| =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 RFC 8410. |
| |
| 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 EXAMPLES |
| |
| 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 2017-2020 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 |
