sha256 encoding probelm on AWS

[Sparticuz]

I'm trying to write a few functions to sign messages in order to send to Amazon's AWS. I've almost got it, but I think I need some help from someone who knows dot net a bit better than me.

I need to sha256 some things (not hmacsha256), but I'm getting some incorrect results. Below is my sha256 function based on the Plain SHA1 function found here: https://www.alphasoftware.com/docume...tal%20Hash.xml

function sha256 as c (string as c)    
    dim data as b
    data = convert_acp_to_utf8(string)
    dim result as b
    dim sham as ::System::Security::Cryptography::SHA256Managed = new ::System::Security::Cryptography::SHA256Managed()
    result = sham.ComputeHash(data)
    
    sha256 = *to_hex(result)


end function

However, it gives me incorrect results. Based on the tests here: http://docs.aws.amazon.com/general/l...est-suite.html when I hash this value:

[COLOR=#444444][FONT=&amp]GET
[/FONT][/COLOR]/
Param1=value1&Param2=value2
host:example.amazonaws.com
x-amz-date:20150830T123600Z

host;x-amz-date
[COLOR=#444444][FONT=&amp]e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855[/FONT][/COLOR]

I should get this value in return (verified with http://www.xorbin.com/tools/sha256-hash-calculator):

[COLOR=#444444][FONT=&amp]816cd5b414d056048ba4f7c5386d6e0533120fb1fcfa93762cf0fc39e2cf19e0[/FONT][/COLOR]

, however I get

9e487d40177520aed8763d24c77c7179f67622debbd2b8188d93138ba6748ade

After doing some research, i found this post on SO: http://stackoverflow.com/questions/1...ng-with-sha256 That states the default encoding for dotnet is utf16, but AWS uses utf8.

So, my question is, how do I change the encoding type for my sha function? It appears that I need to somehow seed my data blob variable as utf8 encoding, but I'm not sure how to do that.
Thanks!

[Sparticuz]

Re: sha256 encoding probelm on AWS

I've figured out that the SHA256 of crlf() is different from the SHA256 of lf. So in my code, I need to convert all crlf's to lf's. The sha256 then works correctly.

[Sparticuz]

Re: sha256 encoding probelm on AWS

Since Alpha doesn't have a lf() function, I wrote one:

FUNCTION lf AS C (count AS N = 1)
	
	dim return as c = ""
	
	while count
		*concat(return,chr(10))
		count = count - 1
	end while
	
	lf = return
	
END FUNCTION

[alexc]

Re: sha256 encoding probelm on AWS

Great work. do you mind posting the final working function up on the board Sparticuz.

[Sparticuz]

Re: sha256 encoding probelm on AWS

Sure thing.

Great work. do you mind posting the final working function up on the board Sparticuz.

[Sparticuz]

Re: sha256 encoding probelm on AWS

So here is my working code: https://gist.github.com/Sparticuz/e5...50f64e8fb27fac

I've confirmed it works with the normal GET test suite found here: http://docs.aws.amazon.com/general/l...est-suite.html

After starting to work with it, the Amazon AWS API is literally the worst API I have ever dealt with. I may abandon this project and turn to using the NodeJS aws-sdk, and call that from xbasic. I'm not sure yet.

But, the code I wrote does work. Again, it works for the normal GET test, I haven't tested it for anything else. It will need alot of work to get it working with other types of requests. (Check the test suite for other types of requests)