While investigating #317, I noticed that it was possible we would access
an uninitialized buffer due to failing to check the return value of
net_ip2host(). This is done in several places. To make such uses safe,
set the host buffer to an empty string on error. It is possible callers
could be improved by handling the error in each spot, but this gives us
some safety.
This splits sign parsing out of parse_time_interval_uint() so that the
negative sign is applied outside of the unsigned context where the
number parsing is done, and after all the checks that it's lower than
(1 << 31)
This fixes issues with settings like `server_reconnect_time`,
`server_connect_timeout` and `lag_max_before_disconnect`, which accepted
-1 as a valid value.
Originally found by oss-fuzz (issue 525) in get_ansi_color using ubsan.
After a lot of analysis I'm 99% sure this isn't security relevant so
it's fine to handle this publicly.
The fix is mainly adding a function that does it right and use it
everywhere. This is harder than it seems because the strtol() family of
functions doesn't have the friendliest of interfaces.
Aside from get_ansi_color(), there were other pieces of code that used
the same (out*10+(*in-'0')) pattern, like the parse_size() and
parse_time_interval() functions, which are mostly used for settings.
Those are interesting cases, since they multiply the parsed number
(resulting in more overflows) and they write to a signed integer
parameter (which can accidentally make the uints negative without UB)
Thanks to Pascal Cuoq for enlightening me about the undefined behavior
of parse_size (and, in particular, the implementation-defined behavior
of one of the WIP versions of this commit, where something like signed
integer overflow happened, but it was legal). Also for writing
tis-interpreter, which is better than ubsan to verify these things.
Original patch by 'Slarky'
According to that ticket, the next major version of solaris won't need
this. Consider reverting this when solaris 11.3 stops being relevant.
It was made redundant by the introduction of the pointer to the GRegex
structure.
Silence the compiler warning in textbuffer.c about preg being
initialized by setting it to NULL.
This patch moves the emitted "tls handshake finished" signal to before
we do validation of the given TLS certificate. This ensures that we
display certificate information before we possibly error out and
disconnects from the server.
This patch removes support for DANE validation of TLS certificates.
There wasn't enough support in the IRC community to push for this on the
majority of bigger IRC networks. If you believe this should be
reintroduced into irssi, then please come up with an implementation that
does not rely on the libval library. It is causing a lot of troubles for
our downstream maintainers.
This patch adds two new options to /CONNECT and /SERVER to let the user
pin either an x509 certificate and/or the public key of a given server.
It is possible to fetch the certificate outside of Irssi itself to
verify the checksum. To fetch the certificate call:
$ openssl s_client -connect chat.freenode.net:6697 < /dev/null 2>/dev/null | \
openssl x509 > freenode.cert
This will download chat.freenode.net:6697's TLS certificate and put it into the
file freenode.cert.
-tls_pinned_cert
----------------
This option allows you to specify the SHA-256 hash of the x509
certificate. When succesfully connected to the server, irssi will verify
that the given server certificate matches the pin set by the user.
The SHA-256 hash of a given certificate can be verified outside of irssi
using the OpenSSL command line tool:
$ openssl x509 -in freenode.cert -fingerprint -sha256 -noout
-tls_pinned_pubkey
------------------
This option allows you to specify the SHA-256 hash of the subject public key
information section of the server certificate. This section contains both the
cryptographic parameters for the public key, but also information about the
algorithm used together with the public key parameters.
When succesfully connected to the server, irssi will verify that the
given public key matches the pin set by the user.
The SHA-256 hash of a public key can be verified outside of irssi using
the OpenSSL command line tool:
$ openssl x509 -in freenode.cert -pubkey -noout | \
openssl pkey -pubin -outform der | \
openssl dgst -sha256 -c | \
tr a-z A-Z
It is possible to specify both -tls_pinned_cert and -tls_pinned_pubkey
together.
This patch adds the TLS_REC structure. This structure is used to emit
information about the TLS handshake from the core of irssi to the
front-end layers such that we can display connection information to the
user.
This patch changes the internal name of SSL to TLS. We also add -tls_*
options to /CONNECT and /SERVER, but make sure that the -ssl_* versions
of the commands continue to work like before.
This patch removes the optional checks for whether to build irssi with
TLS support or not. This will allow us to ship a default configuration
file where we connect to TLS enabled IRC servers out of the box.
