1 files changed, 74 insertions, 0 deletions
diff --git a/doc/man7/X25519.pod b/doc/man7/X25519.pod
new file mode 100644
index 000000000000..7cb6ff6b3bed
--- /dev/null
+++ b/doc/man7/X25519.pod
@@ -0,0 +1,74 @@
+=pod
+
+=head1 NAME
+
+X25519,
+X448
+- EVP_PKEY X25519 and X448 support
+
+=head1 DESCRIPTION
+
+The B<X25519> and B<X448> EVP_PKEY implementation supports key generation and
+key derivation using B<X25519> and B<X448>. It has associated private and public
+key formats compatible with draft-ietf-curdle-pkix-03.
+
+No additional parameters can be set during key generation.
+
+The peer public key must be set using EVP_PKEY_derive_set_peer() when
+performing key derivation.
+
+=head1 NOTES
+
+A context for the B<X25519> algorithm can be obtained by calling:
+
+ EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_X25519, NULL);
+
+For the B<X448> algorithm a context can be obtained by calling:
+
+ EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_X448, NULL);
+
+X25519 or X448 private keys can be set directly using
+L<EVP_PKEY_new_raw_private_key(3)> or loaded from a PKCS#8 private key file
+using L<PEM_read_bio_PrivateKey(3)> (or similar function). Completely new keys
+can also be generated (see the example below). Setting a private key also sets
+the associated public key.
+
+X25519 or X448 public keys can be set directly using
+L<EVP_PKEY_new_raw_public_key(3)> or loaded from a SubjectPublicKeyInfo
+structure in a PEM file using L<PEM_read_bio_PUBKEY(3)> (or similar function).
+
+=head1 EXAMPLE
+
+This example generates an B<X25519> private key and writes it to standard
+output in PEM format:
+
+ #include <openssl/evp.h>
+ #include <openssl/pem.h>
+ ...
+ EVP_PKEY *pkey = NULL;
+ EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_X25519, NULL);
+ EVP_PKEY_keygen_init(pctx);
+ EVP_PKEY_keygen(pctx, &pkey);
+ EVP_PKEY_CTX_free(pctx);
+ PEM_write_PrivateKey(stdout, pkey, NULL, NULL, 0, NULL, NULL);
+
+The key derivation example in L<EVP_PKEY_derive(3)> can be used with
+B<X25519> and B<X448>.
+
+=head1 SEE ALSO
+
+L<EVP_PKEY_CTX_new(3)>,
+L<EVP_PKEY_keygen(3)>,
+L<EVP_PKEY_derive(3)>,
+L<EVP_PKEY_derive_set_peer(3)>
+
+=head1 COPYRIGHT
+
+Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.
+
+Licensed under the OpenSSL license (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