algorithm.
B<exchange> may be NULL in which case the EVP_KEYEXCH algorithm is fetched
implicitly based on the type of EVP_PKEY associated with B<ctx>.
-See L<EVP_KEYEXCH_fetch(3)> for more information about implict fetches.
+See L<provider(7)/Implicit fetch> for more information about implict fetches.
-The EVP_PKEY_derive_init() function is the same as EVP_PKEY_derive() except that
-the EVP_KEYEXCH algorithm is always implicitly fetched.
+The EVP_PKEY_derive_init() function is the same as EVP_PKEY_derive_init_ex()
+except that the EVP_KEYEXCH algorithm is always implicitly fetched.
The EVP_PKEY_derive_set_peer() function sets the peer key: this will normally
be a public key.
In particular a return value of -2 indicates the operation is not supported by
the public key algorithm.
-=head1 EXAMPLE
+=head1 EXAMPLES
Derive shared secret (for example DH or EC keys):