1=pod
2
3=head1 NAME
4
5Ed25519,
6Ed448
7- EVP_PKEY Ed25519 and Ed448 support
8
9=head1 DESCRIPTION
10
11The B<Ed25519> and B<Ed448> EVP_PKEY implementation supports key generation,
12one-shot digest sign and digest verify using PureEdDSA and B<Ed25519> or B<Ed448>
13(see RFC8032). It has associated private and public key formats compatible with
14RFC 8410.
15
16No additional parameters can be set during key generation, one-shot signing or
17verification. In particular, because PureEdDSA is used, a digest must B<NOT> be
18specified when signing or verifying.
19
20=head1 NOTES
21
22The PureEdDSA algorithm does not support the streaming mechanism
23of other signature algorithms using, for example, EVP_DigestUpdate().
24The message to sign or verify must be passed using the one-shot
25EVP_DigestSign() and EVP_DigestVerify() functions.
26
27When calling EVP_DigestSignInit() or EVP_DigestVerifyInit(), the
28digest B<type> parameter B<MUST> be set to B<NULL>.
29
30Applications wishing to sign certificates (or other structures such as
31CRLs or certificate requests) using Ed25519 or Ed448 can either use X509_sign()
32or X509_sign_ctx() in the usual way.
33
34A context for the B<Ed25519> algorithm can be obtained by calling:
35
36 EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_ED25519, NULL);
37
38For the B<Ed448> algorithm a context can be obtained by calling:
39
40 EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_ED448, NULL);
41
42Ed25519 or Ed448 private keys can be set directly using
43L<EVP_PKEY_new_raw_private_key(3)> or loaded from a PKCS#8 private key file
44using L<PEM_read_bio_PrivateKey(3)> (or similar function). Completely new keys
45can also be generated (see the example below). Setting a private key also sets
46the associated public key.
47
48Ed25519 or Ed448 public keys can be set directly using
49L<EVP_PKEY_new_raw_public_key(3)> or loaded from a SubjectPublicKeyInfo
50structure in a PEM file using L<PEM_read_bio_PUBKEY(3)> (or similar function).
51
52Ed25519 and Ed448 can be tested within L<speed(1)> application since version 1.1.1.
53Valid algorithm names are B<ed25519>, B<ed448> and B<eddsa>. If B<eddsa> is
54specified, then both Ed25519 and Ed448 are benchmarked.
55
56=head1 EXAMPLES
57
58This example generates an B<ED25519> private key and writes it to standard
59output in PEM format:
60
61 #include <openssl/evp.h>
62 #include <openssl/pem.h>
63 ...
64 EVP_PKEY *pkey = NULL;
65 EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_ED25519, NULL);
66 EVP_PKEY_keygen_init(pctx);
67 EVP_PKEY_keygen(pctx, &pkey);
68 EVP_PKEY_CTX_free(pctx);
69 PEM_write_PrivateKey(stdout, pkey, NULL, NULL, 0, NULL, NULL);
70
71=head1 SEE ALSO
72
73L<EVP_PKEY_CTX_new(3)>,
74L<EVP_PKEY_keygen(3)>,
75L<EVP_DigestSignInit(3)>,
76L<EVP_DigestVerifyInit(3)>,
77
78=head1 COPYRIGHT
79
80Copyright 2017-2020 The OpenSSL Project Authors. All Rights Reserved.
81
82Licensed under the OpenSSL license (the "License").  You may not use
83this file except in compliance with the License.  You can obtain a copy
84in the file LICENSE in the source distribution or at
85L<https://www.openssl.org/source/license.html>.
86
87=cut
88