Help, SHA-256 Wrong, When bigger than 4096 bytes

[aker]

I want hash 28GB file, Help.

[hutch--]

I would be inclined to have a lok at the crypto API for doing this. MichaelW posted code a while ago that I founds very useful in doing one of the simpler SHA1 hashes and it reliably hashes very large files, well over 2 gig. The main advantage with this code was you could stream the file in blocks and just chomp through very large files. The speed was good as well.

You need to have a reference that does reliable results for the algo you are after, then you can test if your implimentation is correct.

[Astro]

Hi,

Are you counting/processing blocks correctly?

If you are using the Win API for this, check you are loading the data correctly; it maintains a running "total" of the hash so far until you are finished.

Best regards,
Robin.

[aker]

ok..

[N1ghtm4r3]

SHA256Update is made for this problem.
just pass blocks with 4096 bytes length or smaller to SHA256Update in a loop until end of file.

[aker]

Thanks.