Question

我正在尝试使用tutorial中的代码，并且我不断收到一些错误，我无法弄清楚如何解决。

以下行无法执行：

inputByte = Convert.FromBase64String(encryptedText);

它提供了此错误：

Base-64字符数组或字符串的长度无效。

接下来，这一行也无法执行。

Dictionary decryptedParameters = new Dictionary();

返回的错误是：

索引超出了数组的范围。

我该如何解决这个问题？

Class EncryptedActionParameterAttribute：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Threading;
using System.Web.Mvc;
using WebMatrix.WebData;
using Medi.Models;
using System.Security.Cryptography;
using System.IO;

namespace Medi.Filters
  {

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method)]
public class EncryptedActionParameterAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {

        Dictionary<string, object> decryptedParameters = new Dictionary<string, object>();
        if (HttpContext.Current.Request.QueryString.Get("q") != null)
        {
            string encryptedQueryString = HttpContext.Current.Request.QueryString.Get("q");
            string decrptedString = Decrypt(encryptedQueryString.ToString());
            string[] paramsArrs = decrptedString.Split('?');

            for (int i = 0; i < paramsArrs.Length; i++)
            {
                string[] paramArr = paramsArrs[i].Split('=');
                decryptedParameters.Add(paramArr[0], Convert.ToInt32(paramArr[1]));
            }
        }
        for (int i = 0; i < decryptedParameters.Count; i++)
        {
            filterContext.ActionParameters[decryptedParameters.Keys.ElementAt(i)] = decryptedParameters.Values.ElementAt(i);
        }
        base.OnActionExecuting(filterContext);

    }

    private string Decrypt(string encryptedText)
    {
        string key = "jdsg432387#";
        byte[] DecryptKey = { };
        byte[] IV = { 55, 34, 87, 64, 87, 195, 54, 21 };
        byte[] inputByte = new byte[encryptedText.Length];

        DecryptKey = System.Text.Encoding.UTF8.GetBytes(key.Substring(0, 8));
        DESCryptoServiceProvider des = new DESCryptoServiceProvider();
        inputByte = Convert.FromBase64String(encryptedText);
        MemoryStream ms = new MemoryStream();
        CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(DecryptKey, IV), CryptoStreamMode.Write);
        cs.Write(inputByte, 0, inputByte.Length);
        cs.FlushFinalBlock();
        System.Text.Encoding encoding = System.Text.Encoding.UTF8;
        return encoding.GetString(ms.ToArray());
    }
}
}

MyExtensions类：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Text;
using System.Web.Routing;
using System.Security.Cryptography;
using System.IO;

namespace Medi.Models
{
public static class MyExtensions
{
    public static MvcHtmlString EncodedActionLink(this HtmlHelper htmlHelper, string linkText, string actionName, string controllerName, object routeValues, object htmlAttributes)
    {
        string queryString = string.Empty;
        string htmlAttributesString = string.Empty;
        string AreaName = string.Empty;
        if (routeValues != null)
        {
            RouteValueDictionary d = new RouteValueDictionary(routeValues);
            for (int i = 0; i < d.Keys.Count; i++)
            {
                string elementName = d.Keys.ElementAt(i).ToLower();
                if (elementName == "area")
                {
                    AreaName = Convert.ToString(d.Values.ElementAt(i));
                    continue;
                }
                if (i > 0)
                {
                    queryString += "?";
                }
                queryString += d.Keys.ElementAt(i) + "=" + d.Values.ElementAt(i);
            }
        }

        if (htmlAttributes != null)
        {
            RouteValueDictionary d = new RouteValueDictionary(htmlAttributes);
            for (int i = 0; i < d.Keys.Count; i++)
            {
                htmlAttributesString += " " + d.Keys.ElementAt(i) + "=" + d.Values.ElementAt(i);
            }
        }

        //<a href="/Answer?questionId=14">What is Entity Framework??</a>
        StringBuilder ancor = new StringBuilder();
        ancor.Append("<a ");
        if (htmlAttributesString != string.Empty)
        {
            ancor.Append(htmlAttributesString);
        }
        ancor.Append(" href='");
        if (AreaName != string.Empty)
        {
            ancor.Append("/" + AreaName);
        }
        if (controllerName != string.Empty)
        {
            ancor.Append("/" + controllerName);
        }

        if (actionName != "Index")
        {
            ancor.Append("/" + actionName);
        }
        if (queryString != string.Empty)
        {
            ancor.Append("?q=" + Encrypt(queryString));
        }
        ancor.Append("'");
        ancor.Append(">");
        ancor.Append(linkText);
        ancor.Append("</a>");
        return new MvcHtmlString(ancor.ToString());
    }

    private static string Encrypt(string plainText)
    {
        string key = "jdsg432387#";
        byte[] EncryptKey = { };
        byte[] IV = { 55, 34, 87, 64, 87, 195, 54, 21 };
        EncryptKey = System.Text.Encoding.UTF8.GetBytes(key.Substring(0, 8));
        DESCryptoServiceProvider des = new DESCryptoServiceProvider();
        byte[] inputByte = Encoding.UTF8.GetBytes(plainText);
        MemoryStream mStream = new MemoryStream();
        CryptoStream cStream = new CryptoStream(mStream, des.CreateEncryptor(EncryptKey, IV), CryptoStreamMode.Write);
        cStream.Write(inputByte, 0, inputByte.Length);
        cStream.FlushFinalBlock();
        return Convert.ToBase64String(mStream.ToArray());
    }
}
}

Answer 1

我怀疑Base64上的无效长度错误是由于从查询字符串中删除了一些'='符号引起的。

This answer很好地解释了。

base64编码字符串的长度始终是4的倍数。如果它不是4的倍数，则会追加=字符，直到它为止。当值包含= charaters时，形式为？name = value的查询字符串会出现问题（其中一些将被删除，我不记得确切的行为）。在执行base64解码之前，您可以通过附加正确数量的=字符来逃避。

就你的词典而言，你没有提供任何类型参数，编译器不知道你想要什么..

尝试提供如下类型：

Dictionary<string, string> decryptedParameters = new Dictionary<string, string>();

网址加密问题

1 个答案: