如何在c#中加密和解密字符串?


当前回答

一个安全散列数据的好算法是BCrypt:

除了加入盐来抵御彩虹桌的攻击, Bcrypt是一个自适应函数:随着时间的推移,迭代计数可以 增加使它变慢,所以它仍然抵抗蛮力 搜索攻击,即使增加计算能力。

BCrypt有一个很好的。net实现,也可以作为NuGet包使用。

其他回答

下面的代码是Ghazal回答类似问题的改进版本。

public class EncryptionHelper
{
    private Aes aesEncryptor;

    public EncryptionHelper()
    {
    }

    private void BuildAesEncryptor(string key)
    {
        aesEncryptor = Aes.Create();
        var pdb = new Rfc2898DeriveBytes(key, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
        aesEncryptor.Key = pdb.GetBytes(32);
        aesEncryptor.IV = pdb.GetBytes(16);
    }

    public string EncryptString(string clearText, string key)
    {
        BuildAesEncryptor(key);
        var clearBytes = Encoding.Unicode.GetBytes(clearText);
        using (var ms = new MemoryStream())
        {
            using (var cs = new CryptoStream(ms, aesEncryptor.CreateEncryptor(), CryptoStreamMode.Write))
            {
                cs.Write(clearBytes, 0, clearBytes.Length);
            }
            var encryptedText = Convert.ToBase64String(ms.ToArray());
            return encryptedText;
        }
    }

    public string DecryptString(string cipherText, string key)
    {
        BuildAesEncryptor(key);
        cipherText = cipherText.Replace(" ", "+");
        var cipherBytes = Convert.FromBase64String(cipherText);
        using (var ms = new MemoryStream())
        {
            using (var cs = new CryptoStream(ms, aesEncryptor.CreateDecryptor(), CryptoStreamMode.Write))
            {
                cs.Write(cipherBytes, 0, cipherBytes.Length);
            }
            var clearText = Encoding.Unicode.GetString(ms.ToArray());
            return clearText;
        }
    }
}
            using System;
            using System.Collections.Generic;
            using System.Text;
            using System.Text.RegularExpressions;  // This is for password validation
            using System.Security.Cryptography;
            using System.Configuration;  // This is where the hash functions reside

            namespace BullyTracker.Common
            {
                public class HashEncryption
                {
                    //public string GenerateHashvalue(string thisPassword)
                    //{
                    //    MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
                    //    byte[] tmpSource;
                    //    byte[] tmpHash;

                    //    tmpSource = ASCIIEncoding.ASCII.GetBytes(thisPassword); // Turn password into byte array
                    //    tmpHash = md5.ComputeHash(tmpSource);

                    //    StringBuilder sOutput = new StringBuilder(tmpHash.Length);
                    //    for (int i = 0; i < tmpHash.Length; i++)
                    //    {
                    //        sOutput.Append(tmpHash[i].ToString("X2"));  // X2 formats to hexadecimal
                    //    }
                    //    return sOutput.ToString();
                    //}
                    //public Boolean VerifyHashPassword(string thisPassword, string thisHash)
                    //{
                    //    Boolean IsValid = false;
                    //    string tmpHash = GenerateHashvalue(thisPassword); // Call the routine on user input
                    //    if (tmpHash == thisHash) IsValid = true;  // Compare to previously generated hash
                    //    return IsValid;
                    //}
                    public string GenerateHashvalue(string toEncrypt, bool useHashing)
                    {
                        byte[] keyArray;
                        byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);

                        System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
                        // Get the key from config file
                        string key = (string)settingsReader.GetValue("SecurityKey", typeof(String));
                        //System.Windows.Forms.MessageBox.Show(key);
                        if (useHashing)
                        {
                            MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
                            keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
                            hashmd5.Clear();
                        }
                        else
                            keyArray = UTF8Encoding.UTF8.GetBytes(key);

                        TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
                        tdes.Key = keyArray;
                        tdes.Mode = CipherMode.ECB;
                        tdes.Padding = PaddingMode.PKCS7;

                        ICryptoTransform cTransform = tdes.CreateEncryptor();
                        byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
                        tdes.Clear();
                        return Convert.ToBase64String(resultArray, 0, resultArray.Length);
                    }
                    /// <summary>
                    /// DeCrypt a string using dual encryption method. Return a DeCrypted clear string
                    /// </summary>
                    /// <param name="cipherString">encrypted string</param>
                    /// <param name="useHashing">Did you use hashing to encrypt this data? pass true is yes</param>
                    /// <returns></returns>
                    public string Decrypt(string cipherString, bool useHashing)
                    {
                        byte[] keyArray;
                        byte[] toEncryptArray = Convert.FromBase64String(cipherString);

                        System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
                        //Get your key from config file to open the lock!
                        string key = (string)settingsReader.GetValue("SecurityKey", typeof(String));

                        if (useHashing)
                        {
                            MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
                            keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
                            hashmd5.Clear();
                        }
                        else
                            keyArray = UTF8Encoding.UTF8.GetBytes(key);

                        TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
                        tdes.Key = keyArray;
                        tdes.Mode = CipherMode.ECB;
                        tdes.Padding = PaddingMode.PKCS7;

                        ICryptoTransform cTransform = tdes.CreateDecryptor();
                        byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);

                        tdes.Clear();
                        return UTF8Encoding.UTF8.GetString(resultArray);
                    }


                }

            }
using System;
using System.Data;
using System.Configuration;
using System.Text;
using System.Security.Cryptography;

namespace Encription
{
    class CryptorEngine
    {
        public static string Encrypt(string ToEncrypt, bool useHasing)
        {
            byte[] keyArray;
            byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(ToEncrypt);
            //System.Configuration.AppSettingsReader settingsReader = new     AppSettingsReader();
           string Key = "Bhagwati";
            if (useHasing)
            {
                MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
                keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(Key));
                hashmd5.Clear();  
            }
            else
            {
                keyArray = UTF8Encoding.UTF8.GetBytes(Key);
            }
            TripleDESCryptoServiceProvider tDes = new TripleDESCryptoServiceProvider();
            tDes.Key = keyArray;
            tDes.Mode = CipherMode.ECB;
            tDes.Padding = PaddingMode.PKCS7;
            ICryptoTransform cTransform = tDes.CreateEncryptor();
            byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0,     toEncryptArray.Length);
            tDes.Clear();
            return Convert.ToBase64String(resultArray, 0, resultArray.Length);
        }
        public static string Decrypt(string cypherString, bool useHasing)
        {
            byte[] keyArray;
            byte[] toDecryptArray = Convert.FromBase64String(cypherString);
            //byte[] toEncryptArray = Convert.FromBase64String(cypherString);
            //System.Configuration.AppSettingsReader settingReader = new     AppSettingsReader();
            string key = "Bhagwati";
            if (useHasing)
            {
                MD5CryptoServiceProvider hashmd = new MD5CryptoServiceProvider();
                keyArray = hashmd.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
                hashmd.Clear();
            }
            else
            {
                keyArray = UTF8Encoding.UTF8.GetBytes(key);
            }
            TripleDESCryptoServiceProvider tDes = new TripleDESCryptoServiceProvider();
            tDes.Key = keyArray;
            tDes.Mode = CipherMode.ECB;
            tDes.Padding = PaddingMode.PKCS7;
            ICryptoTransform cTransform = tDes.CreateDecryptor();
            try
            {
                byte[] resultArray = cTransform.TransformFinalBlock(toDecryptArray, 0,         toDecryptArray.Length);

                tDes.Clear();
                return UTF8Encoding.UTF8.GetString(resultArray,0,resultArray.Length);
            }
            catch (Exception ex)
            {
                throw ex;
             }
        }
    }
}

加密是编程中非常常见的问题。我认为最好是安装一个包来为您做这个任务。也许是一个简单的开源NuGet项目 简单Aes加密

密钥在配置文件中,因此很容易在生产环境中更改,而且我没有看到任何缺点。

<MessageEncryption>
  <EncryptionKey KeySize="256" Key="3q2+796tvu/erb7v3q2+796tvu/erb7v3q2+796tvu8="/>
</MessageEncryption>

AES算法:

public static class CryptographyProvider
    {
        public static string EncryptString(string plainText, out string Key)
        {
            if (plainText == null || plainText.Length <= 0)
                throw new ArgumentNullException("plainText");

            using (Aes _aesAlg = Aes.Create())
            {
                Key = Convert.ToBase64String(_aesAlg.Key);
                ICryptoTransform _encryptor = _aesAlg.CreateEncryptor(_aesAlg.Key, _aesAlg.IV);

                using (MemoryStream _memoryStream = new MemoryStream())
                {
                    _memoryStream.Write(_aesAlg.IV, 0, 16);
                    using (CryptoStream _cryptoStream = new CryptoStream(_memoryStream, _encryptor, CryptoStreamMode.Write))
                    {
                        using (StreamWriter _streamWriter = new StreamWriter(_cryptoStream))
                        {
                            _streamWriter.Write(plainText);
                        }
                        return Convert.ToBase64String(_memoryStream.ToArray());
                    }
                }
            }
        }
        public static string DecryptString(string cipherText, string Key)
        {

            if (string.IsNullOrEmpty(cipherText))
                throw new ArgumentNullException("cipherText");
            if (string.IsNullOrEmpty(Key))
                throw new ArgumentNullException("Key");

            string plaintext = null;

            byte[] _initialVector = new byte[16];
            byte[] _Key = Convert.FromBase64String(Key);
            byte[] _cipherTextBytesArray = Convert.FromBase64String(cipherText);
            byte[] _originalString = new byte[_cipherTextBytesArray.Length - 16];

            Array.Copy(_cipherTextBytesArray, 0, _initialVector, 0, _initialVector.Length);
            Array.Copy(_cipherTextBytesArray, 16, _originalString, 0, _cipherTextBytesArray.Length - 16);

            using (Aes _aesAlg = Aes.Create())
            {
                _aesAlg.Key = _Key;
                _aesAlg.IV = _initialVector;
                ICryptoTransform decryptor = _aesAlg.CreateDecryptor(_aesAlg.Key, _aesAlg.IV);

                using (MemoryStream _memoryStream = new MemoryStream(_originalString))
                {
                    using (CryptoStream _cryptoStream = new CryptoStream(_memoryStream, decryptor, CryptoStreamMode.Read))
                    {
                        using (StreamReader _streamReader = new StreamReader(_cryptoStream))
                        {
                            plaintext = _streamReader.ReadToEnd();
                        }
                    }
                }
            }
            return plaintext;
        }
    }