SHA1 base64 algorithm in javascript and C#

Question

I'm running some tests comparing the sha1 algorithm implemented in javascript - got from http://pajhome.org.uk/crypt/ - with its implementation in C#.

Using C# to get the hash for {'method':'people.get'} I'm using this statement:

Convert.ToBase64String(new System.Security.Cryptography.SHA1CryptoServiceProvider().ComputeHash(Encoding.ASCII.GetBytes("{'method':'people.get'}")));

which gives me Qy95a0ShZqhbNdt6IF8qNf72jX0=

In javascript I get almost the same: Qy95a0ShZqhbNdt6IF8qNf72jX0 using the statement:

b64_sha1("{'method':'people.get'}");

In the javascript case, the hash doesn't end with a equal (=) sign.

Can this difference cause me troubles in authenticating against a server?

In my case, as many of you may know, the sentence I'm reckoning the hash goes inside the http body and the server will check it.

Thanks

Don · Accepted Answer · 2010-03-17 13:03:25Z

5

Would depend on the receiver but try decoding your result from the javascript with C# and you'll get an exception. The = sign is there to pad the result to the correct length.

http://en.wikipedia.org/wiki/Base64

answered Mar 17, 2010 at 13:03

Don

9,6814 gold badges28 silver badges25 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Andres Over a year ago

Ok, based on that information I saw now that the = sign, as you pointed out, is used for padding the message. Thanks

LukeH Over a year ago

@Andres: You can update line 15 of the sha1.js file from pajhome.org.uk to use = as the padding character.

Andres Over a year ago

Yes, while I was writing the my own answer you were writing this remark. Thanks :)

Ritsaert Hornstra Over a year ago

You could strip all = signs at the end befiore comparison (or pad with = signs to the correct length)

Andres · Accepted Answer · 2010-03-17 13:13:43Z

4

The sha1.js from the lib I mentioned in my question, has a global variable called b64pad, used for the purpose of padding. By default its value is "". Changing to "=" gives the exact hash reckoned by C# API

answered Mar 17, 2010 at 13:13

Andres

3,3666 gold badges30 silver badges32 bronze badges

Collectives™ on Stack Overflow

SHA1 base64 algorithm in javascript and C#

2 Answers 2

4 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related