使用AES加密的帮助类

在开发中经常使用加密/解密对一些内容进行处理，比如密码在存入数据库之前先经过加密处理等等，这里就把一个加密帮助类代码贴出来，供以后查找使用。

这个帮助类主要功能是对字符串和字节数组进行加密解密处理。

public class EncryptionHelper

    {

        //默认密钥向量 

        private static readonly byte[] DefaultKey = {0x12, 0x34, 0x56, 120, 0x90, 0xab, 0xcd, 0xef};



        /// <summary>

        ///     解密字节数组

        /// </summary>

        /// <param name="cipherBytes">密文字节数组</param>

        /// <param name="password">密钥</param>

        /// <returns>解密后字节数组</returns>

        public static byte[] DecryptBytes(byte[] cipherBytes, string password)

        {

            byte[] buffer;

            try

            {

                using (Aes aes = new AesManaged())

                {

                    //设置密钥及密钥向量

                    aes.Key = new Rfc2898DeriveBytes(password, DefaultKey).GetBytes(0x10);

                    aes.IV = aes.Key;

                    using (var memoryStream = new MemoryStream())

                    {

                        using (

                            var cryptoStream = new CryptoStream(memoryStream, aes.CreateDecryptor(),

                                CryptoStreamMode.Write))

                        {

                            cryptoStream.Write(cipherBytes, 0, cipherBytes.Length);

                            cryptoStream.Flush();

                        }

                        //得到解密后的字节数组

                        buffer = memoryStream.ToArray();

                    }

                }

            }

            catch

            {

                buffer = null;

            }

            return buffer;

        }



        /// <summary>

        ///     解密字符串

        /// </summary>

        /// <param name="cipherText">密文</param>

        /// <param name="password">密钥</param>

        /// <returns>解密后字符串</returns>

        public static string DecryptString(string cipherText, string password)

        {

            byte[] decryptBytes = DecryptBytes(Convert.FromBase64String(cipherText), password);

            if (decryptBytes == null)

            {

                return null;

            }

            return Encoding.UTF8.GetString(decryptBytes, 0, decryptBytes.Length);

        }



        /// <summary>

        ///     加密字节数组

        /// </summary>

        /// <param name="plainBytes">明文字节数组</param>

        /// <param name="password">密钥</param>

        /// <returns>加密后字节数组</returns>

        public static byte[] EncryptBytes(byte[] plainBytes, string password)

        {

            byte[] buffer;

            try

            {

                using (Aes aes = new AesManaged())

                {

                    //设置密钥及密钥向量

                    aes.Key = new Rfc2898DeriveBytes(password, DefaultKey).GetBytes(0x10);

                    aes.IV = aes.Key;

                    using (var memoryStream = new MemoryStream())

                    {

                        using (

                            var cryptoStream = new CryptoStream(memoryStream, aes.CreateEncryptor(),

                                CryptoStreamMode.Write))

                        {

                            cryptoStream.Write(plainBytes, 0, plainBytes.Length);

                            cryptoStream.FlushFinalBlock();

                        }

                        //得到加密后的字节数组

                        buffer = memoryStream.ToArray();

                    }

                }

            }

            catch

            {

                buffer = null;

            }

            return buffer;

        }



        /// <summary>

        ///     加密字符串

        /// </summary>

        /// <param name="plainText">明文</param>

        /// <param name="password">密钥</param>

        /// <returns>加密后字符串</returns>

        public static string EncryptString(string plainText, string password)

        {

            byte[] cipherBytes = EncryptBytes(Encoding.UTF8.GetBytes(plainText), password);

            if (cipherBytes == null)

            {

                return null;

            }

            return Convert.ToBase64String(cipherBytes);

        }

    }