opnsense-src/crypto/openssh/sshbuf-getput-basic.c
Ed Maste 27ceebbc24 openssh: simplify login class restrictions
Login class-based restrictions were introduced in 5b400a39b8.  The
code was adapted for sshd's Capsicum sandbox and received many changes
over time, including at least fc3c19a9fc, bd393de91c, and
e8c56fba29.

During an attempt to upstream the work a much simpler approach was
suggested.  Adopt it now in the in-tree OpenSSH to reduce conflicts with
future updates.

Submitted by:	Yuchiro Naito (against OpenSSH-portable on GitHub)
Obtained from:	https://github.com/openssh/openssh-portable/pull/262
Reviewed by:	allanjude, kevans
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D31760
2021-09-01 15:53:09 -04:00

465 lines
9.2 KiB
C

/* $OpenBSD: sshbuf-getput-basic.c,v 1.7 2017/06/01 04:51:58 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.
*/
#define SSHBUF_INTERNAL
#include "includes.h"
#include <sys/types.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "xmalloc.h"
#include "ssherr.h"
#include "sshbuf.h"
int
sshbuf_get(struct sshbuf *buf, void *v, size_t len)
{
const u_char *p = sshbuf_ptr(buf);
int r;
if ((r = sshbuf_consume(buf, len)) < 0)
return r;
if (v != NULL && len != 0)
memcpy(v, p, len);
return 0;
}
int
sshbuf_get_u64(struct sshbuf *buf, u_int64_t *valp)
{
const u_char *p = sshbuf_ptr(buf);
int r;
if ((r = sshbuf_consume(buf, 8)) < 0)
return r;
if (valp != NULL)
*valp = PEEK_U64(p);
return 0;
}
int
sshbuf_get_u32(struct sshbuf *buf, u_int32_t *valp)
{
const u_char *p = sshbuf_ptr(buf);
int r;
if ((r = sshbuf_consume(buf, 4)) < 0)
return r;
if (valp != NULL)
*valp = PEEK_U32(p);
return 0;
}
int
sshbuf_get_u16(struct sshbuf *buf, u_int16_t *valp)
{
const u_char *p = sshbuf_ptr(buf);
int r;
if ((r = sshbuf_consume(buf, 2)) < 0)
return r;
if (valp != NULL)
*valp = PEEK_U16(p);
return 0;
}
int
sshbuf_get_u8(struct sshbuf *buf, u_char *valp)
{
const u_char *p = sshbuf_ptr(buf);
int r;
if ((r = sshbuf_consume(buf, 1)) < 0)
return r;
if (valp != NULL)
*valp = (u_int8_t)*p;
return 0;
}
int
sshbuf_get_string(struct sshbuf *buf, u_char **valp, size_t *lenp)
{
const u_char *val;
size_t len;
int r;
if (valp != NULL)
*valp = NULL;
if (lenp != NULL)
*lenp = 0;
if ((r = sshbuf_get_string_direct(buf, &val, &len)) < 0)
return r;
if (valp != NULL) {
if ((*valp = malloc(len + 1)) == NULL) {
SSHBUF_DBG(("SSH_ERR_ALLOC_FAIL"));
return SSH_ERR_ALLOC_FAIL;
}
if (len != 0)
memcpy(*valp, val, len);
(*valp)[len] = '\0';
}
if (lenp != NULL)
*lenp = len;
return 0;
}
int
sshbuf_get_string_direct(struct sshbuf *buf, const u_char **valp, size_t *lenp)
{
size_t len;
const u_char *p;
int r;
if (valp != NULL)
*valp = NULL;
if (lenp != NULL)
*lenp = 0;
if ((r = sshbuf_peek_string_direct(buf, &p, &len)) < 0)
return r;
if (valp != NULL)
*valp = p;
if (lenp != NULL)
*lenp = len;
if (sshbuf_consume(buf, len + 4) != 0) {
/* Shouldn't happen */
SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
SSHBUF_ABORT();
return SSH_ERR_INTERNAL_ERROR;
}
return 0;
}
int
sshbuf_peek_string_direct(const struct sshbuf *buf, const u_char **valp,
size_t *lenp)
{
u_int32_t len;
const u_char *p = sshbuf_ptr(buf);
if (valp != NULL)
*valp = NULL;
if (lenp != NULL)
*lenp = 0;
if (sshbuf_len(buf) < 4) {
SSHBUF_DBG(("SSH_ERR_MESSAGE_INCOMPLETE"));
return SSH_ERR_MESSAGE_INCOMPLETE;
}
len = PEEK_U32(p);
if (len > SSHBUF_SIZE_MAX - 4) {
SSHBUF_DBG(("SSH_ERR_STRING_TOO_LARGE"));
return SSH_ERR_STRING_TOO_LARGE;
}
if (sshbuf_len(buf) - 4 < len) {
SSHBUF_DBG(("SSH_ERR_MESSAGE_INCOMPLETE"));
return SSH_ERR_MESSAGE_INCOMPLETE;
}
if (valp != NULL)
*valp = p + 4;
if (lenp != NULL)
*lenp = len;
return 0;
}
int
sshbuf_get_cstring(struct sshbuf *buf, char **valp, size_t *lenp)
{
size_t len;
const u_char *p, *z;
int r;
if (valp != NULL)
*valp = NULL;
if (lenp != NULL)
*lenp = 0;
if ((r = sshbuf_peek_string_direct(buf, &p, &len)) != 0)
return r;
/* Allow a \0 only at the end of the string */
if (len > 0 &&
(z = memchr(p , '\0', len)) != NULL && z < p + len - 1) {
SSHBUF_DBG(("SSH_ERR_INVALID_FORMAT"));
return SSH_ERR_INVALID_FORMAT;
}
if ((r = sshbuf_skip_string(buf)) != 0)
return -1;
if (valp != NULL) {
if ((*valp = malloc(len + 1)) == NULL) {
SSHBUF_DBG(("SSH_ERR_ALLOC_FAIL"));
return SSH_ERR_ALLOC_FAIL;
}
if (len != 0)
memcpy(*valp, p, len);
(*valp)[len] = '\0';
}
if (lenp != NULL)
*lenp = (size_t)len;
return 0;
}
int
sshbuf_get_stringb(struct sshbuf *buf, struct sshbuf *v)
{
u_int32_t len;
u_char *p;
int r;
/*
* Use sshbuf_peek_string_direct() to figure out if there is
* a complete string in 'buf' and copy the string directly
* into 'v'.
*/
if ((r = sshbuf_peek_string_direct(buf, NULL, NULL)) != 0 ||
(r = sshbuf_get_u32(buf, &len)) != 0 ||
(r = sshbuf_reserve(v, len, &p)) != 0 ||
(r = sshbuf_get(buf, p, len)) != 0)
return r;
return 0;
}
int
sshbuf_put(struct sshbuf *buf, const void *v, size_t len)
{
u_char *p;
int r;
if ((r = sshbuf_reserve(buf, len, &p)) < 0)
return r;
if (len != 0)
memcpy(p, v, len);
return 0;
}
int
sshbuf_putb(struct sshbuf *buf, const struct sshbuf *v)
{
return sshbuf_put(buf, sshbuf_ptr(v), sshbuf_len(v));
}
int
sshbuf_putf(struct sshbuf *buf, const char *fmt, ...)
{
va_list ap;
int r;
va_start(ap, fmt);
r = sshbuf_putfv(buf, fmt, ap);
va_end(ap);
return r;
}
int
sshbuf_putfv(struct sshbuf *buf, const char *fmt, va_list ap)
{
va_list ap2;
int r, len;
u_char *p;
VA_COPY(ap2, ap);
if ((len = vsnprintf(NULL, 0, fmt, ap2)) < 0) {
r = SSH_ERR_INVALID_ARGUMENT;
goto out;
}
if (len == 0) {
r = 0;
goto out; /* Nothing to do */
}
va_end(ap2);
VA_COPY(ap2, ap);
if ((r = sshbuf_reserve(buf, (size_t)len + 1, &p)) < 0)
goto out;
if ((r = vsnprintf((char *)p, len + 1, fmt, ap2)) != len) {
r = SSH_ERR_INTERNAL_ERROR;
goto out; /* Shouldn't happen */
}
/* Consume terminating \0 */
if ((r = sshbuf_consume_end(buf, 1)) != 0)
goto out;
r = 0;
out:
va_end(ap2);
return r;
}
int
sshbuf_put_u64(struct sshbuf *buf, u_int64_t val)
{
u_char *p;
int r;
if ((r = sshbuf_reserve(buf, 8, &p)) < 0)
return r;
POKE_U64(p, val);
return 0;
}
int
sshbuf_put_u32(struct sshbuf *buf, u_int32_t val)
{
u_char *p;
int r;
if ((r = sshbuf_reserve(buf, 4, &p)) < 0)
return r;
POKE_U32(p, val);
return 0;
}
int
sshbuf_put_u16(struct sshbuf *buf, u_int16_t val)
{
u_char *p;
int r;
if ((r = sshbuf_reserve(buf, 2, &p)) < 0)
return r;
POKE_U16(p, val);
return 0;
}
int
sshbuf_put_u8(struct sshbuf *buf, u_char val)
{
u_char *p;
int r;
if ((r = sshbuf_reserve(buf, 1, &p)) < 0)
return r;
p[0] = val;
return 0;
}
int
sshbuf_put_string(struct sshbuf *buf, const void *v, size_t len)
{
u_char *d;
int r;
if (len > SSHBUF_SIZE_MAX - 4) {
SSHBUF_DBG(("SSH_ERR_NO_BUFFER_SPACE"));
return SSH_ERR_NO_BUFFER_SPACE;
}
if ((r = sshbuf_reserve(buf, len + 4, &d)) < 0)
return r;
POKE_U32(d, len);
if (len != 0)
memcpy(d + 4, v, len);
return 0;
}
int
sshbuf_put_cstring(struct sshbuf *buf, const char *v)
{
return sshbuf_put_string(buf, v, v == NULL ? 0 : strlen(v));
}
int
sshbuf_put_stringb(struct sshbuf *buf, const struct sshbuf *v)
{
return sshbuf_put_string(buf, sshbuf_ptr(v), sshbuf_len(v));
}
int
sshbuf_froms(struct sshbuf *buf, struct sshbuf **bufp)
{
const u_char *p;
size_t len;
struct sshbuf *ret;
int r;
if (buf == NULL || bufp == NULL)
return SSH_ERR_INVALID_ARGUMENT;
*bufp = NULL;
if ((r = sshbuf_peek_string_direct(buf, &p, &len)) != 0)
return r;
if ((ret = sshbuf_from(p, len)) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((r = sshbuf_consume(buf, len + 4)) != 0 || /* Shouldn't happen */
(r = sshbuf_set_parent(ret, buf)) != 0) {
sshbuf_free(ret);
return r;
}
*bufp = ret;
return 0;
}
int
sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len)
{
u_char *d;
const u_char *s = (const u_char *)v;
int r, prepend;
if (len > SSHBUF_SIZE_MAX - 5) {
SSHBUF_DBG(("SSH_ERR_NO_BUFFER_SPACE"));
return SSH_ERR_NO_BUFFER_SPACE;
}
/* Skip leading zero bytes */
for (; len > 0 && *s == 0; len--, s++)
;
/*
* If most significant bit is set then prepend a zero byte to
* avoid interpretation as a negative number.
*/
prepend = len > 0 && (s[0] & 0x80) != 0;
if ((r = sshbuf_reserve(buf, len + 4 + prepend, &d)) < 0)
return r;
POKE_U32(d, len + prepend);
if (prepend)
d[4] = 0;
if (len != 0)
memcpy(d + 4 + prepend, s, len);
return 0;
}
int
sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf,
const u_char **valp, size_t *lenp)
{
const u_char *d;
size_t len, olen;
int r;
if ((r = sshbuf_peek_string_direct(buf, &d, &olen)) < 0)
return r;
len = olen;
/* Refuse negative (MSB set) bignums */
if ((len != 0 && (*d & 0x80) != 0))
return SSH_ERR_BIGNUM_IS_NEGATIVE;
/* Refuse overlong bignums, allow prepended \0 to avoid MSB set */
if (len > SSHBUF_MAX_BIGNUM + 1 ||
(len == SSHBUF_MAX_BIGNUM + 1 && *d != 0))
return SSH_ERR_BIGNUM_TOO_LARGE;
/* Trim leading zeros */
while (len > 0 && *d == 0x00) {
d++;
len--;
}
if (valp != NULL)
*valp = d;
if (lenp != NULL)
*lenp = len;
if (sshbuf_consume(buf, olen + 4) != 0) {
/* Shouldn't happen */
SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
SSHBUF_ABORT();
return SSH_ERR_INTERNAL_ERROR;
}
return 0;
}