[auth.c key.c key.h ssh-keygen.1 ssh-keygen.c sshd_config.5]
[krl.c krl.h PROTOCOL.krl]
add support for Key Revocation Lists (KRLs). These are a compact way to
represent lists of revoked keys and certificates, taking as little as
a single bit of incremental cost to revoke a certificate by serial number.
KRLs are loaded via the existing RevokedKeys sshd_config option.
feedback and ok markus@