OpenBSD-4.6/usr.bin/ssh/bufaux.c
/* $OpenBSD: bufaux.c,v 1.46 2008/06/10 23:21:34 dtucker Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Auxiliary functions for storing and retrieving various data types to/from
* Buffers.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*
*
* SSH2 packet format added by Markus Friedl
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include <openssl/bn.h>
#include <string.h>
#include <stdarg.h>
#include "xmalloc.h"
#include "buffer.h"
#include "log.h"
#include "misc.h"
/*
* Returns integers from the buffer (msb first).
*/
int
buffer_get_short_ret(u_short *ret, Buffer *buffer)
{
u_char buf[2];
if (buffer_get_ret(buffer, (char *) buf, 2) == -1)
return (-1);
*ret = get_u16(buf);
return (0);
}
u_short
buffer_get_short(Buffer *buffer)
{
u_short ret;
if (buffer_get_short_ret(&ret, buffer) == -1)
fatal("buffer_get_short: buffer error");
return (ret);
}
int
buffer_get_int_ret(u_int *ret, Buffer *buffer)
{
u_char buf[4];
if (buffer_get_ret(buffer, (char *) buf, 4) == -1)
return (-1);
*ret = get_u32(buf);
return (0);
}
u_int
buffer_get_int(Buffer *buffer)
{
u_int ret;
if (buffer_get_int_ret(&ret, buffer) == -1)
fatal("buffer_get_int: buffer error");
return (ret);
}
int
buffer_get_int64_ret(u_int64_t *ret, Buffer *buffer)
{
u_char buf[8];
if (buffer_get_ret(buffer, (char *) buf, 8) == -1)
return (-1);
*ret = get_u64(buf);
return (0);
}
u_int64_t
buffer_get_int64(Buffer *buffer)
{
u_int64_t ret;
if (buffer_get_int64_ret(&ret, buffer) == -1)
fatal("buffer_get_int: buffer error");
return (ret);
}
/*
* Stores integers in the buffer, msb first.
*/
void
buffer_put_short(Buffer *buffer, u_short value)
{
char buf[2];
put_u16(buf, value);
buffer_append(buffer, buf, 2);
}
void
buffer_put_int(Buffer *buffer, u_int value)
{
char buf[4];
put_u32(buf, value);
buffer_append(buffer, buf, 4);
}
void
buffer_put_int64(Buffer *buffer, u_int64_t value)
{
char buf[8];
put_u64(buf, value);
buffer_append(buffer, buf, 8);
}
/*
* Returns an arbitrary binary string from the buffer. The string cannot
* be longer than 256k. The returned value points to memory allocated
* with xmalloc; it is the responsibility of the calling function to free
* the data. If length_ptr is non-NULL, the length of the returned data
* will be stored there. A null character will be automatically appended
* to the returned string, and is not counted in length.
*/
void *
buffer_get_string_ret(Buffer *buffer, u_int *length_ptr)
{
u_char *value;
u_int len;
/* Get the length. */
len = buffer_get_int(buffer);
if (len > 256 * 1024) {
error("buffer_get_string_ret: bad string length %u", len);
return (NULL);
}
/* Allocate space for the string. Add one byte for a null character. */
value = xmalloc(len + 1);
/* Get the string. */
if (buffer_get_ret(buffer, value, len) == -1) {
error("buffer_get_string_ret: buffer_get failed");
xfree(value);
return (NULL);
}
/* Append a null character to make processing easier. */
value[len] = '\0';
/* Optionally return the length of the string. */
if (length_ptr)
*length_ptr = len;
return (value);
}
void *
buffer_get_string(Buffer *buffer, u_int *length_ptr)
{
void *ret;
if ((ret = buffer_get_string_ret(buffer, length_ptr)) == NULL)
fatal("buffer_get_string: buffer error");
return (ret);
}
void *
buffer_get_string_ptr(Buffer *buffer, u_int *length_ptr)
{
void *ptr;
u_int len;
len = buffer_get_int(buffer);
if (len > 256 * 1024)
fatal("buffer_get_string_ptr: bad string length %u", len);
ptr = buffer_ptr(buffer);
buffer_consume(buffer, len);
if (length_ptr)
*length_ptr = len;
return (ptr);
}
/*
* Stores and arbitrary binary string in the buffer.
*/
void
buffer_put_string(Buffer *buffer, const void *buf, u_int len)
{
buffer_put_int(buffer, len);
buffer_append(buffer, buf, len);
}
void
buffer_put_cstring(Buffer *buffer, const char *s)
{
if (s == NULL)
fatal("buffer_put_cstring: s == NULL");
buffer_put_string(buffer, s, strlen(s));
}
/*
* Returns a character from the buffer (0 - 255).
*/
int
buffer_get_char_ret(char *ret, Buffer *buffer)
{
if (buffer_get_ret(buffer, ret, 1) == -1) {
error("buffer_get_char_ret: buffer_get_ret failed");
return (-1);
}
return (0);
}
int
buffer_get_char(Buffer *buffer)
{
char ch;
if (buffer_get_char_ret(&ch, buffer) == -1)
fatal("buffer_get_char: buffer error");
return (u_char) ch;
}
/*
* Stores a character in the buffer.
*/
void
buffer_put_char(Buffer *buffer, int value)
{
char ch = value;
buffer_append(buffer, &ch, 1);
}