c# - Return SHA256 hash of PDF page -

-

I am writing a C # WPF application, where I have a 'header' as the first page of the batch of PDF documents. Enter the page. The header page is taken from the first page of the first pdf in the batch.

The user will implicate this process, but I want to ensure that at the later date the user can not run the process again, the other headers will be included.

Then I want to get the SHA256 hash of my plan header page and compare it with the hash of the first page of the second PDFs, if they match, then the first page is like the header page, Do not include the article.

I have suppressed the code below to get the hash of the first page in PDF, but the hash is different each time it is run.

Why is it different every time?

Thanks 

  using System.IO; Using System.Text; Using System.Security.Cryptography; Using PdfSharp.Pdf; Using PdfSharp.Pdf.IO; Namespace Sinkada {Public Class PDF Doc {Private PDF Document PDFFed; Public PDFDoc (string path) {pdfDoc = PdfReader.Open (Path, PdfDocumentOpenMode.Import); } Public string GetPageOneHash () {byte [] hash; PDF page page = PDF file. Page [0]; (Using memorystream stream = new memorystream ()) {PDF document document = new PDF document (); Doc.AddPage (page); Doc.Save (Section, False); SHA256 sha256 = SHA256.Create (); Hash = sha256 Compute hash (stream); } Stringbiller sb = New stringbilder (); For (int i = 0; i & lt; hash.Length; i ++) {sb.Append (hash [i]. Ostring ("x2"); } Return sb.ToString (); }}}}    
 
 
 
 I get the code given below to get a hash The first page in PDF is suppressed, but the hash is run every time.  
 Why is it different every time?   
 You have the hash of page    the hash of a new PDF document on which you add pages to the question  unfortunately for your efforts , PDF documents contain information like date of creation, date of last revision and a unique ID. As these information differs from time to time, when you calculate a hash, you will never receive the same hash (unless you have any conflicts).

Comments

Post a Comment

Popular posts from this blog

php - PDO bindParam() fatal error -

-
I am trying to learn PDO, now I have written this small code, but it gives me a serious error: < P> Fatal error: Call a member function at a non-object dot () ... $ con = new mysqli ("127.0.0.1", "root", "", "csvdangercheck"); $ Query = $ con- & gt; ("Id,` var1`, `var2`) values ​​(" id,: var1,: var2) ";); $ query- & gt; bypass pattern (': id', $ id); $ query- & gt; BindParam (': var1', $ VAL1); $ Query- & gt; bindParam (': var2', $ val2); $ Query-> Executed (); I Trying to use print_r ($ con-> errorInfo ()) but Fatal error: Undefined method mysqli :: errorInfo ( ) ... can someone tell me what am I missing? Flaffeh said, you have PDO Missing Mysqy, try it: $ con = new PDO ('mysql: host = 127.0.0.1; dbname = csvdangercheck', 'root', '');
Read more

logging - How can I log both the Request.InputStream and Response.OutputStream traffic in my ASP.NET MVC3 Application for specific Actions? -

-
For a specific set of tasks, I need to log in to the incoming request inputstream as well as outgoing response. is. I am using an ActionFilterAttribute for this and overriding the OnActionExecuted and OnResultExecuted methods. So I'm starting with this idea ... Public category ActionLoggerAttribute: ActionFilterArrbit {Public Override Zero On-Offed Execution (ActionActioned Contact Filter Filter) {base.OnActionAxecuted (FilterContext); HttpRequestBase request = filterContext.HttpContext.Request; // TODO: Log the request. InputStream} Public Override Zero OnResultExecuted (ResultExecutedContext FilterContext) {base.OnResultExecuted (filterContext); HTTPRPSPointBase Response = FilterContacts Hpptex response; // TODO: Log on Response.OutputStream}} Ideally I'll hook it up with enterprise library logging because I'm already using it for error logging. Am I reaching the input and output stream at the right time? Can I easily use the Enterprise Library to log i
Read more

java - Why my included JSP file won't get processed correctly? -

-
I am trying to create Java web framework (and learning), and on the basis of 'Code Generator In the process of making the material view of the database in the process of development, I stumbled into a difficulty, which I do not know how to solve it. First of all, I want the following index.jsp : & lt; Body & gt; Use all pages to be created. & Lt;% @ include file = "header.jsp"% & gt; & Lt; Hours / & gt; & Lt;% @ included file = "body.jsp"%> & Lt; Hours / & gt; & Lt;% @ include file = "footer.jsp"% & gt; & Lt; / Body & gt; And, in body.jsp , I should have it like this: & lt; Jsp: include page = "$ {Application_modul}"%> Where application_modul is an attribute defined in its controller: request.setAttribute ("application_modul", "USER_ACCOUNT \\ ' View_user_account.jsp "); This file can be found properly, but the processed JSP does
Read more