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)

diff --git a/doc/man7/EVP_KDF-ARGON2.pod b/doc/man7/EVP_KDF-ARGON2.pod
index d41a3179b53b3203409a64d4bcfecd3e8d06af08..ecbd3ad74585d0f058db3e568f612587c0b7b4ef 100644 (file)
--- a/doc/man7/EVP_KDF-ARGON2.pod
+++ b/doc/man7/EVP_KDF-ARGON2.pod
@@ -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