ssh coredump if gssapi-with-mic preferred, but no kinit done (yet)?

David Wolfskill david at catwhisker.org
Sun Jul 1 19:16:59 UTC 2007 

Although I track CURRENT daily on my laptop, I hadn't run into this
issue,  as I don't use KErberos on the laptop.

I try to track CURRENT on a weekly basis for my work desktop, where I do
use Kerberos.  (I ran out of time last Sunday,  because I also update
ports, and OpenOffice took quite a while.)  Thus, I believe that what
caused this would have been committed on or after 24 June, which is when
I built CURRENT previously on the machine.

Although I tend to  use public key authentication (for ssh), we have a
requirement at work that certain machines need to be accessible via ssh
once the requstor has authenticated via Kerberos.  Thus, while the
machines in question will accept (and in some cases, are configured to
prefer) gssapi-with-mic authentication, I'm in the habit of ignoring
that and using the public-key authentication that I'm already set up to
use.

So after building & booting today's CURRENT on the machine:

catmint(7.0-C)[1] uname -a
FreeBSD catmint.mail-abuse.org 7.0-CURRENT FreeBSD 7.0-CURRENT #88: Sun Jul  1 10:30:56 PDT 2007     root at catmint.mail-abuse.org:/common/S4/obj/usr/src/sys/CATMINT  i386
catmint(7.0-C)[2] 

I wanted to do a reality check on a different machine:

catmint(7.0-C)[4] ssh -x repo df /
Segmentation fault (core dumped)
catmint(7.0-C)[5] 

Huh?

OK; a little more detail:

catmint(7.0-C)[8] ssh -vvv -x repo
OpenSSH_4.5p1 FreeBSD-20061110, OpenSSL 0.9.8e 23 Feb 2007
debug1: Reading configuration data /home/dhw/.ssh/config
debug1: Applying options for *
debug1: Reading configuration data /etc/ssh/ssh_config
debug2: ssh_connect: needpriv 0
debug1: Connecting to repo.mail-abuse.org [168.61.10.54] port 22.
debug1: Connection established.
debug1: identity file /home/dhw/.ssh/identity type 0
debug3: Not a RSA1 key file /home/dhw/.ssh/id_rsa.
debug2: key_type_from_name: unknown key type '-----BEGIN'
debug3: key_read: missing keytype
debug2: key_type_from_name: unknown key type 'Proc-Type:'
debug3: key_read: missing keytype
debug2: key_type_from_name: unknown key type 'DEK-Info:'
debug3: key_read: missing keytype
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug2: key_type_from_name: unknown key type '-----END'
debug3: key_read: missing keytype
debug1: identity file /home/dhw/.ssh/id_rsa type 1
debug3: Not a RSA1 key file /home/dhw/.ssh/id_dsa.
debug2: key_type_from_name: unknown key type '-----BEGIN'
debug3: key_read: missing keytype
debug2: key_type_from_name: unknown key type 'Proc-Type:'
debug3: key_read: missing keytype
debug2: key_type_from_name: unknown key type 'DEK-Info:'
debug3: key_read: missing keytype
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug2: key_type_from_name: unknown key type '-----END'
debug3: key_read: missing keytype
debug1: identity file /home/dhw/.ssh/id_dsa type 2
debug1: Remote protocol version 2.0, remote software version OpenSSH_4.5p1 FreeBSD-20061110
debug1: match: OpenSSH_4.5p1 FreeBSD-20061110 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_4.5p1 FreeBSD-20061110
debug2: fd 3 setting O_NONBLOCK
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-dss,ssh-rsa
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc at lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc at lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160 at openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160 at openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib at openssh.com,zlib
debug2: kex_parse_kexinit: none,zlib at openssh.com,zlib
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: first_kex_follows 0 
debug2: kex_parse_kexinit: reserved 0 
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-dss
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc at lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc at lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160 at openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160 at openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib at openssh.com
debug2: kex_parse_kexinit: none,zlib at openssh.com
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: first_kex_follows 0 
debug2: kex_parse_kexinit: reserved 0 
debug2: mac_init: found hmac-md5
debug1: kex: server->client aes128-cbc hmac-md5 none
debug2: mac_init: found hmac-md5
debug1: kex: client->server aes128-cbc hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: dh_gen_key: priv key bits set: 127/256
debug2: bits set: 506/1024
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug3: check_host_in_hostfile: filename /home/dhw/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 82
debug1: Host 'repo.mail-abuse.org' is known and matches the DSA host key.
debug1: Found key in /home/dhw/.ssh/known_hosts:82
debug2: bits set: 528/1024
debug1: ssh_dss_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/david/.ssh/id_rsa (0x28434e20)
debug2: key: /home/david/.ssh/id_dsa (0x28434e30)
debug2: key: /home/dhw/.ssh/id_rsa (0x28434d20)
debug2: key: /home/dhw/.ssh/id_dsa (0x28434d30)
debug1: Authentications that can continue: publickey,gssapi-with-mic
debug3: start over, passed a different list publickey,gssapi-with-mic
debug3: preferred gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup gssapi-with-mic
debug3: remaining preferred: publickey,keyboard-interactive,password
debug3: authmethod_is_enabled gssapi-with-mic
debug1: Next authentication method: gssapi-with-mic
Segmentation fault (core dumped)
catmint(7.0-C)[9] 

Hmmm.... kinky....

OK; how about this:

catmint(7.0-C)[10] kinit
dhw at MAIL-ABUSE.ORG's Password: 
kinit: NOTICE: ticket renewable lifetime is 0
catmint(7.0-C)[11] ssh -x repo uname -a
FreeBSD repo.mail-abuse.org 6.2-STABLE FreeBSD 6.2-STABLE #61: Sun Jul  1 06:28:55 PDT 2007     dhw at repo.mail-abuse.org:/usr/obj/usr/src/sys/SMP_PAE  i386
catmint(7.0-C)[12] 

As a further reality check, I booted back to STABLE & tried the ssh again:

catmint(6.2-S)[1] uname -a
FreeBSD catmint.mail-abuse.org 6.2-STABLE FreeBSD 6.2-STABLE #30: Sun Jul  1 07:05:51 PDT 2007     root at catmint.mail-abuse.org:/common/S1/obj/usr/src/sys/CATMINT  i386
catmint(6.2-S)[2] ssh -x repo uname -a
FreeBSD repo.mail-abuse.org 6.2-STABLE FreeBSD 6.2-STABLE #61: Sun Jul  1 06:28:55 PDT 2007     dhw at repo.mail-abuse.org:/usr/obj/usr/src/sys/SMP_PAE  i386
catmint(6.2-S)[3] uptime
11:33AM  up 2 mins, 2 users, load averages: 0.35, 0.23, 0.09
catmint(6.2-S)[4] 


I'm willing to try some things on the machine to help diagnose the
problem(s) under CURRENT, but there are some things I'd like to do
with it (that will take a few hours,such as a "make release") that
I'd much rather do while it's running STABLE.  And Sundays are about the
only days I can really count on being able to do anything with CURRENT
on the machine.  (I'm in US/PAcific time zone.)

So:  clues?  Would building a debugging version of ssh be a reasonable
step?

Peace,
david
-- 
David H. Wolfskill				david at catwhisker.org
Anything and everything is a (potential) cat toy.

See http://www.catwhisker.org/~david/publickey.gpg for my public key.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 195 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-current/attachments/20070701/8141a8ff/attachment.pgp

More information about the freebsd-current mailing list