bufaux.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* 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 "includes.h"
RCSID("$OpenBSD: bufaux.c,v 1.27 2002/06/26 08:53:12 markus Exp $");
#pragma ident "%Z%%M% %I% %E% SMI"
#include <langinfo.h>
#include <openssl/bn.h>
#include "bufaux.h"
#include "xmalloc.h"
#include "getput.h"
#include "log.h"
#include "g11n.h"
/*
* Stores an BIGNUM in the buffer with a 2-byte msb first bit count, followed
* by (bits+7)/8 bytes of binary data, msb first.
*/
void
buffer_put_bignum(Buffer *buffer, BIGNUM *value)
{
int bits = BN_num_bits(value);
int bin_size = (bits + 7) / 8;
u_char *buf = xmalloc(bin_size);
int oi;
char msg[2];
/* Get the value of in binary */
oi = BN_bn2bin(value, buf);
if (oi != bin_size)
fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d",
oi, bin_size);
/* Store the number of bits in the buffer in two bytes, msb first. */
PUT_16BIT(msg, bits);
buffer_append(buffer, msg, 2);
/* Store the binary data. */
buffer_append(buffer, (char *)buf, oi);
memset(buf, 0, bin_size);
xfree(buf);
}
/*
* Retrieves an BIGNUM from the buffer.
*/
void
buffer_get_bignum(Buffer *buffer, BIGNUM *value)
{
int bits, bytes;
u_char buf[2], *bin;
/* Get the number for bits. */
buffer_get(buffer, (char *) buf, 2);
bits = GET_16BIT(buf);
/* Compute the number of binary bytes that follow. */
bytes = (bits + 7) / 8;
if (bytes > 8 * 1024)
fatal("buffer_get_bignum: cannot handle BN of size %d", bytes);
if (buffer_len(buffer) < bytes)
fatal("buffer_get_bignum: input buffer too small");
bin = buffer_ptr(buffer);
BN_bin2bn(bin, bytes, value);
buffer_consume(buffer, bytes);
}
/*
* Stores an BIGNUM in the buffer in SSH2 format.
*/
void
buffer_put_bignum2(Buffer *buffer, BIGNUM *value)
{
int bytes = BN_num_bytes(value) + 1;
u_char *buf = xmalloc(bytes);
int oi;
int hasnohigh = 0;
buf[0] = '\0';
/* Get the value of in binary */
oi = BN_bn2bin(value, buf+1);
if (oi != bytes-1)
fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d",
oi, bytes);
hasnohigh = (buf[1] & 0x80) ? 0 : 1;
if (value->neg) {
/**XXX should be two's-complement */
int i, carry;
u_char *uc = buf;
log("negativ!");
for (i = bytes-1, carry = 1; i>=0; i--) {
uc[i] ^= 0xff;
if (carry)
carry = !++uc[i];
}
}
buffer_put_string(buffer, buf+hasnohigh, bytes-hasnohigh);
memset(buf, 0, bytes);
xfree(buf);
}
/* XXX does not handle negative BNs */
void
buffer_get_bignum2(Buffer *buffer, BIGNUM *value)
{
u_int len;
u_char *bin = buffer_get_string(buffer, &len);
if (len > 8 * 1024)
fatal("buffer_get_bignum2: cannot handle BN of size %d", len);
BN_bin2bn(bin, len, value);
xfree(bin);
}
/*
* Returns integers from the buffer (msb first).
*/
u_short
buffer_get_short(Buffer *buffer)
{
u_char buf[2];
buffer_get(buffer, (char *) buf, 2);
return GET_16BIT(buf);
}
u_int
buffer_get_int(Buffer *buffer)
{
u_char buf[4];
buffer_get(buffer, (char *) buf, 4);
return GET_32BIT(buf);
}
#ifdef HAVE_U_INT64_T
u_int64_t
buffer_get_int64(Buffer *buffer)
{
u_char buf[8];
buffer_get(buffer, (char *) buf, 8);
return GET_64BIT(buf);
}
#endif
/*
* Stores integers in the buffer, msb first.
*/
void
buffer_put_short(Buffer *buffer, u_short value)
{
char buf[2];
PUT_16BIT(buf, value);
buffer_append(buffer, buf, 2);
}
void
buffer_put_int(Buffer *buffer, u_int value)
{
char buf[4];
PUT_32BIT(buf, value);
buffer_append(buffer, buf, 4);
}
#ifdef HAVE_U_INT64_T
void
buffer_put_int64(Buffer *buffer, u_int64_t value)
{
char buf[8];
PUT_64BIT(buf, value);
buffer_append(buffer, buf, 8);
}
#endif
/*
* 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(Buffer *buffer, u_int *length_ptr)
{
u_char *value;
u_int len;
/* Get the length. */
len = buffer_get_int(buffer);
if (len > 256 * 1024)
fatal("buffer_get_string: bad string length %d", len);
/* Allocate space for the string. Add one byte for a null character. */
value = xmalloc(len + 1);
/* Get the string. */
buffer_get(buffer, value, len);
/* 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;
}
char *
buffer_get_ascii_cstring(Buffer *buffer)
{
char *value;
u_char *p;
u_int len;
value = buffer_get_string(buffer, &len);
/* Look for NULL or high-bit set bytes */
for (p = (u_char *) value ;
p && *p && (!(*p & 0x80)) && (p - (u_char *) value) < len ;
p++) ;
/* If there were any, bomb */
if ((p - (u_char *) value) != len) {
xfree(value);
errno = EILSEQ;
return NULL;
}
return value;
}
u_char *
buffer_get_utf8_cstring(Buffer *buffer)
{
u_char *value, *converted, *estr;
u_int len;
int err;
if ((value = buffer_get_string(buffer, &len)) == NULL) {
return value;
}
converted = g11n_convert_from_utf8(value, &err, &estr);
if (converted != value) xfree(value);
if (err)
fatal("invalid UTF-8 sequence; %s", estr);
return converted;
}
/*
* 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));
}
/*
* ASCII versions of the above
*/
#if 0
void
buffer_put_ascii_string(Buffer *buffer, const void *buf, u_int len)
{
u_char *p;
for (p = (u_char *) buf ;
p && ((p - (u_char *) buf) < len) && *p && (!(*p & 0x80)) ;
p++) ;
if ((p - (u_char *) buf) != len)
verbose("buffer_put_ascii_string: storing a non-ASCII string");
buffer_put_int(buffer, len);
buffer_append(buffer, buf, len);
}
#endif
void
buffer_put_ascii_cstring(Buffer *buffer, const char *s)
{
u_char *estr;
if (s == NULL)
fatal("buffer_put_cstring: s == NULL");
if (!g11n_validate_ascii(s, strlen(s), &estr))
verbose("buffer_put_ascii_cstring: non-ASCII string; %s", estr);
buffer_put_cstring(buffer, s);
}
/*
* UTF-8 versions of the above.
*/
#if 0
void
buffer_put_utf8_string(Buffer *buffer, const void *buf, u_int len)
{
char *converted *estr;
converted = g11n_convert_to_utf8(buf, &err, &estr);
if (!converted && err)
fatal("buffer_put_utf8_string: input not a valid UTF-8 encoding; %s", estr);
if (err)
verbose("buffer_put_utf8_string: input not a valid UTF-8 encoding; %s", estr);
buffer_put_string(buffer, converted, strlen(converted));
if (converted != bug) xfree(converted);
return;
}
#endif
void
buffer_put_utf8_cstring(Buffer *buffer, const u_char *s)
{
u_char *converted, *estr;
int err;
if (s == NULL)
fatal("buffer_put_cstring: s == NULL");
converted = g11n_convert_to_utf8(s, &err, &estr);
if (!converted && err)
fatal("buffer_put_utf8_string: input not a valid UTF-8 encoding; %s", estr);
if (err)
verbose("buffer_put_utf8_string: input not a valid UTF-8 encoding; %s", estr);
buffer_put_cstring(buffer, (const char *) converted);
if (converted != s) xfree(converted);
return;
}
/*
* Returns a character from the buffer (0 - 255).
*/
int
buffer_get_char(Buffer *buffer)
{
char ch;
buffer_get(buffer, &ch, 1);
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);
}