使用IDataProtectionProvider。
首先，配置您的应用程序以使用数据保护：
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddDataProtection();
}
// ...
}
然后您就可以注入IDataProtectionProvider实例并使用它来加密/解密数据：
public class MyService : IService
{
private const string Purpose = "my protection purpose";
private readonly IDataProtectionProvider _provider;
public MyService(IDataProtectionProvider provider)
{
_provider = provider;
}
public string Encrypt(string plainText)
{
var protector = _provider.CreateProtector(Purpose);
return protector.Protect(plainText);
}
public string Decrypt(string cipherText)
{
var protector = _provider.CreateProtector(Purpose);
return protector.Unprotect(cipherText);
}
}
有关详细信息，请参阅this article。
答案 5 :(得分：9)
您可能正在寻找使用用户登录凭据加密数据的ProtectedData类。
答案 6 :(得分：-1)
我看到加密的最简单方法是通过RSA
查看其上的MSDN：http://msdn.microsoft.com/en-us/library/system.security.cryptography.rsacryptoserviceprovider.aspx
它确实涉及使用字节，但是当它归结为它时，您确实希望加密和解密很难弄清楚，否则它很容易被破解。