Not all SASL enabled POP3 servers support the AUTH command on its own
when trying to detect the supported mechanisms. As such changed the
mechanism detection to use the CAPA command instead.
- For all *FUNCTION options, they now all show the complete prototype in
the description. Previously some of them would just refer to a
typedef'ed function pointer in the curl.h header.
- I made the phrasing of that "Pass a pointer to a function that matches
the following prototype" the same for all *FUNCTION option descriptions.
- I removed some uses of 'should'. I think I sometimes over-use this
word as in many places I actually mean MUST or otherwise more specific
and not-so-optional synonyms.
Because pop3_endofresp() is called for each line of data yet is not
passed the line and line length, so we have to use the data pointed to
by pp->linestart_resp which contains the whole packet, the mechanisms
were being detected in one call yet the function would be called for
each line of data.
Using curl with verbose mode enabled would show that one line of data
would be received in response to the AUTH command, before the AUTH
<mechanism> command was sent to the server and then the next few lines
of the original AUTH command would be displayed before the response from
the AUTH <mechanism> command. This would then cause problems when
parsing the CRAM-MD5 challenge data as extra data was contained in the
buffer.
Changed the parsing so that each line is checked for the mechanisms
and the function returns FALSE until the whole of the AUTH response has
been processed.
Added new sections 11. IMAP and 12. LDAP to document adding SASL based
authentication.
Renumbered current sections 11 to 17 as 13 to 19.
Additionally added 19.10 Add CURLOPT_MAIL_CLIENT option.
Previously it wasn't possible to connect to POP3 and not specify the
user name as a CURLE_ACCESS_DENIED error would be returned. This error
occurred because USER would be sent to the server with a blank user name
if no mailbox user was specified as the server would reply with -ERR.
This wasn't a problem prior to the 7.26.0 release but with the
introduction of custom commands the user and/or application developer
might want to issue a CAPA command without having to log in as a
specific mailbox user.
Additionally this fix won't send the newly introduced AUTH command if no
user name is specified.
This is done introducing tags <file1> to <file4> besides existing <file> one,
as well as corresponding <stripfile1> to <stripfile4> ones, that can be used
in the <verify> section in the same way as the non-numbered ones.
Rather than encoding the password message itself the
smtp_state_authpasswd_resp() function now delegates the work to the same
function that smtp_state_authlogin_resp() and smtp_authenticate() use
when constructing the encoded user name.
In preparation for moving to the SASL module re-factored the
smtp_auth_login_user() function to smtp_auth_login() so that it can be
used for both user names and passwords as sending both of these under
the login authentication mechanism is the same.
Introduce SUPPORTCAPA and SUPPORTAUTH config commands to allow further
pop3 test server expansion for tests that require CAPA or AUTH support,
although this will need some extra work to make it fully functional.
The POP3 protocol doesn't really have the concept of error codes and
uses +, +OK and -ERR in response to commands to indicate continue,
success and error.
The AUTH command is one of those commands that requires multiple pieces
of data to be sent to the server where the server will respond with + as
part of the handshaking. This meant changing the values before
continuing with the next stage of adding authentication support.
Changed the order of the state machine to match the order of actual
events.
Reworked some comments and function parameter positioning that I missed
the other day.
Added support for detecting the supported SASL authentication mechanisms
via the AUTH command. There are two ways of detecting them, either by
using the AUTH command, that will return -ERR if not supported or by
using the CAPA command which will return SASL and the list of mechanisms
if supported, not include SASL if SASL authentication is not supported
or -ERR if the CAPA command is not supported. As such it seems simpler
to use the AUTH command and fallback to normal clear text authentication
if the the command is not supported.
Additionally updated the test cases to return -ERR when the AUTH command
is encountered. Additional test cases will be added when support for the
individual authentication mechanisms is added.
Moved EOB definition into header file.
Switched the logic around in pop3_endofresp() to allow for the
introduction of auth-mechanism detection.
Repositioned second and third function variables where they will fit
within the 78 character line limit.
Tidied up some comments.
