On Mon, 9 Sep 2013, Viktor Dukhovni wrote:
On Mon, Sep 09, 2013 at 10:52:26AM -0400, Paul Wouters wrote:
Mail servers and mail clients do not treat email addresses as
case-insensitive. When encoding an LHS with base32, the case matters.
Using the wrong case will cause you to not find the SMIMEA / OPENPGPKEY
record.
This is not accurate. While domain part of an email address is
case-insensitive, the case-sensitivity of the local-part is a
local matter. SMTP relays MUST NOT change the case of the local
part of envelope addresses. On arrival at the destination domain,
that domain's mail system may choose to treat local-parts case
insensitively, but remote systems must not rely on this.
Therefore, <[email protected]> and <[email protected]> are a-priori
distinct addresses except perhaps in the hands of the MTAs that
handle example.com mail.
[ The fact that most systems are in practice case-insensitive is not
sufficient to invalidate the right of some to be case sensitive as
they see fit. ]
The _last_ thing I want to do is having an email client not encrypt a
message because someone mailed [email protected] instead of
[email protected].
So I think our choices are:
1) do a lookup for the case "as is" and a lookup for lowercased (serial
or parallel)
2) lowercase and lookup once.
What I do _not_ think is a valid choice is "only do the as is case
lookup".
Paul
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