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 1.27 2002/06/26 08:53:12 markus Exp $");
41 RCSID("$FreeBSD: src/crypto/openssh/bufaux.c,v 1.2.2.4 2002/07/03 22:11:41 des Exp $");
42 RCSID("$DragonFly: src/crypto/openssh/Attic/bufaux.c,v 1.2 2003/06/17 04:24:36 dillon Exp $");
44 #include <openssl/bn.h>
51 * Stores an BIGNUM in the buffer with a 2-byte msb first bit count, followed
52 * by (bits+7)/8 bytes of binary data, msb first.
55 buffer_put_bignum(Buffer *buffer, BIGNUM *value)
57 int bits = BN_num_bits(value);
58 int bin_size = (bits + 7) / 8;
59 u_char *buf = xmalloc(bin_size);
63 /* Get the value of in binary */
64 oi = BN_bn2bin(value, buf);
66 fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d",
69 /* Store the number of bits in the buffer in two bytes, msb first. */
71 buffer_append(buffer, msg, 2);
72 /* Store the binary data. */
73 buffer_append(buffer, (char *)buf, oi);
75 memset(buf, 0, bin_size);
80 * Retrieves an BIGNUM from the buffer.
83 buffer_get_bignum(Buffer *buffer, BIGNUM *value)
88 /* Get the number for bits. */
89 buffer_get(buffer, (char *) buf, 2);
90 bits = GET_16BIT(buf);
91 /* Compute the number of binary bytes that follow. */
92 bytes = (bits + 7) / 8;
94 fatal("buffer_get_bignum: cannot handle BN of size %d", bytes);
95 if (buffer_len(buffer) < bytes)
96 fatal("buffer_get_bignum: input buffer too small");
97 bin = buffer_ptr(buffer);
98 BN_bin2bn(bin, bytes, value);
99 buffer_consume(buffer, bytes);
103 * Stores an BIGNUM in the buffer in SSH2 format.
106 buffer_put_bignum2(Buffer *buffer, BIGNUM *value)
108 int bytes = BN_num_bytes(value) + 1;
109 u_char *buf = xmalloc(bytes);
114 /* Get the value of in binary */
115 oi = BN_bn2bin(value, buf+1);
117 fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d",
119 hasnohigh = (buf[1] & 0x80) ? 0 : 1;
121 /**XXX should be two's-complement */
125 for (i = bytes-1, carry = 1; i>=0; i--) {
131 buffer_put_string(buffer, buf+hasnohigh, bytes-hasnohigh);
132 memset(buf, 0, bytes);
136 /* XXX does not handle negative BNs */
138 buffer_get_bignum2(Buffer *buffer, BIGNUM *value)
141 u_char *bin = buffer_get_string(buffer, &len);
144 fatal("buffer_get_bignum2: cannot handle BN of size %d", len);
145 BN_bin2bn(bin, len, value);
149 * Returns integers from the buffer (msb first).
153 buffer_get_short(Buffer *buffer)
157 buffer_get(buffer, (char *) buf, 2);
158 return GET_16BIT(buf);
162 buffer_get_int(Buffer *buffer)
166 buffer_get(buffer, (char *) buf, 4);
167 return GET_32BIT(buf);
170 #ifdef HAVE_U_INT64_T
172 buffer_get_int64(Buffer *buffer)
176 buffer_get(buffer, (char *) buf, 8);
177 return GET_64BIT(buf);
182 * Stores integers in the buffer, msb first.
185 buffer_put_short(Buffer *buffer, u_short value)
189 PUT_16BIT(buf, value);
190 buffer_append(buffer, buf, 2);
194 buffer_put_int(Buffer *buffer, u_int value)
198 PUT_32BIT(buf, value);
199 buffer_append(buffer, buf, 4);
202 #ifdef HAVE_U_INT64_T
204 buffer_put_int64(Buffer *buffer, u_int64_t value)
208 PUT_64BIT(buf, value);
209 buffer_append(buffer, buf, 8);
214 * Returns an arbitrary binary string from the buffer. The string cannot
215 * be longer than 256k. The returned value points to memory allocated
216 * with xmalloc; it is the responsibility of the calling function to free
217 * the data. If length_ptr is non-NULL, the length of the returned data
218 * will be stored there. A null character will be automatically appended
219 * to the returned string, and is not counted in length.
222 buffer_get_string(Buffer *buffer, u_int *length_ptr)
227 /* Get the length. */
228 len = buffer_get_int(buffer);
229 if (len > 256 * 1024)
230 fatal("buffer_get_string: bad string length %d", len);
231 /* Allocate space for the string. Add one byte for a null character. */
232 value = xmalloc(len + 1);
233 /* Get the string. */
234 buffer_get(buffer, value, len);
235 /* Append a null character to make processing easier. */
237 /* Optionally return the length of the string. */
244 * Stores and arbitrary binary string in the buffer.
247 buffer_put_string(Buffer *buffer, const void *buf, u_int len)
249 buffer_put_int(buffer, len);
250 buffer_append(buffer, buf, len);
253 buffer_put_cstring(Buffer *buffer, const char *s)
256 fatal("buffer_put_cstring: s == NULL");
257 buffer_put_string(buffer, s, strlen(s));
261 * Returns a character from the buffer (0 - 255).
264 buffer_get_char(Buffer *buffer)
268 buffer_get(buffer, &ch, 1);
273 * Stores a character in the buffer.
276 buffer_put_char(Buffer *buffer, int value)
280 buffer_append(buffer, &ch, 1);