[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 1.17 2001/01/21 19:05:45 markus 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.
 */
int
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 = (u_char *) buffer_ptr(buffer);
	BN_bin2bn(bin, bytes, value);
	buffer_consume(buffer, bytes);

	return 2 + 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);
}

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

/*
 * 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.
 */
char *
buffer_get_string(Buffer *buffer, u_int *length_ptr)
{
	u_int len;
	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"
	40	RCSID("$OpenBSD: bufaux.c,v 1.17 2001/01/21 19:05:45 markus Exp $");
	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",
65	oi, bin_size);
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	*/
80	int
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");
93	bin = (u_char *) buffer_ptr(buffer);
94	BN_bin2bn(bin, bytes, value);
95	buffer_consume(buffer, bytes);
96
97	return 2 + bytes;
98	}
99
100	/*
101	* Stores an BIGNUM in the buffer in SSH2 format.
102	*/
103	void
104	buffer_put_bignum2(Buffer buffer, BIGNUM value)
105	{
106	int bytes = BN_num_bytes(value) + 1;
107	u_char *buf = xmalloc(bytes);
108	int oi;
109	int hasnohigh = 0;
110	buf[0] = '\0';
111	/* Get the value of in binary */
112	oi = BN_bn2bin(value, buf+1);
113	if (oi != bytes-1)
114	fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d",
115	oi, bytes);
116	hasnohigh = (buf[1] & 0x80) ? 0 : 1;
117	if (value->neg) {
118	/*XXX should be two's-complement /
119	int i, carry;
120	u_char *uc = buf;
121	log("negativ!");
122	for(i = bytes-1, carry = 1; i>=0; i--) {
123	uc[i] ^= 0xff;
124	if(carry)
125	carry = !++uc[i];
126	}
127	}
128	buffer_put_string(buffer, buf+hasnohigh, bytes-hasnohigh);
129	memset(buf, 0, bytes);
130	xfree(buf);
131	}
132
133	int
134	buffer_get_bignum2(Buffer buffer, BIGNUM value)
135	{
136	/*XXX should be two's-complement /
137	int len;
138	u_char bin = (u_char )buffer_get_string(buffer, (u_int *)&len);
139	BN_bin2bn(bin, len, value);
140	xfree(bin);
141	return len;
142	}
143
144	/*
145	* Returns an integer from the buffer (4 bytes, msb first).
146	*/
147	u_int
148	buffer_get_int(Buffer *buffer)
149	{
150	u_char buf[4];
151	buffer_get(buffer, (char *) buf, 4);
152	return GET_32BIT(buf);
153	}
154
155	#ifdef HAVE_U_INT64_T
156	u_int64_t
157	buffer_get_int64(Buffer *buffer)
158	{
159	u_char buf[8];
160	buffer_get(buffer, (char *) buf, 8);
161	return GET_64BIT(buf);
162	}
163	#endif
164
165	/*
166	* Stores an integer in the buffer in 4 bytes, msb first.
167	*/
168	void
169	buffer_put_int(Buffer *buffer, u_int value)
170	{
171	char buf[4];
172	PUT_32BIT(buf, value);
173	buffer_append(buffer, buf, 4);
174	}
175
176	#ifdef HAVE_U_INT64_T
177	void
178	buffer_put_int64(Buffer *buffer, u_int64_t value)
179	{
180	char buf[8];
181	PUT_64BIT(buf, value);
182	buffer_append(buffer, buf, 8);
183	}
184	#endif
185
186	/*
187	* Returns an arbitrary binary string from the buffer. The string cannot
188	* be longer than 256k. The returned value points to memory allocated
189	* with xmalloc; it is the responsibility of the calling function to free
190	* the data. If length_ptr is non-NULL, the length of the returned data
191	* will be stored there. A null character will be automatically appended
192	* to the returned string, and is not counted in length.
193	*/
194	char *
195	buffer_get_string(Buffer buffer, u_int length_ptr)
196	{
197	u_int len;
198	char *value;
199	/* Get the length. */
200	len = buffer_get_int(buffer);
201	if (len > 256 * 1024)
202	fatal("Received packet with bad string length %d", len);
203	/* Allocate space for the string. Add one byte for a null character. */
204	value = xmalloc(len + 1);
205	/* Get the string. */
206	buffer_get(buffer, value, len);
207	/* Append a null character to make processing easier. */
208	value[len] = 0;
209	/* Optionally return the length of the string. */
210	if (length_ptr)
211	*length_ptr = len;
212	return value;
213	}
214
215	/*
216	* Stores and arbitrary binary string in the buffer.
217	*/
218	void
219	buffer_put_string(Buffer buffer, const void buf, u_int len)
220	{
221	buffer_put_int(buffer, len);
222	buffer_append(buffer, buf, len);
223	}
224	void
225	buffer_put_cstring(Buffer buffer, const char s)
226	{
227	buffer_put_string(buffer, s, strlen(s));
228	}
229
230	/*
231	* Returns a character from the buffer (0 - 255).
232	*/
233	int
234	buffer_get_char(Buffer *buffer)
235	{
236	char ch;
237	buffer_get(buffer, &ch, 1);
238	return (u_char) ch;
239	}
240
241	/*
242	* Stores a character in the buffer.
243	*/
244	void
245	buffer_put_char(Buffer *buffer, int value)
246	{
247	char ch = value;
248	buffer_append(buffer, &ch, 1);
249	}