On 20 Jan 2017, at 13:00, Ben Laurie <[email protected]> wrote:
> Why do you need the obsolete hash functions?
I am still in the middle of some inventory work with the help of a few friendly
enterprise & cloud folks.
But it is nog looking good -- so far its seems that:
- md4 is rarely used (i,e.a actually called).
- md5 is very often used for
- salted password
- creating all sorts of unguessable IDs.
- generation of a randomish token/digest
- creating/protecting session cookies
- creating 12/23/34/1221231.txt file trees or similar equal wear file /
tmp file fanout.
- checksumming a file along the lines of taking an fstat() snapshot.
- commonly used UUID gen.
- content-digest generation for things like cache headers, imap/sieve
breakout.
- file integrity.
- sha1 is used a factor 10x less. Mostly:
- salted password
- creating/protecting session cookies
- sha256 && 512 seems to be used about as often md4.
Though nothing stopping us from having a snotty warning/#define to discourage
use - and wack the 60 or so distinct places/ where MD5 is currently used in
subversion/httpd and friends and upping this to at least sha256.
I guess cryptographically there is little point between an MD5 and the last 16
bytes of a SHA256 ? Correct ?
As in a lot of above case - the MD5 is not exposed - does not actually need to
be an MD5 for interoperability purposes.
Dw.
