use own implementation of HTTPSConnection (myHTTPSConnection)
instead the one provided by M2Crypto (httpslib.HTTPConnection)
And in proxy case use myProxyHTTPSConnection.
all credits go to wfrisch
The old code could potentially yield to a use-after-free situation,
which results in UB. For this, consider the following scenario, where
osc performs several HTTPS requests (assumption: the server supports
ssl session resumption):
- HTTPS Request 1:
* a new SSL *s connection is established, which also creates a new
SSL_SESSION *ss => ss->references == 1
* once the handshake is done, the ss is put into the session cache
(see ssl_update_cache) => ss->references == 2
- osc saves the session ss in a class variable
- s is SSL_free()d, which calls SSL_SESSION_free => ss->references == 1
- HTTPS Request 2:
* setup a new SSL *s connection that reuses the saved session ss
=> ss->references == 2
* once the handshake is done, ssl_update_cache is called, which is a
NOP, because s->hit == 1 (that is, the session was resumed)
* osc saves the session ss in a class variable
* s is SSL_free()d, which calls SSL_SESSION_free => ss->references == 1
...
> 2 hours later (see tls1_default_timeout)
...
- HTTPS Request 256:
* setup a new SSL *s connection that reuses the saved session ss
=> ss->references == 2
* once the handshake is done, ssl_update_cache is called, but is
_no_ NOP anymore
* ssl_update_cache flushes the session cache (this is done every
255/256 (depending on the way we count) connections) => ss is
SSL_SESSION_free()d => ss->references == 1
* osc saves the session ss in a class variable
* s is SSL_free()d, which calls SSL_SESSION_free:
since ss->references == 1, ss is eventually free()d
- HTTPS Request 257:
* setup a new SSL *s connection that reuses the saved session ss
Since ss does not exist anymore, the remaining program execution is UB.
(Note: SSL_free(...) is _NOT_ called, if M2Crypto 0.29 is used.
M2Crypto 0.30 calls SSL_free(...) again.)
Due to a bug in OpenSSL_1_1_0h (see openssl commit 8e405776858) the
scenario from above can be triggered with exactly 2 HTTPS requests (the
SSL_SESSION is not cached, because we configured SSL_VERIFY_PEER, but
no sid_ctx was set). This is fixed in openssl commit c4fa1f7fc01.
In order to reliably reuse a session, we probably need to listen to the
session cache changes. Such callbacks could be registered via
SSL_CTX_sess_set_new_cb and/or SSL_CTX_sess_set_remove_cb, but both
functions are not provided by M2Crypto. Another idea is to directly utilize
the session cache, but this also has to be implemented in M2Crypto first.
Yet another approach is to retrieve the session via SSL_get1_session, which
increases the session's refcnt, but this also needs to be implemented in
M2Crypto first (if we choose to use this approach, we also have to make
sure that we eventually free the session manually...).
Fixes: #398 ("SIGSEGV on \"osc commit\"")
Do not pass a family parameter to SSL.Connection's constructor if it
does not support it. If the family parameter is not supported, we
_try_ to fallback to socket.AF_INET, which is implicitly used by
older versions of the SSL.Connection class.
Fixes: #274 ("osc 0.157 Exception AttributeError: "Connection
instance has no attribute 'ssl_close_flag'"")
Currently osc can't access API URLs which share the same IP address
with other SSL-enabled sites, complaining about certificate
not matching hostname.
This change solves this problem by instructing M2Crypto.SSL.Connection
to send the desired hostname to https server using TLS SNI extension,
thus allowing the server to present the right certificate and choose
the right virtual site.
This is useful for those who can't afford to have a separate IP address
for OBS API.
For TLS SNI to work correctly, M2Crypto should be patched:
https://bugzilla.osafoundation.org/show_bug.cgi?id=13073
Some distributions (like Fedora) already include this patch.
For unpatched M2Crypto osc degrades to operation without TLS SNI.
Signed-off-by: Oleg Girko <ol@infoserver.lv>
If http_debug is set we redirect sys.stdout to an StringIO
instance in order to do some header filtering (see conf module)
so we have to use the "original" stdout for printing the certificate
information.
raw_input has been removed and equals to input in py3. Unfortunatelly no
__future__ statement exists for that. Ensure all modules uses
osc.core.raw_input except osc.cmdln, where there is NameError way
implemented.
The most visible change in python3 - removal of print statement and all
the crufty
print >> sys.stderr, foo,
The from __future__ import print_function makes it available in python
2.6
Some modules (httplib, StringIO, ...) were renamed in python3. This
patch try to import the proper symbols from python3 and then fallback to
python2 in a case ImportError will appear.
There is one exception, python 2.7 got the io module with StringIO, but
it allow unicode arguments only. Therefor the old module is poked before
new one.
This patch workarounds the BEAST attack in the client side
making OSC to prefer TLS v1.1 or v1.2 ciphers/key exchanges
when available.
Now, as long as openSUSE API webservers do not support
these protocols it will prefer the RC4-SHA1 combination to
be in the safe side.
Now "myProxyHTTPSConnection" inherits from "M2Crypto.httpslib.ProxyHTTPSConnection" _and_ "httplib.HTTPSConnection".
The latter class is only used to call "httplib.HTTPSConnection.endheaders". This multiple inheritance shouldn't have any side-effects
because "M2Crypto.httpslib.ProxyHTTPSConnection" already inherits from "httplib.HTTPSConnection" (and mro will pick the methods from
"M2Crypto.httpslib.ProxyHTTPSConnection" first).
