net: Compute protocol sequence numbers and fragment IDs using MD5.

2011-08-16T01:57:20Z

Computers have become a lot faster since we compromised on the partial MD4 hash which we use currently for performance reasons. MD5 is a much safer choice, and is inline with both RFC1948 and other ISS generators (OpenBSD, Solaris, etc.) Furthermore, only having 24-bits of the sequence number be truly unpredictable is a very serious limitation. So the periodic regeneration and 8-bit counter have been removed. We compute and use a full 32-bit sequence number. For ipv6, DCCP was found to use a 32-bit truncated initial sequence number (it needs 43-bits) and that is fixed here as well. Reported-by: Dan Kaminsky Tested-by: Willy Tarreau Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

kernel.git/net/core/secure_seq.c, branch linux-2.6.32.y

net: Compute protocol sequence numbers and fragment IDs using MD5.