blob: 79f8bbd49667f528e6f56d39459c51573a4a2e57 [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"
Damien Miller3b235662002-04-23 20:42:36 +100040RCSID("$OpenBSD: bufaux.c,v 1.25 2002/04/20 09:14:58 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 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100052void
53buffer_put_bignum(Buffer *buffer, BIGNUM *value)
54{
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);
63 if (oi != bin_size)
64 fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d",
Damien Miller9f0f5c62001-12-21 14:45:46 +110065 oi, bin_size);
Damien Miller95def091999-11-25 00:26:21 +110066
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. */
Damien Miller7684ee12000-03-17 23:40:15 +110071 buffer_append(buffer, (char *)buf, oi);
Damien Miller5428f641999-11-25 11:54:57 +110072
Damien Miller95def091999-11-25 00:26:21 +110073 memset(buf, 0, bin_size);
74 xfree(buf);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100075}
76
Damien Miller95def091999-11-25 00:26:21 +110077/*
78 * Retrieves an BIGNUM from the buffer.
79 */
Damien Miller76e1e362002-01-22 23:15:57 +110080void
Damien Millerd4a8b7e1999-10-27 13:42:43 +100081buffer_get_bignum(Buffer *buffer, BIGNUM *value)
82{
Damien Miller95def091999-11-25 00:26:21 +110083 int bits, bytes;
Ben Lindstrom46c16222000-12-22 01:43:59 +000084 u_char buf[2], *bin;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100085
Damien Miller95def091999-11-25 00:26:21 +110086 /* 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");
Damien Miller4a8ed542002-01-22 23:33:31 +110093 bin = buffer_ptr(buffer);
Damien Miller95def091999-11-25 00:26:21 +110094 BN_bin2bn(bin, bytes, value);
95 buffer_consume(buffer, bytes);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100096}
97
Damien Miller95def091999-11-25 00:26:21 +110098/*
Damien Millerb38eff82000-04-01 11:09:21 +100099 * Stores an BIGNUM in the buffer in SSH2 format.
100 */
101void
102buffer_put_bignum2(Buffer *buffer, BIGNUM *value)
103{
104 int bytes = BN_num_bytes(value) + 1;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000105 u_char *buf = xmalloc(bytes);
Damien Millerb38eff82000-04-01 11:09:21 +1000106 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",
Damien Miller9f0f5c62001-12-21 14:45:46 +1100113 oi, bytes);
Damien Millerb38eff82000-04-01 11:09:21 +1000114 hasnohigh = (buf[1] & 0x80) ? 0 : 1;
115 if (value->neg) {
116 /**XXX should be two's-complement */
117 int i, carry;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000118 u_char *uc = buf;
Damien Millerb38eff82000-04-01 11:09:21 +1000119 log("negativ!");
Damien Miller9f0f5c62001-12-21 14:45:46 +1100120 for (i = bytes-1, carry = 1; i>=0; i--) {
Damien Millerb38eff82000-04-01 11:09:21 +1000121 uc[i] ^= 0xff;
Ben Lindstrom1c37c6a2001-12-06 18:00:18 +0000122 if (carry)
Damien Millerb38eff82000-04-01 11:09:21 +1000123 carry = !++uc[i];
124 }
125 }
126 buffer_put_string(buffer, buf+hasnohigh, bytes-hasnohigh);
127 memset(buf, 0, bytes);
128 xfree(buf);
129}
130
Damien Miller76e1e362002-01-22 23:15:57 +1100131void
Damien Millerb38eff82000-04-01 11:09:21 +1000132buffer_get_bignum2(Buffer *buffer, BIGNUM *value)
133{
134 /**XXX should be two's-complement */
135 int len;
Damien Miller4a8ed542002-01-22 23:33:31 +1100136 u_char *bin = buffer_get_string(buffer, (u_int *)&len);
Damien Millerb38eff82000-04-01 11:09:21 +1000137 BN_bin2bn(bin, len, value);
138 xfree(bin);
Damien Millerb38eff82000-04-01 11:09:21 +1000139}
Damien Millerb38eff82000-04-01 11:09:21 +1000140/*
Damien Miller3b235662002-04-23 20:42:36 +1000141 * Returns integers from the buffer (msb first).
Damien Miller95def091999-11-25 00:26:21 +1100142 */
Damien Miller3b235662002-04-23 20:42:36 +1000143
144u_short
145buffer_get_short(Buffer *buffer)
146{
147 u_char buf[2];
148 buffer_get(buffer, (char *) buf, 2);
149 return GET_16BIT(buf);
150}
151
Ben Lindstrom46c16222000-12-22 01:43:59 +0000152u_int
Damien Miller95def091999-11-25 00:26:21 +1100153buffer_get_int(Buffer *buffer)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000154{
Ben Lindstrom46c16222000-12-22 01:43:59 +0000155 u_char buf[4];
Damien Miller95def091999-11-25 00:26:21 +1100156 buffer_get(buffer, (char *) buf, 4);
157 return GET_32BIT(buf);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000158}
159
Ben Lindstrom16a86be2001-01-23 16:26:52 +0000160#ifdef HAVE_U_INT64_T
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000161u_int64_t
162buffer_get_int64(Buffer *buffer)
163{
164 u_char buf[8];
165 buffer_get(buffer, (char *) buf, 8);
166 return GET_64BIT(buf);
167}
Ben Lindstrom16a86be2001-01-23 16:26:52 +0000168#endif
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000169
Damien Miller95def091999-11-25 00:26:21 +1100170/*
Damien Miller3b235662002-04-23 20:42:36 +1000171 * Stores integers in the buffer, msb first.
Damien Miller95def091999-11-25 00:26:21 +1100172 */
Damien Miller5f056372000-04-16 12:31:48 +1000173void
Damien Miller3b235662002-04-23 20:42:36 +1000174buffer_put_short(Buffer *buffer, u_short value)
175{
176 char buf[2];
177 PUT_16BIT(buf, value);
178 buffer_append(buffer, buf, 2);
179}
180
181void
Ben Lindstrom46c16222000-12-22 01:43:59 +0000182buffer_put_int(Buffer *buffer, u_int value)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000183{
Damien Miller95def091999-11-25 00:26:21 +1100184 char buf[4];
185 PUT_32BIT(buf, value);
186 buffer_append(buffer, buf, 4);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000187}
188
Ben Lindstrom16a86be2001-01-23 16:26:52 +0000189#ifdef HAVE_U_INT64_T
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000190void
191buffer_put_int64(Buffer *buffer, u_int64_t value)
192{
193 char buf[8];
194 PUT_64BIT(buf, value);
195 buffer_append(buffer, buf, 8);
196}
Ben Lindstrom16a86be2001-01-23 16:26:52 +0000197#endif
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000198
Damien Miller95def091999-11-25 00:26:21 +1100199/*
200 * Returns an arbitrary binary string from the buffer. The string cannot
201 * be longer than 256k. The returned value points to memory allocated
202 * with xmalloc; it is the responsibility of the calling function to free
203 * the data. If length_ptr is non-NULL, the length of the returned data
204 * will be stored there. A null character will be automatically appended
205 * to the returned string, and is not counted in length.
206 */
Damien Miller5a6b4fe2001-12-21 14:56:54 +1100207void *
Ben Lindstrom46c16222000-12-22 01:43:59 +0000208buffer_get_string(Buffer *buffer, u_int *length_ptr)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000209{
Ben Lindstrom46c16222000-12-22 01:43:59 +0000210 u_int len;
Damien Miller5a6b4fe2001-12-21 14:56:54 +1100211 u_char *value;
Damien Miller95def091999-11-25 00:26:21 +1100212 /* Get the length. */
213 len = buffer_get_int(buffer);
214 if (len > 256 * 1024)
Ben Lindstromcd8bbce2002-03-27 17:23:44 +0000215 fatal("buffer_get_string: bad string length %d", len);
Damien Miller95def091999-11-25 00:26:21 +1100216 /* Allocate space for the string. Add one byte for a null character. */
217 value = xmalloc(len + 1);
218 /* Get the string. */
219 buffer_get(buffer, value, len);
220 /* Append a null character to make processing easier. */
221 value[len] = 0;
222 /* Optionally return the length of the string. */
223 if (length_ptr)
224 *length_ptr = len;
225 return value;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000226}
227
Damien Miller95def091999-11-25 00:26:21 +1100228/*
229 * Stores and arbitrary binary string in the buffer.
230 */
Damien Miller5f056372000-04-16 12:31:48 +1000231void
Ben Lindstrom46c16222000-12-22 01:43:59 +0000232buffer_put_string(Buffer *buffer, const void *buf, u_int len)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000233{
Damien Miller95def091999-11-25 00:26:21 +1100234 buffer_put_int(buffer, len);
235 buffer_append(buffer, buf, len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000236}
Damien Miller5f056372000-04-16 12:31:48 +1000237void
Damien Millerb38eff82000-04-01 11:09:21 +1000238buffer_put_cstring(Buffer *buffer, const char *s)
239{
Ben Lindstrom88aa1b42002-03-22 01:47:52 +0000240 if (s == NULL)
241 fatal("buffer_put_cstring: s == NULL");
Damien Millerb38eff82000-04-01 11:09:21 +1000242 buffer_put_string(buffer, s, strlen(s));
243}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000244
Damien Miller95def091999-11-25 00:26:21 +1100245/*
246 * Returns a character from the buffer (0 - 255).
247 */
Damien Miller5f056372000-04-16 12:31:48 +1000248int
Damien Miller95def091999-11-25 00:26:21 +1100249buffer_get_char(Buffer *buffer)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000250{
Damien Miller95def091999-11-25 00:26:21 +1100251 char ch;
252 buffer_get(buffer, &ch, 1);
Ben Lindstrom46c16222000-12-22 01:43:59 +0000253 return (u_char) ch;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000254}
255
Damien Miller95def091999-11-25 00:26:21 +1100256/*
257 * Stores a character in the buffer.
258 */
Damien Miller5f056372000-04-16 12:31:48 +1000259void
Damien Miller95def091999-11-25 00:26:21 +1100260buffer_put_char(Buffer *buffer, int value)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000261{
Damien Miller95def091999-11-25 00:26:21 +1100262 char ch = value;
263 buffer_append(buffer, &ch, 1);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000264}