[jpake.c schnorr.c]
check that received values are smaller than the group size in the
disabled and unfinished J-PAKE code.
avoids catastrophic security failure found by Sebastien Martini
[auth2-jpake.c jpake.c jpake.h monitor_wrap.c monitor_wrap.h schnorr.c]
[sshconnect2.c]
refactor the (disabled) Schnorr proof code to make it a little more
generally useful
[auth.h auth2.c monitor.c monitor.h monitor_wrap.c monitor_wrap.h]
[readconf.c readconf.h servconf.c servconf.h ssh2.h ssh_config.5]
[sshconnect2.c sshd_config.5 jpake.c jpake.h schnorr.c auth2-jpake.c]
[Makefile.in]
Add support for an experimental zero-knowledge password authentication
method using the J-PAKE protocol described in F. Hao, P. Ryan,
"Password Authenticated Key Exchange by Juggling", 16th Workshop on
Security Protocols, Cambridge, April 2008.
This method allows password-based authentication without exposing
the password to the server. Instead, the client and server exchange
cryptographic proofs to demonstrate of knowledge of the password while
revealing nothing useful to an attacker or compromised endpoint.
This is experimental, work-in-progress code and is presently
compiled-time disabled (turn on -DJPAKE in Makefile.inc).
"just commit it. It isn't too intrusive." deraadt@