sshd: switch authentication to sshbuf API; ok djm@

Compare pointers to NULL rather than 0.

ok djm@

New key API: refactor key-related functions to be more library-like,
existing API is offered as a set of wrappers.

with and ok markus@

Thanks also to Ben Hawkes, David Tomaschik, Ivan Fratric, Matthew
Dempsky and Ron Bowes for a detailed review a few months ago.

don't count on things that accept arguments by reference to clear
things for us on error; most things do, but it's unsafe form.

unifdef -DBSD_AUTH
unifdef -USKEY

These options have been in use for some years;
ok markus@ "no objection" millert@

almost entirely get rid of the culture of ".h files that include .h files"
ok djm, sort of ok stevesk
makes the pain stop in one easy step

Put $OpenBSD$ tags back (as comments) to replace the RCSID()s that
Theo nuked - our scripts to sync -portable need them in the files

introduce xcalloc() and xasprintf() failure-checked allocations functions
and use them throughout openssh

xcalloc is particularly important because malloc(nmemb * size) is a
dangerous idiom (subject to integer overflow) and it is time for it to
die

feedback and ok deraadt@

RCSID() can die

branches: 1.6.4; 1.6.6;
Have keyboard-interactive code call the drivers even for responses for
invalid logins. This allows the drivers themselves to decide how to handle
them and prevent leaking information where possible. Existing behaviour for
bsdauth is maintained by checking authctxt->valid in the bsdauth driver.
Note that any third-party kbdint drivers will now need to be able to handle
responses for invalid logins. ok markus@

branches: 1.5.8; 1.5.10;
minor KNF

KNF done automatically while reading....

branches: 1.3.2;
integrate privilege separated openssh; its turned off by default for now.
work done by me and markus@

basic KNF done while i was looking for something else

branches: 1.1.2; 1.1.4; 1.1.6;
improved kbd-interactive support. work by per@appgate.com and me

Compare pointers to NULL rather than 0.

ok djm@

New key API: refactor key-related functions to be more library-like,
existing API is offered as a set of wrappers.

with and ok markus@

Thanks also to Ben Hawkes, David Tomaschik, Ivan Fratric, Matthew
Dempsky and Ron Bowes for a detailed review a few months ago.

don't count on things that accept arguments by reference to clear
things for us on error; most things do, but it's unsafe form.

unifdef -DBSD_AUTH
unifdef -USKEY

These options have been in use for some years;
ok markus@ "no objection" millert@

almost entirely get rid of the culture of ".h files that include .h files"
ok djm, sort of ok stevesk
makes the pain stop in one easy step

Put $OpenBSD$ tags back (as comments) to replace the RCSID()s that
Theo nuked - our scripts to sync -portable need them in the files

introduce xcalloc() and xasprintf() failure-checked allocations functions
and use them throughout openssh

xcalloc is particularly important because malloc(nmemb * size) is a
dangerous idiom (subject to integer overflow) and it is time for it to
die

feedback and ok deraadt@

RCSID() can die

branches: 1.6.4; 1.6.6;
Have keyboard-interactive code call the drivers even for responses for
invalid logins. This allows the drivers themselves to decide how to handle
them and prevent leaking information where possible. Existing behaviour for
bsdauth is maintained by checking authctxt->valid in the bsdauth driver.
Note that any third-party kbdint drivers will now need to be able to handle
responses for invalid logins. ok markus@

branches: 1.5.8; 1.5.10;
minor KNF

KNF done automatically while reading....

branches: 1.3.2;
integrate privilege separated openssh; its turned off by default for now.
work done by me and markus@

basic KNF done while i was looking for something else

branches: 1.1.2; 1.1.4; 1.1.6;
improved kbd-interactive support. work by per@appgate.com and me