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c# 加密与解密 RRS feed

  • 问题

  • 在使用c#进行文件加密然后再自己解密,出来的结果都是乱码。如自己加密然后再解密word ,cad或不定格式文件时需如何处理。我现已处理好含有中文内容的文本文件的方法了。盼高手给与指点……
    2009年4月20日 14:22

答案

  • // Hi, 对 txt, word, cad 的加密解密都是一样的, 以下代码是从网上收集的还未来得及整理,
    // 经测试几种文件类型都是没有问题的,希望对你有帮助。
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using MyCryptoHelp;
    using System.Security.Cryptography;
    using System.IO;
    
    namespace MyCryptoHelp
    {
        /// <summary>
        /// 异常处理类
        /// </summary>
        public class CryptoHelpException : ApplicationException
        {
            public CryptoHelpException(string msg) : base(msg) { }
        }
    
        /// <summary>
        /// CryptHelp
        /// </summary>
        public class CryptoHelp
        {
            private const ulong FC_TAG = 0xFC010203040506CF;
    
            private const int BUFFER_SIZE = 128 * 1024;
    
            /// <summary>
            /// 检验两个Byte数组是否相同
            /// </summary>
            /// <param name="b1">Byte数组</param>
            /// <param name="b2">Byte数组</param>
            /// <returns>true-相等</returns>
            private static bool CheckByteArrays(byte[] b1, byte[] b2)
            {
                if (b1.Length == b2.Length)
                {
                    for (int i = 0; i < b1.Length; ++i)
                    {
                        if (b1[i] != b2[i])
                            return false;
                    }
                    return true;
                }
                return false;
            }
    
            /// <summary>
            /// 创建Rijndael SymmetricAlgorithm
            /// </summary>
            /// <param name="password">密码</param>
            /// <param name="salt"></param>
            /// <returns>加密对象</returns>
            private static SymmetricAlgorithm CreateRijndael(string password, byte[] salt)
            {
                PasswordDeriveBytes pdb = new PasswordDeriveBytes(password, salt, "SHA256", 1000);
    
                SymmetricAlgorithm sma = Rijndael.Create();
                sma.KeySize = 256;
                sma.Key = pdb.GetBytes(32);
                sma.Padding = PaddingMode.PKCS7;
                return sma;
            }
    
            /// <summary>
            /// 加密文件随机数生成
            /// </summary>
            private static RandomNumberGenerator rand = new RNGCryptoServiceProvider();
    
            /// <summary>
            /// 生成指定长度的随机Byte数组
            /// </summary>
            /// <param name="count">Byte数组长度</param>
            /// <returns>随机Byte数组</returns>
            private static byte[] GenerateRandomBytes(int count)
            {
                byte[] bytes = new byte[count];
                rand.GetBytes(bytes);
                return bytes;
            }
    
            /// <summary>
            /// 加密文件
            /// </summary>
            /// <param name="inFile">待加密文件</param>
            /// <param name="outFile">加密后输入文件</param>
            /// <param name="password">加密密码</param>
            public static void EncryptFile(string inFile, string outFile, string password)
            {
                using (FileStream fin = File.OpenRead(inFile),
                    fout = File.OpenWrite(outFile))
                {
                    long lSize = fin.Length; // 输入文件长度
                    int size = (int)lSize;
                    byte[] bytes = new byte[BUFFER_SIZE]; // 缓存
                    int read = -1; // 输入文件读取数量
                    int value = 0;
    
                    // 获取IV和salt
                    byte[] IV = GenerateRandomBytes(16);
                    byte[] salt = GenerateRandomBytes(16);
    
                    // 创建加密对象
                    SymmetricAlgorithm sma = CryptoHelp.CreateRijndael(password, salt);
                    sma.IV = IV;
    
                    // 在输出文件开始部分写入IV和salt
                    fout.Write(IV, 0, IV.Length);
                    fout.Write(salt, 0, salt.Length);
    
                    // 创建散列加密
                    HashAlgorithm hasher = SHA256.Create();
                    using (CryptoStream cout = new CryptoStream(fout, sma.CreateEncryptor(), CryptoStreamMode.Write),
                        chash = new CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write))
                    {
                        BinaryWriter bw = new BinaryWriter(cout);
                        bw.Write(lSize);
    
                        bw.Write(FC_TAG);
    
                        // 读写字节块到加密流缓冲区
                        while ((read = fin.Read(bytes, 0, bytes.Length)) != 0)
                        {
                            cout.Write(bytes, 0, read);
                            chash.Write(bytes, 0, read);
                            value += read;
                        }
                        // 关闭加密流
                        chash.Flush();
                        chash.Close();
    
                        // 读取散列
                        byte[] hash = hasher.Hash;
    
                        // 输入文件写入散列
                        cout.Write(hash, 0, hash.Length);
    
                        // 关闭文件流
                        cout.Flush();
                        cout.Close();
                    }
                }
            }
    
            /// <summary>
            /// 解密文件
            /// </summary>
            /// <param name="inFile">待解密文件</param>
            /// <param name="outFile">解密后输出文件</param>
            /// <param name="password">解密密码</param>
            public static void DecryptFile(string inFile, string outFile, string password)
            {
                // 创建打开文件流
                using (FileStream fin = File.OpenRead(inFile),
                    fout = File.OpenWrite(outFile))
                {
                    int size = (int)fin.Length;
                    byte[] bytes = new byte[BUFFER_SIZE];
                    int read = -1;
                    int value = 0;
                    int outValue = 0;
    
                    byte[] IV = new byte[16];
                    fin.Read(IV, 0, 16);
                    byte[] salt = new byte[16];
                    fin.Read(salt, 0, 16);
    
                    SymmetricAlgorithm sma = CryptoHelp.CreateRijndael(password, salt);
                    sma.IV = IV;
    
                    value = 32;
                    long lSize = -1;
    
                    // 创建散列对象, 校验文件
                    HashAlgorithm hasher = SHA256.Create();
    
                    using (CryptoStream cin = new CryptoStream(fin, sma.CreateDecryptor(), CryptoStreamMode.Read),
                        chash = new CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write))
                    {
                        // 读取文件长度
                        BinaryReader br = new BinaryReader(cin);
                        lSize = br.ReadInt64();
                        ulong tag = br.ReadUInt64();
    
                        if (FC_TAG != tag)
                            throw new CryptoHelpException("文件被破坏");
    
                        long numReads = lSize / BUFFER_SIZE;
    
                        long slack = (long)lSize % BUFFER_SIZE;
    
                        for (int i = 0; i < numReads; ++i)
                        {
                            read = cin.Read(bytes, 0, bytes.Length);
                            fout.Write(bytes, 0, read);
                            chash.Write(bytes, 0, read);
                            value += read;
                            outValue += read;
                        }
    
                        if (slack > 0)
                        {
                            read = cin.Read(bytes, 0, (int)slack);
                            fout.Write(bytes, 0, read);
                            chash.Write(bytes, 0, read);
                            value += read;
                            outValue += read;
                        }
    
                        chash.Flush();
                        chash.Close();
    
                        fout.Flush();
                        fout.Close();
    
                        byte[] curHash = hasher.Hash;
    
                        // 获取比较和旧的散列对象
                        byte[] oldHash = new byte[hasher.HashSize / 8];
                        read = cin.Read(oldHash, 0, oldHash.Length);
                        if ((oldHash.Length != read) || (!CheckByteArrays(oldHash, curHash)))
                            throw new CryptoHelpException("文件被破坏");
                    }
    
                    if (outValue != lSize)
                        throw new CryptoHelpException("文件大小不匹配");
                }
            }
        }
    }
    
    
    // 调用
    
    public class TestClass
    {
        [STAThread]
        static void Main()
        {
            CryptoHelp.EncryptFile(@"C:\01.docx", @"C:\02.et", "123456");
            CryptoHelp.DecryptFile(@"C:\02.et", @"C:\03.docx", "123456");
        }
    }


    知识改变命运,奋斗成就人生!
    2009年4月20日 17:12
    版主

全部回复

  • // Hi, 对 txt, word, cad 的加密解密都是一样的, 以下代码是从网上收集的还未来得及整理,
    // 经测试几种文件类型都是没有问题的,希望对你有帮助。
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using MyCryptoHelp;
    using System.Security.Cryptography;
    using System.IO;
    
    namespace MyCryptoHelp
    {
        /// <summary>
        /// 异常处理类
        /// </summary>
        public class CryptoHelpException : ApplicationException
        {
            public CryptoHelpException(string msg) : base(msg) { }
        }
    
        /// <summary>
        /// CryptHelp
        /// </summary>
        public class CryptoHelp
        {
            private const ulong FC_TAG = 0xFC010203040506CF;
    
            private const int BUFFER_SIZE = 128 * 1024;
    
            /// <summary>
            /// 检验两个Byte数组是否相同
            /// </summary>
            /// <param name="b1">Byte数组</param>
            /// <param name="b2">Byte数组</param>
            /// <returns>true-相等</returns>
            private static bool CheckByteArrays(byte[] b1, byte[] b2)
            {
                if (b1.Length == b2.Length)
                {
                    for (int i = 0; i < b1.Length; ++i)
                    {
                        if (b1[i] != b2[i])
                            return false;
                    }
                    return true;
                }
                return false;
            }
    
            /// <summary>
            /// 创建Rijndael SymmetricAlgorithm
            /// </summary>
            /// <param name="password">密码</param>
            /// <param name="salt"></param>
            /// <returns>加密对象</returns>
            private static SymmetricAlgorithm CreateRijndael(string password, byte[] salt)
            {
                PasswordDeriveBytes pdb = new PasswordDeriveBytes(password, salt, "SHA256", 1000);
    
                SymmetricAlgorithm sma = Rijndael.Create();
                sma.KeySize = 256;
                sma.Key = pdb.GetBytes(32);
                sma.Padding = PaddingMode.PKCS7;
                return sma;
            }
    
            /// <summary>
            /// 加密文件随机数生成
            /// </summary>
            private static RandomNumberGenerator rand = new RNGCryptoServiceProvider();
    
            /// <summary>
            /// 生成指定长度的随机Byte数组
            /// </summary>
            /// <param name="count">Byte数组长度</param>
            /// <returns>随机Byte数组</returns>
            private static byte[] GenerateRandomBytes(int count)
            {
                byte[] bytes = new byte[count];
                rand.GetBytes(bytes);
                return bytes;
            }
    
            /// <summary>
            /// 加密文件
            /// </summary>
            /// <param name="inFile">待加密文件</param>
            /// <param name="outFile">加密后输入文件</param>
            /// <param name="password">加密密码</param>
            public static void EncryptFile(string inFile, string outFile, string password)
            {
                using (FileStream fin = File.OpenRead(inFile),
                    fout = File.OpenWrite(outFile))
                {
                    long lSize = fin.Length; // 输入文件长度
                    int size = (int)lSize;
                    byte[] bytes = new byte[BUFFER_SIZE]; // 缓存
                    int read = -1; // 输入文件读取数量
                    int value = 0;
    
                    // 获取IV和salt
                    byte[] IV = GenerateRandomBytes(16);
                    byte[] salt = GenerateRandomBytes(16);
    
                    // 创建加密对象
                    SymmetricAlgorithm sma = CryptoHelp.CreateRijndael(password, salt);
                    sma.IV = IV;
    
                    // 在输出文件开始部分写入IV和salt
                    fout.Write(IV, 0, IV.Length);
                    fout.Write(salt, 0, salt.Length);
    
                    // 创建散列加密
                    HashAlgorithm hasher = SHA256.Create();
                    using (CryptoStream cout = new CryptoStream(fout, sma.CreateEncryptor(), CryptoStreamMode.Write),
                        chash = new CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write))
                    {
                        BinaryWriter bw = new BinaryWriter(cout);
                        bw.Write(lSize);
    
                        bw.Write(FC_TAG);
    
                        // 读写字节块到加密流缓冲区
                        while ((read = fin.Read(bytes, 0, bytes.Length)) != 0)
                        {
                            cout.Write(bytes, 0, read);
                            chash.Write(bytes, 0, read);
                            value += read;
                        }
                        // 关闭加密流
                        chash.Flush();
                        chash.Close();
    
                        // 读取散列
                        byte[] hash = hasher.Hash;
    
                        // 输入文件写入散列
                        cout.Write(hash, 0, hash.Length);
    
                        // 关闭文件流
                        cout.Flush();
                        cout.Close();
                    }
                }
            }
    
            /// <summary>
            /// 解密文件
            /// </summary>
            /// <param name="inFile">待解密文件</param>
            /// <param name="outFile">解密后输出文件</param>
            /// <param name="password">解密密码</param>
            public static void DecryptFile(string inFile, string outFile, string password)
            {
                // 创建打开文件流
                using (FileStream fin = File.OpenRead(inFile),
                    fout = File.OpenWrite(outFile))
                {
                    int size = (int)fin.Length;
                    byte[] bytes = new byte[BUFFER_SIZE];
                    int read = -1;
                    int value = 0;
                    int outValue = 0;
    
                    byte[] IV = new byte[16];
                    fin.Read(IV, 0, 16);
                    byte[] salt = new byte[16];
                    fin.Read(salt, 0, 16);
    
                    SymmetricAlgorithm sma = CryptoHelp.CreateRijndael(password, salt);
                    sma.IV = IV;
    
                    value = 32;
                    long lSize = -1;
    
                    // 创建散列对象, 校验文件
                    HashAlgorithm hasher = SHA256.Create();
    
                    using (CryptoStream cin = new CryptoStream(fin, sma.CreateDecryptor(), CryptoStreamMode.Read),
                        chash = new CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write))
                    {
                        // 读取文件长度
                        BinaryReader br = new BinaryReader(cin);
                        lSize = br.ReadInt64();
                        ulong tag = br.ReadUInt64();
    
                        if (FC_TAG != tag)
                            throw new CryptoHelpException("文件被破坏");
    
                        long numReads = lSize / BUFFER_SIZE;
    
                        long slack = (long)lSize % BUFFER_SIZE;
    
                        for (int i = 0; i < numReads; ++i)
                        {
                            read = cin.Read(bytes, 0, bytes.Length);
                            fout.Write(bytes, 0, read);
                            chash.Write(bytes, 0, read);
                            value += read;
                            outValue += read;
                        }
    
                        if (slack > 0)
                        {
                            read = cin.Read(bytes, 0, (int)slack);
                            fout.Write(bytes, 0, read);
                            chash.Write(bytes, 0, read);
                            value += read;
                            outValue += read;
                        }
    
                        chash.Flush();
                        chash.Close();
    
                        fout.Flush();
                        fout.Close();
    
                        byte[] curHash = hasher.Hash;
    
                        // 获取比较和旧的散列对象
                        byte[] oldHash = new byte[hasher.HashSize / 8];
                        read = cin.Read(oldHash, 0, oldHash.Length);
                        if ((oldHash.Length != read) || (!CheckByteArrays(oldHash, curHash)))
                            throw new CryptoHelpException("文件被破坏");
                    }
    
                    if (outValue != lSize)
                        throw new CryptoHelpException("文件大小不匹配");
                }
            }
        }
    }
    
    
    // 调用
    
    public class TestClass
    {
        [STAThread]
        static void Main()
        {
            CryptoHelp.EncryptFile(@"C:\01.docx", @"C:\02.et", "123456");
            CryptoHelp.DecryptFile(@"C:\02.et", @"C:\03.docx", "123456");
        }
    }


    知识改变命运,奋斗成就人生!
    2009年4月20日 17:12
    版主
  • 你搜集的资料真的很好,但有些看不懂。

    2009年4月22日 12:30

  • 呵呵,谢谢,你可以了解一下加密技术方法的知识及常用的类,熟悉了这些代码自己就不难懂了
    知识改变命运,奋斗成就人生!
    2009年4月22日 12:33
    版主