119 lines
3.8 KiB
C#
119 lines
3.8 KiB
C#
using System;
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using System.IO;
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using System.Security.Cryptography;
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using System.Text;
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namespace SimApi.Helpers;
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public static class SimApiAesUtil
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{
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// 密钥长度：256位 (32字节)
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private const int KeySize = 256;
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// 块大小：128位 (16字节)
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private const int BlockSize = 128;
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// 加密模式 - 重命名以避免与枚举类型冲突
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private const CipherMode AesCipherMode = CipherMode.CBC;
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// 填充模式 - 重命名以避免与枚举类型冲突
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private const PaddingMode AesPaddingMode = PaddingMode.PKCS7;
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/// <summary>
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/// AES 加密
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/// </summary>
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/// <param name="plainText">明文</param>
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/// <param name="key">字符串密钥（将被处理为256位）</param>
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/// <returns>加密后的Base64字符串（包含IV）</returns>
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public static string Encrypt(string plainText, string key)
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{
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if (string.IsNullOrEmpty(plainText))
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throw new ArgumentNullException(nameof(plainText));
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if (string.IsNullOrEmpty(key))
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throw new ArgumentNullException(nameof(key));
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// 处理密钥为指定长度
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var keyBytes = ProcessKey(key);
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// 生成随机IV
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var iv = GenerateRandomIv();
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using var aes = CreateAesProvider(keyBytes, iv);
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using var encryptor = aes.CreateEncryptor(aes.Key, aes.IV);
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using var ms = new MemoryStream();
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// 先写入IV，解密时需要用到
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ms.Write(iv, 0, iv.Length);
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using (var cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))
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using (var sw = new StreamWriter(cs))
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{
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sw.Write(plainText);
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}
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return Convert.ToBase64String(ms.ToArray());
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}
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/// <summary>
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/// AES 解密
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/// </summary>
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/// <param name="cipherText">加密后的Base64字符串</param>
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/// <param name="key">字符串密钥（与加密时相同）</param>
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/// <returns>解密后的明文</returns>
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public static string Decrypt(string cipherText, string key)
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{
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if (string.IsNullOrEmpty(cipherText))
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throw new ArgumentNullException(nameof(cipherText));
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if (string.IsNullOrEmpty(key))
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throw new ArgumentNullException(nameof(key));
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var cipherBytes = Convert.FromBase64String(cipherText);
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// 从加密数据中提取IV
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var iv = new byte[BlockSize / 8];
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Array.Copy(cipherBytes, 0, iv, 0, iv.Length);
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// 处理密钥为指定长度
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var keyBytes = ProcessKey(key);
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using var aes = CreateAesProvider(keyBytes, iv);
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using var decryptor = aes.CreateDecryptor(aes.Key, aes.IV);
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using var ms = new MemoryStream(cipherBytes, iv.Length, cipherBytes.Length - iv.Length);
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using var cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read);
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using var sr = new StreamReader(cs);
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return sr.ReadToEnd();
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}
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/// <summary>
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/// 处理密钥为指定长度（256位）
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/// </summary>
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private static byte[] ProcessKey(string key)
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{
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// 使用SHA256哈希处理密钥，确保得到32字节(256位)的密钥
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return SHA256.HashData(Encoding.UTF8.GetBytes(key));
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}
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/// <summary>
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/// 生成随机初始化向量
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/// </summary>
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private static byte[] GenerateRandomIv()
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{
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using var aes = Aes.Create();
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aes.BlockSize = BlockSize;
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aes.GenerateIV();
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return aes.IV;
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}
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/// <summary>
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/// 创建并配置AES加密服务提供器
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/// </summary>
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private static Aes CreateAesProvider(byte[] key, byte[] iv)
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{
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var aes = Aes.Create();
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aes.KeySize = KeySize;
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aes.BlockSize = BlockSize;
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aes.Mode = AesCipherMode;
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aes.Padding = AesPaddingMode;
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aes.Key = key;
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aes.IV = iv;
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return aes;
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}
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} |