C#对字符和文件的加密解密类

转自: http://www.cnblogs.com/bluescreen/archive/2012/02/17/2355731.htmlpublic class strorfilepass { /// <summary> /// 初始化安全类 /// </summary> public strorfilepass() { ///默认密码 key = "www.qhjsw.net"; } private string key; //默认密钥 private byte[] sKey; private byte[] sIV; #region 加密字符串 /// <summary> /// 加密字符串 /// </summary> /// <param name="inputStr">输入字符串</param> /// <param name="keyStr">密码，可以为""</param> /// <returns>输出加密后字符串</returns> public string EncryptString(string inputStr, string keyStr) { DESCryptoServiceProvider des = new DESCryptoServiceProvider(); if (keyStr == "") keyStr = key; byte[] inputByteArray = Encoding.Default.GetBytes(inputStr); byte[] keyByteArray = Encoding.Default.GetBytes(keyStr); SHA1 ha = new SHA1Managed(); byte[] hb = ha.ComputeHash(keyByteArray); sKey = new byte[8]; sIV = new byte[8]; for (int i = 0; i < 8; i++) sKey[i] = hb[i]; for (int i = 8; i < 16; i++) sIV[i - 8] = hb[i]; des.Key = sKey; des.IV = sIV; MemoryStream ms = new MemoryStream(); CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write); cs.Write(inputByteArray, 0, inputByteArray.Length); cs.FlushFinalBlock(); StringBuilder ret = new StringBuilder(); foreach (byte b in ms.ToArray()) { ret.AppendFormat("{0:X2}", b); } cs.Close(); ms.Close(); return ret.ToString(); } /// <summary> /// 解密字符串 /// </summary> /// <param name="inputStr">要解密的字符串</param> /// <param name="keyStr">密钥</param> /// <returns>解密后的结果</returns> public string DecryptString(string inputStr, string keyStr) { DESCryptoServiceProvider des = new DESCryptoServiceProvider(); if (keyStr == "") keyStr = key; byte[] inputByteArray = new byte[inputStr.Length / 2]; for (int x = 0; x < inputStr.Length / 2; x++) { int i = (Convert.ToInt32(inputStr.Substring(x * 2, 2), 16)); inputByteArray[x] = (byte)i; } byte[] keyByteArray = Encoding.Default.GetBytes(keyStr); SHA1 ha = new SHA1Managed(); byte[] hb = ha.ComputeHash(keyByteArray); sKey = new byte[8]; sIV = new byte[8]; for (int i = 0; i < 8; i++) sKey[i] = hb[i]; for (int i = 8; i < 16; i++) sIV[i - 8] = hb[i]; des.Key = sKey; des.IV = sIV; MemoryStream ms = new MemoryStream(); CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write); cs.Write(inputByteArray, 0, inputByteArray.Length); cs.FlushFinalBlock(); StringBuilder ret = new StringBuilder(); return System.Text.Encoding.Default.GetString(ms.ToArray()); } #endregion #region 加密文件 /// <summary> /// 加密文件 /// </summary> /// <param name="filePath">输入文件路径</param> /// <param name="savePath">加密后输出文件路径</param> /// <param name="keyStr">密码，可以为""</param> /// <returns></returns> public bool EncryptFile(string filePath, string savePath, string keyStr) { try { DESCryptoServiceProvider des = new DESCryptoServiceProvider(); if (keyStr == "") keyStr = key; FileStream fs = File.OpenRead(filePath); byte[] inputByteArray = new byte[fs.Length]; fs.Read(inputByteArray, 0, (int)fs.Length); fs.Close(); byte[] keyByteArray = Encoding.Default.GetBytes(keyStr); SHA1 ha = new SHA1Managed(); byte[] hb = ha.ComputeHash(keyByteArray); sKey = new byte[8]; sIV = new byte[8]; for (int i = 0; i < 8; i++) sKey[i] = hb[i]; for (int i = 8; i < 16; i++) sIV[i - 8] = hb[i]; des.Key = sKey; des.IV = sIV; MemoryStream ms = new MemoryStream(); CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write); cs.Write(inputByteArray, 0, inputByteArray.Length); cs.FlushFinalBlock(); fs = File.OpenWrite(savePath); foreach (byte b in ms.ToArray()) { fs.WriteByte(b); } fs.Close(); cs.Close(); ms.Close(); return true; } catch{ return false; } } #endregion #region 解密文件 /// <summary> /// 解密文件 /// </summary> /// <param name="filePath">输入文件路径</param> /// <param name="savePath">解密后输出文件路径</param> /// <param name="keyStr">密码，可以为""</param> /// <returns></returns> public bool DecryptFile(string filePath, string savePath, string keyStr) { try { DESCryptoServiceProvider des = new DESCryptoServiceProvider(); if (keyStr == "") keyStr = key; FileStream fs = File.OpenRead(filePath); byte[] inputByteArray = new byte[fs.Length]; fs.Read(inputByteArray, 0, (int)fs.Length); fs.Close(); byte[] keyByteArray = Encoding.Default.GetBytes(keyStr); SHA1 ha = new SHA1Managed(); byte[] hb = ha.ComputeHash(keyByteArray); sKey = new byte[8]; sIV = new byte[8]; for (int i = 0; i < 8; i++) sKey[i] = hb[i]; for (int i = 8; i < 16; i++) sIV[i - 8] = hb[i]; des.Key = sKey; des.IV = sIV; MemoryStream ms = new MemoryStream(); CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write); cs.Write(inputByteArray, 0, inputByteArray.Length); cs.FlushFinalBlock(); fs = File.OpenWrite(savePath); foreach (byte b in ms.ToArray()) { fs.WriteByte(b); } fs.Close(); cs.Close(); ms.Close(); return true; } catch { return false; } } #endregion # region 大文件加密 /// <summary> /// 加密文件 /// </summary> /// <param name="filePath">输入文件路径</param> /// <param name="savePath">加密后输出文件路径</param> /// <param name="keyStr">密码，可以为""</param> /// <returns></returns> public bool BEncryptFile(string filePath, string savePath, string keyStr) { try { DESCryptoServiceProvider des = new DESCryptoServiceProvider(); if (keyStr == "") keyStr = key; FileStream fs = File.OpenRead(filePath); byte[] inputByteArray = new byte[500]; long Myfilesize = fs.Length; int Mycompletedsize = 0; byte[] keyByteArray = Encoding.Default.GetBytes(keyStr); SHA1 ha = new SHA1Managed(); byte[] hb = ha.ComputeHash(keyByteArray); sKey = new byte[8]; sIV = new byte[8]; for (int i = 0; i < 8; i++) sKey[i] = hb[i]; for (int i = 8; i < 16; i++) sIV[i - 8] = hb[i]; des.Key = sKey; des.IV = sIV; FileStream ms = File.OpenWrite(savePath); CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write); while (Mycompletedsize < Myfilesize) { int length = fs.Read(inputByteArray, 0, 500); cs.Write(inputByteArray, 0, length); Mycompletedsize += length; } cs.FlushFinalBlock(); fs.Close(); fs.Dispose(); cs.Close(); cs.Dispose(); ms.Close(); ms.Dispose(); return true; } catch { return false; } } /// <summary> /// 解密文件 /// </summary> /// <param name="filePath">输入文件路径</param> /// <param name="savePath">解密后输出文件路径</param> /// <param name="keyStr">密码，可以为""</param> /// <returns></returns> public bool BDecryptFile(string filePath, string savePath, string keyStr) { try { DESCryptoServiceProvider des = new DESCryptoServiceProvider(); if (keyStr == "") keyStr = key; FileStream fs = File.OpenRead(filePath); byte[] inputByteArray = new byte[500]; long Myfilesize = fs.Length; int Mycompletedsize = 0; byte[] keyByteArray = Encoding.Default.GetBytes(keyStr); SHA1 ha = new SHA1Managed(); byte[] hb = ha.ComputeHash(keyByteArray); sKey = new byte[8]; sIV = new byte[8]; for (int i = 0; i < 8; i++) sKey[i] = hb[i]; for (int i = 8; i < 16; i++) sIV[i - 8] = hb[i]; des.Key = sKey; des.IV = sIV; FileStream ms = File.OpenWrite(savePath); CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write); while (Mycompletedsize < Myfilesize) { int length = fs.Read(inputByteArray, 0, 500); cs.Write(inputByteArray, 0, length); Mycompletedsize += length; } cs.FlushFinalBlock(); fs.Close(); fs.Dispose(); cs.Close(); cs.Dispose(); ms.Close(); ms.Dispose(); return true; } catch { return false; } } #endregion }