如何在c#中加密和解密字符串?


当前回答

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Security.Cryptography;
using System.IO;
using System.Text;  

/// <summary>
/// Summary description for Encryption
/// </summary>
public class Encryption
{
    public TripleDES CreateDES(string key)
    {
        MD5 md5 = new MD5CryptoServiceProvider();
        TripleDES des = new TripleDESCryptoServiceProvider();
        des.Key = md5.ComputeHash(Encoding.Unicode.GetBytes(key));
        des.IV = new byte[des.BlockSize / 8];
        return des;
    }
    public  byte[] Encryptiondata(string PlainText)
    {
        TripleDES des = CreateDES("DreamMLMKey");
        ICryptoTransform ct = des.CreateEncryptor();
        byte[] input = Encoding.Unicode.GetBytes(PlainText);
        return ct.TransformFinalBlock(input, 0, input.Length);
    }

    public string Decryptiondata(string CypherText)
    {
        string stringToDecrypt = CypherText.Replace(" ", "+");
        int len = stringToDecrypt.Length;
        byte[] inputByteArray = Convert.FromBase64String(stringToDecrypt); 

        byte[] b = Convert.FromBase64String(CypherText);
        TripleDES des = CreateDES("DreamMLMKey");
        ICryptoTransform ct = des.CreateDecryptor();
        byte[] output = ct.TransformFinalBlock(b, 0, b.Length);
        return Encoding.Unicode.GetString(output);
    }
    public string Decryptiondataurl(string CypherText)
    {
        string newcyperttext=CypherText.Replace(' ', '+');
        byte[] b = Convert.FromBase64String(newcyperttext);
        TripleDES des = CreateDES("DreamMLMKey");
        ICryptoTransform ct = des.CreateDecryptor();
        byte[] output = ct.TransformFinalBlock(b, 0, b.Length);
        return Encoding.Unicode.GetString(output);
    }


    #region  encryption & Decription
    public  string Encrypt(string input, string key)
    {
        byte[] inputArray = UTF8Encoding.UTF8.GetBytes(input);
        TripleDESCryptoServiceProvider tripleDES = new TripleDESCryptoServiceProvider();
        tripleDES.Key = UTF8Encoding.UTF8.GetBytes(key);
        tripleDES.Mode = CipherMode.ECB;
        tripleDES.Padding = PaddingMode.PKCS7;
        ICryptoTransform cTransform = tripleDES.CreateEncryptor();
        byte[] resultArray = cTransform.TransformFinalBlock(inputArray, 0, inputArray.Length);
        tripleDES.Clear();
        return Convert.ToBase64String(resultArray, 0, resultArray.Length);
    }
    public  string Decrypt(string input, string key)
    {
        byte[] inputArray = Convert.FromBase64String(input);
        TripleDESCryptoServiceProvider tripleDES = new TripleDESCryptoServiceProvider();
        tripleDES.Key = UTF8Encoding.UTF8.GetBytes(key);
        tripleDES.Mode = CipherMode.ECB;
        tripleDES.Padding = PaddingMode.PKCS7;
        ICryptoTransform cTransform = tripleDES.CreateDecryptor();
        byte[] resultArray = cTransform.TransformFinalBlock(inputArray, 0, inputArray.Length);
        tripleDES.Clear();
        return UTF8Encoding.UTF8.GetString(resultArray);
    }

    public string encrypt(string encryptString)
    {
        string EncryptionKey = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        byte[] clearBytes = Encoding.Unicode.GetBytes(encryptString);
        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();
                }
                encryptString = Convert.ToBase64String(ms.ToArray());
            }
        }
        return encryptString;
    }

    public string Decrypt(string cipherText)
    {
        string EncryptionKey = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        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;
    }

    #endregion
}

其他回答

支持mattmanser的回答。下面是一个使用MachineKey类加密/解密URL安全值的示例。

Something to bear in mind, as mentioned before, this will use Machine config settings (https://msdn.microsoft.com/en-us/library/ff649308.aspx). You can set encryption and decryption key/algorithm manually (you might need this specially if your site is running on multiple servers) in web.config file. You can generate keys from IIS (see here: https://blogs.msdn.microsoft.com/vijaysk/2009/05/13/iis-7-tip-10-you-can-generate-machine-keys-from-the-iis-manager/) or can use an online machine key generator like: http://www.developerfusion.com/tools/generatemachinekey/

    private static readonly UTF8Encoding Encoder = new UTF8Encoding();

    public static string Encrypt(string unencrypted)
    {
        if (string.IsNullOrEmpty(unencrypted)) 
            return string.Empty;

        try
        {
            var encryptedBytes = MachineKey.Protect(Encoder.GetBytes(unencrypted));

            if (encryptedBytes != null && encryptedBytes.Length > 0)
                return HttpServerUtility.UrlTokenEncode(encryptedBytes);    
        }
        catch (Exception)
        {
            return string.Empty;
        }

        return string.Empty;
    }

    public static string Decrypt(string encrypted)
    {
        if (string.IsNullOrEmpty(encrypted)) 
            return string.Empty;

        try
        {
            var bytes = HttpServerUtility.UrlTokenDecode(encrypted);
            if (bytes != null && bytes.Length > 0)
            {
                var decryptedBytes = MachineKey.Unprotect(bytes);
                if(decryptedBytes != null && decryptedBytes.Length > 0)
                    return Encoder.GetString(decryptedBytes);
            }

        }
        catch (Exception)
        {
            return string.Empty;
        }

        return string.Empty;
    }

免责声明:此解决方案只能用于未公开的静态数据(例如配置文件或DB)。只有在这种情况下,快速和肮脏的解决方案才能被认为比@jbtule的解决方案更好,因为它的维护更低。

原来的帖子: 我发现jbtule的答案对于一个快速和肮脏的安全AES字符串加密有点复杂,Brett的答案有一个错误,初始化向量是一个固定的值,使它容易受到填充攻击,所以我修复了Brett的代码,并添加了一个随机IV,添加到chitered字符串,创建一个不同的加密值,每个加密相同的值:

加密:

public static string Encrypt(string clearText)
{            
    byte[] clearBytes = Encoding.Unicode.GetBytes(clearText);
    using (Aes encryptor = Aes.Create())
    {
        byte[] IV = new byte[15];
        rand.NextBytes(IV);
        Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, IV);
        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(IV) + Convert.ToBase64String(ms.ToArray());
        }
    }
    return clearText;
}

解密:

public static string Decrypt(string cipherText)
{
    byte[] IV = Convert.FromBase64String(cipherText.Substring(0, 20));
    cipherText = cipherText.Substring(20).Replace(" ", "+");
    byte[] cipherBytes = Convert.FromBase64String(cipherText);
    using (Aes encryptor = Aes.Create())
    {
        Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, IV);
        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;
}

将EncryptionKey替换为您的密钥。 在我的实现中,密钥被保存在配置文件(web.config\app.config)中,因为您不应该将其硬编码保存。配置文件也应该加密,这样密钥就不会被保存为明文。

protected static string _Key = "";
protected static string EncryptionKey
{
    get
    {
        if (String.IsNullOrEmpty(_Key))
        {
            _Key = ConfigurationManager.AppSettings["AESKey"].ToString();
        }

        return _Key;
    }
}
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;
             }
        }
    }
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Security.Cryptography;
using System.IO;
using System.Text;  

/// <summary>
/// Summary description for Encryption
/// </summary>
public class Encryption
{
    public TripleDES CreateDES(string key)
    {
        MD5 md5 = new MD5CryptoServiceProvider();
        TripleDES des = new TripleDESCryptoServiceProvider();
        des.Key = md5.ComputeHash(Encoding.Unicode.GetBytes(key));
        des.IV = new byte[des.BlockSize / 8];
        return des;
    }
    public  byte[] Encryptiondata(string PlainText)
    {
        TripleDES des = CreateDES("DreamMLMKey");
        ICryptoTransform ct = des.CreateEncryptor();
        byte[] input = Encoding.Unicode.GetBytes(PlainText);
        return ct.TransformFinalBlock(input, 0, input.Length);
    }

    public string Decryptiondata(string CypherText)
    {
        string stringToDecrypt = CypherText.Replace(" ", "+");
        int len = stringToDecrypt.Length;
        byte[] inputByteArray = Convert.FromBase64String(stringToDecrypt); 

        byte[] b = Convert.FromBase64String(CypherText);
        TripleDES des = CreateDES("DreamMLMKey");
        ICryptoTransform ct = des.CreateDecryptor();
        byte[] output = ct.TransformFinalBlock(b, 0, b.Length);
        return Encoding.Unicode.GetString(output);
    }
    public string Decryptiondataurl(string CypherText)
    {
        string newcyperttext=CypherText.Replace(' ', '+');
        byte[] b = Convert.FromBase64String(newcyperttext);
        TripleDES des = CreateDES("DreamMLMKey");
        ICryptoTransform ct = des.CreateDecryptor();
        byte[] output = ct.TransformFinalBlock(b, 0, b.Length);
        return Encoding.Unicode.GetString(output);
    }


    #region  encryption & Decription
    public  string Encrypt(string input, string key)
    {
        byte[] inputArray = UTF8Encoding.UTF8.GetBytes(input);
        TripleDESCryptoServiceProvider tripleDES = new TripleDESCryptoServiceProvider();
        tripleDES.Key = UTF8Encoding.UTF8.GetBytes(key);
        tripleDES.Mode = CipherMode.ECB;
        tripleDES.Padding = PaddingMode.PKCS7;
        ICryptoTransform cTransform = tripleDES.CreateEncryptor();
        byte[] resultArray = cTransform.TransformFinalBlock(inputArray, 0, inputArray.Length);
        tripleDES.Clear();
        return Convert.ToBase64String(resultArray, 0, resultArray.Length);
    }
    public  string Decrypt(string input, string key)
    {
        byte[] inputArray = Convert.FromBase64String(input);
        TripleDESCryptoServiceProvider tripleDES = new TripleDESCryptoServiceProvider();
        tripleDES.Key = UTF8Encoding.UTF8.GetBytes(key);
        tripleDES.Mode = CipherMode.ECB;
        tripleDES.Padding = PaddingMode.PKCS7;
        ICryptoTransform cTransform = tripleDES.CreateDecryptor();
        byte[] resultArray = cTransform.TransformFinalBlock(inputArray, 0, inputArray.Length);
        tripleDES.Clear();
        return UTF8Encoding.UTF8.GetString(resultArray);
    }

    public string encrypt(string encryptString)
    {
        string EncryptionKey = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        byte[] clearBytes = Encoding.Unicode.GetBytes(encryptString);
        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();
                }
                encryptString = Convert.ToBase64String(ms.ToArray());
            }
        }
        return encryptString;
    }

    public string Decrypt(string cipherText)
    {
        string EncryptionKey = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        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;
    }

    #endregion
}

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;
        }
    }
}