如何在c#中加密和解密字符串?
当前回答
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
public class Program
{
public static void Main()
{
var key = Encoding.UTF8.GetBytes("SUkbqO2ycDo7QwpR25kfgmC7f8CoyrZy");
var data = Encoding.UTF8.GetBytes("testData");
//Encrypt data
var encrypted = CryptoHelper.EncryptData(data,key);
//Decrypt data
var decrypted = CryptoHelper.DecryptData(encrypted,key);
//Display result
Console.WriteLine(Encoding.UTF8.GetString(decrypted));
}
}
public static class CryptoHelper
{
public static byte[] EncryptData(byte[] data, byte[] key)
{
using (var aesAlg = Aes.Create())
{
aesAlg.Mode = CipherMode.CBC;
using (var encryptor = aesAlg.CreateEncryptor(key, aesAlg.IV))
{
using (var msEncrypt = new MemoryStream())
{
msEncrypt.Write(aesAlg.IV, 0, aesAlg.IV.Length);
using (var csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
csEncrypt.Write(data, 0, data.Length);
return msEncrypt.ToArray();
}
}
}
}
public static byte[] DecryptData(byte[] encrypted, byte[] key)
{
var iv = new byte[16];
Buffer.BlockCopy(encrypted, 0, iv, 0, iv.Length);
using (var aesAlg = Aes.Create())
{
aesAlg.Mode = CipherMode.CBC;
using (var decryptor = aesAlg.CreateDecryptor(key, iv))
{
using (var msDecrypt = new MemoryStream(encrypted, iv.Length, encrypted.Length - iv.Length))
{
using (var csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (var resultStream = new MemoryStream())
{
csDecrypt.CopyTo(resultStream);
return resultStream.ToArray();
}
}
}
}
}
}
}
其他回答
下面是一个使用RSA的例子。
重要:使用RSA加密KeySize - MinimumPadding加密的数据大小是有限制的。例如256字节(假设2048位密钥)- 42字节(最小OEAP填充)= 214字节(最大明文大小)
用RSA密钥替换your_rsa_key。
var provider = new System.Security.Cryptography.RSACryptoServiceProvider();
provider.ImportParameters(your_rsa_key);
var encryptedBytes = provider.Encrypt(
System.Text.Encoding.UTF8.GetBytes("Hello World!"), true);
string decryptedTest = System.Text.Encoding.UTF8.GetString(
provider.Decrypt(encryptedBytes, true));
更多信息,请访问MSDN - RSACryptoServiceProvider
这是布雷特安排在这里的课程。然而,我做了一个轻微的编辑,因为我在使用URL字符串加密和解密时收到了错误“无效的长度为一个Base-64字符数组”。
public class CryptoURL
{
private static byte[] _salt = Encoding.ASCII.GetBytes("Catto_Salt_Enter_Any_Value99");
/// <summary>
/// Encrypt the given string using AES. The string can be decrypted using
/// DecryptStringAES(). The sharedSecret parameters must match.
/// The SharedSecret for the Password Reset that is used is in the next line
/// string sharedSecret = "OneUpSharedSecret9";
/// </summary>
/// <param name="plainText">The text to encrypt.</param>
/// <param name="sharedSecret">A password used to generate a key for encryption.</param>
public static string EncryptString(string plainText, string sharedSecret)
{
if (string.IsNullOrEmpty(plainText))
throw new ArgumentNullException("plainText");
if (string.IsNullOrEmpty(sharedSecret))
throw new ArgumentNullException("sharedSecret");
string outStr = null; // Encrypted string to return
RijndaelManaged aesAlg = null; // RijndaelManaged object used to encrypt the data.
try
{
// generate the key from the shared secret and the salt
Rfc2898DeriveBytes key = new Rfc2898DeriveBytes(sharedSecret, _salt);
// Create a RijndaelManaged object
aesAlg = new RijndaelManaged();
aesAlg.Key = key.GetBytes(aesAlg.KeySize / 8);
// Create a decryptor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
using (MemoryStream msEncrypt = new MemoryStream())
{
// prepend the IV
msEncrypt.Write(BitConverter.GetBytes(aesAlg.IV.Length), 0, sizeof(int));
msEncrypt.Write(aesAlg.IV, 0, aesAlg.IV.Length);
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
//Write all data to the stream.
swEncrypt.Write(plainText);
}
}
outStr = HttpServerUtility.UrlTokenEncode(msEncrypt.ToArray());
//outStr = Convert.ToBase64String(msEncrypt.ToArray());
// you may need to add a reference. right click reference in solution explorer => "add Reference" => .NET tab => select "System.Web"
}
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
// Return the encrypted bytes from the memory stream.
return outStr;
}
/// <summary>
/// Decrypt the given string. Assumes the string was encrypted using
/// EncryptStringAES(), using an identical sharedSecret.
/// </summary>
/// <param name="cipherText">The text to decrypt.</param>
/// <param name="sharedSecret">A password used to generate a key for decryption.</param>
public static string DecryptString(string cipherText, string sharedSecret)
{
if (string.IsNullOrEmpty(cipherText))
throw new ArgumentNullException("cipherText");
if (string.IsNullOrEmpty(sharedSecret))
throw new ArgumentNullException("sharedSecret");
// Declare the RijndaelManaged object
// used to decrypt the data.
RijndaelManaged aesAlg = null;
// Declare the string used to hold
// the decrypted text.
string plaintext = null;
byte[] inputByteArray;
try
{
// generate the key from the shared secret and the salt
Rfc2898DeriveBytes key = new Rfc2898DeriveBytes(sharedSecret, _salt);
// Create the streams used for decryption.
//byte[] bytes = Convert.FromBase64String(cipherText);
inputByteArray = HttpServerUtility.UrlTokenDecode(cipherText);
using (MemoryStream msDecrypt = new MemoryStream(inputByteArray))
{
// Create a RijndaelManaged object
// with the specified key and IV.
aesAlg = new RijndaelManaged();
aesAlg.Key = key.GetBytes(aesAlg.KeySize / 8);
// Get the initialization vector from the encrypted stream
aesAlg.IV = ReadByteArray(msDecrypt);
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
plaintext = srDecrypt.ReadToEnd();
}
}
}
catch (System.Exception ex)
{
return "ERROR";
//throw ex;
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
return plaintext;
}
static string ConvertStringArrayToString(string[] array)
{
//
// Concatenate all the elements into a StringBuilder.
//
StringBuilder builder = new StringBuilder();
foreach (string value in array)
{
builder.Append(value);
builder.Append('.');
}
return builder.ToString();
}
private static byte[] ReadByteArray(Stream s)
{
byte[] rawLength = new byte[sizeof(int)];
if (s.Read(rawLength, 0, rawLength.Length) != rawLength.Length)
{
throw new SystemException("Stream did not contain properly formatted byte array");
}
byte[] buffer = new byte[BitConverter.ToInt32(rawLength, 0)];
if (s.Read(buffer, 0, buffer.Length) != buffer.Length)
{
throw new SystemException("Did not read byte array properly");
}
return buffer;
}
}
参考c#中加密和解密字符串,我找到了一个很好的解决方案:
static readonly string PasswordHash = "P@@Sw0rd";
static readonly string SaltKey = "S@LT&KEY";
static readonly string VIKey = "@1B2c3D4e5F6g7H8";
对于加密
public static string Encrypt(string plainText)
{
byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
byte[] keyBytes = new Rfc2898DeriveBytes(PasswordHash, Encoding.ASCII.GetBytes(SaltKey)).GetBytes(256 / 8);
var symmetricKey = new RijndaelManaged() { Mode = CipherMode.CBC, Padding = PaddingMode.Zeros };
var encryptor = symmetricKey.CreateEncryptor(keyBytes, Encoding.ASCII.GetBytes(VIKey));
byte[] cipherTextBytes;
using (var memoryStream = new MemoryStream())
{
using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
cipherTextBytes = memoryStream.ToArray();
cryptoStream.Close();
}
memoryStream.Close();
}
return Convert.ToBase64String(cipherTextBytes);
}
对解密
public static string Decrypt(string encryptedText)
{
byte[] cipherTextBytes = Convert.FromBase64String(encryptedText);
byte[] keyBytes = new Rfc2898DeriveBytes(PasswordHash, Encoding.ASCII.GetBytes(SaltKey)).GetBytes(256 / 8);
var symmetricKey = new RijndaelManaged() { Mode = CipherMode.CBC, Padding = PaddingMode.None };
var decryptor = symmetricKey.CreateDecryptor(keyBytes, Encoding.ASCII.GetBytes(VIKey));
var memoryStream = new MemoryStream(cipherTextBytes);
var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);
byte[] plainTextBytes = new byte[cipherTextBytes.Length];
int decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
memoryStream.Close();
cryptoStream.Close();
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount).TrimEnd("\0".ToCharArray());
}
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;
}
}
}
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;
}
}
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