mirror of
https://github.com/freebsd/freebsd-src
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314 lines
7.8 KiB
C
314 lines
7.8 KiB
C
/* $OpenBSD: ssh-ed25519.c,v 1.19 2022/10/28 00:44:44 djm Exp $ */
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/*
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* Copyright (c) 2013 Markus Friedl <markus@openbsd.org>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include "includes.h"
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#include <sys/types.h>
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#include <limits.h>
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#include "crypto_api.h"
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#include <string.h>
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#include <stdarg.h>
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#include "log.h"
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#include "sshbuf.h"
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#define SSHKEY_INTERNAL
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#include "sshkey.h"
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#include "ssherr.h"
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#include "ssh.h"
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static void
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ssh_ed25519_cleanup(struct sshkey *k)
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{
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freezero(k->ed25519_pk, ED25519_PK_SZ);
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freezero(k->ed25519_sk, ED25519_SK_SZ);
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k->ed25519_pk = NULL;
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k->ed25519_sk = NULL;
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}
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static int
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ssh_ed25519_equal(const struct sshkey *a, const struct sshkey *b)
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{
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if (a->ed25519_pk == NULL || b->ed25519_pk == NULL)
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return 0;
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if (memcmp(a->ed25519_pk, b->ed25519_pk, ED25519_PK_SZ) != 0)
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return 0;
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return 1;
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}
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static int
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ssh_ed25519_serialize_public(const struct sshkey *key, struct sshbuf *b,
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enum sshkey_serialize_rep opts)
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{
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int r;
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if (key->ed25519_pk == NULL)
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return SSH_ERR_INVALID_ARGUMENT;
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if ((r = sshbuf_put_string(b, key->ed25519_pk, ED25519_PK_SZ)) != 0)
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return r;
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return 0;
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}
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static int
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ssh_ed25519_serialize_private(const struct sshkey *key, struct sshbuf *b,
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enum sshkey_serialize_rep opts)
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{
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int r;
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if ((r = sshbuf_put_string(b, key->ed25519_pk, ED25519_PK_SZ)) != 0 ||
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(r = sshbuf_put_string(b, key->ed25519_sk, ED25519_SK_SZ)) != 0)
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return r;
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return 0;
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}
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static int
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ssh_ed25519_generate(struct sshkey *k, int bits)
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{
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if ((k->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL ||
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(k->ed25519_sk = malloc(ED25519_SK_SZ)) == NULL)
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return SSH_ERR_ALLOC_FAIL;
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crypto_sign_ed25519_keypair(k->ed25519_pk, k->ed25519_sk);
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return 0;
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}
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static int
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ssh_ed25519_copy_public(const struct sshkey *from, struct sshkey *to)
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{
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if (from->ed25519_pk == NULL)
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return 0; /* XXX SSH_ERR_INTERNAL_ERROR ? */
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if ((to->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL)
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return SSH_ERR_ALLOC_FAIL;
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memcpy(to->ed25519_pk, from->ed25519_pk, ED25519_PK_SZ);
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return 0;
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}
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static int
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ssh_ed25519_deserialize_public(const char *ktype, struct sshbuf *b,
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struct sshkey *key)
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{
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u_char *pk = NULL;
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size_t len = 0;
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int r;
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if ((r = sshbuf_get_string(b, &pk, &len)) != 0)
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return r;
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if (len != ED25519_PK_SZ) {
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freezero(pk, len);
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return SSH_ERR_INVALID_FORMAT;
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}
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key->ed25519_pk = pk;
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return 0;
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}
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static int
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ssh_ed25519_deserialize_private(const char *ktype, struct sshbuf *b,
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struct sshkey *key)
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{
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int r;
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size_t sklen = 0;
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u_char *ed25519_sk = NULL;
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if ((r = ssh_ed25519_deserialize_public(NULL, b, key)) != 0)
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goto out;
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if ((r = sshbuf_get_string(b, &ed25519_sk, &sklen)) != 0)
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goto out;
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if (sklen != ED25519_SK_SZ) {
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r = SSH_ERR_INVALID_FORMAT;
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goto out;
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}
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key->ed25519_sk = ed25519_sk;
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ed25519_sk = NULL; /* transferred */
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/* success */
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r = 0;
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out:
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freezero(ed25519_sk, sklen);
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return r;
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}
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static int
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ssh_ed25519_sign(struct sshkey *key,
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u_char **sigp, size_t *lenp,
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const u_char *data, size_t datalen,
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const char *alg, const char *sk_provider, const char *sk_pin, u_int compat)
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{
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u_char *sig = NULL;
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size_t slen = 0, len;
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unsigned long long smlen;
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int r, ret;
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struct sshbuf *b = NULL;
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if (lenp != NULL)
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*lenp = 0;
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if (sigp != NULL)
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*sigp = NULL;
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if (key == NULL ||
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sshkey_type_plain(key->type) != KEY_ED25519 ||
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key->ed25519_sk == NULL ||
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datalen >= INT_MAX - crypto_sign_ed25519_BYTES)
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return SSH_ERR_INVALID_ARGUMENT;
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smlen = slen = datalen + crypto_sign_ed25519_BYTES;
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if ((sig = malloc(slen)) == NULL)
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return SSH_ERR_ALLOC_FAIL;
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if ((ret = crypto_sign_ed25519(sig, &smlen, data, datalen,
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key->ed25519_sk)) != 0 || smlen <= datalen) {
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r = SSH_ERR_INVALID_ARGUMENT; /* XXX better error? */
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goto out;
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}
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/* encode signature */
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if ((b = sshbuf_new()) == NULL) {
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r = SSH_ERR_ALLOC_FAIL;
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goto out;
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}
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if ((r = sshbuf_put_cstring(b, "ssh-ed25519")) != 0 ||
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(r = sshbuf_put_string(b, sig, smlen - datalen)) != 0)
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goto out;
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len = sshbuf_len(b);
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if (sigp != NULL) {
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if ((*sigp = malloc(len)) == NULL) {
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r = SSH_ERR_ALLOC_FAIL;
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goto out;
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}
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memcpy(*sigp, sshbuf_ptr(b), len);
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}
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if (lenp != NULL)
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*lenp = len;
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/* success */
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r = 0;
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out:
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sshbuf_free(b);
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if (sig != NULL)
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freezero(sig, slen);
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return r;
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}
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static int
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ssh_ed25519_verify(const struct sshkey *key,
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const u_char *sig, size_t siglen,
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const u_char *data, size_t dlen, const char *alg, u_int compat,
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struct sshkey_sig_details **detailsp)
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{
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struct sshbuf *b = NULL;
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char *ktype = NULL;
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const u_char *sigblob;
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u_char *sm = NULL, *m = NULL;
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size_t len;
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unsigned long long smlen = 0, mlen = 0;
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int r, ret;
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if (key == NULL ||
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sshkey_type_plain(key->type) != KEY_ED25519 ||
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key->ed25519_pk == NULL ||
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dlen >= INT_MAX - crypto_sign_ed25519_BYTES ||
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sig == NULL || siglen == 0)
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return SSH_ERR_INVALID_ARGUMENT;
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if ((b = sshbuf_from(sig, siglen)) == NULL)
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return SSH_ERR_ALLOC_FAIL;
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if ((r = sshbuf_get_cstring(b, &ktype, NULL)) != 0 ||
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(r = sshbuf_get_string_direct(b, &sigblob, &len)) != 0)
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goto out;
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if (strcmp("ssh-ed25519", ktype) != 0) {
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r = SSH_ERR_KEY_TYPE_MISMATCH;
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goto out;
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}
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if (sshbuf_len(b) != 0) {
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r = SSH_ERR_UNEXPECTED_TRAILING_DATA;
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goto out;
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}
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if (len > crypto_sign_ed25519_BYTES) {
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r = SSH_ERR_INVALID_FORMAT;
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goto out;
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}
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if (dlen >= SIZE_MAX - len) {
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r = SSH_ERR_INVALID_ARGUMENT;
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goto out;
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}
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smlen = len + dlen;
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mlen = smlen;
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if ((sm = malloc(smlen)) == NULL || (m = malloc(mlen)) == NULL) {
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r = SSH_ERR_ALLOC_FAIL;
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goto out;
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}
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memcpy(sm, sigblob, len);
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memcpy(sm+len, data, dlen);
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if ((ret = crypto_sign_ed25519_open(m, &mlen, sm, smlen,
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key->ed25519_pk)) != 0) {
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debug2_f("crypto_sign_ed25519_open failed: %d", ret);
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}
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if (ret != 0 || mlen != dlen) {
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r = SSH_ERR_SIGNATURE_INVALID;
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goto out;
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}
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/* XXX compare 'm' and 'data' ? */
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/* success */
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r = 0;
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out:
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if (sm != NULL)
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freezero(sm, smlen);
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if (m != NULL)
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freezero(m, smlen); /* NB mlen may be invalid if r != 0 */
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sshbuf_free(b);
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free(ktype);
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return r;
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}
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/* NB. not static; used by ED25519-SK */
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const struct sshkey_impl_funcs sshkey_ed25519_funcs = {
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/* .size = */ NULL,
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/* .alloc = */ NULL,
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/* .cleanup = */ ssh_ed25519_cleanup,
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/* .equal = */ ssh_ed25519_equal,
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/* .ssh_serialize_public = */ ssh_ed25519_serialize_public,
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/* .ssh_deserialize_public = */ ssh_ed25519_deserialize_public,
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/* .ssh_serialize_private = */ ssh_ed25519_serialize_private,
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/* .ssh_deserialize_private = */ ssh_ed25519_deserialize_private,
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/* .generate = */ ssh_ed25519_generate,
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/* .copy_public = */ ssh_ed25519_copy_public,
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/* .sign = */ ssh_ed25519_sign,
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/* .verify = */ ssh_ed25519_verify,
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};
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const struct sshkey_impl sshkey_ed25519_impl = {
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/* .name = */ "ssh-ed25519",
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/* .shortname = */ "ED25519",
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/* .sigalg = */ NULL,
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/* .type = */ KEY_ED25519,
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/* .nid = */ 0,
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/* .cert = */ 0,
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/* .sigonly = */ 0,
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/* .keybits = */ 256,
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/* .funcs = */ &sshkey_ed25519_funcs,
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};
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const struct sshkey_impl sshkey_ed25519_cert_impl = {
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/* .name = */ "ssh-ed25519-cert-v01@openssh.com",
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/* .shortname = */ "ED25519-CERT",
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/* .sigalg = */ NULL,
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/* .type = */ KEY_ED25519_CERT,
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/* .nid = */ 0,
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/* .cert = */ 1,
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/* .sigonly = */ 0,
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/* .keybits = */ 256,
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/* .funcs = */ &sshkey_ed25519_funcs,
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};
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