2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * Auxiliary functions for storing and retrieving various data types to/from
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".
15 * SSH2 packet format added by Markus Friedl
16 * Copyright (c) 2000 Markus Friedl. All rights reserved.
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions
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.
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.
40 RCSID("$OpenBSD: bufaux.c,v 1.17 2001/01/21 19:05:45 markus Exp $");
42 #include <openssl/bn.h>
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.
53 buffer_put_bignum(Buffer *buffer, BIGNUM *value)
55 int bits = BN_num_bits(value);
56 int bin_size = (bits + 7) / 8;
57 u_char *buf = xmalloc(bin_size);
61 /* Get the value of in binary */
62 oi = BN_bn2bin(value, buf);
64 fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d",
67 /* Store the number of bits in the buffer in two bytes, msb first. */
69 buffer_append(buffer, msg, 2);
70 /* Store the binary data. */
71 buffer_append(buffer, (char *)buf, oi);
73 memset(buf, 0, bin_size);
78 * Retrieves an BIGNUM from the buffer.
81 buffer_get_bignum(Buffer *buffer, BIGNUM *value)
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);
101 * Stores an BIGNUM in the buffer in SSH2 format.
104 buffer_put_bignum2(Buffer *buffer, BIGNUM *value)
106 int bytes = BN_num_bytes(value) + 1;
107 u_char *buf = xmalloc(bytes);
111 /* Get the value of in binary */
112 oi = BN_bn2bin(value, buf+1);
114 fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d",
116 hasnohigh = (buf[1] & 0x80) ? 0 : 1;
118 /**XXX should be two's-complement */
122 for(i = bytes-1, carry = 1; i>=0; i--) {
128 buffer_put_string(buffer, buf+hasnohigh, bytes-hasnohigh);
129 memset(buf, 0, bytes);
134 buffer_get_bignum2(Buffer *buffer, BIGNUM *value)
136 /**XXX should be two's-complement */
138 u_char *bin = (u_char *)buffer_get_string(buffer, (u_int *)&len);
139 BN_bin2bn(bin, len, value);
145 * Returns an integer from the buffer (4 bytes, msb first).
148 buffer_get_int(Buffer *buffer)
151 buffer_get(buffer, (char *) buf, 4);
152 return GET_32BIT(buf);
155 #ifdef HAVE_U_INT64_T
157 buffer_get_int64(Buffer *buffer)
160 buffer_get(buffer, (char *) buf, 8);
161 return GET_64BIT(buf);
166 * Stores an integer in the buffer in 4 bytes, msb first.
169 buffer_put_int(Buffer *buffer, u_int value)
172 PUT_32BIT(buf, value);
173 buffer_append(buffer, buf, 4);
176 #ifdef HAVE_U_INT64_T
178 buffer_put_int64(Buffer *buffer, u_int64_t value)
181 PUT_64BIT(buf, value);
182 buffer_append(buffer, buf, 8);
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.
195 buffer_get_string(Buffer *buffer, u_int *length_ptr)
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. */
209 /* Optionally return the length of the string. */
216 * Stores and arbitrary binary string in the buffer.
219 buffer_put_string(Buffer *buffer, const void *buf, u_int len)
221 buffer_put_int(buffer, len);
222 buffer_append(buffer, buf, len);
225 buffer_put_cstring(Buffer *buffer, const char *s)
227 buffer_put_string(buffer, s, strlen(s));
231 * Returns a character from the buffer (0 - 255).
234 buffer_get_char(Buffer *buffer)
237 buffer_get(buffer, &ch, 1);
242 * Stores a character in the buffer.
245 buffer_put_char(Buffer *buffer, int value)
248 buffer_append(buffer, &ch, 1);