用C#实现AES加密和解密

    AES 是一个新的可以用于保护电子数据的加密算法。明确地说，AES 是一个迭代的、对称密钥分组的密码，它可以使用128、192 和 256 位密钥，并且用 128 位（16字节）分组加密和解密数据。与公共密钥密码使用密钥对不同，对称密钥密码使用相同的密钥加密和解密数据。通过分组密码返回的加密数据 的位数与输入数据相同。迭代加密使用一个循环结构，在该循环中重复置换（permutations ）和替换(substitutions）输入数据。

需要加入引用   using System.Security.Cryptography;

/// <summary>
/// 有密码的AES加密
/// </summary>
/// <param name="text">加密字符</param>
/// <param name="password">加密的密码</param>
/// <param name="iv">密钥</param>
/// <returns></returns>
public static string AESEncrypt(string text, string password, string iv)
{
RijndaelManaged rijndaelCipher = new RijndaelManaged();

rijndaelCipher.Mode = CipherMode.CBC;

rijndaelCipher.Padding = PaddingMode.PKCS7;

rijndaelCipher.KeySize = 128;

rijndaelCipher.BlockSize = 128;

byte[] pwdBytes = System.Text.Encoding.UTF8.GetBytes(password);

byte[] keyBytes = new byte[16];

int len = pwdBytes.Length;

if (len > keyBytes.Length) len = keyBytes.Length;

System.Array.Copy(pwdBytes, keyBytes, len);

rijndaelCipher.Key = keyBytes;


byte[] ivBytes = System.Text.Encoding.UTF8.GetBytes(iv);
rijndaelCipher.IV = ivBytes;

ICryptoTransform transform = rijndaelCipher.CreateEncryptor();

byte[] plainText = Encoding.UTF8.GetBytes(text);

byte[] cipherBytes = transform.TransformFinalBlock(plainText, 0, plainText.Length);

return Convert.ToBase64String(cipherBytes);

}

/// <summary>
/// 随机生成密钥
/// </summary>
/// <returns></returns>
public static string GetIv(int n)
{
char[] arrChar = new char[]{
'a','b','d','c','e','f','g','h','i','j','k','l','m','n','p','r','q','s','t','u','v','w','z','y','x',
'0','1','2','3','4','5','6','7','8','9',
'A','B','C','D','E','F','G','H','I','J','K','L','M','N','Q','P','R','T','S','V','U','W','X','Y','Z'
};

StringBuilder num = new StringBuilder();

Random rnd = new Random(DateTime.Now.Millisecond);
for (int i = 0; i < n; i++)
{
num.Append(arrChar[rnd.Next(0, arrChar.Length)].ToString());

}

return num.ToString();
}

/// <summary>
/// AES解密
/// </summary>
/// <param name="text"></param>
/// <param name="password"></param>
/// <param name="iv"></param>
/// <returns></returns>
public static string AESDecrypt(string text, string password, string iv)
{
RijndaelManaged rijndaelCipher = new RijndaelManaged();

rijndaelCipher.Mode = CipherMode.CBC;

rijndaelCipher.Padding = PaddingMode.PKCS7;

rijndaelCipher.KeySize = 128;

rijndaelCipher.BlockSize = 128;

byte[] encryptedData = Convert.FromBase64String(text);

byte[] pwdBytes = System.Text.Encoding.UTF8.GetBytes(password);

byte[] keyBytes = new byte[16];

int len = pwdBytes.Length;

if (len > keyBytes.Length) len = keyBytes.Length;

System.Array.Copy(pwdBytes, keyBytes, len);

rijndaelCipher.Key = keyBytes;

byte[] ivBytes = System.Text.Encoding.UTF8.GetBytes(iv);
rijndaelCipher.IV = ivBytes;

ICryptoTransform transform = rijndaelCipher.CreateDecryptor();

byte[] plainText = transform.TransformFinalBlock(encryptedData, 0, encryptedData.Length);

return Encoding.UTF8.GetString(plainText);

}