I'm trying to optimize my ASP.NET thumbnailing script, so it doesn't resize all the images all the time, and one part of the problem is choosing the hash function for the thumbnail naming/checking procedure.Is crc32 up to the task - I'm asking cause the input data is small(only relative path, size and date)?
View 1 RepliesI've a pre-supplied public function in classic asp that creates a hash value - it is pretty complex and I'd rather not convert it to .net if at all possible (mainly as I don't understand half of what it does!) I'm running it under IIS7 on VWD2008 express. How would you call a function in that asp file? do you have to redirect or as it is #included into the asp.net file, is there an eaiser way? At the moment the complier does not spot the function and says it is not declared.
View 2 RepliesI need to create a hash key on my tables for uniqueness and someone mentioned to me about md5. But I have read about checksum and binary sum; would this not serve the same purpose? To ensure no duplicates in a specific field.
How can implement this? do I need to write code in my vb application which populates the tables with stored procedures or can I do this from SQL server 2005 studio express?
Is there a in built function in ASP.NET to hash passwords??
View 5 RepliesI am tasked with a project to convert words from strings to numbers . I have to do this while ensuring collision-avoidance. i.e training -> 10232323
We are storing the numbers in a database and when we retrieve the records from the database, we will reverse hash and convert the number back to a string
10232323 -> training
As you might have guessed - this is not an area that I am familiar with. I researched the overridable System.Object.GetHashCode() method, but Microsoft warns that there is little guarantee that the default implementation of GetHashCode() avoids collisions.
So I am left stuck. I would like to create an algorithm, but I have no idea where to start.
Also, the function should accept unicode characters - in the event the company decides to internationalize.
Hopefully someone knows a way to fix this issue, but here is my problem. I need to be able to recreate a md5 hash that will be the equivalent of the hash that php would generate.
The encoding I have tried is listed below. None of these will produce the same values.
UnicodeEncoding
UTF7Encoding
UTF8Encoding
UTF32Encoding
i am having 2 different txt files saved namely a.txt and a1.txt and my data in that is
a.txt 23ABCD444455510000GFHDHHD
a1.txt 2323143333344435.678gfdsfgskf
Now i would like to add those 2 values which are in bold and i have display the sum..
I'm having some evils trying to get my GridView control to behave. I have the below code, which successfully displays all the files in the directory. However I require two changes, both of which I am struggling with:
a) Currently the URL you get when clicking on the URL field is [URL] (ie my home directory with the filename). What I require is that the 'Display Text' be the filename only, and the URL be my desired text followed by the filename eg: [URL]
b) I want only to see the files that start with a certain prefix eg "Pay". I can do that with something like: string[] filelist = Directory.GetFiles((@"C:MFData","Pay*.*"); but this doesn't like to bind to my Gridview!
const string DocumentFolderPhysicalPath = (@"C:MFData");
const string DocumentFolderUrl = (@"C:MFData"); [URL]; ; // now it is hardcoded but you could retreive it automatically
HyperLinkField hyperLinkField = new HyperLinkField();
hyperLinkField.DataTextField = "Name";
hyperLinkField.DataNavigateUrlFields = new string[] { "Name" };
//Would like this to work!
//HyperLinkField hyperLinkField2 = new HyperLinkField();
//hyperLinkField2.DataTextField = "Destination";
//hyperLinkField2.DataNavigateUrlFields = new string[] { (@"C:MFData") + "Name" };
GridView1.DataSource = GetDocuments(DocumentFolderPhysicalPath);
GridView1.Columns.Add(hyperLinkField);
GridView1.DataBind();
private System.IO.FileInfo[] GetDocuments(string physicalPath)
{
System.IO.DirectoryInfo directory =
new System.IO.DirectoryInfo(physicalPath);
if (directory.Exists)
{
return directory.GetFiles();
}
else
{
throw new System.IO.DirectoryNotFoundException(physicalPath);
}
}
I'm trying to read all filenames from a specified (server- not client) folder, and insert all the filenames into a javascript Array. It should behave like the Directory.GetFiles method in ASP.NET C#. I created a new array, and I just need the loop method (Javascript or jQuery) to iterate in the specific folder, and insert all the filenames into the array.
View 2 RepliesI've an arraylist having 30000 items in it, what's the best way of creating a text file on the fly from an ASP.NEt page? Currently I'm using the code below but it times out with large data,
Using fileStr As New FileStream(sFileName, FileMode.Create, FileAccess.Write)
Using writer As New StreamWriter(fileStr)
writer.WriteLine("Error Messages") [code].....
I'm using ASP.NET membership for a site that will serve primarily sophisticated users. I understand the difference between hashed and encrypted passwords, and I'm trying to decide between the two.After my last client complained bitterly about hashed passwords being a total PITA, I've started to favor encrypted passwords. But someone suggested this just isn't secure enough.So my question is: What, exactly are the risks of encrypting passwords? Any person with the ability to steal passwords by decrypting them from the database would surely have the ability to reset them if they were hashed, no? I'm having trouble seeing where someone could cause trouble with encrypted passwords but couldn't with hashed ones. Making it convenient for users is also important.
View 4 RepliesI'm administrating servers running IIS 6, hosting a website on ASP.NET 2.0. Yesterday I installed .Net framework 3.5, and all my user authentication system was lost. Users can't log in, because their password arn't getting authenticated, maybe because the hash function has changed in 3.5??? I can't really get to the code, but I know it uses an extention called CodeSmith.Do you know of any break my upgrade the 3.5 ugrade could couse?
View 1 RepliesEssentially, if the file already exists, I want to append an index number to the end of the filename, incrementing upwards from 1. The following almost works, but adds numbers on as it increments upwards:
[Code]....
E.g.
Filename.txt
Filename1.txt
Filename12.txt
Filename123.txt
I want it to do the following:
Filename.txt
Filename1.txt
Filename2.txt
Filename3.txt
there is a better way to code this anyway.
I have number of files stored in a folder.
I want to write a wcf service to ruturn a list of filenames based on the text typed in a text box.
The structure of the method i need is something like this :
[Code]....
The requirments is to return only the filenames that starts with the typed text. Only the file name part is required not the full path.
I have one main doubt for long perioad, If we access the DB using SqlDataSource and ObjectDataSource, Can i know which is the fastest accessing the DB.
View 5 RepliesI am trying to complete my function below but got lost in the different methods out there. It will always return 1 row and I need to get the values of the record and ADD into a new row. The function returns a DataTable.
[Code]....
I have a bytes of data. Eg : 1024 bytes. And in that, say "Name Age Occupation" etc. All are only values. I have another skeleton xml which will have the <Name/><Age/> etc.
I need to loop through the bytes, say first 5 bytes is Name, Next 2 bytes is Age etc and fill up in this XML. I'll have 1000s of records and so need to know which way is the fastest.
Will the code be fastest or is there any way i can do by XSLT or similar component?
I'm using Webservice which will return the data from the database through datatable and I'll convert the datatable into byte array. In front end, I'll reconvert the bytearray to datatable and used ajaxloader to display it in the form.. It is dynamic loading. So, for each click, it is taking 10 seconds to retreive the data regardless of the size of the data. So, I used static datatable and I've loaded all data in that datatable in page load event. But, no reaction. It is taking only same time. Even, there is no data to retreive, the ajax loader is going on loading for 10 seconds. Problem is with Ajax or my webservice?? Plz, tell me some other idea??!!
[Code]....
I am a .NET / C# back end guy. I am working on a app that will have about 200 different data entry screens. For me exposing DTO as a collection for CRUD (IUpdatable and IQueryable) is the easy part, I can do it in my sleep :-). What I am trying to decide is what type of front end technology will allow me to develop these data entry screens fast. They don't have to be fancy but they are not just plain grid either and on average they have about 15 form fields and some client side data validation (no db look up) Options I am looking at are
Use ExtJS on the front and REST / JSON on the back. ASP.NET RIA but I do not know SL (Well XAML) Plain ASP.NET / MVC One idea I had was the DTO will contain the meta data about the form (As Attributes) and the form can be dynamically generated, but I do not want to reinvent the wheel if there is an easier way. I have looked at RAD software but all of them look at the DB and generate screens. I'd rather want something that can look at my DTO and generate screens.
I am trying to run a linq query but I need the result as a datatable as I am using that to store records from different queries in the same viewstate object.The 2 versions below compile, but return an empty set. The exact error is "Value cannot be null.Parameter name: source". (and yes I have checked there is data):
MyDatabaseDataContext db = new MyDatabaseDataContext(conn);
IEnumerable<DataRow> queryProjects =
(from DataRow p in db.STREAM_PROJECTs.AsEnumerable()
[code]...
I'm just wondering if the built in Hashing in the ASP.Net membership good password security, or if there is more that I should do to protect my passwords? If so, what should I look into for a higher level of security?
View 2 RepliesSo, I am the approach David Hayden posted on his blog [URL] to create a salt and hash the user's password by taking the user's raw password and the generated salt and using SHA1 to hash the value. I then store the salt and the hashed password in the database. zhe website is currently load balanced, so I was wondering if resulting hash value would be the same for both servers. Here is the snippet of code posted on David Hayden's blog:
private static string CreateSalt(int size)
{
//Generate a cryptographic random number.
RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
byte[] buff = new byte[size];
rng.GetBytes(buff);
// Return a Base64 string representation of the random number.
return Convert.ToBase64String(buff);
}
private static string CreatePasswordHash(string pwd, string salt)
{
string saltAndPwd = String.Concat(pwd, salt);
string hashedPwd =
FormsAuthentication.HashPasswordForStoringInConfigFile(
saltAndPwd, "sha1");
return hashedPwd;
}
The reason I ask is that this code uses the code snippet: FormsAuthentication.HashPasswordForStoringInConfigFile(saltAndPwd, "sha1");
I am planning to write a custom 'password reset control' that allows an Administrator to reset the user's password, while using the ASP.NET built-in 'login' and 'create new user' controls. For this reason, I will need the hashing algorithm (hopefully I can call some .NET class and method) to perform this.
View 1 RepliesI am using ASP.NET 3.5 and SQL Server 2005.currently while creating users, the password will be stored in the database using SHA256 algorithm. And in the Log In time entered password will be hashed with a salt and this salted password only transmitted through network (javascript). This is for incresing security without using SSL connection.I am planning to use ASP.NET 3.5 login controls How can I use client side hashing (SHA256 salted hashing) along with ASP.NET Login Controls. And also each login attempt should be logged, in a separate database table with IP address, user agent and so on.
View 3 RepliesI want to apply some better security measures to an existing web application. Currently, my connection string contains the user name and password in plain text. I'm also using a custom membership provider, which stores user names and passwords in the web.config file as plain text [URL] I would like to secure this information using an algorithm such as SHA1.
View 1 Replies