Re: [Chicken-hackers] possible bug in simple-sha1

[Kristian Lein-Mathisen]

Hi Peter,

and thanks for your swift reply.

I tried changing the foreign type of len from int to integer and size_t, but unfortunately neither had any impact.

Note that the signature of SHA1Update function is size_t, so the foreign binding should probably be set to size_t too regardless of not fixing this problem or not.

K.

On Sun, Jun 2, 2019 at 1:01 PM Peter Bex <address@hidden> wrote:

On Sun, Jun 02, 2019 at 12:39:25PM +0200, Kristian Lein-Mathisen wrote:
> Hi guys,
>
> I've come across a strange problem with simple-sha1. Sometimes it reports
> the wrong hash for large files when I use the sha1sum procedure. I don't
> know if the problem is there for strings.
>
> 1216 address@hidden ~/archive  ➤ csi -R simple-sha1 -p '(sha1sum "MOV_0384.mp4")'
> ; sha1sum "MOV_0384.mp4"
> cb491b2f692dc3e9269a633f54eceb85269b0442
> 3b673158654ddc9bb668b5eafc050c8be66ad968
>  ./xz2/dcim/phone/100ANDRO/MOV_0384.mp4
>
> >From not-very-rigorous testing, it seems it happens on all files that are
> bigger than the 512M mark:

This just screams "overflow"; (integer-length (* 512 1024 1024) => 30

Are you using CHICKEN 4 or CHICKEN 5?

Even CHICKEN 4 should deal with this correctly by overflowing into a
flonum.  That would be a bug in the egg, then.

Perhaps the fix is changing:
(define update (foreign-lambda void "SHA1Update" c-pointer c-pointer int))
into:
(define update (foreign-lambda void "SHA1Update" c-pointer c-pointer integer))

Can you try?

Cheers,
Peter