This was the order before 46a6b06282 ("openssl: Only announce ECDH
groups actually supported by OpenSSL") but that's not really the reason
for this change. It's related to the Android app, where we previously
didn't support these DH groups in BoringSSL and added the curve25519
plugin after the openssl plugin instead. This resulted in the same
order, i.e. ECDH groups before curve25519. With the switch to OpenSSL
and the mentioned commit, this changed and curve25519 was now the first
group that was proposed and used for the KE payload. Not really an
issue you'd think, however, there are apparently Zyxel Firewalls with
older firmware versions (some forum posts mentioned a fix in V5.31) that
can't handle KE payloads with DH groups > 21 (ecp521). So with
curve25519 (31) proposed in the KE payload, they silently dropped the
IKE_SA_INIT request and no connection could be established.
The x509 plugin retrieves serial numbers with two's complement
encoding whereas the openssl plugin partially returns them without
leading zeroes.
Serial numbers in X.509 certificates, X.509 CRL, X.509 attribute
certificates, OCSP Requests and OCSP responses are now returned in
canonical form without prepended zero octets.
The pattern currently is to call get_cache(), generate the encoding
if that failed and then store it with cache(). The latter adopts the
passed encoding and frees any stored encoding. However, the latter means
that if two threads concurrently fail to get a cached encoding and then
both generate and store one, one of the threads might use an encoding
that was freed by the other thread.
Since encodings are not expected to change, we can avoid this issue by
not replacing an existing cache entry and instead return that (while
freeing the passed value instead of the cached one).
Closesstrongswan/strongswan#1231
This avoids the use of a variable length array, which should probably
be avoided in general due to potential performance, portability and
security issues (not in this particular case, though).
Closesstrongswan/strongswan#1095
More of this code was already removed with previous commits.
While versions < 1.1.1 are not officially supported anymore, 1.0.2 might
still be in use because before 3.x that was the latest version with
official FIPS support (OpenSSL apparently also provides extended commercial
support for it).
The old API has been deprecated with OpenSSL 3 and direct access to the
state isn't possible via EVP API. In the future we might just remove this
implementation but we'd probably have to implement EAP-AKA' first, which
uses HMAC-SHA-256 with IKEv2's prf+ construct to derive keys instead
of this weird construct (plus what fips-prf builds around it) that's used
by EAP-AKA.
The HKDF-Expand() function defined in RFC 5869 is basically the same as
IKEv2's prf+(), so we can use the former to implement the latter.
However, we can only support HMAC-based PRFs this way, which should be
fine as others are rarely used.
There is a conflict between atexit() handlers registered by OpenSSL and
some executables (e.g. swanctl or pki) to deinitialize libstrongswan.
Because plugins are usually loaded after atexit() has been called, the
handler registered by OpenSSL will run before our handler. So when the
latter destroys the plugins it's a bad idea to try to access any OpenSSL
objects as they might already be invalid.
Fixes: f556fce16b ("openssl: Load "legacy" provider in OpenSSL 3 for algorithms like MD4, DES etc.")
Closesstrongswan/strongswan#921
We still require these algorithms for e.g. EAP-MSCHAPv2, so the option is
enabled, by default. To use other providers (e.g. fips or even custom
ones), the option can be disabled and the providers to load/activate can
be configured in openssl.cnf. For instance, the following has the same
effect as enabling the option:
openssl_conf = openssl_init
[openssl_init]
providers = providers
[providers]
default = activate
legacy = activate
[activate]
activate = yes
Determined by whether the library provides curves for it or not.
For instance, in the OpenSSL 3 FIPS provider the Brainpool curves are
not included. And in the Fedora package several weak curves are
explicitly patched out and the Brainpool curves are omitted even in
non-FIPS mode.
Using the workaround with the EVP interface, which we use to derive shared
keys since 74e02ff5e6 ("openssl: Mainly use EVP interface for ECDH"),
would actually require us to register the OIDs of these curves as NID.
Otherwise, the two EC_GROUPs used by private and public key objects
are not considered the same and the key derivation fails.
Since the curves are supported by OpenSSL since 1.0.2 it's probably rare to
find a version without them nowadays. One exception is the old BoringSSL
version we still use on Android, which defines the NIDs but not the curve
data. However, that version also lacks support to register OIDs as NIDs,
so the only option to support these groups there would be to got back to not
using the EVP interface, which isn't in anyone's interest. If there really
is a need for them there, we could probably patch BoringSSL or use OpenSSL.
OpenSSL enforces a minimum of 14 bytes (112 bits) on the key size when
used in FIPS-mode (as required by SP 800-131A). So by using an empty
string, instantiation always failed. 32 bytes (256 bits) should be safe
for now.
Closesstrongswan/strongswan#557
Tobias Brunner