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.
The `salt_len` field is signed because negative values are used to indicate
automatic salt lengths when generating signatures. This must never be the
case when validating them.
Not checking this could lead to an integer overflow below. The value is
assigned to the `len` field of a chunk (`size_t`), which is further used
in calculations to check the padding structure and (if that is passed by
a matching crafted signature value) eventually a memcpy() that will result
in a segmentation fault.
Fixes: 7d6b81648b ("gmp: Add support for RSASSA-PSS signature verification")
Fixes: CVE-2021-41990
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
If a PKCS#11 library/token doesn't provide one or more attributes via
C_GetAttributeValue(), we get back CKR_ATTRIBUTE_TYPE_INVALID (similar
for protected attributes where CKR_ATTRIBUTE_SENSITIVE is returned).
This is not an error as the spec demands that all attributes have been
processed with the unavailable attributes having set their length
field to CK_UNAVAILABLE_INFORMATION.
We use this to handle the CKA_TRUSTED attribute, which some tokens
apparently don't support. We previously used a version check to remove
the attribute from the call but even the latest spec doesn't make the
attribute mandatory (it's just in a list of "common" attributes for
CKO_CERTIFICATE objects, without a default value), so there are current
tokens that don't support it and prevent us from enumerating certificates.
While CCM is available in earlier versions, we only use it with
OpenSSL 1.1.0 and newer because the generic control variables are not
available before and we default to GCM for them.
Closesstrongswan/strongswan#353.
If we pass a pointer to NULL, the memory allocated by OpenSSL has to be
freed with OPENSSL_free(). Otherwise, this can lead to random
crashes/freezes for Windows builds as seen on AppVeyor. To not
complicate things for callers of this macro, we allocate our own memory,
which we already do for other i2d_* calls.
Tobias Brunner