vb.net验证码破解 vb 验证码

求一个vb.net写的验证码？

建一个YanzhenCard.aspx文件

成都创新互联公司业务包括：成品网站、企业产品展示型网站建设、品牌网站制作、电子商务型网站建设、成都外贸网站建设公司(多语言)、成都商城网站开发、按需制作网站、全网营销推广等。效率优先，品质保证，用心服务是我们的核心价值观，我们将继续以良好的信誉为基础，秉承稳固与发展、求实与创新的精神，为客户提供更全面、更优质的互联网服务！

保留%@ Page Language="VB" AutoEventWireup="false" CodeFile="YanzhenCard.aspx.vb" Inherits="YanzhenCard" %,其余删除

如下是代码:

Imports System.IO

Imports System.Drawing

Partial Class YanzhenCard

Inherits System.Web.UI.Page

Private Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

If Not IsPostBack Then

Dim VNum As String = GenerateRandom(4)

Session("VNum") = VNum

ValidateCode(VNum)

End If

End Sub

Private Sub ValidateCode(ByVal VNum As String)

Dim Gheight As Integer = CType((VNum.Length * 15), Integer)

Dim Img As Bitmap = New Bitmap(Gheight, 20) 'Bitmap是用于处理由像素数据定义的图像

Dim g As Graphics = Graphics.FromImage(Img) 'Graphics.FromImage 从指定的Image创建新的Graphics

g.DrawString(VNum, New Font("Arial", 12), New SolidBrush(Color.Red), 5, 0) 'g.DrawString()在指定位置并且用指定的Brush和Font对象绘制指定的文本字符串。

Dim ms As MemoryStream = New MemoryStream '创建其支持存储区为内存的流。

Img.Save(ms, System.Drawing.Imaging.ImageFormat.Png)

Response.ClearContent()

Response.ContentType = "image/PNG"

Response.BinaryWrite(ms.ToArray)

Response.Write(VNum)

g.Dispose()

Img.Dispose()

Response.End()

End Sub

Private Shared constant As Char() = {"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"}

Public Shared Function GenerateRandom(ByVal Length As Integer) As String

Dim newRandom As System.Text.StringBuilder = New System.Text.StringBuilder(26)

Dim rd As Random = New Random

Dim i As Integer = 0

While i Length

newRandom.Append(constant(rd.Next(26)))

System.Math.Min(System.Threading.Interlocked.Increment(i), i - 1)

End While

Return newRandom.ToString

End Function

End Class

调用方法:asp:ImageButton ID="Yanzhengma_Card" runat="server" ImageUrl="YanzhenCard.aspx" Height="20px" Width="75px" BorderColor="#6699cc" BorderStyle="Solid" BorderWidth="1px" /

vb.net如何使用HttpWebRequest模拟登陆带验证码的网站

一般登陆网站时候首先要打开一个网页对吧？

那首先要 GET 一个网址。GetResponse后，得到的流就是这个页面的源码。

源码里肯定会包含这个验证码的提问段（可能是个图片的网址，也可能是个 5+5=？ 之类的字符串之类的），可以分析一下这段代码出现的位置，让程序自动寻找。找到这个图片的网址，把这个图片 GET 下来，然后，就是orc识别或你人工识别咯。。。

求vb.net软件的破解教程

网上一搜一大把，不知道你要那种？

我空间里有Win7下的破解方法：

XP下更容易了.

vb.net中实现rsa加密解密 急！急！

我觉得你的并不是RSA加密解密算法。

在.net的有一个System.Security.Cryptography的命名空间，里面有一RSACryptoServiceProvider的类用来对byte进行RSA加密解密。

具体例子如下：

using System;

using System.Security.Cryptography;

using System.Text;

class RSACSPSample

{

static void Main()

{

try

{

//Create a UnicodeEncoder to convert between byte array and string.

UnicodeEncoding ByteConverter = new UnicodeEncoding();

//Create byte arrays to hold original, encrypted, and decrypted data.

byte[] dataToEncrypt = ByteConverter.GetBytes("Data to Encrypt");

byte[] encryptedData;

byte[] decryptedData;

//Create a new instance of RSACryptoServiceProvider to generate

//public and private key data.

RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();

//Pass the data to ENCRYPT, the public key information

//(using RSACryptoServiceProvider.ExportParameters(false),

//and a boolean flag specifying no OAEP padding.

encryptedData = RSAEncrypt(dataToEncrypt,RSA.ExportParameters(false), false);

//Pass the data to DECRYPT, the private key information

//(using RSACryptoServiceProvider.ExportParameters(true),

//and a boolean flag specifying no OAEP padding.

decryptedData = RSADecrypt(encryptedData,RSA.ExportParameters(true), false);

//Display the decrypted plaintext to the console.

Console.WriteLine("Decrypted plaintext: {0}", ByteConverter.GetString(decryptedData));

}

catch(ArgumentNullException)

{

//Catch this exception in case the encryption did

//not succeed.

Console.WriteLine("Encryption failed.");

}

}

static public byte[] RSAEncrypt(byte[] DataToEncrypt, RSAParameters RSAKeyInfo, bool DoOAEPPadding)

{

try

{

//Create a new instance of RSACryptoServiceProvider.

RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();

//Import the RSA Key information. This only needs

//toinclude the public key information.

RSA.ImportParameters(RSAKeyInfo);

//Encrypt the passed byte array and specify OAEP padding.

//OAEP padding is only available on Microsoft Windows XP or

//later.

return RSA.Encrypt(DataToEncrypt, DoOAEPPadding);

}

//Catch and display a CryptographicException

//to the console.

catch(CryptographicException e)

{

Console.WriteLine(e.Message);

return null;

}

}

static public byte[] RSADecrypt(byte[] DataToDecrypt, RSAParameters RSAKeyInfo,bool DoOAEPPadding)

{

try

{

//Create a new instance of RSACryptoServiceProvider.

RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();

//Import the RSA Key information. This needs

//to include the private key information.

RSA.ImportParameters(RSAKeyInfo);

//Decrypt the passed byte array and specify OAEP padding.

//OAEP padding is only available on Microsoft Windows XP or

//later.

return RSA.Decrypt(DataToDecrypt, DoOAEPPadding);

}

//Catch and display a CryptographicException

//to the console.

catch(CryptographicException e)

{

Console.WriteLine(e.ToString());

return null;

}

}

}

[Visual Basic]

Try

'Create a new RSACryptoServiceProvider object.

Dim RSA As New RSACryptoServiceProvider()

'Export the key information to an RSAParameters object.

'Pass false to export the public key information or pass

'true to export public and private key information.

Dim RSAParams As RSAParameters = RSA.ExportParameters(False)

Catch e As CryptographicException

'Catch this exception in case the encryption did

'not succeed.

Console.WriteLine(e.Message)

End Try

[C#]

try

{

//Create a new RSACryptoServiceProvider object.

RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();

//Export the key information to an RSAParameters object.

//Pass false to export the public key information or pass

//true to export public and private key information.

RSAParameters RSAParams = RSA.ExportParameters(false);

}

catch(CryptographicException e)

{

//Catch this exception in case the encryption did

//not succeed.

Console.WriteLine(e.Message);

}