ikiwiki/doc/plugins/openid/troubleshooting.mdwn

**TL;DR**

[[!toc levels=3]]

# An odyssey through lots of things that have to be right before OpenID works

Having just (at last) made an ikiwiki installation accept my
OpenID, I have learned many of the things that may have to be checked
when getting the [[plugins/openid]] plugin to work. (These are probably
the reasons why [ikiwiki.info](/) itself won't accept my OpenID!)

Just to describe my OpenID setup a bit (and why it makes a good stress-test
for the OpenID plugin :).

I'm using my personal home page URL as my OpenID. My page lives at
a shared-hosting service I have hired. It contains links that delegate
my OpenID processing to [indieauth.com](https://indieauth.com).

IndieAuth, in turn, uses
[rel-me authentication](http://microformats.org/wiki/RelMeAuth) to find
an [OAuth](http://microformats.org/wiki/OAuth) provider that can authenticate
me. (At present, I am using [github](http://github.com) for that, which
is an OAuth provider but not an OpenID provider, so the gatewaying provided
by IndieAuth solves that problem.) As far as ikiwiki is concerned,
IndieAuth is my OpenID provider; the details beyond that are transparent.

So, what were the various issues I had to sort out before my first successful
login with the [[plugins/openid]] plugin?

## no_identity_server: Could not determine ID provider from URL.

This is the message [ikiwiki.info](/) shows as soon as I enter my home URL
as an OpenID. It is also the first one I got on my own ikiwiki installation.

### various possible causes ...

There could be lots of causes. Maybe:

* the offered OpenID is an `https:` URL and there is an issue in checking
    the certificate, so the page can't be retrieved?
* the page can be retrieved, but it isn't well-formed HTML and the library
    can't parse it for the needed OpenID links?
* ...?

### make a luckier setting of useragent ?!

In my case, it was none of the above. It turns out my shared-hosting provider
has a rule that refuses requests with `User-Agent: libwww-perl/6.03` (!!).
This is the sort of problem that's really hard to anticipate or plan around.
I could fix it (_for this case!_) by changing `useragent:` in `ikiwiki.setup`
to a different string that my goofy provider lets through.

__Recommendation:__ set `useragent:` in `ikiwiki.setup` to some
unlikely-to-be-blacklisted value. I can't guess what the best
unlikely-to-be-blacklisted value is; if there is one, it's probably the
next one all the rude bots will be using anyway, and some goofy provider
like mine will blacklist it.

## Error: OpenID failure: naive_verify_failed_network: Could not contact ID provider to verify response.

Again, this could have various causes. It was helpful to bump the debug level
and get some logging, to see:

    500 Can't connect to indieauth.com:443 (Net::SSL from Crypt-SSLeay can't
    verify hostnames; either install IO::Socket::SSL or turn off verification
    by setting the PERL_LWP_SSL_VERIFY_HOSTNAME environment variable to 0)

I don't belong to the camp that solves every verification problem by turning
verification off, so this meant finding out how to get verification to be done.
It turns out there are two different Perl modules that can be used for SSL:

* `IO::Socket::SSL` (verifies hostnames)
* `Net::SSL` (_does not_ verify hostnames)

Both were installed on my hosted server. How was Perl deciding which one
to use?

### set `PERL_NET_HTTPS_SSL_SOCKET_CLASS` appropriately

It turns out
[there's an environment variable](https://rt.cpan.org/Public/Bug/Display.html?id=71599).
So just set `PERL_NET_HTTPS_SSL_SOCKET_CLASS` to `IO::Socket::SSL` and the
right module gets used, right?

[Wrong](https://github.com/csirtgadgets/LWPx-ParanoidAgent/commit/fed6f7d7df8619df0754e8883cfad2ac15703a38#diff-2).
That change was made to `ParanoidAgent.pm` back in November 2013 because of an
unrelated [bug](https://github.com/csirtgadgets/LWPx-ParanoidAgent/issues/4)
in `IO::Socket::SSL`. Essentially, _hmm, something goes wrong in
`IO::Socket::SSL` when reading certain large documents, so we'll fix it by
forcing the use of `Net::SSL` instead (the one that never verifies hostnames!),
no matter what the admin has set `PERL_NET_HTTPS_SSL_SOCKET_CLASS` to!_

### undo change that broke `PERL_NET_HTTPS_SSL_SOCKET_CLASS`

Plenty of [comments](https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=738493)
quickly appeared about how good an idea that wasn't, and it was corrected in
June 2014 with [one commit](https://github.com/csirtgadgets/LWPx-ParanoidAgent/commit/a92ed8f45834a6167ff62d3e7330bb066b307a35)
to fix the original reading-long-documents issue in `IO::Socket::SSL` and
[another commit](https://github.com/csirtgadgets/LWPx-ParanoidAgent/commit/815c691ad5554a219769a90ca5f4001ae22a4019)
that reverts the forcing of `Net::SSL` no matter how the environment is set.

Unfortunately, there isn't a release in CPAN yet that includes those two
commits, but they are only a few lines to edit into your own locally-installed
module.

## Still naive_verify_failed_network, new improved reason

    500 Can't connect to indieauth.com:443 (SSL connect attempt failed
    with unknown error error:14090086:SSL
    routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed)

Yay, at least it's trying to verify! Now why can't it verify IndieAuth's
certificate?

[Here's why](https://tools.ietf.org/html/rfc6066#section-3). As it turns out,
[indieauth.com](https://indieauth.com/) is itself a virtual host on a shared
server. If you naively try

    openssl s_client -connect indieauth.com:443

you get back a certificate for [indieweb.org](https://indieweb.org/)
instead, so the hostname won't verify. If you explicitly indicate what server
name you're connecting to:

    openssl s_client -connect indieauth.com:443 -servername indieauth.com

then, magically, the correct certificate comes back.

### ensure `OpenSSL`, `Net::SSLeay`, `IO::Socket::SSL` new enough for SNI

If your `openssl` doesn't recognize the `-servername` option, it is too old
to do SNI, and a newer version needs to be built and installed. In fact,
even though SNI support was reportedly backported into OpenSSL 0.9.8f, it will
not be used by `IO::Socket::SSL` unless it is
[1.0 or higher](http://search.cpan.org/~sullr/IO-Socket-SSL-1.998/lib/IO/Socket/SSL.pod#SNI_Support).

Then a recent `Net::SSLeay` perl module needs to be built and linked against it.

### Local OpenSSL installation will need certs to trust

Bear in mind that the OpenSSL distribution doesn't come with a collection
of trusted issuer certs. If a newer version is built and installed locally
(say, on a shared server where the system locations can't be written), it will
need to be given a directory of trusted issuer certs, say by linking to the
system-provided ones. However, a change to the certificate hash algorithm used
for the symlinks in that directory was [reportedly](http://www.cilogon.org/openssl1)
made with OpenSSL 1.0.0. So if the system-provided trusted certificate directory
was set up for an earlier OpenSSL version, all the certificates in it will be
fine but the hash symlinks will be wrong. That can be fixed by linking only the
named certificate files from the system directory into the newly-installed one,
and then running the new version of `c_rehash` there.

## Still certificate verify failed

Using [SNI](https://tools.ietf.org/html/rfc6066#section-3)-supporting versions
of `IO::Socket::SSL`, `Net::SSLeay`, and `OpenSSL` doesn't do any good if an
upper layer hasn't passed down the name of the host being connected to so the
SSL layer can SNI for it.

### ensure that `LWPx::ParanoidAgent` passes server name to SSL layer for SNI

That was fixed in `LWPx::ParanoidAgent` with
[this commit](https://github.com/csirtgadgets/LWPx-ParanoidAgent/commit/df6df19ccdeeb717c709cccb011af35d3713f546),
which needs to be backported by hand if it hasn't made it into a CPAN release
yet.

Only that still doesn't end the story, because that hand didn't know what
[this hand](https://github.com/noxxi/p5-io-socket-ssl/commit/4f83a3cd85458bd2141f0a9f22f787174d51d587#diff-1)
was doing. What good is passing the name in
`PeerHost` if the SSL code looks in `PeerAddr` first ... and then, if that
doesn't match a regex for a hostname, decides you didn't supply one at all,
without even looking at `PeerHost`?

Happily, is is possible to assign a key that _explicitly_ supplies the
server name for SNI:

    --- LWPx/Protocol/http_paranoid.pm    2014-09-08 03:33:00.000000000 -0400
    +++ LWPx/Protocol/http_paranoid.pm    2014-09-08 03:33:27.000000000 -0400
    @@ -73,6 +73,7 @@
            close($el);
             $sock = $self->socket_class->new(PeerAddr => $addr,
                                              PeerHost => $host,
    +                                         SSL_hostname => $host,
                                              PeerPort => $port,
                                              Proto    => 'tcp',
                                              Timeout  => $conn_timeout,

... not submitted upstream yet, so needs to be applied by hand.

# Success!!

And with that, ladies and gents, I got my first successful OpenID login!
I'm pretty sure that if the same fixes can be applied to
[ikiwiki.info](/) itself, a wider range of OpenID logins (like mine, for
example :) will work here too.

-- Chap