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.
Reworked the command sending from two specific LIST and RETR command
functions into a single command based function as well as the two
associated response handlers into a generic command handler.
This feature allows the user to specify and use additional POP3
commands such as UIDL and DELE via libcurl's CURLOPT_CUSTOMREQUEST or
curl's -X command line option.
Simplified the code to remove the need for a separate "LIST <msg id>"
command handler and state machine and instead use the LIST command
handler for both operations.
Moved the server greeting response handling code from the statemach_act
functions to separate response functions. This makes the code simpler
to follow and provides consistency with the other responses that are
handled here.
Curl_protocol_connect() now does the tunneling through the HTTP proxy if
requested instead of letting each protocol specific connection function
do it.
Curl_pop3_write() would drop the final CRLF of a message as it was
considered part of the EOB as opposed to part of the message. Whilst
the EOB sequence needs to be searched for by the function only the
final 3 characters should be removed as per RFC-1939 section 3.
Reported by: Rich Gray
Bug: http://curl.haxx.se/mail/lib-2012-02/0051.html
Protocols (IMAP, POP3 and SMTP) that use the path part of a URL in a
decoded manner now use the new Curl_urldecode() function to reject URLs
with embedded control codes (anything that is or decodes to a byte value
less than 32).
URLs containing such codes could easily otherwise be used to do harm and
allow users to do unintended actions with otherwise innocent tools and
applications. Like for example using a URL like
pop3://pop3.example.com/1%0d%0aDELE%201 when the app wants a URL to get
a mail and instead this would delete one.
This flaw is considered a security vulnerability: CVE-2012-0036
Security advisory at: http://curl.haxx.se/docs/adv_20120124.html
Reported by: Dan Fandrich
Fixed a problem in POP3 and IMAP where a connection would fail when
CURLUSESSL_TRY was specified for a server that didn't support
SSL/TLS connections rather than continuing.
The STARTTLS response code in SMTP, POP3 and IMAP would return
CURLE_LOGIN_DENIED rather than CURLE_USE_SSL_FAILED when SSL/TLS
was not available on the server.
Reported by: Gokhan Sengun
Bug: http://curl.haxx.se/mail/lib-2012-01/0018.html
Changed the eob detection to work across the whole of the buffer so that
lines that begin with a dot (which the server will have escaped) are
passed to the client application correctly.
Curl_pop3_write() now has a state machine that scans for the end of a
POP3 body so that the CR LF '.' CR LF sequence can come in everything
from one up to five subsequent packets.
Test case 810 is modified to use SLOWDOWN which makes the server pause
between each single byte and thus makes the POP3 body get sent to curl
basically one byte at a time.
By setting PROTOPT_NOURLQUERY in the protocol handler struct, the
protocol will get the "query part" of the URL cut off before the data is
handled by the protocol-specific code. This makes libcurl adhere to
RFC3986 section 2.2.
Test 1220 is added to verify a file:// URL with query-part.
Now called 'use_ssl' instead, which better matches the current CURLOPT
name and since the option is used for all pingpong protocols (at least)
it makes sense to not use 'ftp' in the name.
After a PORT has been issued, and the multi handle would switch to the
CURLM_STATE_DO_MORE state (which is unique for FTP), libcurl would
return the wrong fdset to wait for when curl_multi_fdset() is
called. The code would blindly assume that it was waiting for a connect
of the second connection, while that isn't true immediately after the
PORT command.
Also, the function multi.c:domore_getsock() was highly FTP-centric and
therefore ugly to keep in protocol-agnostic code. I solved this problem
by introducing a new function pointer in the Curl_handler struct called
domore_getsock() which is only called during the DOMORE state for
protocols that set that pointer.
The new ftp.c:ftp_domore_getsock() function now returns fdset info about
the control connection's command/response handling while such a state is
in use, and goes over to waiting for a writable second connection first
once the commands are done.
The original problem could be seen by running test 525 and checking the
time stamps in the FTP server log. I can verify that this fix at least
fixes this problem.
Bug: http://curl.haxx.se/mail/lib-2011-10/0250.html
Reported by: Gokhan Sengun
As I modified conn->bits.tcpconnect to become an array that holds one
bool for each potential connection all uses of that struct field must
index it correctly.
The new http_proxy.* files now host HTTP proxy specific code (500+ lines
moved out from http.c), and as a consequence there is a macro introduced
for the Curl_proxyCONNECT() function so that code can use it without
actually supporting proxy (or HTTP) in builds.
The PROT_* set of internal defines for the protocols is no longer
used. We now use the same bits internally as we have defined in the
public header using the CURLPROTO_ prefix. This is for simplicity and
because the PROT_* prefix was already used duplicated internally for a
set of KRB4 values.
The PROTOPT_* defines were moved up to just below the struct definition
within which they are used.
The protocol handler struct got a 'flags' field for special information
and characteristics of the given protocol.
This now enables us to move away central protocol information such as
CLOSEACTION and DUALCHANNEL from single defines in a central place, out
to each protocol's definition. It also made us stop abusing the protocol
field for other info than the protocol, and we could start cleaning up
other protocol-specific things by adding flags bits to set in the
handler struct.
The "protocol" field connectdata struct was removed as well and the code
now refers directly to the conn->handler->protocol field instead. To
make things work properly, the code now always store a conn->given
pointer that points out the original handler struct so that the code can
learn details from the original protocol even if conn->handler is
modified along the way - for example when switching to go over a HTTP
proxy.
It helps to prevent a hangup with some FTP servers in case idle session
timeout has exceeded. But it may be useful also for other protocols
that send any quit message on disconnect. Currently used by FTP, POP3,
IMAP and SMTP.
If you pass a URL to pop3 that does not contain a message ID as
part of the URL, it will currently ask for 'INBOX' which just
causes the pop3 server to return an error.
The change makes libcurl treat en empty message ID as a request
for LIST (list of pop3 message IDs). User's code could then
parse this and download individual messages as desired.
