add documentation

[openssl.git] / doc / apps / pkeyutl.pod

diff --git a/doc/apps/pkeyutl.pod b/doc/apps/pkeyutl.pod
index 91eeda548872d682cd83a0c79e06aba7f785215d..8a455b8187063e74fcb54be82d950d39cf23b38b 100644 (file)
--- a/doc/apps/pkeyutl.pod
+++ b/doc/apps/pkeyutl.pod
@@ -240,6 +240,11 @@ verify operations use ECDSA and derive uses ECDH. Currently there are no
 additional options other than B<digest>. Only the SHA1 digest can be used and
 this digest is assumed by default.
 
+=head1 X25519 ALGORITHM
+
+The X25519 algorithm supports key derivation only. Currently there are no
+additional options.
+
 =head1 EXAMPLES
 
 Sign some data using a private key: