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Re: Reproducing a hash code

• To: mathgroup at smc.vnet.net
• Subject: [mg82989] Re: Reproducing a hash code
• From: michael.p.croucher at googlemail.com
• Date: Tue, 6 Nov 2007 03:42:22 -0500 (EST)
• References: <fgmppa$9i5$1@smc.vnet.net>

On 5 Nov, 10:03, "Steve Luttrell"
<steve at _removemefirst_luttrell.org.uk> wrote:
> I am trying to get results from Mathematica's Hash function (for hash type
> "MD5") that are consistent with the results obtained using "openssl md5" in
> Linux.
>
> The particular example I would like to reproduce is onhttp://wiki.secondlife.com/wiki/LlMD5String, where
>
> "Hello, Avatar!:0"
>
> hashes to (for hash type "MD5")
>
> 112abd47ceaae1c05a826828650434a6
>
> In Mathematica 6 (Windows Vista, Intel hardware), doing the obvious
>
> Hash["Hello, Avatar!:0", "MD5"] // BaseForm[#, 16] &
>
> I get the following result
>
> a8c2ab1662a37cb9f8ea5af154a48c52
>
> This is not the same as expected. Does anyone know how to get consistent
> results?
>
> --
> Steve Luttrell
> West Malvern, UK

Hi Steve

It seems that Mathematica includes the enclosing quotes "" when it
generate it's hash:

As you point out, in Mathematica 6 (on windows and Linux) if we do
Hash["Hello, Avatar!:0", "MD5"] // BaseForm[#, 16] &
we get
a8c2ab1662a37cb9f8ea5af154a48c52

Now onto our linux box - if we do (notice the extra quotes I have
added)

echo -n '"Hello, Avatar!:0"' | openssl md5

we get

a8c2ab1662a37cb9f8ea5af154a48c52

as before.
Hope this helps,
Mike