As a client, require all peers (i.e. other IRC servers) to support secure
renegotiation. Break handshakes with servers that don't. We do not
renegotiate our sessions, but this is the most secure option regardless.
As a client, disable TLS Session Tickets. The server side MbedTLS code
does not have any ticket callbacks configured, so an MbedTLS IRC Server
will not issue tickets -- however, others could. Server connections are
not expected to be short-lived enough to benefit from the usage of tickets,
and their issuance harms forward secrecy.
I have removed all non-MbedTLS-specific code from this backend and
copied the non-OpenSSL-specific portions of the OpenSSL backend code
over; as it seems to be more reliable.
If initialising the server context fails, but the client one succeeds,
we will not only leak memory, but the error message reported for
initialising the server context might not make sense, because we
initialise the client context after and that could erase or change the
list of queued errors.
This scenario is considered rare. Nevertheless, we now initialise the
client context after *successfully* initialising the server context.
Commit 5c8da48 introduced a fix for issue #186 by freeing the old SSL_CTX
structure before constructing a new one, which could disconnect existing
clients otherwise.
Unfortunately, the freeing is done first, which means that if setting up
a new structure fails for any reason, there will be no usable structures
left, but they are still referenced.
This fix moves the freeing to the end of the function, using intermediate
new variables in the meantime. This problem was discovered while testing
against OpenSSL 1.1.0 RC6.
LibreSSL does not have the new version macros & functions that OpenSSL
1.1.0 implements. This causes a compile-time failure against LibreSSL.
Further, the runtime function for returning the library version returns
the wrong number (the hardcoded constant number SSLEAY_VERSION_NUMBER
aka OPENSSL_VERSION_NUMBER, instead of LIBRESSL_VERSION_NUMBER).
Add more ifdef soup to remedy the situation.
The code already assumes the presence of fopen(3) and errno, and, by
extension, fclose(3) and strerror(3), so just use those instead of the
BIO wrappers.
Additionally, don't fail to initialise if the DH file does exist but
parsing it fails, as per the pre-existing comment about them being
optional.
* Move certificate, key, DH parameters and configuration to heap
(Documentation states that setting new configuration, e.g.
during a rehash, is unsupported while connections using that
configuration are active)
This is the same approach as the fix for #186
Refcount these structures so as to not introduce a memory leak
On rehash, it will use new structures only if there are no
errors in constructing them
* Add better error-reporting (strings in addition to numbers)
where possible
* Coalesce several connection memory allocations into one function
* Reduce boilerplate where possible (Charybdis targets C99)
* Support private key being in certificate file, and having no
DH parameters file
* Correct erroneous closing comment
openssl:
* Don't manually initialise libssl 1.1.0 -- it does this automatically
* SSL_library_init() should be called first otherwise
* Move SSL_CTX construction to rb_setup_ssl_server()
* Test for all required files (certificate & key) before doing anything
* Free the old CTX before constructing a new one (Fixes#186)
* Properly abort rb_setup_ssl_server() on CTX construction failures
* Support ECDHE on more than one curve on OpenSSL 1.0.2 and above
* Clean up ifdef indentation
* Fix DH parameters memory leak
mbedtls:
* Fix certificate fingerprint generation
* Fix library linking order
* Fix incorrect printf()-esque argument count
* Return digest length for fingerprints instead of 1, consistent
with the other backends
sslproc / ssld:
* Fingerprint methods have no assocated file descriptors
* Send TLS information (cipher, fingerprint) before data
* Use correct header length for fingerprint method
Authored-by: Aaron Jones <aaronmdjones@gmail.com>
Authored-by: William Pitcock <nenolod@dereferenced.org>
Authored-by: Simon Arlott <sa.me.uk>
Nothing in the Charybdis or libratbox code calls rb_get_pseudo_random
and under OpenSSL it uses RAND_pseudo_bytes() which is both dangerous
and removed in OpenSSL version 1.1.0.
