SHA1 hash question

Posted by phenevo on Stack Overflow See other posts from Stack Overflow or by phenevo
Published on 2010-02-26T13:54:00Z Indexed on 2010/05/31 7:23 UTC
Read the original article Hit count: 487

Filed under:

c#

|

sha1

Hi,

I have this method to hash a string:

 byte[] buffer = enc.GetBytes(text);
 SHA1CryptoServiceProvider cryptoTransformSHA1 =
                new SHA1CryptoServiceProvider();
 string hash = BitConverter.ToString(
                cryptoTransformSHA1.ComputeHash(buffer)).Replace("-", "");

 return hash;

My question is:

Is the resulting hash always the same for the same string?

I hashed a string a couple of days ago and it seems that it now resulted in another hash, but i'm not sure.

© Stack Overflow or respective owner

Related posts about c#

.NET WebRequest.PreAuthenticate not quite what it sounds like

as seen on West-Wind - Search for 'West-Wind'
I’ve run into the problem a few times now: How to pre-authenticate .NET WebRequest calls doing an HTTP call to the server – essentially send authentication credentials on the very first request instead of waiting for a server challenge first? At first glance this sound like it should be easy:… >>> More
HttpWebRequest and Ignoring SSL Certificate Errors

as seen on West-Wind - Search for 'West-Wind'
Man I can't believe this. I'm still mucking around with OFX servers and it drives me absolutely crazy how some these servers are just so unbelievably misconfigured. I've recently hit three different 3 major brokerages which fail HTTP validation with bad or corrupt certificates at least according to… >>> More
The dynamic Type in C# Simplifies COM Member Access from Visual FoxPro

as seen on West-Wind - Search for 'West-Wind'
I’ve written quite a bit about Visual FoxPro interoperating with .NET in the past both for ASP.NET interacting with Visual FoxPro COM objects as well as Visual FoxPro calling into .NET code via COM Interop. COM Interop with Visual FoxPro has a number of problems but one of them at least got a lot… >>> More
Dynamic Type to do away with Reflection

as seen on West-Wind - Search for 'West-Wind'
The dynamic type in C# 4.0 is a welcome addition to the language. One thing I’ve been doing a lot with it is to remove explicit Reflection code that’s often necessary when you ‘dynamically’ need to walk and object hierarchy. In the past I’ve had a number of ReflectionUtils that used string based expressions… >>> More
Finding a Relative Path in .NET

as seen on West-Wind - Search for 'West-Wind'
Here’s a nice and simple path utility that I’ve needed in a number of applications: I need to find a relative path based on a base path. So if I’m working in a folder called c:\temp\templates\ and I want to find a relative path for c:\temp\templates\subdir\test.txt I want to receive back subdir\test… >>> More

Related posts about sha1

PBKDF2-HMAC-SHA1

as seen on Stack Overflow - Search for 'Stack Overflow'
To generate a valid pairwise master key for a WPA2 network a router uses the PBKDF2-HMAC-SHA1 algorithm. I understand that the sha1 function is performed 4096 times to derive the PMK, however I have two questions about the process. Excuse the pseudo code. 1) How is the input to the first instance… >>> More
Is it possible to get identical SHA1 hash?

as seen on Stack Overflow - Search for 'Stack Overflow'
Given two different strings S1 and S2 (S1 != S2) is it possible that: SHA1(S1) == SHA1(S2) is True? If yes - with what probability? Is there a upper bound on the length of a string, for which probably of getting duplicates is 0? If not - why not? Thanks >>> More
Is it possible to convert a 40-character SHA1 hash to a 20-character SHA1 hash?

as seen on Stack Overflow - Search for 'Stack Overflow'
My problem is a bit hairy, and I may be asking the wrong questions, so please bear with me... I have a legacy MySQL database which stores the user passwords & salts for a membership system. Both of these values have been hashed using the Ruby framework - roughly like this: hashedsalt = … >>> More
Is there any difference between md5 and sha1 in this situation?

as seen on Stack Overflow - Search for 'Stack Overflow'
It is known that 1. if ( md5(a) == md5(b) ) 2. then ( md5(a.z) == md5(b.z) ) 3. but ( md5(z.a) != md5(z.b) ) where the dots concatenate the strings. What happens in the second row if we change all the md5 to sha1? So: 1. if ( sha1(c) == sha1(d) ) 2. then ( sha1(c.z)… >>> More
iPhone: convert string using HMAC-SHA1

as seen on Stack Overflow - Search for 'Stack Overflow'
hi all, i want to generate HMAC-SHA1 of NSString type variable. I see the post but this method give me error in CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC); and NSString *hash = [HMAC base64Encoding]; line. Please suggest how can I generate the HMAC-SHA1 of any string… >>> More