openssl/doc/man7/Ed25519.pod
Matt Caswell 1cb7eff45b Update copyright year
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9847)
2019-09-10 13:56:40 +01:00

87 lines
2.9 KiB
Text

=pod
=head1 NAME
Ed25519,
Ed448
- EVP_PKEY Ed25519 and Ed448 support
=head1 DESCRIPTION
The B<Ed25519> and B<Ed448> EVP_PKEY implementation supports key generation,
one-shot digest sign and digest verify using PureEdDSA and B<Ed25519> or B<Ed448>
(see RFC8032). It has associated private and public key formats compatible with
draft-ietf-curdle-pkix-04.
No additional parameters can be set during key generation, one-shot signing or
verification. In particular, because PureEdDSA is used, a digest must B<NOT> be
specified when signing or verifying.
=head1 NOTES
The PureEdDSA algorithm does not support the streaming mechanism
of other signature algorithms using, for example, EVP_DigestUpdate().
The message to sign or verify must be passed using the one-shot
EVP_DigestSign() and EVP_DigestVerify() functions.
When calling EVP_DigestSignInit() or EVP_DigestVerifyInit(), the
digest B<type> parameter B<MUST> be set to B<NULL>.
Applications wishing to sign certificates (or other structures such as
CRLs or certificate requests) using Ed25519 or Ed448 can either use X509_sign()
or X509_sign_ctx() in the usual way.
A context for the B<Ed25519> algorithm can be obtained by calling:
EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_ED25519, NULL);
For the B<Ed448> algorithm a context can be obtained by calling:
EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_ED448, NULL);
Ed25519 or Ed448 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.
Ed25519 or Ed448 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).
Ed25519 and Ed448 can be tested within L<speed(1)> application since version 1.1.1.
Valid algorithm names are B<ed25519>, B<ed448> and B<eddsa>. If B<eddsa> is
specified, then both Ed25519 and Ed448 are benchmarked.
=head1 EXAMPLES
This example generates an B<ED25519> 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_ED25519, 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);
=head1 SEE ALSO
L<EVP_PKEY_CTX_new(3)>,
L<EVP_PKEY_keygen(3)>,
L<EVP_DigestSignInit(3)>,
L<EVP_DigestVerifyInit(3)>,
=head1 COPYRIGHT
Copyright 2017-2019 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