DOC: Clarify EVP_MAC_init() params vs. EVP_MAC_CTX_set_params()
Fixes
@@ -118,12 +118,15 @@ I<ctx>.
=head2 Computing functions
-EVP_MAC_init() sets up the underlying context with information given
+EVP_MAC_init() sets up the underlying context I<ctx> with information given
via the I<key> and I<params> arguments. The MAC I<key> has a length of
I<keylen> and the parameters in I<params> are processed before setting
-the key. If I<key> is NULL, the key must be set via params either
+the key. If I<key> is NULL, the key must be set via I<params> either
as part of this call or separately using EVP_MAC_CTX_set_params().
-This should be called before calling EVP_MAC_update() and EVP_MAC_final().
+Providing non-NULL I<params> to this function is equivalent to calling
+EVP_MAC_CTX_set_params() with those I<params> for the same I<ctx> beforehand.
+
+EVP_MAC_init() should be called before EVP_MAC_update() and EVP_MAC_final().
EVP_MAC_update() adds I<datalen> bytes from I<data> to the MAC input.
