blob: de5b3ca1aa57ec4876140096001e7e3cd3d2be36 [file] [log] [blame]
Damien Millerce986542013-07-18 16:12:44 +10001/* $OpenBSD: bufaux.c,v 1.52 2013/07/12 00:19:58 djm Exp $ */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002/*
Damien Miller95def091999-11-25 00:26:21 +11003 * Author: Tatu Ylonen <ylo@cs.hut.fi>
Damien Miller95def091999-11-25 00:26:21 +11004 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
Damien Miller95def091999-11-25 00:26:21 +11006 * Auxiliary functions for storing and retrieving various data types to/from
7 * Buffers.
8 *
Damien Millere4340be2000-09-16 13:29:08 +11009 * As far as I am concerned, the code I have written for this software
10 * can be used freely for any purpose. Any derived versions of this
11 * software must be clearly marked as such, and if the derived work is
12 * incompatible with the protocol description in the RFC file, it must be
13 * called by a name other than "ssh" or "Secure Shell".
Damien Millerb38eff82000-04-01 11:09:21 +100014 *
Damien Millere4340be2000-09-16 13:29:08 +110015 *
16 * SSH2 packet format added by Markus Friedl
17 * Copyright (c) 2000 Markus Friedl. All rights reserved.
18 *
19 * Redistribution and use in source and binary forms, with or without
20 * modification, are permitted provided that the following conditions
21 * are met:
22 * 1. Redistributions of source code must retain the above copyright
23 * notice, this list of conditions and the following disclaimer.
24 * 2. Redistributions in binary form must reproduce the above copyright
25 * notice, this list of conditions and the following disclaimer in the
26 * documentation and/or other materials provided with the distribution.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Damien Miller95def091999-11-25 00:26:21 +110038 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100039
40#include "includes.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100041
Damien Millerd7834352006-08-05 12:39:39 +100042#include <sys/types.h>
43
Damien Millerd4a8b7e1999-10-27 13:42:43 +100044#include <openssl/bn.h>
Damien Millere3476ed2006-07-24 14:13:33 +100045
46#include <string.h>
Damien Millerd7834352006-08-05 12:39:39 +100047#include <stdarg.h>
Damien Millere3476ed2006-07-24 14:13:33 +100048
Damien Millerd4a8b7e1999-10-27 13:42:43 +100049#include "xmalloc.h"
Damien Millerd7834352006-08-05 12:39:39 +100050#include "buffer.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000051#include "log.h"
Damien Miller3f941882006-03-31 23:13:02 +110052#include "misc.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100053
Damien Miller95def091999-11-25 00:26:21 +110054/*
Damien Miller3b235662002-04-23 20:42:36 +100055 * Returns integers from the buffer (msb first).
Damien Miller95def091999-11-25 00:26:21 +110056 */
Damien Miller3b235662002-04-23 20:42:36 +100057
Darren Tucker50dbe832004-11-05 20:41:24 +110058int
59buffer_get_short_ret(u_short *ret, Buffer *buffer)
Damien Miller3b235662002-04-23 20:42:36 +100060{
61 u_char buf[2];
Ben Lindstrome1353632002-06-23 21:29:23 +000062
Darren Tucker50dbe832004-11-05 20:41:24 +110063 if (buffer_get_ret(buffer, (char *) buf, 2) == -1)
64 return (-1);
Damien Miller3f941882006-03-31 23:13:02 +110065 *ret = get_u16(buf);
Darren Tucker50dbe832004-11-05 20:41:24 +110066 return (0);
67}
68
69u_short
70buffer_get_short(Buffer *buffer)
71{
72 u_short ret;
73
74 if (buffer_get_short_ret(&ret, buffer) == -1)
75 fatal("buffer_get_short: buffer error");
76
77 return (ret);
78}
79
80int
81buffer_get_int_ret(u_int *ret, Buffer *buffer)
82{
83 u_char buf[4];
84
85 if (buffer_get_ret(buffer, (char *) buf, 4) == -1)
86 return (-1);
Damien Millerd6fc3062010-04-16 15:51:45 +100087 if (ret != NULL)
88 *ret = get_u32(buf);
Darren Tucker50dbe832004-11-05 20:41:24 +110089 return (0);
Damien Miller3b235662002-04-23 20:42:36 +100090}
91
Ben Lindstrom46c16222000-12-22 01:43:59 +000092u_int
Damien Miller95def091999-11-25 00:26:21 +110093buffer_get_int(Buffer *buffer)
Damien Millerd4a8b7e1999-10-27 13:42:43 +100094{
Darren Tucker50dbe832004-11-05 20:41:24 +110095 u_int ret;
Ben Lindstrome1353632002-06-23 21:29:23 +000096
Darren Tucker50dbe832004-11-05 20:41:24 +110097 if (buffer_get_int_ret(&ret, buffer) == -1)
98 fatal("buffer_get_int: buffer error");
99
100 return (ret);
101}
102
103int
104buffer_get_int64_ret(u_int64_t *ret, Buffer *buffer)
105{
106 u_char buf[8];
107
108 if (buffer_get_ret(buffer, (char *) buf, 8) == -1)
109 return (-1);
Damien Millerd6fc3062010-04-16 15:51:45 +1000110 if (ret != NULL)
111 *ret = get_u64(buf);
Darren Tucker50dbe832004-11-05 20:41:24 +1100112 return (0);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000113}
114
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000115u_int64_t
116buffer_get_int64(Buffer *buffer)
117{
Darren Tucker50dbe832004-11-05 20:41:24 +1100118 u_int64_t ret;
Ben Lindstrome1353632002-06-23 21:29:23 +0000119
Darren Tucker50dbe832004-11-05 20:41:24 +1100120 if (buffer_get_int64_ret(&ret, buffer) == -1)
121 fatal("buffer_get_int: buffer error");
122
123 return (ret);
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000124}
125
Damien Miller95def091999-11-25 00:26:21 +1100126/*
Damien Miller3b235662002-04-23 20:42:36 +1000127 * Stores integers in the buffer, msb first.
Damien Miller95def091999-11-25 00:26:21 +1100128 */
Damien Miller5f056372000-04-16 12:31:48 +1000129void
Damien Miller3b235662002-04-23 20:42:36 +1000130buffer_put_short(Buffer *buffer, u_short value)
131{
132 char buf[2];
Ben Lindstrome1353632002-06-23 21:29:23 +0000133
Damien Miller3f941882006-03-31 23:13:02 +1100134 put_u16(buf, value);
Damien Miller3b235662002-04-23 20:42:36 +1000135 buffer_append(buffer, buf, 2);
136}
137
138void
Ben Lindstrom46c16222000-12-22 01:43:59 +0000139buffer_put_int(Buffer *buffer, u_int value)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000140{
Damien Miller95def091999-11-25 00:26:21 +1100141 char buf[4];
Ben Lindstrome1353632002-06-23 21:29:23 +0000142
Damien Miller3f941882006-03-31 23:13:02 +1100143 put_u32(buf, value);
Damien Miller95def091999-11-25 00:26:21 +1100144 buffer_append(buffer, buf, 4);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000145}
146
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000147void
148buffer_put_int64(Buffer *buffer, u_int64_t value)
149{
150 char buf[8];
Ben Lindstrome1353632002-06-23 21:29:23 +0000151
Damien Miller3f941882006-03-31 23:13:02 +1100152 put_u64(buf, value);
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000153 buffer_append(buffer, buf, 8);
154}
155
Damien Miller95def091999-11-25 00:26:21 +1100156/*
157 * Returns an arbitrary binary string from the buffer. The string cannot
158 * be longer than 256k. The returned value points to memory allocated
159 * with xmalloc; it is the responsibility of the calling function to free
160 * the data. If length_ptr is non-NULL, the length of the returned data
161 * will be stored there. A null character will be automatically appended
162 * to the returned string, and is not counted in length.
163 */
Damien Miller5a6b4fe2001-12-21 14:56:54 +1100164void *
Darren Tucker50dbe832004-11-05 20:41:24 +1100165buffer_get_string_ret(Buffer *buffer, u_int *length_ptr)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000166{
Damien Miller5a6b4fe2001-12-21 14:56:54 +1100167 u_char *value;
Ben Lindstrome1353632002-06-23 21:29:23 +0000168 u_int len;
169
Damien Miller95def091999-11-25 00:26:21 +1100170 /* Get the length. */
Damien Miller17751bc2010-02-12 07:35:08 +1100171 if (buffer_get_int_ret(&len, buffer) != 0) {
172 error("buffer_get_string_ret: cannot extract length");
173 return (NULL);
174 }
Darren Tucker50dbe832004-11-05 20:41:24 +1100175 if (len > 256 * 1024) {
176 error("buffer_get_string_ret: bad string length %u", len);
177 return (NULL);
178 }
Damien Miller95def091999-11-25 00:26:21 +1100179 /* Allocate space for the string. Add one byte for a null character. */
180 value = xmalloc(len + 1);
181 /* Get the string. */
Darren Tucker50dbe832004-11-05 20:41:24 +1100182 if (buffer_get_ret(buffer, value, len) == -1) {
183 error("buffer_get_string_ret: buffer_get failed");
Darren Tuckera627d422013-06-02 07:31:17 +1000184 free(value);
Darren Tucker50dbe832004-11-05 20:41:24 +1100185 return (NULL);
186 }
Damien Miller95def091999-11-25 00:26:21 +1100187 /* Append a null character to make processing easier. */
Darren Tucker2a8b1382008-06-11 09:35:37 +1000188 value[len] = '\0';
Damien Miller95def091999-11-25 00:26:21 +1100189 /* Optionally return the length of the string. */
190 if (length_ptr)
191 *length_ptr = len;
Darren Tucker50dbe832004-11-05 20:41:24 +1100192 return (value);
193}
194
195void *
196buffer_get_string(Buffer *buffer, u_int *length_ptr)
197{
198 void *ret;
199
200 if ((ret = buffer_get_string_ret(buffer, length_ptr)) == NULL)
201 fatal("buffer_get_string: buffer error");
202 return (ret);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000203}
204
Damien Millerda108ec2010-08-31 22:36:39 +1000205char *
206buffer_get_cstring_ret(Buffer *buffer, u_int *length_ptr)
207{
208 u_int length;
209 char *cp, *ret = buffer_get_string_ret(buffer, &length);
210
211 if (ret == NULL)
212 return NULL;
213 if ((cp = memchr(ret, '\0', length)) != NULL) {
214 /* XXX allow \0 at end-of-string for a while, remove later */
215 if (cp == ret + length - 1)
216 error("buffer_get_cstring_ret: string contains \\0");
217 else {
218 bzero(ret, length);
Darren Tuckera627d422013-06-02 07:31:17 +1000219 free(ret);
Damien Millerda108ec2010-08-31 22:36:39 +1000220 return NULL;
221 }
222 }
223 if (length_ptr != NULL)
224 *length_ptr = length;
225 return ret;
226}
227
228char *
229buffer_get_cstring(Buffer *buffer, u_int *length_ptr)
230{
231 char *ret;
232
233 if ((ret = buffer_get_cstring_ret(buffer, length_ptr)) == NULL)
234 fatal("buffer_get_cstring: buffer error");
235 return ret;
236}
237
Damien Millerdb255ca2008-05-19 14:59:37 +1000238void *
Darren Tuckerebc71d92010-01-12 19:45:59 +1100239buffer_get_string_ptr_ret(Buffer *buffer, u_int *length_ptr)
Damien Millerdb255ca2008-05-19 14:59:37 +1000240{
241 void *ptr;
242 u_int len;
243
Darren Tuckerebc71d92010-01-12 19:45:59 +1100244 if (buffer_get_int_ret(&len, buffer) != 0)
245 return NULL;
246 if (len > 256 * 1024) {
247 error("buffer_get_string_ptr: bad string length %u", len);
248 return NULL;
249 }
Damien Millerdb255ca2008-05-19 14:59:37 +1000250 ptr = buffer_ptr(buffer);
251 buffer_consume(buffer, len);
252 if (length_ptr)
253 *length_ptr = len;
254 return (ptr);
255}
256
Darren Tuckerebc71d92010-01-12 19:45:59 +1100257void *
258buffer_get_string_ptr(Buffer *buffer, u_int *length_ptr)
259{
260 void *ret;
261
262 if ((ret = buffer_get_string_ptr_ret(buffer, length_ptr)) == NULL)
263 fatal("buffer_get_string_ptr: buffer error");
264 return (ret);
265}
266
Damien Miller95def091999-11-25 00:26:21 +1100267/*
268 * Stores and arbitrary binary string in the buffer.
269 */
Damien Miller5f056372000-04-16 12:31:48 +1000270void
Ben Lindstrom46c16222000-12-22 01:43:59 +0000271buffer_put_string(Buffer *buffer, const void *buf, u_int len)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000272{
Damien Miller95def091999-11-25 00:26:21 +1100273 buffer_put_int(buffer, len);
274 buffer_append(buffer, buf, len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000275}
Damien Miller5f056372000-04-16 12:31:48 +1000276void
Damien Millerb38eff82000-04-01 11:09:21 +1000277buffer_put_cstring(Buffer *buffer, const char *s)
278{
Ben Lindstrom88aa1b42002-03-22 01:47:52 +0000279 if (s == NULL)
280 fatal("buffer_put_cstring: s == NULL");
Damien Millerb38eff82000-04-01 11:09:21 +1000281 buffer_put_string(buffer, s, strlen(s));
282}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000283
Damien Miller95def091999-11-25 00:26:21 +1100284/*
285 * Returns a character from the buffer (0 - 255).
286 */
Damien Miller5f056372000-04-16 12:31:48 +1000287int
Damien Millerce986542013-07-18 16:12:44 +1000288buffer_get_char_ret(u_char *ret, Buffer *buffer)
Darren Tucker50dbe832004-11-05 20:41:24 +1100289{
290 if (buffer_get_ret(buffer, ret, 1) == -1) {
291 error("buffer_get_char_ret: buffer_get_ret failed");
292 return (-1);
293 }
294 return (0);
295}
296
297int
Damien Miller95def091999-11-25 00:26:21 +1100298buffer_get_char(Buffer *buffer)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000299{
Damien Millerce986542013-07-18 16:12:44 +1000300 u_char ch;
Ben Lindstrome1353632002-06-23 21:29:23 +0000301
Darren Tucker50dbe832004-11-05 20:41:24 +1100302 if (buffer_get_char_ret(&ch, buffer) == -1)
303 fatal("buffer_get_char: buffer error");
Damien Millerce986542013-07-18 16:12:44 +1000304 return ch;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000305}
306
Damien Miller95def091999-11-25 00:26:21 +1100307/*
308 * Stores a character in the buffer.
309 */
Damien Miller5f056372000-04-16 12:31:48 +1000310void
Damien Miller95def091999-11-25 00:26:21 +1100311buffer_put_char(Buffer *buffer, int value)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000312{
Damien Miller95def091999-11-25 00:26:21 +1100313 char ch = value;
Ben Lindstrome1353632002-06-23 21:29:23 +0000314
Damien Miller95def091999-11-25 00:26:21 +1100315 buffer_append(buffer, &ch, 1);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000316}