Added SASL CANCELLATION keywords to differentiate these tests from the
upcoming SASL downgrade tests.

The comment in the code mentions the zero terminating after having
copied data, but it mistakingly zero terminated the source data and not
the destination! This caused the test 864 problem discussed on the list:

http://curl.haxx.se/mail/lib-2013-12/0113.html


Signed-off-by: Daniel Stenberg <daniel@haxx.se>

This reverts commit 727d798d.

Although highlighted by a bug in commit 1cfb436a, APOP
authentication could be chosen if the server was to reply with an empty
or missing timestamp in the server greeting and APOP was given in the
capability list by the server.

Added a loop to pop3_statemach_act() in which Curl_pp_readresp() is
called until the cache is drained. Without this multiple responses
received in a single packet could result in a hang or delay.

Similar to the processing of untagged CAPABILITY responses in IMAP and
multi-line EHLO responses in SMTP, moved the processing of multi-line
CAPA responses to pop3_state_capa_resp().

In an effort to reduce what pop3_endofresp() does and bring the POP3
source back inline with the IMAP and SMTP protocols, moved the APOP
detection into pop3_state_servergreet_resp().

Bug: http://curl.haxx.se/bug/view.cgi?id=1313
Reported-by: Viktor Szakáts

... it could be misleading a reader into thinking it _has_ to be encoded.

Added support for downgrading the SASL authentication mechanism when the
decoding of CRAM-MD5, DIGEST-MD5 and NTLM messages fails. This enhances
the previously added support for graceful cancellation by allowing the
client to retry a lesser SASL mechanism such as LOGIN or PLAIN, or even
APOP / clear text (in the case of POP3 and IMAP) when supported by the
server.

smtp.c:478:21: error: unused variable 'smtpc' [-Werror=unused-variable]

In preparation for the upcoming SASL downgrade feature renamed the
imap__perform_authenticate(), pop3__perform_authenticate() and
smtp__perform_authenticate() functions.

... for the pending 7.34.0 release

Upped the contributor count

24 new great friends

Security flaw CVE-2013-6422

This is conceptually the same problem and fix that 3c3622b6 brought to the
OpenSSL backend and that resulted in CVE-2013-4545.

This version of the problem was independently introduced to the GnuTLS
backend with commit 59cf93cc, present in the code since the libcurl
7.21.4 release.

Advisory: http://curl.haxx.se/docs/adv_20131217.html
Bug: http://curl.haxx.se/mail/lib-2013-11/0214.html
Reported-by: Marc Deslauriers

...also added as KNOWN_BUG #87 with reference to bug #1294