Because `keylen` is unsigned the subtraction results in an integer
underflow if the key length is < 11 bytes.
This is only a problem when verifying signatures with a public key (for
private keys the plugin enforces a minimum modulus length) and to do so
we usually only use trusted keys. However, the x509 plugin actually
calls issued_by() on a parsed certificate to check if it is self-signed,
which is the reason this issue was found by OSS-Fuzz in the first place.
So, unfortunately, this can be triggered by sending an invalid client
cert to a peer.
Fixes: 5955db5b12 ("gmp: Don't parse PKCS1 v1.5 RSA signatures to verify them")
Fixes: CVE-2018-17540
Instead we generate the expected signature encoding and compare it to the
decrypted value.
Due to the lenient nature of the previous parsing code (minimum padding
length was not enforced, the algorithmIdentifier/OID parser accepts arbitrary
data after OIDs and in the parameters field etc.) it was susceptible to
Daniel Bleichenbacher's low-exponent attack (from 2006!), which allowed
forging signatures for keys that use low public exponents (i.e. e=3).
Since the public exponent is usually set to 0x10001 (65537) since quite a
while, the flaws in the previous code should not have had that much of a
practical impact in recent years.
Fixes: CVE-2018-16151, CVE-2018-16152
This also changes how unknown/corrupted memory is handled in the free()
and realloc() hooks in general.
Incorporates changes provided by Thomas Egerer who ran into a similar
issue.
Due to the mangled C++ function names it's tricky to be more specific. The
"leaked" allocations are from a static hashtable containing EC groups.
There is another leak caused by the locking allocator singleton
(triggered by the first function that uses it, usually initialization of
a cipher, but could be a hasher in other test runners), but we can avoid
that with a Botan config option.
Simplifies public key loading and this way unencrypted PKCS#8-encoded
keys can be loaded directly without pkcs8 plugin (code for encrypted
keys could probably later be added, if necessary).
It also simplifies the implementation of private_key_t::get_public_key()
a lot.
Without OID we can't generate an algorithmIdentifier when loading the
key again. And older versions of OpenSSL insist on a public key when
e.g. converting a key to PKCS#8.
Simply unwrapping the ECPrivateKey structure avoids log messages when
parsing other keys in the KEY_ANY case.
Support MD5 in the Botan plugin if supported by Botan.
MD5 is required for RADIUS and obviously EAP-MD5,
and also for non-PKCS#8 encoded, encrypted private keys.
Botan only allows RSA generating keys >= 1,024 bits, which makes
the RSA test suite fail. It is questionable whether it makes
sense to test 768 bit RSA keys anymore. They are too weak
from today's perspective anyway.
This requires config changes if filelog is used with a path that
contains dots. This path must now be defined in the `path` setting of an
arbitrarily named subsection of `filelog`. Without that change the
whole strongswan.conf file will fail to load, which some users might
not notice immediately.
For inbound processing, it can be rather useful to apply the mark to the
packet in the SA, so the associated policy with that mark implicitly matches.
When using %unique as match mark, we don't know the mark beforehand, so
we most likely want to set the mark we match against.
%unique (and the upcoming %same key) are usable in specific contexts only.
To restrict the user from using it in other places where it does not get the
expected results, reject such keywords unless explicitly allowed.
The type of the value was incorrect (void**) if NULL was passed to cas_ptr()
as expected value, which caused a compiler warning with Clang because
__atomic_compare_exchange_n() expects the types of the first two arguments
to be the same.
There was a potential chance for a race condition if the ensured section
was purged for some reason before using it later.
This also changes the behavior for NULL/empty strings via load_string*
with merge == FALSE, which now purges the config/section.
Similar to the `also` keyword in ipsec.conf, the new syntax allows adding
one or more references to other sections, which means all the settings and
subsections defined there are inherited (values may be overridden, even
with an empty value to clear it).
It's important to note that all subsections are inherited, so if this is
used to reference a connection in swanctl.conf all auth rounds and
children are inherited. There is currently no syntax to limit the
inclusion level or clear inherited sections (but as mentioned, settings
in those inherited sections may be overridden).
Another property is that inherited settings or sections always follow
explicitly defined entries in the current section when they are enumerated.
This is relevant if the order is important (e.g. for auth rounds if `round`
is not specified).
References are evaluated dynamically at runtime, so referring to
sections later in the config file or included via other files is no
problem.
The colon used as separator to reference other sections may be used in
section names by writing :: (e.g. for Windows log file paths).
This is based on a patch originally written in 2016.
This was quite confusing previously: While calling insert_before()
and then remove_at() properly replaced the current item, calling them the
other way around inserted the new item before the previous item because
remove_at() changed the enumerator's position to the previous item.
The behavior in corner cases (calling the methods before or after
enumeration) is also changed slightly.
Allow charon to start as a non-root user without CAP_CHOWN and still be
able to change the group on files that need to be accessed by charon
after capabilities have been dropped. This requires the user charon starts
as to have access to socket/pidfile directory as well as belong to the
group that charon will run as after dropping capabilities.
Closesstrongswan/strongswan#105.
The keylength fix for ChaCha20Poly1305 (5a7b0be2) removes the keylength
attribute from the AEAD transform. This breaks compatibility between
versions with the patch and those without. The ChaCha20Poly1305 AEAD
won't match in proposals between such versions, and if no other algorithm
is available, negotiating SAs fails.
As a migration strategy, this patch introduces a new string identifier for a
ChaCha20Poly1305 proposal keyword which uses the explicit keylength, exactly
as it was used before the mentioned patch. Administrators that care about
the use of that AEAD with old clients can temporarily add this keyword to
the list of proposals, until all clients have been upgraded.
The used approach is the least invasive, as it just adds an additional
keyword that can't do any harm if not explicitly configured. Nontheless
allows it the administrator to smoothly keep ChaCha20Poly1305 working,
even if upgrading all peers simultaneously is not an option. It requires
manual configuration edits, though, but we assume that ChaCha20Poly1305
is not that widely used, and not as the only transform in proposals.
Removing the compat keyword in a future version is an option; it might
be helpful for other implementations, though, that falsely use an
explicit key length in ChaCha20Poly1305 AEAD transforms.
ambiso