Without this we only would learn that the algorithm isn't actually
available (e.g. due to FIPS mode) when set_key() is called later, so there
isn't any automatic fallback to other implementations.
Fixes#3284.
Resolves conflicts with building against wolfSSL when
`--enable-opensslextra` is set, namely the `WOLFSSL_HMAC_H_`,
`RNG` and `ASN1_*` name conflicts.
Closesstrongswan/strongswan#151.
According to the documentation, it's generally not necessary to manually
seed OpenSSL's DRBG (and it actually can cause the daemon to lock up
during start up on systems with low entropy if OpenSSL is already trying
to seed it itself and holds the lock). While that might already have been
the case with earlier versions, it's not explicitly stated in their
documentation. So we keep the code for these versions.
Usually, changing this won't be necessary (actually, some plugins
specifically use different DRGBs for RNG_WEAK in order to separate
the public nonces from random data used for e.g. DH).
But for experts with special plugin configurations this might be
more flexible and avoids code changes.
The main fixes are
* the generation of fingerprints for RSA, ECDSA, and EdDSA
* the encoding of ECDSA private keys
* calculating p and q for RSA private keys
* deriving the public key for raw Ed25519 private keys
Also, instead of numeric literals for buffer lengths ASN.1 related
constants are used.
Instead, create a socket when necessary. Apparently, it can prevent
the agent from getting terminated (e.g. during system shutdown) if e.g.
charon-nm is still running with an open connection to the agent.
The functional reference created by ENGINE_init() was never released,
only the structural one created by ENGINE_by_id(). The functional
reference includes an implicit structural reference, which is also
released by ENGINE_finish().
Closesstrongswan/strongswan#119.
As per RFC 8032, section 5.1.7 (and section 8.4) we have to make sure s, which
is the scalar in the second half of the signature value, is smaller than L.
Without that check, L can be added to most signatures at least once to create
another valid signature for the same public key and message.
This could be problematic if, for instance, a blacklist is based on hashes
of certificates. A new certificate could be created with a different
signature (without knowing the signature key) by simply adding L to s.
Currently, both OpenSSL 1.1.1 and Botan 2.8.0 are vulnerable to this, which is
why the unit test currently only warns about it.
OpenSSL 1.1.1 introduces DRGBs and provides two sources (same security
profile etc. but separate internal state), which allows us to use one for
RNG_WEAK (e.g. for nonces that are directly publicly visible) and the other
for stronger random data like keys.
While X25519 was already added with 1.1.0a, its use would be a lot more
complicated, as the helpers like EVP_PKEY_new_raw_public_key() were only
added in 1.1.1, which also added X448.
According to gcrypt.h these callbacks are not used anymore since
version 1.6 and with clang these actually cause deprecation warnings
that let the build on travis (-Werror) fail.
Tobias Brunner