blob: 4ea6af1b658aa431b4c6bf7740c6fd9794bfd1f9 [file] [log] [blame]
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001/*
Damien Miller95def091999-11-25 00:26:21 +11002 * Author: Tatu Ylonen <ylo@cs.hut.fi>
Damien Miller95def091999-11-25 00:26:21 +11003 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
Damien Miller95def091999-11-25 00:26:21 +11005 * Auxiliary functions for storing and retrieving various data types to/from
6 * Buffers.
7 *
Damien Millere4340be2000-09-16 13:29:08 +11008 * 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".
Damien Millerb38eff82000-04-01 11:09:21 +100013 *
Damien Millere4340be2000-09-16 13:29:08 +110014 *
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.
Damien Miller95def091999-11-25 00:26:21 +110037 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100038
39#include "includes.h"
Darren Tucker56c95982004-12-11 13:34:56 +110040RCSID("$OpenBSD: bufaux.c,v 1.34 2004/12/06 16:00:43 markus Exp $");
Damien Millerd4a8b7e1999-10-27 13:42:43 +100041
Damien Millerd4a8b7e1999-10-27 13:42:43 +100042#include <openssl/bn.h>
Damien Millerd4a8b7e1999-10-27 13:42:43 +100043#include "bufaux.h"
44#include "xmalloc.h"
45#include "getput.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000046#include "log.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100047
Damien Miller95def091999-11-25 00:26:21 +110048/*
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 */
Darren Tucker50dbe832004-11-05 20:41:24 +110052int
53buffer_put_bignum_ret(Buffer *buffer, const BIGNUM *value)
Damien Millerd4a8b7e1999-10-27 13:42:43 +100054{
Damien Miller95def091999-11-25 00:26:21 +110055 int bits = BN_num_bits(value);
56 int bin_size = (bits + 7) / 8;
Ben Lindstrom46c16222000-12-22 01:43:59 +000057 u_char *buf = xmalloc(bin_size);
Damien Miller95def091999-11-25 00:26:21 +110058 int oi;
59 char msg[2];
Damien Millerd4a8b7e1999-10-27 13:42:43 +100060
Damien Miller95def091999-11-25 00:26:21 +110061 /* Get the value of in binary */
62 oi = BN_bn2bin(value, buf);
Darren Tucker50dbe832004-11-05 20:41:24 +110063 if (oi != bin_size) {
64 error("buffer_put_bignum_ret: BN_bn2bin() failed: oi %d != bin_size %d",
Damien Miller9f0f5c62001-12-21 14:45:46 +110065 oi, bin_size);
Darren Tucker50dbe832004-11-05 20:41:24 +110066 return (-1);
67 }
Damien Miller95def091999-11-25 00:26:21 +110068
69 /* Store the number of bits in the buffer in two bytes, msb first. */
70 PUT_16BIT(msg, bits);
71 buffer_append(buffer, msg, 2);
72 /* Store the binary data. */
Damien Miller7684ee12000-03-17 23:40:15 +110073 buffer_append(buffer, (char *)buf, oi);
Damien Miller5428f641999-11-25 11:54:57 +110074
Damien Miller95def091999-11-25 00:26:21 +110075 memset(buf, 0, bin_size);
76 xfree(buf);
Darren Tucker50dbe832004-11-05 20:41:24 +110077
78 return (0);
79}
80
81void
82buffer_put_bignum(Buffer *buffer, const BIGNUM *value)
83{
84 if (buffer_put_bignum_ret(buffer, value) == -1)
85 fatal("buffer_put_bignum: buffer error");
Damien Millerd4a8b7e1999-10-27 13:42:43 +100086}
87
Damien Miller95def091999-11-25 00:26:21 +110088/*
89 * Retrieves an BIGNUM from the buffer.
90 */
Darren Tucker50dbe832004-11-05 20:41:24 +110091int
92buffer_get_bignum_ret(Buffer *buffer, BIGNUM *value)
Damien Millerd4a8b7e1999-10-27 13:42:43 +100093{
Darren Tuckerc0815c92003-09-22 21:05:50 +100094 u_int bits, bytes;
Ben Lindstrom46c16222000-12-22 01:43:59 +000095 u_char buf[2], *bin;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100096
Damien Miller95def091999-11-25 00:26:21 +110097 /* Get the number for bits. */
Darren Tucker50dbe832004-11-05 20:41:24 +110098 if (buffer_get_ret(buffer, (char *) buf, 2) == -1) {
99 error("buffer_get_bignum_ret: invalid length");
100 return (-1);
101 }
Damien Miller95def091999-11-25 00:26:21 +1100102 bits = GET_16BIT(buf);
103 /* Compute the number of binary bytes that follow. */
104 bytes = (bits + 7) / 8;
Darren Tucker50dbe832004-11-05 20:41:24 +1100105 if (bytes > 8 * 1024) {
106 error("buffer_get_bignum_ret: cannot handle BN of size %d", bytes);
107 return (-1);
108 }
109 if (buffer_len(buffer) < bytes) {
110 error("buffer_get_bignum_ret: input buffer too small");
111 return (-1);
112 }
Damien Miller4a8ed542002-01-22 23:33:31 +1100113 bin = buffer_ptr(buffer);
Damien Miller95def091999-11-25 00:26:21 +1100114 BN_bin2bn(bin, bytes, value);
Darren Tucker50dbe832004-11-05 20:41:24 +1100115 if (buffer_consume_ret(buffer, bytes) == -1) {
116 error("buffer_get_bignum_ret: buffer_consume failed");
117 return (-1);
118 }
119 return (0);
120}
121
122void
123buffer_get_bignum(Buffer *buffer, BIGNUM *value)
124{
125 if (buffer_get_bignum_ret(buffer, value) == -1)
126 fatal("buffer_get_bignum: buffer error");
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000127}
128
Damien Miller95def091999-11-25 00:26:21 +1100129/*
Damien Millerb38eff82000-04-01 11:09:21 +1000130 * Stores an BIGNUM in the buffer in SSH2 format.
131 */
Darren Tucker50dbe832004-11-05 20:41:24 +1100132int
133buffer_put_bignum2_ret(Buffer *buffer, const BIGNUM *value)
Damien Millerb38eff82000-04-01 11:09:21 +1000134{
Darren Tucker0acc92a2004-02-24 09:21:41 +1100135 u_int bytes;
136 u_char *buf;
Damien Millerb38eff82000-04-01 11:09:21 +1000137 int oi;
Darren Tuckerc0815c92003-09-22 21:05:50 +1000138 u_int hasnohigh = 0;
Ben Lindstrome1353632002-06-23 21:29:23 +0000139
Darren Tucker0acc92a2004-02-24 09:21:41 +1100140 if (BN_is_zero(value)) {
141 buffer_put_int(buffer, 0);
Darren Tucker50dbe832004-11-05 20:41:24 +1100142 return 0;
Darren Tucker0acc92a2004-02-24 09:21:41 +1100143 }
Darren Tucker50dbe832004-11-05 20:41:24 +1100144 if (value->neg) {
145 error("buffer_put_bignum2_ret: negative numbers not supported");
146 return (-1);
147 }
Darren Tucker0acc92a2004-02-24 09:21:41 +1100148 bytes = BN_num_bytes(value) + 1; /* extra padding byte */
Darren Tucker50dbe832004-11-05 20:41:24 +1100149 if (bytes < 2) {
150 error("buffer_put_bignum2_ret: BN too small");
151 return (-1);
152 }
Darren Tucker0acc92a2004-02-24 09:21:41 +1100153 buf = xmalloc(bytes);
Darren Tucker56c95982004-12-11 13:34:56 +1100154 buf[0] = 0x00;
Damien Millerb38eff82000-04-01 11:09:21 +1000155 /* Get the value of in binary */
156 oi = BN_bn2bin(value, buf+1);
Darren Tucker50dbe832004-11-05 20:41:24 +1100157 if (oi != bytes-1) {
158 error("buffer_put_bignum2_ret: BN_bn2bin() failed: "
Darren Tucker0acc92a2004-02-24 09:21:41 +1100159 "oi %d != bin_size %d", oi, bytes);
Darren Tucker50dbe832004-11-05 20:41:24 +1100160 xfree(buf);
161 return (-1);
162 }
Damien Millerb38eff82000-04-01 11:09:21 +1000163 hasnohigh = (buf[1] & 0x80) ? 0 : 1;
Damien Millerb38eff82000-04-01 11:09:21 +1000164 buffer_put_string(buffer, buf+hasnohigh, bytes-hasnohigh);
165 memset(buf, 0, bytes);
166 xfree(buf);
Darren Tucker50dbe832004-11-05 20:41:24 +1100167 return (0);
168}
169
170void
171buffer_put_bignum2(Buffer *buffer, const BIGNUM *value)
172{
173 if (buffer_put_bignum2_ret(buffer, value) == -1)
174 fatal("buffer_put_bignum2: buffer error");
175}
176
177int
178buffer_get_bignum2_ret(Buffer *buffer, BIGNUM *value)
179{
180 u_int len;
181 u_char *bin;
182
183 if ((bin = buffer_get_string_ret(buffer, &len)) == NULL) {
184 error("buffer_get_bignum2_ret: invalid bignum");
185 return (-1);
186 }
187
188 if (len > 0 && (bin[0] & 0x80)) {
189 error("buffer_get_bignum2_ret: negative numbers not supported");
190 return (-1);
191 }
192 if (len > 8 * 1024) {
193 error("buffer_get_bignum2_ret: cannot handle BN of size %d", len);
194 return (-1);
195 }
196 BN_bin2bn(bin, len, value);
197 xfree(bin);
198 return (0);
Damien Millerb38eff82000-04-01 11:09:21 +1000199}
200
Damien Miller76e1e362002-01-22 23:15:57 +1100201void
Damien Millerb38eff82000-04-01 11:09:21 +1000202buffer_get_bignum2(Buffer *buffer, BIGNUM *value)
203{
Darren Tucker50dbe832004-11-05 20:41:24 +1100204 if (buffer_get_bignum2_ret(buffer, value) == -1)
205 fatal("buffer_get_bignum2: buffer error");
Damien Millerb38eff82000-04-01 11:09:21 +1000206}
Darren Tucker0acc92a2004-02-24 09:21:41 +1100207
Damien Millerb38eff82000-04-01 11:09:21 +1000208/*
Damien Miller3b235662002-04-23 20:42:36 +1000209 * Returns integers from the buffer (msb first).
Damien Miller95def091999-11-25 00:26:21 +1100210 */
Damien Miller3b235662002-04-23 20:42:36 +1000211
Darren Tucker50dbe832004-11-05 20:41:24 +1100212int
213buffer_get_short_ret(u_short *ret, Buffer *buffer)
Damien Miller3b235662002-04-23 20:42:36 +1000214{
215 u_char buf[2];
Ben Lindstrome1353632002-06-23 21:29:23 +0000216
Darren Tucker50dbe832004-11-05 20:41:24 +1100217 if (buffer_get_ret(buffer, (char *) buf, 2) == -1)
218 return (-1);
219 *ret = GET_16BIT(buf);
220 return (0);
221}
222
223u_short
224buffer_get_short(Buffer *buffer)
225{
226 u_short ret;
227
228 if (buffer_get_short_ret(&ret, buffer) == -1)
229 fatal("buffer_get_short: buffer error");
230
231 return (ret);
232}
233
234int
235buffer_get_int_ret(u_int *ret, Buffer *buffer)
236{
237 u_char buf[4];
238
239 if (buffer_get_ret(buffer, (char *) buf, 4) == -1)
240 return (-1);
241 *ret = GET_32BIT(buf);
242 return (0);
Damien Miller3b235662002-04-23 20:42:36 +1000243}
244
Ben Lindstrom46c16222000-12-22 01:43:59 +0000245u_int
Damien Miller95def091999-11-25 00:26:21 +1100246buffer_get_int(Buffer *buffer)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000247{
Darren Tucker50dbe832004-11-05 20:41:24 +1100248 u_int ret;
Ben Lindstrome1353632002-06-23 21:29:23 +0000249
Darren Tucker50dbe832004-11-05 20:41:24 +1100250 if (buffer_get_int_ret(&ret, buffer) == -1)
251 fatal("buffer_get_int: buffer error");
252
253 return (ret);
254}
255
256int
257buffer_get_int64_ret(u_int64_t *ret, Buffer *buffer)
258{
259 u_char buf[8];
260
261 if (buffer_get_ret(buffer, (char *) buf, 8) == -1)
262 return (-1);
263 *ret = GET_64BIT(buf);
264 return (0);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000265}
266
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000267u_int64_t
268buffer_get_int64(Buffer *buffer)
269{
Darren Tucker50dbe832004-11-05 20:41:24 +1100270 u_int64_t ret;
Ben Lindstrome1353632002-06-23 21:29:23 +0000271
Darren Tucker50dbe832004-11-05 20:41:24 +1100272 if (buffer_get_int64_ret(&ret, buffer) == -1)
273 fatal("buffer_get_int: buffer error");
274
275 return (ret);
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000276}
277
Damien Miller95def091999-11-25 00:26:21 +1100278/*
Damien Miller3b235662002-04-23 20:42:36 +1000279 * Stores integers in the buffer, msb first.
Damien Miller95def091999-11-25 00:26:21 +1100280 */
Damien Miller5f056372000-04-16 12:31:48 +1000281void
Damien Miller3b235662002-04-23 20:42:36 +1000282buffer_put_short(Buffer *buffer, u_short value)
283{
284 char buf[2];
Ben Lindstrome1353632002-06-23 21:29:23 +0000285
Damien Miller3b235662002-04-23 20:42:36 +1000286 PUT_16BIT(buf, value);
287 buffer_append(buffer, buf, 2);
288}
289
290void
Ben Lindstrom46c16222000-12-22 01:43:59 +0000291buffer_put_int(Buffer *buffer, u_int value)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000292{
Damien Miller95def091999-11-25 00:26:21 +1100293 char buf[4];
Ben Lindstrome1353632002-06-23 21:29:23 +0000294
Damien Miller95def091999-11-25 00:26:21 +1100295 PUT_32BIT(buf, value);
296 buffer_append(buffer, buf, 4);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000297}
298
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000299void
300buffer_put_int64(Buffer *buffer, u_int64_t value)
301{
302 char buf[8];
Ben Lindstrome1353632002-06-23 21:29:23 +0000303
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000304 PUT_64BIT(buf, value);
305 buffer_append(buffer, buf, 8);
306}
307
Damien Miller95def091999-11-25 00:26:21 +1100308/*
309 * Returns an arbitrary binary string from the buffer. The string cannot
310 * be longer than 256k. The returned value points to memory allocated
311 * with xmalloc; it is the responsibility of the calling function to free
312 * the data. If length_ptr is non-NULL, the length of the returned data
313 * will be stored there. A null character will be automatically appended
314 * to the returned string, and is not counted in length.
315 */
Damien Miller5a6b4fe2001-12-21 14:56:54 +1100316void *
Darren Tucker50dbe832004-11-05 20:41:24 +1100317buffer_get_string_ret(Buffer *buffer, u_int *length_ptr)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000318{
Damien Miller5a6b4fe2001-12-21 14:56:54 +1100319 u_char *value;
Ben Lindstrome1353632002-06-23 21:29:23 +0000320 u_int len;
321
Damien Miller95def091999-11-25 00:26:21 +1100322 /* Get the length. */
323 len = buffer_get_int(buffer);
Darren Tucker50dbe832004-11-05 20:41:24 +1100324 if (len > 256 * 1024) {
325 error("buffer_get_string_ret: bad string length %u", len);
326 return (NULL);
327 }
Damien Miller95def091999-11-25 00:26:21 +1100328 /* Allocate space for the string. Add one byte for a null character. */
329 value = xmalloc(len + 1);
330 /* Get the string. */
Darren Tucker50dbe832004-11-05 20:41:24 +1100331 if (buffer_get_ret(buffer, value, len) == -1) {
332 error("buffer_get_string_ret: buffer_get failed");
333 xfree(value);
334 return (NULL);
335 }
Damien Miller95def091999-11-25 00:26:21 +1100336 /* Append a null character to make processing easier. */
337 value[len] = 0;
338 /* Optionally return the length of the string. */
339 if (length_ptr)
340 *length_ptr = len;
Darren Tucker50dbe832004-11-05 20:41:24 +1100341 return (value);
342}
343
344void *
345buffer_get_string(Buffer *buffer, u_int *length_ptr)
346{
347 void *ret;
348
349 if ((ret = buffer_get_string_ret(buffer, length_ptr)) == NULL)
350 fatal("buffer_get_string: buffer error");
351 return (ret);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000352}
353
Damien Miller95def091999-11-25 00:26:21 +1100354/*
355 * Stores and arbitrary binary string in the buffer.
356 */
Damien Miller5f056372000-04-16 12:31:48 +1000357void
Ben Lindstrom46c16222000-12-22 01:43:59 +0000358buffer_put_string(Buffer *buffer, const void *buf, u_int len)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000359{
Damien Miller95def091999-11-25 00:26:21 +1100360 buffer_put_int(buffer, len);
361 buffer_append(buffer, buf, len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000362}
Damien Miller5f056372000-04-16 12:31:48 +1000363void
Damien Millerb38eff82000-04-01 11:09:21 +1000364buffer_put_cstring(Buffer *buffer, const char *s)
365{
Ben Lindstrom88aa1b42002-03-22 01:47:52 +0000366 if (s == NULL)
367 fatal("buffer_put_cstring: s == NULL");
Damien Millerb38eff82000-04-01 11:09:21 +1000368 buffer_put_string(buffer, s, strlen(s));
369}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000370
Damien Miller95def091999-11-25 00:26:21 +1100371/*
372 * Returns a character from the buffer (0 - 255).
373 */
Damien Miller5f056372000-04-16 12:31:48 +1000374int
Darren Tucker50dbe832004-11-05 20:41:24 +1100375buffer_get_char_ret(char *ret, Buffer *buffer)
376{
377 if (buffer_get_ret(buffer, ret, 1) == -1) {
378 error("buffer_get_char_ret: buffer_get_ret failed");
379 return (-1);
380 }
381 return (0);
382}
383
384int
Damien Miller95def091999-11-25 00:26:21 +1100385buffer_get_char(Buffer *buffer)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000386{
Damien Miller95def091999-11-25 00:26:21 +1100387 char ch;
Ben Lindstrome1353632002-06-23 21:29:23 +0000388
Darren Tucker50dbe832004-11-05 20:41:24 +1100389 if (buffer_get_char_ret(&ch, buffer) == -1)
390 fatal("buffer_get_char: buffer error");
Ben Lindstrom46c16222000-12-22 01:43:59 +0000391 return (u_char) ch;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000392}
393
Damien Miller95def091999-11-25 00:26:21 +1100394/*
395 * Stores a character in the buffer.
396 */
Damien Miller5f056372000-04-16 12:31:48 +1000397void
Damien Miller95def091999-11-25 00:26:21 +1100398buffer_put_char(Buffer *buffer, int value)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000399{
Damien Miller95def091999-11-25 00:26:21 +1100400 char ch = value;
Ben Lindstrome1353632002-06-23 21:29:23 +0000401
Damien Miller95def091999-11-25 00:26:21 +1100402 buffer_append(buffer, &ch, 1);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000403}