From: Eric Sunshine <sunshine@sunshineco.com>
Date: Sun, 01 Nov 2015 08:30:08 GMT
Subject: Re: [PATCH] Limit the size of the data block passed to SHA1_Update()
Message-ID: <CAPig+cSLoC-O1YneUVRjBpZzHLmASmRQx_+8b2dsk34ReU-ovw@mail.gmail.com>
In-Reply-To: <1446359536-25829-1-git-send-email-apahlevan@ieee.org>

On Sun, Nov 1, 2015 at 1:32 AM,  <atousa.p@gmail.com> wrote:
> Some implementations of SHA_Updates have inherent limits
> on the max chunk size. SHA1_MAX_BLOCK_SIZE can be defined
> to set the max chunk size supported, if required.  This is
> enabled for OSX CommonCrypto library and set to 1GiB.
>
> Signed-off-by: Atousa Pahlevan Duprat <apahlevan@ieee.org>
> ---
> diff --git a/compat/sha1_chunked.c b/compat/sha1_chunked.c
> new file mode 100644
> index 0000000..bf62b1b
> --- /dev/null
> +++ b/compat/sha1_chunked.c
> @@ -0,0 +1,21 @@
> +#include "cache.h"
> +
> +#ifdef SHA1_MAX_BLOCK_SIZE

This file is only compiled when SHA1_MAX_BLOCK_SIZE is defined, so
does this #ifdef serve a purpose?

> +int git_SHA1_Update(SHA_CTX *c, const void *data, size_t len)
> +{
> +       size_t nr;
> +       size_t total = 0;
> +       char *cdata = (char*)data;

Nit: This could be 'const char *'.

> +       while (len > 0) {
> +               nr = len;
> +               if (nr > SHA1_MAX_BLOCK_SIZE)
> +                       nr = SHA1_MAX_BLOCK_SIZE;
> +               SHA1_Update(c, cdata, nr);
> +               total += nr;
> +               cdata += nr;
> +               len -= nr;
> +       }
> +       return total;
> +}
> +#endif