問題描述

對 c# 非常陌生，目前在解密長密碼時遇到問題，錯誤為

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

指定的密鑰不是該算法的有效大小

Specified key is not a valid size for this algorithm

我知道這與不支持加密密碼位長度有關，但不確定如何采用建議的方法來允許這些更長的密碼.

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.

這是我的加密和解密

cipherKey":0123456789abcdef"，cipherVector":有點酷"

"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;
        }
    }

}
}

推薦答案

函數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);

這篇關于指定的填充模式對此算法無效 - c# - System.Security.Cryptography的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！