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
428 lines
9.8 KiB
C
428 lines
9.8 KiB
C
/* $OpenBSD: sshbuf.c,v 1.19 2022/12/02 04:40:27 djm Exp $ */
|
|
/*
|
|
* Copyright (c) 2011 Damien Miller
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
|
|
#include "includes.h"
|
|
|
|
#include <sys/types.h>
|
|
#include <signal.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
|
|
#include "ssherr.h"
|
|
#define SSHBUF_INTERNAL
|
|
#include "sshbuf.h"
|
|
#include "misc.h"
|
|
|
|
#ifdef SSHBUF_DEBUG
|
|
# define SSHBUF_TELL(what) do { \
|
|
printf("%s:%d %s: %s size %zu alloc %zu off %zu max %zu\n", \
|
|
__FILE__, __LINE__, __func__, what, \
|
|
buf->size, buf->alloc, buf->off, buf->max_size); \
|
|
fflush(stdout); \
|
|
} while (0)
|
|
#else
|
|
# define SSHBUF_TELL(what)
|
|
#endif
|
|
|
|
struct sshbuf {
|
|
u_char *d; /* Data */
|
|
const u_char *cd; /* Const data */
|
|
size_t off; /* First available byte is buf->d + buf->off */
|
|
size_t size; /* Last byte is buf->d + buf->size - 1 */
|
|
size_t max_size; /* Maximum size of buffer */
|
|
size_t alloc; /* Total bytes allocated to buf->d */
|
|
int readonly; /* Refers to external, const data */
|
|
u_int refcount; /* Tracks self and number of child buffers */
|
|
struct sshbuf *parent; /* If child, pointer to parent */
|
|
};
|
|
|
|
static inline int
|
|
sshbuf_check_sanity(const struct sshbuf *buf)
|
|
{
|
|
SSHBUF_TELL("sanity");
|
|
if (__predict_false(buf == NULL ||
|
|
(!buf->readonly && buf->d != buf->cd) ||
|
|
buf->refcount < 1 || buf->refcount > SSHBUF_REFS_MAX ||
|
|
buf->cd == NULL ||
|
|
buf->max_size > SSHBUF_SIZE_MAX ||
|
|
buf->alloc > buf->max_size ||
|
|
buf->size > buf->alloc ||
|
|
buf->off > buf->size)) {
|
|
/* Do not try to recover from corrupted buffer internals */
|
|
SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
|
|
ssh_signal(SIGSEGV, SIG_DFL);
|
|
raise(SIGSEGV);
|
|
return SSH_ERR_INTERNAL_ERROR;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
sshbuf_maybe_pack(struct sshbuf *buf, int force)
|
|
{
|
|
SSHBUF_DBG(("force %d", force));
|
|
SSHBUF_TELL("pre-pack");
|
|
if (buf->off == 0 || buf->readonly || buf->refcount > 1)
|
|
return;
|
|
if (force ||
|
|
(buf->off >= SSHBUF_PACK_MIN && buf->off >= buf->size / 2)) {
|
|
memmove(buf->d, buf->d + buf->off, buf->size - buf->off);
|
|
buf->size -= buf->off;
|
|
buf->off = 0;
|
|
SSHBUF_TELL("packed");
|
|
}
|
|
}
|
|
|
|
struct sshbuf *
|
|
sshbuf_new(void)
|
|
{
|
|
struct sshbuf *ret;
|
|
|
|
if ((ret = calloc(sizeof(*ret), 1)) == NULL)
|
|
return NULL;
|
|
ret->alloc = SSHBUF_SIZE_INIT;
|
|
ret->max_size = SSHBUF_SIZE_MAX;
|
|
ret->readonly = 0;
|
|
ret->refcount = 1;
|
|
ret->parent = NULL;
|
|
if ((ret->cd = ret->d = calloc(1, ret->alloc)) == NULL) {
|
|
free(ret);
|
|
return NULL;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
struct sshbuf *
|
|
sshbuf_from(const void *blob, size_t len)
|
|
{
|
|
struct sshbuf *ret;
|
|
|
|
if (blob == NULL || len > SSHBUF_SIZE_MAX ||
|
|
(ret = calloc(sizeof(*ret), 1)) == NULL)
|
|
return NULL;
|
|
ret->alloc = ret->size = ret->max_size = len;
|
|
ret->readonly = 1;
|
|
ret->refcount = 1;
|
|
ret->parent = NULL;
|
|
ret->cd = blob;
|
|
ret->d = NULL;
|
|
return ret;
|
|
}
|
|
|
|
int
|
|
sshbuf_set_parent(struct sshbuf *child, struct sshbuf *parent)
|
|
{
|
|
int r;
|
|
|
|
if ((r = sshbuf_check_sanity(child)) != 0 ||
|
|
(r = sshbuf_check_sanity(parent)) != 0)
|
|
return r;
|
|
if (child->parent != NULL && child->parent != parent)
|
|
return SSH_ERR_INTERNAL_ERROR;
|
|
child->parent = parent;
|
|
child->parent->refcount++;
|
|
return 0;
|
|
}
|
|
|
|
struct sshbuf *
|
|
sshbuf_fromb(struct sshbuf *buf)
|
|
{
|
|
struct sshbuf *ret;
|
|
|
|
if (sshbuf_check_sanity(buf) != 0)
|
|
return NULL;
|
|
if ((ret = sshbuf_from(sshbuf_ptr(buf), sshbuf_len(buf))) == NULL)
|
|
return NULL;
|
|
if (sshbuf_set_parent(ret, buf) != 0) {
|
|
sshbuf_free(ret);
|
|
return NULL;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
void
|
|
sshbuf_free(struct sshbuf *buf)
|
|
{
|
|
if (buf == NULL)
|
|
return;
|
|
/*
|
|
* The following will leak on insane buffers, but this is the safest
|
|
* course of action - an invalid pointer or already-freed pointer may
|
|
* have been passed to us and continuing to scribble over memory would
|
|
* be bad.
|
|
*/
|
|
if (sshbuf_check_sanity(buf) != 0)
|
|
return;
|
|
|
|
/*
|
|
* If we are a parent with still-extant children, then don't free just
|
|
* yet. The last child's call to sshbuf_free should decrement our
|
|
* refcount to 0 and trigger the actual free.
|
|
*/
|
|
buf->refcount--;
|
|
if (buf->refcount > 0)
|
|
return;
|
|
|
|
/*
|
|
* If we are a child, the free our parent to decrement its reference
|
|
* count and possibly free it.
|
|
*/
|
|
sshbuf_free(buf->parent);
|
|
buf->parent = NULL;
|
|
|
|
if (!buf->readonly) {
|
|
explicit_bzero(buf->d, buf->alloc);
|
|
free(buf->d);
|
|
}
|
|
freezero(buf, sizeof(*buf));
|
|
}
|
|
|
|
void
|
|
sshbuf_reset(struct sshbuf *buf)
|
|
{
|
|
u_char *d;
|
|
|
|
if (buf->readonly || buf->refcount > 1) {
|
|
/* Nonsensical. Just make buffer appear empty */
|
|
buf->off = buf->size;
|
|
return;
|
|
}
|
|
if (sshbuf_check_sanity(buf) != 0)
|
|
return;
|
|
buf->off = buf->size = 0;
|
|
if (buf->alloc != SSHBUF_SIZE_INIT) {
|
|
if ((d = recallocarray(buf->d, buf->alloc, SSHBUF_SIZE_INIT,
|
|
1)) != NULL) {
|
|
buf->cd = buf->d = d;
|
|
buf->alloc = SSHBUF_SIZE_INIT;
|
|
}
|
|
}
|
|
explicit_bzero(buf->d, buf->alloc);
|
|
}
|
|
|
|
size_t
|
|
sshbuf_max_size(const struct sshbuf *buf)
|
|
{
|
|
return buf->max_size;
|
|
}
|
|
|
|
size_t
|
|
sshbuf_alloc(const struct sshbuf *buf)
|
|
{
|
|
return buf->alloc;
|
|
}
|
|
|
|
const struct sshbuf *
|
|
sshbuf_parent(const struct sshbuf *buf)
|
|
{
|
|
return buf->parent;
|
|
}
|
|
|
|
u_int
|
|
sshbuf_refcount(const struct sshbuf *buf)
|
|
{
|
|
return buf->refcount;
|
|
}
|
|
|
|
int
|
|
sshbuf_set_max_size(struct sshbuf *buf, size_t max_size)
|
|
{
|
|
size_t rlen;
|
|
u_char *dp;
|
|
int r;
|
|
|
|
SSHBUF_DBG(("set max buf = %p len = %zu", buf, max_size));
|
|
if ((r = sshbuf_check_sanity(buf)) != 0)
|
|
return r;
|
|
if (max_size == buf->max_size)
|
|
return 0;
|
|
if (buf->readonly || buf->refcount > 1)
|
|
return SSH_ERR_BUFFER_READ_ONLY;
|
|
if (max_size > SSHBUF_SIZE_MAX)
|
|
return SSH_ERR_NO_BUFFER_SPACE;
|
|
/* pack and realloc if necessary */
|
|
sshbuf_maybe_pack(buf, max_size < buf->size);
|
|
if (max_size < buf->alloc && max_size > buf->size) {
|
|
if (buf->size < SSHBUF_SIZE_INIT)
|
|
rlen = SSHBUF_SIZE_INIT;
|
|
else
|
|
rlen = ROUNDUP(buf->size, SSHBUF_SIZE_INC);
|
|
if (rlen > max_size)
|
|
rlen = max_size;
|
|
SSHBUF_DBG(("new alloc = %zu", rlen));
|
|
if ((dp = recallocarray(buf->d, buf->alloc, rlen, 1)) == NULL)
|
|
return SSH_ERR_ALLOC_FAIL;
|
|
buf->cd = buf->d = dp;
|
|
buf->alloc = rlen;
|
|
}
|
|
SSHBUF_TELL("new-max");
|
|
if (max_size < buf->alloc)
|
|
return SSH_ERR_NO_BUFFER_SPACE;
|
|
buf->max_size = max_size;
|
|
return 0;
|
|
}
|
|
|
|
size_t
|
|
sshbuf_len(const struct sshbuf *buf)
|
|
{
|
|
if (sshbuf_check_sanity(buf) != 0)
|
|
return 0;
|
|
return buf->size - buf->off;
|
|
}
|
|
|
|
size_t
|
|
sshbuf_avail(const struct sshbuf *buf)
|
|
{
|
|
if (sshbuf_check_sanity(buf) != 0 || buf->readonly || buf->refcount > 1)
|
|
return 0;
|
|
return buf->max_size - (buf->size - buf->off);
|
|
}
|
|
|
|
const u_char *
|
|
sshbuf_ptr(const struct sshbuf *buf)
|
|
{
|
|
if (sshbuf_check_sanity(buf) != 0)
|
|
return NULL;
|
|
return buf->cd + buf->off;
|
|
}
|
|
|
|
u_char *
|
|
sshbuf_mutable_ptr(const struct sshbuf *buf)
|
|
{
|
|
if (sshbuf_check_sanity(buf) != 0 || buf->readonly || buf->refcount > 1)
|
|
return NULL;
|
|
return buf->d + buf->off;
|
|
}
|
|
|
|
int
|
|
sshbuf_check_reserve(const struct sshbuf *buf, size_t len)
|
|
{
|
|
int r;
|
|
|
|
if ((r = sshbuf_check_sanity(buf)) != 0)
|
|
return r;
|
|
if (buf->readonly || buf->refcount > 1)
|
|
return SSH_ERR_BUFFER_READ_ONLY;
|
|
SSHBUF_TELL("check");
|
|
/* Check that len is reasonable and that max_size + available < len */
|
|
if (len > buf->max_size || buf->max_size - len < buf->size - buf->off)
|
|
return SSH_ERR_NO_BUFFER_SPACE;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
sshbuf_allocate(struct sshbuf *buf, size_t len)
|
|
{
|
|
size_t rlen, need;
|
|
u_char *dp;
|
|
int r;
|
|
|
|
SSHBUF_DBG(("allocate buf = %p len = %zu", buf, len));
|
|
if ((r = sshbuf_check_reserve(buf, len)) != 0)
|
|
return r;
|
|
/*
|
|
* If the requested allocation appended would push us past max_size
|
|
* then pack the buffer, zeroing buf->off.
|
|
*/
|
|
sshbuf_maybe_pack(buf, buf->size + len > buf->max_size);
|
|
SSHBUF_TELL("allocate");
|
|
if (len + buf->size <= buf->alloc)
|
|
return 0; /* already have it. */
|
|
|
|
/*
|
|
* Prefer to alloc in SSHBUF_SIZE_INC units, but
|
|
* allocate less if doing so would overflow max_size.
|
|
*/
|
|
need = len + buf->size - buf->alloc;
|
|
rlen = ROUNDUP(buf->alloc + need, SSHBUF_SIZE_INC);
|
|
SSHBUF_DBG(("need %zu initial rlen %zu", need, rlen));
|
|
if (rlen > buf->max_size)
|
|
rlen = buf->alloc + need;
|
|
SSHBUF_DBG(("adjusted rlen %zu", rlen));
|
|
if ((dp = recallocarray(buf->d, buf->alloc, rlen, 1)) == NULL) {
|
|
SSHBUF_DBG(("realloc fail"));
|
|
return SSH_ERR_ALLOC_FAIL;
|
|
}
|
|
buf->alloc = rlen;
|
|
buf->cd = buf->d = dp;
|
|
if ((r = sshbuf_check_reserve(buf, len)) < 0) {
|
|
/* shouldn't fail */
|
|
return r;
|
|
}
|
|
SSHBUF_TELL("done");
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
sshbuf_reserve(struct sshbuf *buf, size_t len, u_char **dpp)
|
|
{
|
|
u_char *dp;
|
|
int r;
|
|
|
|
if (dpp != NULL)
|
|
*dpp = NULL;
|
|
|
|
SSHBUF_DBG(("reserve buf = %p len = %zu", buf, len));
|
|
if ((r = sshbuf_allocate(buf, len)) != 0)
|
|
return r;
|
|
|
|
dp = buf->d + buf->size;
|
|
buf->size += len;
|
|
if (dpp != NULL)
|
|
*dpp = dp;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
sshbuf_consume(struct sshbuf *buf, size_t len)
|
|
{
|
|
int r;
|
|
|
|
SSHBUF_DBG(("len = %zu", len));
|
|
if ((r = sshbuf_check_sanity(buf)) != 0)
|
|
return r;
|
|
if (len == 0)
|
|
return 0;
|
|
if (len > sshbuf_len(buf))
|
|
return SSH_ERR_MESSAGE_INCOMPLETE;
|
|
buf->off += len;
|
|
/* deal with empty buffer */
|
|
if (buf->off == buf->size)
|
|
buf->off = buf->size = 0;
|
|
SSHBUF_TELL("done");
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
sshbuf_consume_end(struct sshbuf *buf, size_t len)
|
|
{
|
|
int r;
|
|
|
|
SSHBUF_DBG(("len = %zu", len));
|
|
if ((r = sshbuf_check_sanity(buf)) != 0)
|
|
return r;
|
|
if (len == 0)
|
|
return 0;
|
|
if (len > sshbuf_len(buf))
|
|
return SSH_ERR_MESSAGE_INCOMPLETE;
|
|
buf->size -= len;
|
|
SSHBUF_TELL("done");
|
|
return 0;
|
|
}
|
|
|