This reverts git commit f972813ecd.
The sk algorithms need to remain in the sigalgs list so that they
are included in the server-sig-algs ext-info message sent by
the server. RFC8308 for server-sig-algs requires that all algorithms are
listed (though OpenSSH client 8.4p1 tested doesn't require that)
We fix a bad_bufptr() failure from a previous commit. We now limit
the allowed characters to those that will definitely be safe
in a shell. Some scripts/programs may use arbitrary environment
variables without escaping correctly - that could be a problem
in a restricted environment.
The current allowed set is a-z A-Z 0-9 .,_-+@
This also adds a test for SSH_PUBKEYINFO, by default it only runs
under github actions (or "act -j build").
This allows ASLR to re-randomize the address
space for every connection, preventing some
vulnerabilities from being exploitable by
repeated probing.
Overhead (memory and time) is yet to be confirmed.
At present this is only enabled on Linux. Other BSD platforms
with fexecve() would probably also work though have not been tested.
Lower class levels are less well defined, and non-interactive
SSH can carry various different types of applications.
This change also sets lowdelay class (AF21) earlier in an an outbound
dbclient session
The previous TOS values are deprecated and not used by modern traffic
classifiers. This sets AF21 for "interactive" traffic (with a tty).
Non-tty traffic sets AF11 - that indicates high throughput but is not
lowest priority (which would be CS1 or LE).
This differs from the CS1 used by OpenSSH, it lets interactive git over SSH
have higher priority than background least effort traffic. Dropbear's settings
here should be suitable with the diffservs used by CAKE qdisc.
The previous TOS values are deprecated and not used by modern traffic
classifiers. This sets AF21 for "interactive" traffic (with a tty).
Non-tty traffic sets AF11 - that indicates high throughput but is not
lowest priority (which would be CS1 or LE).
This differs from the CS1 used by OpenSSH, it lets interactive git over SSH
have higher priority than background least effort traffic. Dropbear's settings
here should be suitable with the diffservs used by CAKE qdisc.
