blake2: add EVP_MAC man page

Signed-off-by: Antoine Salon <asalon@vmware.com>

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7726)

doc/man3/EVP_MAC.pod

@@ -87,9 +87,6 @@ through diverse controls.
 This should be called before calling EVP_MAC_update() and
 EVP_MAC_final().
 
-EVP_MAC_reset() resets the computation for the given context.
-This may not be supported by the MAC implementation.
-
 EVP_MAC_update() adds C<datalen> bytes from C<data> to the MAC input.
 
 EVP_MAC_final() does the final computation and stores the result in
@@ -171,18 +168,23 @@ Some MAC implementations require an IV, this control sets the IV.
 
 =item B<EVP_MAC_CTRL_SET_CUSTOM>
 
-This control expects two arguments: C<unsigned char *key>, C<size_t keylen>
+This control expects two arguments: C<unsigned char *custom>, C<size_t customlen>
 
-Some MAC implementations (KMAC) require an Customization String,
+Some MAC implementations (KMAC, BLAKE2) accept a Customization String,
 this control sets the Customization String. The default value is "".
 
+=item B<EVP_MAC_CTRL_SET_SALT>
+
+This control expects two arguments: C<unsigned char *salt>, C<size_t saltlen>
+
+This option is used by BLAKE2 MAC.
+
 =item B<EVP_MAC_CTRL_SET_XOF>
 
 This control expects one argument: C<int xof>
 
 This option is used by KMAC.
 
-
 =item B<EVP_MAC_CTRL_SET_FLAGS>
 
 This control expects one argument: C<unsigned long flags>
@@ -231,7 +233,7 @@ created EVP_MAC_CTX, or NULL if allocation failed.
 
 EVP_MAC_CTX_free() returns nothing at all.
 
-EVP_MAC_CTX_copy(), EVP_MAC_reset(), EVP_MAC_init(), EVP_MAC_update(),
+EVP_MAC_CTX_copy(), EVP_MAC_init(), EVP_MAC_update(),
 and EVP_MAC_final() return 1 on success, 0 on error.
 
 EVP_MAC_ctrl(), EVP_MAC_ctrl_str(), EVP_MAC_str2ctrl() and
@@ -346,6 +348,7 @@ F<./foo>)
 
 =head1 SEE ALSO
 
+L<EVP_MAC_BLAKE2(7)>,
 L<EVP_MAC_CMAC(7)>,
 L<EVP_MAC_GMAC(7)>,
 L<EVP_MAC_HMAC(7)>,

doc/man7/EVP_MAC_BLAKE2.pod

@@ -0,0 +1,114 @@
+=pod
+
+=head1 NAME
+
+EVP_MAC_BLAKE2 - The BLAKE2 EVP_MAC implementation
+
+=head1 DESCRIPTION
+
+Support for computing BLAKE2 MACs through the B<EVP_MAC> API.
+
+=head2 Numeric identity
+
+B<EVP_MAC_BLAKE2B> and B<EVP_MAC_BLAKE2S> are the numeric identities for this
+implementation, and can be used in functions like EVP_MAC_CTX_new_id() and
+EVP_get_macbynid().
+
+=head2 Supported controls
+
+The supported controls are:
+
+=over 4
+
+=item B<EVP_MAC_CTRL_SET_KEY>
+
+This is a string value of at most 64 bytes for EVP_MAC_BLAKE2B
+or 32 for EVP_MAC_BLAKE2S and at least 1 byte in both cases.
+This must be set before calling EVP_MAC_init().
+
+EVP_MAC_ctrl_str() takes two type strings for this control:
+
+=over 4
+
+=item "key"
+
+The value string is used as is.
+
+=item "hexkey"
+
+The value string is expected to be a hexadecimal number, which will be
+decoded before passing on as control value.
+
+=back
+
+=item B<EVP_MAC_CTRL_SET_CUSTOM>
+
+This is an optional string value of at most 16 bytes for EVP_MAC_BLAKE2B
+or 8 for EVP_MAC_BLAKE2S, set to all-NULL by default.
+If used this must be set before calling EVP_MAC_init().
+
+EVP_MAC_ctrl_str() takes two type strings for this control:
+
+=over 4
+
+=item "custom"
+
+The value string is used as is.
+
+=item "hexcustom"
+
+The value string is expected to be a hexadecimal number, which will be
+decoded before passing on as control value.
+
+=back
+
+=item B<EVP_MAC_CTRL_SET_SALT>
+
+This is an optional string value of at most 16 bytes for EVP_MAC_BLAKE2B
+or 8 for EVP_MAC_BLAKE2S, set to all-NULL by default.
+If used this must be set before calling EVP_MAC_init().
+
+EVP_MAC_ctrl_str() takes two type strings for this control:
+
+=over 4
+
+=item "salt"
+
+The value string is used as is.
+
+=item "hexsalt"
+
+The value string is expected to be a hexadecimal number, which will be
+decoded before passing on as control value.
+
+=back
+
+=item B<EVP_MAC_CTRL_SET_SIZE>
+
+EVP_MAC_ctrl_str() type string: "outlen"
+
+This is an optional value string containing a decimal number between 1 and
+32 for EVP_MAC_BLAKE2S or 64 for EVP_MAC_BLAKE2B.
+If it is not set it uses the default digest size of 32 and 64 respectively.
+If used this must be set before calling EVP_MAC_init().
+
+=back
+
+=head1 SEE ALSO
+
+L<EVP_MAC_ctrl(3)>, L<EVP_MAC(3)/CONTROLS>
+
+=head1 HISTORY
+
+The macros and functions described here were added to OpenSSL 3.0.0.
+
+=head1 COPYRIGHT
+
+Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
+
+Licensed under the Apache License 2.0 (the "License").  You may not use
+this file except in compliance with the License.  You can obtain a copy
+in the file LICENSE in the source distribution or at
+L<https://www.openssl.org/source/license.html>.
+
+=cut