Ed25519, Ed448 - EVP_PKEY Ed25519 and Ed448 support
The
Ed25519 and
Ed448 EVP_PKEY implementation supports key
generation, one-shot digest sign and digest verify using PureEdDSA and
Ed25519 or
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
NOT be specified when signing or verifying.
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
type parameter
MUST be set to
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
Ed25519 algorithm can be obtained by calling:
EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_ED25519, NULL);
For the
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
EVP_PKEY_new_raw_private_key(3) or loaded from a PKCS#8 private key
file using
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
EVP_PKEY_new_raw_public_key(3) or loaded from a SubjectPublicKeyInfo
structure in a PEM file using
PEM_read_bio_PUBKEY(3) (or similar
function).
Ed25519 and Ed448 can be tested within
speed(1) application since version
1.1.1. Valid algorithm names are
ed25519,
ed448 and
eddsa. If
eddsa is specified, then both Ed25519 and Ed448 are
benchmarked.
This example generates an
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);
EVP_PKEY_CTX_new(3),
EVP_PKEY_keygen(3),
EVP_DigestSignInit(3),
EVP_DigestVerifyInit(3),
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
<https://www.openssl.org/source/license.html>.