[Pkg-xmpp-devel] Bug#810741: gsasl: produces unhelpful error message on Kerberos failure

Michael Gold mgold at qnx.com
Mon Jan 11 20:10:00 UTC 2016


Package: gsasl
Version: 1.8.0-8

As I noted in Debian bug #810727, I need to use the proper hostname to
connect to my SMTP server; otherwise Kerberos authentication will fail.
But this wasn't easy to figure out, as the message returned by msmtp is
kind of useless (it seems to just print whatever text is returned by GNU
SASL):
	msmtp: GNU SASL: GSSAPI error in client while negotiating security
	context in gss_init_sec_context() in SASL library.  This is most
	likely due insufficient credentials or malicious interactions.

This makes it seem like I used a bad password or the SMTP server didn't
like the ticket.  In fact, the Kerberos server didn't recognise the
hostname, and according to a Wireshark dump returned a perfectly clear
error message:
	krb-error
		pvno: 5
		msg-type: krb-error (30)
		stime: 2016-01-11 16:08:01 (UTC)
		susec: 299239
		error-code: eRR-S-PRINCIPAL-UNKNOWN (7)
		realm: EXAMPLE.COM
		sname
			name-type: kRB5-NT-SRV-HST (3)
			name-string: 2 items
				KerberosString: smtp
				KerberosString: smtp-server.EXAMPLE.COM

I suggest a message like the following, based on the libkrb5 text:
	"Server not found in Kerberos database:
	 smtp/smtp-server.example.com at EXAMPLE.COM"

- Michael


-- System Information:
Debian Release: stretch/sid
  APT prefers testing
  APT policy: (500, 'testing'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.3.0-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_CA.UTF-8, LC_CTYPE=en_CA.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages gsasl depends on:
ii  dpkg               1.18.4
ii  install-info       6.0.0.dfsg.1-4
ii  libc6              2.21-6
ii  libgnutls-deb0-28  3.3.19-1
ii  libgsasl7          1.8.0-8

gsasl recommends no packages.

gsasl suggests no packages.

-- no debconf information
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: not available
URL: <http://lists.alioth.debian.org/pipermail/pkg-xmpp-devel/attachments/20160111/52efe74f/attachment.sig>
-------------- next part --------------
---------------------------------------------------------------------
This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful.


More information about the Pkg-xmpp-devel mailing list