topic unprivileged user gets ssh error accessing host key file in Operating System - OpenVMS

unprivileged user gets ssh error accessing host key file

Eric W. Robertson — Sat, 21 Nov 2009 14:35:20 GMT

I noticed today that a regular old unprivileged OpenVMS account (i.e. the only process privileges for the account are NETMBX and TMPMBX) gets the following error message when the account is used to attempt a connection to another host using ssh:

warning: Error trying to access file /etc/ssh2/hostkey.pub.
warning: Unable to load public host key from /etc/ssh2/hostkey.pub
srvr1$dka0:[sys0.syscommon.][sysexe]tcpip$ssh_ssh2.exe: FATAL: BUILD12$:[TCPIP_V56_BLECO4.SRC.SSH2]AUTHC-HOSTBASED.C;1:181 Ssh2AuthH
ostBasedClient (function name unavailable) Assertion failed: gdata->pubkey_algorithm != ((void *) 0)

%TCPIP-F-SSH_FATAL, non-specific fatal error condition

has anyone else seen this error using this type of account? The system on which this happens is running OpenVMS Alpha V8.3 using TCPIP Services for OpenVMS V5.6 ECO 4. As always, any wisdom is greatly appreciated.

Eric

Re: unprivileged user gets ssh error accessing host key file

Steven Schweda — Sat, 21 Nov 2009 14:48:40 GMT

I'd guess that "/etc/ssh2/hostkey.pub" is
actually
TCPIP$SSH_DEVICE:[TCPIP$SSH.SSH2]HOSTKEY.PUB
and around here:

ALP $ dire /secu TCPIP$SSH_DEVICE:[TCPIP$SSH.SSH2]HOSTKEY

Directory SYS$SYSDEVICE:[TCPIP$SSH.SSH2]

HOSTKEY.;1 [TCPIP$AUX,TCPIP$SSH] (RWD,RWD,,)
HOSTKEY.PUB;1 [TCPIP$AUX,TCPIP$SSH] (RWD,RWD,R,R)

Total of 2 files.

The _private_ key file, "HOSTKEY.", is
restricted, but anyone should be able to read
the public key file.

For completeness:

ALP $ dire /secu TCPIP$SSH_DEVICE:[TCPIP$SSH]SSH2

Directory SYS$SYSDEVICE:[TCPIP$SSH]

SSH2.DIR;1 [TCPIP$AUX,TCPIP$SSH] (RWE,RWE,RE,E)

Total of 1 file.

ALP $ dire /secu TCPIP$SSH_DEVICE:[000000]TCPIP$SSH

Directory SYS$SYSDEVICE:[000000]

TCPIP$SSH.DIR;1 [TCPIP$AUX,TCPIP$SSH] (RWE,RWE,RE,E)

Total of 1 file.

ALP $ tcpip show version

HP TCP/IP Services for OpenVMS Alpha Version V5.6 - ECO 4
on a COMPAQ Professional Workstation XP1000 running OpenVMS V8.3

And no, I don't see that problem here.

Re: unprivileged user gets ssh error accessing host key file

Eric W. Robertson — Mon, 23 Nov 2009 15:12:09 GMT

Steven,

Thanks! For some reason the SYS$SYSDEVICE:[TCPIP$SSH.SSH2]hostkey.pub file protection specified NO ACCESS to WORLD on my system. Once I set this file's protection to WORLD:READ, the unprivileged user account can now successfully ssh to another host. Thanks again for the file security information.

Eric