From: "Chris Haynes" <chris(_at_)harvington(_dot_)org(_dot_)uk>
Date: 2004/07/31 Sat PM 12:26:06 EDT
To: spf-discuss(_at_)v2(_dot_)listbox(_dot_)com
Subject: Re: [spf-discuss] Case Sensitivity
As I said on spf-help, it's my understanding that people are allowed to use
upper-case wherever and wherever they wish in domain names contained in eMail
addresses. The identification of the domains is intended to be
case-insensitive.
AFAIK, DNS systems handle domain names in a 'canonical' lower-case form.
I therefore think that the problem is in SPF: It should normalize the domain
names received in SMTP messages to lower-case before undertaking SPF tests.
(And were I implementing an SPF tool, I would also ensure that any domain
string
I obtained from DNS was also in lower-case - just to make sure).
As I can't see this lower-case normalization required in the SPF ietf-drafts,
it looks to me like it is an omission from the SPF specs, not a tool
implementation error.
Chris Haynes
<marc(_at_)alaia(_dot_)net>alerted everyone:
Hey, everyone. A situation has come up on the SPF-Help list where a
receiver
is rejecting inbound mail from a domain and it turns out that the problem is
case sensitivity. A test using libspf2 verified that libspf2, at least, is
case
sensitive.
Is this an implementation issue or a spec issue, or not an issue at all?
What
I mean is:
- Are all DNS-related issues supposed to be case-insensitive, so this does
not
need to be in the spec, but certain implementations have implemented it wrong?
- Are all DNS-related issues not specified, so the SPF spec needs to say?
- Or do people need to be aware that case may cause their mail to be
rejected?
Evidence presented below....
Regards,
Marc Alaia
srs# spfquery -debug -ip 216.39.67.112 -sender cwjobs-
e2-27265112(_at_)ProcessRequest(_dot_)com -helo DAL1BS110.PROCESSREQUEST.COM
spf_dns_null.c:64 Debug: DNS pre-cache lookup: ProcessRequest.com TXT
(16)
spf_dns_resolv.c:144 Debug: DNS resolv looking for: ProcessRequest.com
TXT
(16)
spf_dns_null.c:94 Debug: DNS pre-cache found: ProcessRequest.com TXT
(16) TTL: 1800 RR found: 1 herrno: 0 source: resolv
spf_get_spf.c:116 Debug: found SPF record: v=spf1 ptr -all
spf_dns_null.c:64 Debug: DNS pre-cache lookup:
112.67.39.216.in-addr.arpa
PTR (12)
spf_dns_resolv.c:144 Debug: DNS resolv looking for: 112.67.39.216.in-addr.
arpa PTR (12)
spf_dns_null.c:94 Debug: DNS pre-cache found:
112.67.39.216.in-addr.arpa
PTR (12) TTL: 1800 RR found: 1 herrno: 0 source: resolv
spf_eval_id.c:551 Debug: found 1 PTR records for 216.39.67.112 (herrno:
0)
spf_dns_null.c:64 Debug: DNS pre-cache lookup:
dal1bs110.processrequest.
com A (1)
spf_dns_resolv.c:144 Debug: DNS resolv looking for:
dal1bs110.processrequest.
com A (1)
spf_dns_null.c:94 Debug: DNS pre-cache found: dal1bs110.processrequest.
com A (1) TTL: 30 RR found: 1 herrno: 0 source: resolv
spf_eval_id.c:569 Debug: 0: found 1 A records for dal1bs110.
processrequest.com (herrno: 0)
spf_eval_id.c:586 Debug: 0: 0: found 216.39.67.112
spf_eval_id.c:597 Debug: ProcessRequest.com ==
dal1bs110.processrequest.com
spf_eval_id.c:605 Debug: sRequest.com == srequest.com SPF header:
version: 1 mech 2/4 mod 0/0 len=8
SPF record: v=spf1 ptr -all
err = No errors (0)
err_msg =
fail
Please see
http://spf.pobox.com/why.html?sender=cwjobs-e2-27265112%40ProcessRequest.com&ip=
216.39.67.112&receiver=spfquery
spfquery: domain of ProcessRequest.com does not designate 216.39.67.112 as
permitted sender
Received-SPF: fail (spfquery: domain of ProcessRequest.com does not
designate
216.39.67.112 as permitted sender) client-ip=216.39.67.112; envelope-
from=cwjobs-e2-27265112(_at_)ProcessRequest(_dot_)com;
helo=DAL1BS110.PROCESSREQUEST.COM;
Maybe it's the case (ProcessRequest.com vs processrequest.com) that's
giving
problems here?? If that's not it, i see no reason why it should fail.
Ah yes, it definatelly is case related:
srs# spfquery -ip 216.39.67.112 -sender
cwjobs-e2-27265112(_at_)processrequest(_dot_)com
-helo DAL1BS110.processrequest.com pass
spfquery: domain of processrequest.com designates 216.39.67.112 as
permitted
sender
Received-SPF: pass (spfquery: domain of processrequest.com designates
216.39.67.112 as permitted sender) client-ip=216.39.67.112; envelope-
from=cwjobs-e2-27265112(_at_)processrequest(_dot_)com;
helo=DAL1BS110.processrequest.com;
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