[gssapi-openssh.git] / openssh / bufaux.c

/*
 * 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 1.22 2002/01/18 18:14:17 stevesk Exp $");

#include <openssl/bn.h>
#include "bufaux.h"
#include "xmalloc.h"
#include "getput.h"
#include "log.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 (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);
}

void
buffer_get_bignum2(Buffer *buffer, BIGNUM *value)
{
	/**XXX should be two's-complement */
	int len;
	u_char *bin = buffer_get_string(buffer, (u_int *)&len);
	BN_bin2bn(bin, len, value);
	xfree(bin);
}

/*
 * Returns an integer from the buffer (4 bytes, msb first).
 */
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 an integer in the buffer in 4 bytes, msb first.
 */
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_int len;
	u_char *value;
	/* Get the length. */
	len = buffer_get_int(buffer);
	if (len > 256 * 1024)
		fatal("Received packet with 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;
}

/*
 * 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)
{
	buffer_put_string(buffer, s, strlen(s));
}

/*
 * 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);
}
Commit	Line	Data
3c0ef626	1	/*
	2	* Author: Tatu Ylonen <ylo@cs.hut.fi>
	3	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	4	* All rights reserved
	5	* Auxiliary functions for storing and retrieving various data types to/from
	6	* Buffers.
	7	*
	8	* As far as I am concerned, the code I have written for this software
	9	* can be used freely for any purpose. Any derived versions of this
	10	* software must be clearly marked as such, and if the derived work is
	11	* incompatible with the protocol description in the RFC file, it must be
	12	* called by a name other than "ssh" or "Secure Shell".
	13	*
	14	*
	15	* SSH2 packet format added by Markus Friedl
	16	* Copyright (c) 2000 Markus Friedl. All rights reserved.
	17	*
	18	* Redistribution and use in source and binary forms, with or without
	19	* modification, are permitted provided that the following conditions
	20	* are met:
	21	* 1. Redistributions of source code must retain the above copyright
	22	* notice, this list of conditions and the following disclaimer.
	23	* 2. Redistributions in binary form must reproduce the above copyright
	24	* notice, this list of conditions and the following disclaimer in the
	25	* documentation and/or other materials provided with the distribution.
	26	*
	27	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	28	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	29	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	30	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	31	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	32	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	33	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	34	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	35	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	36	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	37	*/
	38
	39	#include "includes.h"
e9a17296	40	RCSID("$OpenBSD: bufaux.c,v 1.22 2002/01/18 18:14:17 stevesk Exp $");
3c0ef626	41
	42	#include <openssl/bn.h>
	43	#include "bufaux.h"
	44	#include "xmalloc.h"
	45	#include "getput.h"
	46	#include "log.h"
	47
	48	/*
	49	* Stores an BIGNUM in the buffer with a 2-byte msb first bit count, followed
	50	* by (bits+7)/8 bytes of binary data, msb first.
	51	*/
	52	void
	53	buffer_put_bignum(Buffer buffer, BIGNUM value)
	54	{
	55	int bits = BN_num_bits(value);
	56	int bin_size = (bits + 7) / 8;
	57	u_char *buf = xmalloc(bin_size);
	58	int oi;
	59	char msg[2];
	60
	61	/* Get the value of in binary */
	62	oi = BN_bn2bin(value, buf);
	63	if (oi != bin_size)
	64	fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d",
e9a17296	65	oi, bin_size);
3c0ef626	66
	67	/* Store the number of bits in the buffer in two bytes, msb first. */
	68	PUT_16BIT(msg, bits);
	69	buffer_append(buffer, msg, 2);
	70	/* Store the binary data. */
	71	buffer_append(buffer, (char *)buf, oi);
	72
	73	memset(buf, 0, bin_size);
	74	xfree(buf);
	75	}
	76
	77	/*
	78	* Retrieves an BIGNUM from the buffer.
	79	*/
e9a17296	80	void
3c0ef626	81	buffer_get_bignum(Buffer buffer, BIGNUM value)
	82	{
	83	int bits, bytes;
	84	u_char buf[2], *bin;
	85
	86	/* Get the number for bits. */
	87	buffer_get(buffer, (char *) buf, 2);
	88	bits = GET_16BIT(buf);
	89	/* Compute the number of binary bytes that follow. */
	90	bytes = (bits + 7) / 8;
	91	if (buffer_len(buffer) < bytes)
	92	fatal("buffer_get_bignum: input buffer too small");
e9a17296	93	bin = buffer_ptr(buffer);
3c0ef626	94	BN_bin2bn(bin, bytes, value);
3c0ef626	95	buffer_consume(buffer, bytes);
3c0ef626	96	}
	97
	98	/*
	99	* Stores an BIGNUM in the buffer in SSH2 format.
	100	*/
	101	void
	102	buffer_put_bignum2(Buffer buffer, BIGNUM value)
	103	{
	104	int bytes = BN_num_bytes(value) + 1;
	105	u_char *buf = xmalloc(bytes);
	106	int oi;
	107	int hasnohigh = 0;
	108	buf[0] = '\0';
	109	/* Get the value of in binary */
	110	oi = BN_bn2bin(value, buf+1);
	111	if (oi != bytes-1)
	112	fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d",
e9a17296	113	oi, bytes);
3c0ef626	114	hasnohigh = (buf[1] & 0x80) ? 0 : 1;
	115	if (value->neg) {
	116	/*XXX should be two's-complement /
	117	int i, carry;
	118	u_char *uc = buf;
	119	log("negativ!");
e9a17296	120	for (i = bytes-1, carry = 1; i>=0; i--) {
3c0ef626	121	uc[i] ^= 0xff;
e9a17296	122	if (carry)
3c0ef626	123	carry = !++uc[i];
	124	}
	125	}
	126	buffer_put_string(buffer, buf+hasnohigh, bytes-hasnohigh);
	127	memset(buf, 0, bytes);
	128	xfree(buf);
	129	}
	130
e9a17296	131	void
3c0ef626	132	buffer_get_bignum2(Buffer buffer, BIGNUM value)
	133	{
	134	/*XXX should be two's-complement /
	135	int len;
e9a17296	136	u_char bin = buffer_get_string(buffer, (u_int )&len);
3c0ef626	137	BN_bin2bn(bin, len, value);
3c0ef626	138	xfree(bin);
3c0ef626	139	}
	140
	141	/*
	142	* Returns an integer from the buffer (4 bytes, msb first).
	143	*/
	144	u_int
	145	buffer_get_int(Buffer *buffer)
	146	{
	147	u_char buf[4];
	148	buffer_get(buffer, (char *) buf, 4);
	149	return GET_32BIT(buf);
	150	}
	151
	152	#ifdef HAVE_U_INT64_T
	153	u_int64_t
	154	buffer_get_int64(Buffer *buffer)
	155	{
	156	u_char buf[8];
	157	buffer_get(buffer, (char *) buf, 8);
	158	return GET_64BIT(buf);
	159	}
	160	#endif
	161
	162	/*
	163	* Stores an integer in the buffer in 4 bytes, msb first.
	164	*/
	165	void
	166	buffer_put_int(Buffer *buffer, u_int value)
	167	{
	168	char buf[4];
	169	PUT_32BIT(buf, value);
	170	buffer_append(buffer, buf, 4);
	171	}
	172
	173	#ifdef HAVE_U_INT64_T
	174	void
	175	buffer_put_int64(Buffer *buffer, u_int64_t value)
	176	{
	177	char buf[8];
	178	PUT_64BIT(buf, value);
	179	buffer_append(buffer, buf, 8);
	180	}
	181	#endif
	182
	183	/*
	184	* Returns an arbitrary binary string from the buffer. The string cannot
	185	* be longer than 256k. The returned value points to memory allocated
	186	* with xmalloc; it is the responsibility of the calling function to free
	187	* the data. If length_ptr is non-NULL, the length of the returned data
	188	* will be stored there. A null character will be automatically appended
	189	* to the returned string, and is not counted in length.
	190	*/
e9a17296	191	void *
3c0ef626	192	buffer_get_string(Buffer buffer, u_int length_ptr)
	193	{
	194	u_int len;
e9a17296	195	u_char *value;
3c0ef626	196	/* Get the length. */
	197	len = buffer_get_int(buffer);
	198	if (len > 256 * 1024)
	199	fatal("Received packet with bad string length %d", len);
	200	/* Allocate space for the string. Add one byte for a null character. */
	201	value = xmalloc(len + 1);
	202	/* Get the string. */
	203	buffer_get(buffer, value, len);
	204	/* Append a null character to make processing easier. */
	205	value[len] = 0;
	206	/* Optionally return the length of the string. */
	207	if (length_ptr)
	208	*length_ptr = len;
	209	return value;
	210	}
	211
	212	/*
	213	* Stores and arbitrary binary string in the buffer.
	214	*/
	215	void
	216	buffer_put_string(Buffer buffer, const void buf, u_int len)
	217	{
	218	buffer_put_int(buffer, len);
	219	buffer_append(buffer, buf, len);
	220	}
	221	void
	222	buffer_put_cstring(Buffer buffer, const char s)
	223	{
	224	buffer_put_string(buffer, s, strlen(s));
	225	}
	226
	227	/*
	228	* Returns a character from the buffer (0 - 255).
	229	*/
	230	int
	231	buffer_get_char(Buffer *buffer)
	232	{
	233	char ch;
	234	buffer_get(buffer, &ch, 1);
	235	return (u_char) ch;
	236	}
	237
	238	/*
	239	* Stores a character in the buffer.
	240	*/
	241	void
	242	buffer_put_char(Buffer *buffer, int value)
	243	{
	244	char ch = value;
	245	buffer_append(buffer, &ch, 1);
	246	}