Wanted: VB.NET user

From:	Peter (BOUGHTONP)	2 Oct 2006 10:26
To:	ALL	1 of 13

30763.1

Can someone please confirm what the output of this function is:

VB code:

Imports System.Security.Cryptography
Private Function ComputeHash(ByVal Key As String) As String
	Dim objSHA1 As New SHA1CryptoServiceProvider
	objSHA1.ComputeHash(System.Text.Encoding.UTF8.GetBytes(Key.ToCharArray))
	Dim buffer() As Byte = objSHA1.Hash
	Dim HashValue As String = System.Convert.ToBase64String(buffer)
	Return HashValue
End Function

When the value "SENTRYORD01154321SENTRYORD01154321" is passed in.

Also, can anyone confirm if the SHA1CryptoServiceProvider.ComputeHash bit is using 28-bit SHA-1 encryption or something else?

Thanks.

3.1415P265E589T932E846R64338

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From:	Ally	2 Oct 2006 17:45
To:	Peter (BOUGHTONP)	2 of 13

30763.2 In reply to 30763.1
Good lord. I dunno if this'll help. Have you heard of "slobber"? Do you tend to think of it as a positive term? Because the one thing that dogs can be trusted to do, besides thumping gaseous dead rats out their ass and besides biting everybody, is to slobber all over themselves and you. You need to do some serious thinking about whether a dog is really what you need in your life right now.

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From:	Peter (BOUGHTONP)	2 Oct 2006 18:11
To:	Ally	3 of 13

30763.3 In reply to 30763.2
It doesn't itself, but a page linked from it does: quote: The hash size for the SHA1 algorithm is 160 bits. Which is 20 bytes, not 28, and that probably explains why the expected result was different. Ta. `3.1415P265E589T932E846R64338`

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From:	Mal (BAD)	2 Oct 2006 21:20
To:	Peter (BOUGHTONP)	4 of 13

30763.4 In reply to 30763.3
I was under the impression that a SHA1 hash was always 20 bytes in length.

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From:	Peter (BOUGHTONP)	2 Oct 2006 21:29
To:	Mal (BAD)	5 of 13

30763.5 In reply to 30763.4
As far as I can tell, you're right. I'm trying to figure out where 28 characters comes into things, but I've not figured it out yet. :S `3.1415P265E589T932E846R64338`

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From:	Mal (BAD)	2 Oct 2006 22:20
To:	Peter (BOUGHTONP)	6 of 13

30763.6 In reply to 30763.5
Which 28 characters are those then?

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From:	Peter (BOUGHTONP)	2 Oct 2006 22:25
To:	Mal (BAD)	7 of 13

30763.7 In reply to 30763.6
The ones that this Hash function returns: quote: http://www.cfquickdocs.com/?getDoc=hash # SHA: Generates a 28-character string using the Secure Hash Standard SHA-1 algorithm specified by Nation Institute of Standards and Technology (NIST) FIPS-180-2. # SHA-256: Generates a 44-character string using the SHA-256 algorithm specified by FIPS-180-2. # SHA-384: Generates a 64-character string using the SHA-384 algorithm specified by FIPS-180-2. # SHA-512: Generates an 88-character string using the SHA-1 algorithm specified by FIPS-180-2. `3.1415P265E589T932E846R64338`

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From:	Mal (BAD)	2 Oct 2006 22:28
To:	Peter (BOUGHTONP)	8 of 13

30763.8 In reply to 30763.7

Weird. What do you get when you pass your test string then?

It should be: 303569615317dc99a7029efb15a01a43a5ad39d3

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From:	Mal (BAD)	2 Oct 2006 22:31
To:	Peter (BOUGHTONP)	9 of 13

30763.9 In reply to 30763.7
Actually, one of the comments at the bottom of that page indicates that the documented returned string lengths are wrong and you actually get 40 characters when using SHA1, which is correct.

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From:	Peter (BOUGHTONP)	2 Oct 2006 22:36
To:	Mal (BAD)	10 of 13

30763.10 In reply to 30763.8
Can't remember, but it wasn't Hex, it was the one that tends to end in = or ==. Ah, could it be non-Hex base-16? 16*2 +8 = 40 Hex characters, like what you have there. `3.1415P265E589T932E846R64338`

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From:	Peter (BOUGHTONP)	2 Oct 2006 22:41
To:	Mal (BAD)	11 of 13

30763.11 In reply to 30763.9
Yeah, but the example I was running was returning 28 characters, as was the expected output from that VB function, but they were a different 28 characters, so it must have been that one function is hashing before converting to Base64 (I don't get that - how does 20 in Base64 make 28? :S) and the other one was... doing something else but still producing a Base64 number. `3.1415P265E589T932E846R64338`

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From:	Mal (BAD)	2 Oct 2006 22:49
To:	Peter (BOUGHTONP)	12 of 13

30763.12 In reply to 30763.11
Now I understand. Still odd though.

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From:	Peter (BOUGHTONP)	2 Oct 2006 22:53
To:	Mal (BAD)	13 of 13

30763.13 In reply to 30763.12

Ah, yeah, that table helps it make sense.

But yes very odd.

Now I can go to bed without it keeping me awake all night. :]

3.1415P265E589T932E846R64338

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