指定的填充模式对此算法无效 - c# - System.Security.Cryptography

问题描述

对 c# 非常陌生，目前在解密长密码时遇到问题，错误为

pretty new to c# and currently having a problem decrypting long passwords with an error of

指定的密钥不是该算法的有效大小

Specified key is not a valid size for this algorithm

我知道这与不支持加密密码位长度有关，但不确定如何采用建议的方法来允许这些更长的密码.

I know this has something to do with the encrypted password bits length not being supported but unsure how to go about suggested ways to allow for these longer passwords.

这是我的加密和解密

cipherKey":0123456789abcdef"，cipherVector":有点酷"

"cipherKey": "0123456789abcdef", "cipherVector": "somereallycooliv"

using System;
using System.Security.Cryptography;
using System.IO;
using System.Text;

namespace DataApi
{
public class Encryption
{
    private readonly IConfigurationService _configService;


    private const string _vector = "cipherVector";
    private const string _key = "cipherKey";

    public Encryption(IConfigurationService configService)
    {
        _configService = configService;
    }
    public string EncryptString(string text)
    {
        if(string.IsNullOrEmpty(text))
        {
            return "";
        }
        try
        {

      var key = Encoding.UTF8.GetBytes(_configService.Get(_key));
        byte[] IV = Encoding.ASCII.GetBytes(_configService.Get(_vector));

        using (var aesAlg = Aes.Create())
        {
            using (var encryptor = aesAlg.CreateEncryptor(key, IV))
            {
                using (var msEncrypt = new MemoryStream())
                {
                    using (var csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                    using (var swEncrypt = new StreamWriter(csEncrypt))
                    {
                        swEncrypt.Write(text);
                    }

                    var decryptedContent = msEncrypt.ToArray();

                    var result = new byte[IV.Length + decryptedContent.Length];

                    Buffer.BlockCopy(IV, 0, result, 0, IV.Length);
                    Buffer.BlockCopy(decryptedContent, 0, result, IV.Length, decryptedContent.Length);

                    return Convert.ToBase64String(result);
                }
            }
        }
        }
        catch(Exception e) {
             Loggifer.Error("Unable to encrypt string: "+text , e );

            throw e;
        }
    }

    public string DecryptString(string cipherText)
    {
        if(string.IsNullOrEmpty(cipherText))
        {
            return "";
        }
        try
        {
            var fullCipher = Convert.FromBase64String(cipherText);

            byte[] IV = Encoding.ASCII.GetBytes(_configService.Get(_vector));
            var cipher = new byte[16];

            Buffer.BlockCopy(fullCipher, 0, IV, 0, IV.Length);
            Buffer.BlockCopy(fullCipher, IV.Length, cipher, 0, IV.Length);
            var key = Encoding.UTF8.GetBytes(_configService.Get(_key));

            using (var aesAlg = Aes.Create())
            {
                using (var decryptor = aesAlg.CreateDecryptor(key, IV))
                {
                    string result;
                    using (var msDecrypt = new MemoryStream(cipher))
                    {
                        using (var csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                        {
                            using (var srDecrypt = new StreamReader(csDecrypt))
                            {
                                result = srDecrypt.ReadToEnd();
                            }
                        }
                    }

                    return result;
                }
            }
        }
        catch (Exception e)
        {
            Loggifer.Error("Unable to decrypt string: "+cipherText , e );
            throw e;
        }
    }

}
}

推荐答案

函数public string DecryptString(string cipherText)

 var cipher = new byte[fullCipher.Length - IV.Length];

和

 Buffer.BlockCopy(fullCipher, IV.Length, cipher, 0, fullCipher.Length - IV.Length);

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