/// <summary>
/// 随机打乱字符串中的所有字符
/// </summary>
/// <param name="str">需要被打乱的字符串</param>
/// <param name="seed">种子</param>
/// <returns>被打乱的字符串</returns>
public static string Shuffle(string str, int?seed = null)
{
KGuard.Requires <ArgumentNullException>(str != null);
var random = KUtil.MakeRandom(seed);
var requested = new string[str.Length];
for (var i = 0; i < str.Length; i++)
{
var index = random.Next(0, str.Length - 1);
requested[i] = requested[i] ?? str.Substring(i, 1);
requested[index] = requested[index] ?? str.Substring(index, 1);
if (index == i)
{
continue;
}
var temp = requested[i];
requested[i] = requested[index];
requested[index] = temp;
}
return(KArray.Reduce(requested, (v1, v2) => v1 + v2, string.Empty));
}
/// <summary>
/// 加密
/// </summary>
/// <param name="content">加密内容</param>
/// <param name="key">密钥</param>
/// <returns></returns>
public string Encrypt(byte[] content, byte[] key)
{
rijndaelManaged.GenerateIV();
var aesEncrypt = rijndaelManaged.CreateEncryptor(key, rijndaelManaged.IV);
var aesBuffer = aesEncrypt.TransformFinalBlock(content, 0, content.Length);
var ivAesBuffer = KArray.Merge(rijndaelManaged.IV, aesBuffer);
return(Encode(Convert.ToBase64String(rijndaelManaged.IV),
Convert.ToBase64String(aesBuffer),
Convert.ToBase64String(HMac(ivAesBuffer, key))));
}
/// <summary>
/// 解密被加密的内容
/// </summary>
/// <param name="str">需要解密的字符串</param>
/// <param name="key">密钥</param>
/// <returns>解密后的值</returns>
public byte[] Decrypt(string str, byte[] key)
{
string iv, value, hmac;
Decode(str, out iv, out value, out hmac);
var aesBuffer = Convert.FromBase64String(value);
var ivBuffer = Convert.FromBase64String(iv);
var ivAesBuffer = KArray.Merge(rijndaelManaged.IV, aesBuffer);
if (Convert.ToBase64String(HMac(ivAesBuffer, key)) != hmac)
{
throw new Exception("HMac validation failed");
}
var aesDecrypt = rijndaelManaged.CreateDecryptor(key, ivBuffer);
aesBuffer = aesDecrypt.TransformFinalBlock(aesBuffer, 0, aesBuffer.Length);
return(aesBuffer);
}
