Commit 496002ea1c (released in 7.20.1) broke FTPS when using the
multi interface and OpenSSL was used. The condition for the non-blocking
connect was incorrect.
Reported by: Georg Lippitsch
Bug: http://curl.haxx.se/mail/lib-2010-07/0270.html
Was seeing spurious SSL connection aborts using libcurl and
OpenSSL. I tracked it down to uncleared error state on the
OpenSSL error stack - patch attached deals with that.
Rough idea of problem:
Code that uses libcurl calls some library that uses OpenSSL but
don't clear the OpenSSL error stack after an error.
ssluse.c calls SSL_read which eventually gets an EWOULDBLOCK from
the OS. Returns -1 to indicate an error
ssluse.c calls SSL_get_error. First thing, SSL_get_error calls
ERR_get_error to check the OpenSSL error stack, finds an old
error and returns SSL_ERROR_SSL instead of SSL_ERROR_WANT_READ or
SSL_ERROR_WANT_WRITE.
ssluse.c returns an error and aborts the connection
Solution:
Clear the openssl error stack before calling SSL_* operation if
we're going to call SSL_get_error afterwards.
Notes:
This is much more likely to happen with multi because it's easier
to intersperse other calls to the OpenSSL library in the same
thread.
John-Mark Bell filed bug #3000052 that identified a problem (with
an associated patch) with the OpenSSL handshake state machine
when the multi interface is used:
Performing an https request using a curl multi handle and using
select or epoll to wait for events results in a hang. It appears
that the cause is the fix for bug #2958179, which makes
ossl_connect_common unconditionally return from the step 2 loop
when fetching from a multi handle.
When ossl_connect_step2 has completed, it updates
connssl->connecting_state to ssl_connect_3. ossl_connect_common
will then return to the caller, as a multi handle is in
use. Eventually, the client code will call curl_multi_fdset to
obtain an updated fdset to select or epoll on. For https
requests, curl_multi_fdset will cause https_getsock to be called.
https_getsock will only return a socket handle if the
connecting_state is ssl_connect_2_reading or
ssl_connect_2_writing. Therefore, the client will never obtain a
valid fdset, and thus not drive the multi handle, resulting in a
hang.
(http://curl.haxx.se/bug/view.cgi?id=3000052)
FTP(S) use two connections that can be set to different recv and
send functions independently, so by introducing recv+send pairs
in the same manner we already have sockets/connections we can
work with FTPS fine.
This commit fixes the FTPS regression introduced in change d64bd82.
Howard Chu brought the bulk work of this patch that properly
moves out the sending and recving of data to the parts of the
code that are properly responsible for the various ways of doing
so.
Daniel Stenberg assisted with polishing a few bits and fixed some
minor flaws in the original patch.
Another upside of this patch is that we now abuse CURLcodes less
with the "magic" -1 return codes and instead use CURLE_AGAIN more
consistently.
ossl_connect_step3() increments an SSL session handle reference counter on
each call. When sessions are re-used this reference counter may be
incremented many times, but it will be decremented only once when done (by
Curl_ossl_session_free()); and the internal OpenSSL data will not be freed
if this reference count remains positive. When a session is re-used the
reference counter should be corrected by explicitly calling
SSL_SESSION_free() after each consecutive SSL_get1_session() to avoid
introducing a memory leak.
(http://curl.haxx.se/bug/view.cgi?id=2926284)
the client certificate. It also disable the key name test as some engines
can select a private key/cert automatically (When there is only one key
and/or certificate on the hardware device used by the engine)
(http://curl.haxx.se/bug/view.cgi?id=2861587) identifying that libcurl used
the OpenSSL function X509_load_crl_file() wrongly and failed if it would
load a CRL file with more than one certificate within. This is now fixed.
powered libcurl in 7.19.6. If there was a X509v3 Subject Alternative Name
field in the certficate it had to match and so even if non-DNS and non-IP
entry was present it caused the verification to fail.
each test, so that the test suite can now be used to actually test the
verification of cert names etc. This made an error show up in the OpenSSL-
specific code where it would attempt to match the CN field even if a
subjectAltName exists that doesn't match. This is now fixed and verified
in test 311.
and the name length differ in those cases and thus leave the matching function
unmodified from before, as the matching functions never have to bother with
the zero bytes in legitimate cases. Peter Sylvester helped me realize that
this fix is slightly better as it leaves more code unmodified and makes the
detection a bit more obvious in the code.
should introduce an option to disable SNI, but as we're in feature freeze
now I've addressed the obvious bug here (pointed out by Peter Sylvester): we
shouldn't try to enable SNI when SSLv2 or SSLv3 is explicitly selected.
Code for OpenSSL and GnuTLS was fixed. NSS doesn't seem to have a particular
option for SNI, or are we simply not using it?
(http://curl.haxx.se/bug/view.cgi?id=2829955) mentioning the recent SSL cert
verification flaw found and exploited by Moxie Marlinspike. The presentation
he did at Black Hat is available here:
https://www.blackhat.com/html/bh-usa-09/bh-usa-09-archives.html#Marlinspike
Apparently at least one CA allowed a subjectAltName or CN that contain a
zero byte, and thus clients that assumed they would never have zero bytes
were exploited to OK a certificate that didn't actually match the site. Like
if the name in the cert was "example.com\0theatualsite.com", libcurl would
happily verify that cert for example.com.
libcurl now better use the length of the extracted name, not assuming it is
zero terminated.
only in some OpenSSL installs - like on Windows) isn't thread-safe and we
agreed that moving it to the global_init() function is a decent way to deal
with this situation.
"you replaced the old SSLeay_add_ssl_algorithms() call
with OpenSSL_add_all_algorithms(), however unlike the name suggests,
the second function is not a superset of the first. When using SSL
both these functions will need to be called in order to offer complete
functionality"
out that OpenSSL-powered libcurl didn't support the SHA-2 digest algorithm,
and provided the solution too: to use OpenSSL_add_all_algorithms() instead
of the older SSLeay_* alternative. OpenSSL_add_all_algorithms was added in
OpenSSL 0.9.5
don't know how they got wrong in the first place, but using this output
format makes it possible to quite easily separate the string into an array
of multiple items.
(http://curl.haxx.se/bug/view.cgi?id=2786255) with a patch, identifying how
libcurl did not deal with SSL session ids properly if the server rejected a
re-use of one. Starting now, it will forget the rejected one and remember
the new. This change was for OpenSSL only, it is likely that other SSL lib
code needs similar fixes.
disable "rfc4507bis session ticket support". rfc4507bis was later turned
into the proper RFC5077 it seems: http://tools.ietf.org/html/rfc5077
The enabled extension concerns the session management. I wonder how often
libcurl stops a connection and then resumes a TLS session. also, sending the
session data is some overhead. .I suggest that you just use your proposed
patch (which explicitly disables TICKET).
If someone writes an application with libcurl and openssl who wants to
enable the feature, one can do this in the SSL callback.
Sharad Gupta brought this to my attention. Peter Sylvester helped me decide
on the proper action.
clarity. This does fix one problem that causes ;type=i FTP URLs
to fail in the Turkish locale when CURLOPT_PROXY_TRANSFER_MODE is
used (test case 561)
Added tests 561 and 1092 through 1094 to test various combinations
of ;type= and ;mode= URLs that could potentially fail in the Turkish
locale.
(http://curl.haxx.se/bug/view.cgi?id=2154627) which pointed out that libcurl
uses strcasecmp() in multiple places where it causes failures when the
Turkish locale is used. This is because 'i' and 'I' isn't the same letter so
strcasecmp() on those letters are different in Turkish than in English (or
just about all other languages). I thus introduced a totally new internal
function in libcurl (called Curl_ascii_equal) for doing case insentive
comparisons for english-(ascii?) style strings that thus will make "file"
and "FILE" match even if the Turkish locale is selected.
2008-09-24 stable snapshot have a buf_mem_st.length structure member with
'int' data type.
OpenSSL un-released 0.9.9 CVS version has a buf_mem_st.length structure member
with 'size_t' data type since 2007-Oct-09.
These 4 typecasts should silence compiler warnings in all cases.
enabling this feature with CURLOPT_CERTINFO for a request using SSL (HTTPS
or FTPS), libcurl will gather lots of server certificate info and that info
can then get extracted by a client after the request has completed with
curl_easy_getinfo()'s CURLINFO_CERTINFO option. Linus Nielsen Feltzing
helped me test and smoothen out this feature.
Unfortunately, this feature currently only works with libcurl built to use
OpenSSL.
This feature was sponsored by networking4all.com - thanks!
true bug in libcurl built with OpenSSL. It made curl_easy_getinfo() more or
less always return 0 for CURLINFO_SSL_VERIFYRESULT because the function that
would set it to something non-zero would return before the assign in almost
all error cases. The internal variable is now set to non-zero from the start
of the function only to get cleared later on if things work out fine.
libraries are supported. Starting now, each underlying SSL library support
code does a set of defines for the 16 functions the generic layer (sslgen.c)
uses (all these new function defines use the prefix "curlssl_"). This
greatly simplified the generic layer in readability by involving much less
#ifdefs and other preprocessor stuff and should make it easier for people to
make libcurl work with new SSL libraries.
Hopefully I can later on document these 16 functions somewhat as well.
I also made most of the internal SSL-dependent functions (using Curl_ssl_
prefix) #defined to nothing when no SSL support is requested - previously
they would unnecessarily call mostly empty functions.
better control at the exact state of the connection's SSL status so that we
know exactly when it has completed the SSL negotiation or not so that there
won't be accidental re-uses of connections that are wrongly believed to be
in SSL-completed-negotiate state.
CURLE_PEER_FAILED_VERIFICATION (standard CURL_NO_OLDIES style), and made this
return code get used by the previous SSH MD5 fingerprint check in case it
fails.
and allow reuse by multiple protocols. Several unused error codes were
removed. In all cases, macros were added to preserve source (and binary)
compatibility with the old names. These macros are subject to removal at
a future date, but probably not before 2009. An application can be
tested to see if it is using any obsolete code by compiling it with the
CURL_NO_OLDIES macro defined.
Documented some newer error codes in libcurl-error(3)
passed to it with curl_easy_setopt()! Previously it has always just refered
to the data, forcing the user to keep the data around until libcurl is done
with it. That is now history and libcurl will instead clone the given
strings and keep private copies.
fail to connect if there is no Common Name field found in the remote cert.
We should deprecate the support for this set to 1 anyway soon, since the
feature is pointless and most likely never really used by anyone.
peer's name in the SSL certificate when built for OpenSSL. The leak happens
for libcurls with CURL_DOES_CONVERSIONS enabled that fail to convert the CN
name from UTF8.
and CURLOPT_CONNECTTIMEOUT_MS that, as their names should hint, do the
timeouts with millisecond resolution instead. The only restriction to that
is the alarm() (sometimes) used to abort name resolves as that uses full
seconds. I fixed the FTP response timeout part of the patch.
Internally we now count and keep the timeouts in milliseconds but it also
means we multiply set timeouts with 1000. The effect of this is that no
timeout can be set to more than 2^31 milliseconds (on 32 bit systems), which
equals 24.86 days. We probably couldn't before either since the code did
*1000 on the timeout values on several places already.
