Release notes are available at https://www.openssh.com/txt/release-9.2 OpenSSH 9.2 contains fixes for two security problems and a memory safety problem. The memory safety problem is not believed to be exploitable. These fixes have already been committed to OpenSSH 9.1 in FreeBSD. Some other notable items from the release notes: * ssh(1): add a new EnableEscapeCommandline ssh_config(5) option that controls whether the client-side ~C escape sequence that provides a command-line is available. Among other things, the ~C command-line could be used to add additional port-forwards at runtime. * sshd(8): add support for channel inactivity timeouts via a new sshd_config(5) ChannelTimeout directive. This allows channels that have not seen traffic in a configurable interval to be automatically closed. Different timeouts may be applied to session, X11, agent and TCP forwarding channels. * sshd(8): add a sshd_config UnusedConnectionTimeout option to terminate client connections that have no open channels for a length of time. This complements the ChannelTimeout option above. * sshd(8): add a -V (version) option to sshd like the ssh client has. * scp(1), sftp(1): add a -X option to both scp(1) and sftp(1) to allow control over some SFTP protocol parameters: the copy buffer length and the number of in-flight requests, both of which are used during upload/download. Previously these could be controlled in sftp(1) only. This makes them available in both SFTP protocol clients using the same option character sequence. * ssh-keyscan(1): allow scanning of complete CIDR address ranges, e.g. "ssh-keyscan 192.168.0.0/24". If a CIDR range is passed, then it will be expanded to all possible addresses in the range including the all-0s and all-1s addresses. bz#976 * ssh(1): support dynamic remote port forwarding in escape command-line's -R processing. bz#3499 MFC after: 1 week Sponsored by: The FreeBSD Foundation
388 lines
10 KiB
C
388 lines
10 KiB
C
/* $OpenBSD: ssh-xmss.c,v 1.14 2022/10/28 00:44:44 djm Exp $*/
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/*
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* Copyright (c) 2017 Stefan-Lukas Gazdag.
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* Copyright (c) 2017 Markus Friedl.
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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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#ifdef WITH_XMSS
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#define SSHKEY_INTERNAL
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#include <sys/types.h>
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#include <limits.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdarg.h>
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#include <stdint.h>
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#include <unistd.h>
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#include "log.h"
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#include "sshbuf.h"
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#include "sshkey.h"
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#include "sshkey-xmss.h"
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#include "ssherr.h"
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#include "ssh.h"
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#include "xmss_fast.h"
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static void
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ssh_xmss_cleanup(struct sshkey *k)
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{
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freezero(k->xmss_pk, sshkey_xmss_pklen(k));
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freezero(k->xmss_sk, sshkey_xmss_sklen(k));
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sshkey_xmss_free_state(k);
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free(k->xmss_name);
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free(k->xmss_filename);
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k->xmss_pk = NULL;
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k->xmss_sk = NULL;
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k->xmss_name = NULL;
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k->xmss_filename = NULL;
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}
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static int
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ssh_xmss_equal(const struct sshkey *a, const struct sshkey *b)
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{
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if (a->xmss_pk == NULL || b->xmss_pk == NULL)
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return 0;
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if (sshkey_xmss_pklen(a) != sshkey_xmss_pklen(b))
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return 0;
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if (memcmp(a->xmss_pk, b->xmss_pk, sshkey_xmss_pklen(a)) != 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_xmss_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->xmss_name == NULL || key->xmss_pk == NULL ||
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sshkey_xmss_pklen(key) == 0)
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return SSH_ERR_INVALID_ARGUMENT;
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if ((r = sshbuf_put_cstring(b, key->xmss_name)) != 0 ||
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(r = sshbuf_put_string(b, key->xmss_pk,
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sshkey_xmss_pklen(key))) != 0 ||
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(r = sshkey_xmss_serialize_pk_info(key, b, opts)) != 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_xmss_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 (key->xmss_name == NULL)
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return SSH_ERR_INVALID_ARGUMENT;
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/* Note: can't reuse ssh_xmss_serialize_public because of sk order */
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if ((r = sshbuf_put_cstring(b, key->xmss_name)) != 0 ||
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(r = sshbuf_put_string(b, key->xmss_pk,
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sshkey_xmss_pklen(key))) != 0 ||
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(r = sshbuf_put_string(b, key->xmss_sk,
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sshkey_xmss_sklen(key))) != 0 ||
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(r = sshkey_xmss_serialize_state_opt(key, b, opts)) != 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_xmss_copy_public(const struct sshkey *from, struct sshkey *to)
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{
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int r = SSH_ERR_INTERNAL_ERROR;
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u_int32_t left;
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size_t pklen;
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if ((r = sshkey_xmss_init(to, from->xmss_name)) != 0)
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return r;
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if (from->xmss_pk == NULL)
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return 0; /* XXX SSH_ERR_INTERNAL_ERROR ? */
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if ((pklen = sshkey_xmss_pklen(from)) == 0 ||
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sshkey_xmss_pklen(to) != pklen)
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return SSH_ERR_INTERNAL_ERROR;
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if ((to->xmss_pk = malloc(pklen)) == NULL)
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return SSH_ERR_ALLOC_FAIL;
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memcpy(to->xmss_pk, from->xmss_pk, pklen);
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/* simulate number of signatures left on pubkey */
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left = sshkey_xmss_signatures_left(from);
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if (left)
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sshkey_xmss_enable_maxsign(to, left);
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return 0;
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}
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static int
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ssh_xmss_deserialize_public(const char *ktype, struct sshbuf *b,
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struct sshkey *key)
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{
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size_t len = 0;
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char *xmss_name = NULL;
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u_char *pk = NULL;
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int ret = SSH_ERR_INTERNAL_ERROR;
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if ((ret = sshbuf_get_cstring(b, &xmss_name, NULL)) != 0)
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goto out;
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if ((ret = sshkey_xmss_init(key, xmss_name)) != 0)
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goto out;
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if ((ret = sshbuf_get_string(b, &pk, &len)) != 0)
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goto out;
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if (len == 0 || len != sshkey_xmss_pklen(key)) {
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ret = SSH_ERR_INVALID_FORMAT;
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goto out;
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}
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key->xmss_pk = pk;
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pk = NULL;
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if (!sshkey_is_cert(key) &&
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(ret = sshkey_xmss_deserialize_pk_info(key, b)) != 0)
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goto out;
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/* success */
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ret = 0;
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out:
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free(xmss_name);
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freezero(pk, len);
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return ret;
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}
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static int
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ssh_xmss_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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char *xmss_name = NULL;
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size_t pklen = 0, sklen = 0;
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u_char *xmss_pk = NULL, *xmss_sk = NULL;
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/* Note: can't reuse ssh_xmss_deserialize_public because of sk order */
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if ((r = sshbuf_get_cstring(b, &xmss_name, NULL)) != 0 ||
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(r = sshbuf_get_string(b, &xmss_pk, &pklen)) != 0 ||
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(r = sshbuf_get_string(b, &xmss_sk, &sklen)) != 0)
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goto out;
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if (!sshkey_is_cert(key) &&
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(r = sshkey_xmss_init(key, xmss_name)) != 0)
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goto out;
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if (pklen != sshkey_xmss_pklen(key) ||
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sklen != sshkey_xmss_sklen(key)) {
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r = SSH_ERR_INVALID_FORMAT;
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goto out;
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}
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key->xmss_pk = xmss_pk;
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key->xmss_sk = xmss_sk;
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xmss_pk = xmss_sk = NULL;
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/* optional internal state */
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if ((r = sshkey_xmss_deserialize_state_opt(key, b)) != 0)
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goto out;
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/* success */
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r = 0;
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out:
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free(xmss_name);
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freezero(xmss_pk, pklen);
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freezero(xmss_sk, sklen);
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return r;
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}
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static int
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ssh_xmss_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 = 0, required_siglen;
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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_XMSS ||
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key->xmss_sk == NULL ||
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sshkey_xmss_params(key) == NULL)
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return SSH_ERR_INVALID_ARGUMENT;
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if ((r = sshkey_xmss_siglen(key, &required_siglen)) != 0)
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return r;
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if (datalen >= INT_MAX - required_siglen)
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return SSH_ERR_INVALID_ARGUMENT;
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smlen = slen = datalen + required_siglen;
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if ((sig = malloc(slen)) == NULL)
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return SSH_ERR_ALLOC_FAIL;
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if ((r = sshkey_xmss_get_state(key, 1)) != 0)
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goto out;
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if ((ret = xmss_sign(key->xmss_sk, sshkey_xmss_bds_state(key), sig, &smlen,
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data, datalen, sshkey_xmss_params(key))) != 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-xmss@openssh.com")) != 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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if ((ret = sshkey_xmss_update_state(key, 1)) != 0) {
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/* discard signature since we cannot update the state */
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if (r == 0 && sigp != NULL && *sigp != NULL) {
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explicit_bzero(*sigp, len);
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free(*sigp);
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}
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if (sigp != NULL)
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*sigp = NULL;
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if (lenp != NULL)
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*lenp = 0;
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r = ret;
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}
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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_xmss_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, required_siglen;
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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_XMSS ||
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key->xmss_pk == NULL ||
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sshkey_xmss_params(key) == NULL ||
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sig == NULL || siglen == 0)
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return SSH_ERR_INVALID_ARGUMENT;
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if ((r = sshkey_xmss_siglen(key, &required_siglen)) != 0)
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return r;
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if (dlen >= INT_MAX - required_siglen)
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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-xmss@openssh.com", 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 != required_siglen) {
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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 = xmss_sign_open(m, &mlen, sm, smlen,
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key->xmss_pk, sshkey_xmss_params(key))) != 0) {
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debug2_f("xmss_sign_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);
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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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static const struct sshkey_impl_funcs sshkey_xmss_funcs = {
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/* .size = */ NULL,
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/* .alloc = */ NULL,
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/* .cleanup = */ ssh_xmss_cleanup,
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/* .equal = */ ssh_xmss_equal,
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/* .ssh_serialize_public = */ ssh_xmss_serialize_public,
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/* .ssh_deserialize_public = */ ssh_xmss_deserialize_public,
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/* .ssh_serialize_private = */ ssh_xmss_serialize_private,
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/* .ssh_deserialize_private = */ ssh_xmss_deserialize_private,
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/* .generate = */ sshkey_xmss_generate_private_key,
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/* .copy_public = */ ssh_xmss_copy_public,
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/* .sign = */ ssh_xmss_sign,
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/* .verify = */ ssh_xmss_verify,
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};
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const struct sshkey_impl sshkey_xmss_impl = {
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/* .name = */ "ssh-xmss@openssh.com",
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/* .shortname = */ "XMSS",
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/* .sigalg = */ NULL,
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/* .type = */ KEY_XMSS,
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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_xmss_funcs,
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};
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const struct sshkey_impl sshkey_xmss_cert_impl = {
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/* .name = */ "ssh-xmss-cert-v01@openssh.com",
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/* .shortname = */ "XMSS-CERT",
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/* .sigalg = */ NULL,
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/* .type = */ KEY_XMSS_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_xmss_funcs,
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};
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#endif /* WITH_XMSS */
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