+=head1 RETURN VALUES
+
+EVP_MD_meth_new() and EVP_MD_meth_dup() return a pointer to a newly
+created B<EVP_MD>, or NULL on failure.
+All EVP_MD_meth_set_*() functions return 1.
+EVP_MD_get_input_blocksize(), EVP_MD_meth_get_result_size(),
+EVP_MD_meth_get_app_datasize() and EVP_MD_meth_get_flags() return the
+indicated sizes or flags.
+All other EVP_CIPHER_meth_get_*() functions return pointers to their
+respective B<md> function.
+