not NULL. Otherwise, they return the parameters associated with the
provider side algorithm I<provctx>.
+All MAC implementations are expected to handle the following parameters:
-Parameters currently recognised by built-in macs are as follows. Not all
-parameters are relevant to, or are understood by all macs:
+=over 4
+
+=item with OSSL_FUNC_set_ctx_params():
=over 4
Sets the key in the associated MAC ctx. This is identical to passing a I<key>
argument to the OSSL_FUNC_mac_init() function.
-=item "iv" (B<OSSL_MAC_PARAM_IV>) <octet string>
-
-Sets the IV of the underlying cipher, when applicable.
-
-=item "custom" (B<OSSL_MAC_PARAM_CUSTOM>) <UTF8 string>
-
-Sets the custom string in the associated MAC ctx.
-
-=item "salt" (B<OSSL_MAC_PARAM_SALT>) <octet string>
-
-Sets the salt of the underlying cipher, when applicable.
-
-=item "xof" (B<OSSL_MAC_PARAM_BLOCK_XOF>) <integer>
-
-Sets XOF mode in the associated MAC ctx.
-0 means no XOF mode, 1 means XOF mode.
-
-=item "digest-noinit" (B<OSSL_MAC_PARAM_DIGEST_NOINIT>) <integer>
-
-A simple flag to set the MAC digest to not initialise the
-implementation specific data. The value 0 or 1 is expected.
-
-=item "digest-oneshot" (B<OSSL_MAC_PARAM_DIGEST_ONESHOT>) <integer>
-
-A simple flag to set the MAC digest to be a oneshot operation.
-The value 0 or 1 is expected.
-
-
-=for comment We need to investigate if this is the right approach
-
-=item "cipher" (B<OSSL_MAC_PARAM_CIPHER>) <UTF8 string>
-
-=item "digest" (B<OSSL_MAC_PARAM_DIGEST>) <UTF8 string>
-
-Sets the name of the underlying cipher or digest to be used.
-It must name a suitable algorithm for the MAC that's being used.
+=back
-=item "properties" (B<OSSL_MAC_PARAM_PROPERTIES>) <UTF8 string>
+=item with OSSL_FUNC_get_params():
-Sets the properties to be queried when trying to fetch the underlying algorithm.
-This must be given together with the algorithm naming parameter to be
-considered valid.
+=over 4
=item "size" (B<OSSL_MAC_PARAM_SIZE>) <integer>
-Can be used to get the resulting MAC size.
+Can be used to get the default MAC size (which might be the only allowable
+MAC size for the implementation).
-With some MAC algorithms, it can also be used to set the size that the
-resulting MAC should have.
-Allowable sizes are decided within each implementation.
+Note that some implementations allow setting the size that the resulting MAC
+should have as well, see the documentation of the implementation.
+
+=back
=back
=head1 SEE ALSO
-L<provider(7)>, L<EVP_MAC_init(3)>
+L<provider(7)>,
+L<EVP_MAC-BLAKE2(7)>, L<EVP_MAC-CMAC(7)>, L<EVP_MAC-GMAC(7)>,
+L<EVP_MAC-HMAC(7)>, L<EVP_MAC-KMAC(7)>, L<EVP_MAC-Poly1305(7)>,
+L<EVP_MAC-Siphash(7)>
+
=head1 HISTORY