doc: Document properties param for Argon2 KDF

The Argon2 KDF uses OSSL_KDF_PARAM_PROPERTIES to fetch implementations
of blake2bmac and blake2b512 if ctx->mac and ctx->md are NULL. This
isn't documented in the manpage, so users that might, for example, want
to fetch an instance of Argon2 with the -fips property query to obtain
a working Argon2 KDF even though the default property query requires
fips=yes are left wondering why this fails.

Fortunately, EVP_KDF(3)/PARAMETERS already explains what the properties
are used for, so we really just need to add a single line.

Signed-off-by: Clemens Lang <cllang@redhat.com>

Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/25306)
This commit is contained in:
Clemens Lang 2024-08-28 17:18:03 +02:00 committed by Tomas Mraz
parent 80008d4a94
commit 6772c2ab1b

View File

@ -44,6 +44,8 @@ The supported parameters are:
=item "size" (B<OSSL_KDF_PARAM_SIZE>) <unsigned integer>
=item "properties" (B<OSSL_KDF_PARAM_PROPERTIES>) <UTF8 string>
These parameters work as described in L<EVP_KDF(3)/PARAMETERS>.
Note that RFC 9106 recommends 128 bits salt for most applications, or 64 bits