crypto/dist/ssh/bufaux.c

   1 /*      $NetBSD: bufaux.c,v 1.9 2006/09/28 21:22:14 christos Exp $      */
   2 /* $OpenBSD: bufaux.c,v 1.46 2008/06/10 23:21:34 dtucker Exp $ */
   3 /*
   4  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   5  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   6  *                    All rights reserved
   7  * Auxiliary functions for storing and retrieving various data types to/from
   8  * Buffers.
   9  *
  10  * As far as I am concerned, the code I have written for this software
  11  * can be used freely for any purpose.  Any derived versions of this
  12  * software must be clearly marked as such, and if the derived work is
  13  * incompatible with the protocol description in the RFC file, it must be
  14  * called by a name other than "ssh" or "Secure Shell".
  15  *
  16  *
  17  * SSH2 packet format added by Markus Friedl
  18  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  19  *
  20  * Redistribution and use in source and binary forms, with or without
  21  * modification, are permitted provided that the following conditions
  22  * are met:
  23  * 1. Redistributions of source code must retain the above copyright
  24  *    notice, this list of conditions and the following disclaimer.
  25  * 2. Redistributions in binary form must reproduce the above copyright
  26  *    notice, this list of conditions and the following disclaimer in the
  27  *    documentation and/or other materials provided with the distribution.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  30  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  31  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  32  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  33  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  34  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  35  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  36  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  37  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  38  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  39  */
  40
  41 #include "includes.h"
  42 __RCSID("$NetBSD: bufaux.c,v 1.9 2006/09/28 21:22:14 christos Exp $");
  43 #include <sys/types.h>
  44
  45 #include <openssl/bn.h>
  46
  47 #include <string.h>
  48 #include <stdarg.h>
  49 #include <time.h>
  50
  51 #include "xmalloc.h"
  52 #include "buffer.h"
  53 #include "log.h"
  54 #include "misc.h"
  55
  56 /*
  57  * Returns integers from the buffer (msb first).
  58  */
  59
  60 int
  61 buffer_get_short_ret(u_short *ret, Buffer *buffer)
  62 {
  63         u_char buf[2];
  64
  65         if (buffer_get_ret(buffer, (char *) buf, 2) == -1)
  66                 return (-1);
  67         *ret = get_u16(buf);
  68         return (0);
  69 }
  70
  71 u_short
  72 buffer_get_short(Buffer *buffer)
  73 {
  74         u_short ret = 0;        /* XXX: GCC */
  75
  76         if (buffer_get_short_ret(&ret, buffer) == -1)
  77                 fatal("buffer_get_short: buffer error");
  78
  79         return (ret);
  80 }
  81
  82 int
  83 buffer_get_int_ret(u_int *ret, Buffer *buffer)
  84 {
  85         u_char buf[4];
  86
  87         if (buffer_get_ret(buffer, (char *) buf, 4) == -1)
  88                 return (-1);
  89         *ret = get_u32(buf);
  90         return (0);
  91 }
  92
  93 u_int
  94 buffer_get_int(Buffer *buffer)
  95 {
  96         u_int ret = 0;  /* XXX: GCC */
  97
  98         if (buffer_get_int_ret(&ret, buffer) == -1)
  99                 fatal("buffer_get_int: buffer error");
 100
 101         return (ret);
 102 }
 103
 104 int
 105 buffer_get_int64_ret(u_int64_t *ret, Buffer *buffer)
 106 {
 107         u_char buf[8];
 108
 109         if (buffer_get_ret(buffer, (char *) buf, 8) == -1)
 110                 return (-1);
 111         *ret = get_u64(buf);
 112         return (0);
 113 }
 114
 115 u_int64_t
 116 buffer_get_int64(Buffer *buffer)
 117 {
 118         u_int64_t ret = 0;      /* XXX: GCC */
 119
 120         if (buffer_get_int64_ret(&ret, buffer) == -1)
 121                 fatal("buffer_get_int: buffer error");
 122
 123         return (ret);
 124 }
 125
 126 /*
 127  * Stores integers in the buffer, msb first.
 128  */
 129 void
 130 buffer_put_short(Buffer *buffer, u_short value)
 131 {
 132         char buf[2];
 133
 134         put_u16(buf, value);
 135         buffer_append(buffer, buf, 2);
 136 }
 137
 138 void
 139 buffer_put_int(Buffer *buffer, u_int value)
 140 {
 141         char buf[4];
 142
 143         put_u32(buf, value);
 144         buffer_append(buffer, buf, 4);
 145 }
 146
 147 void
 148 buffer_put_int64(Buffer *buffer, u_int64_t value)
 149 {
 150         char buf[8];
 151
 152         put_u64(buf, value);
 153         buffer_append(buffer, buf, 8);
 154 }
 155
 156 /*
 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  */
 164 void *
 165 buffer_get_string_ret(Buffer *buffer, u_int *length_ptr)
 166 {
 167         u_char *value;
 168         u_int len;
 169
 170         /* Get the length. */
 171         len = buffer_get_int(buffer);
 172         if (len > 256 * 1024) {
 173                 error("buffer_get_string_ret: bad string length %u", len);
 174                 return (NULL);
 175         }
 176         /* Allocate space for the string.  Add one byte for a null character. */
 177         value = xmalloc(len + 1);
 178         /* Get the string. */
 179         if (buffer_get_ret(buffer, value, len) == -1) {
 180                 error("buffer_get_string_ret: buffer_get failed");
 181                 xfree(value);
 182                 return (NULL);
 183         }
 184         /* Append a null character to make processing easier. */
 185         value[len] = '\0';
 186         /* Optionally return the length of the string. */
 187         if (length_ptr)
 188                 *length_ptr = len;
 189         return (value);
 190 }
 191
 192 void *
 193 buffer_get_string(Buffer *buffer, u_int *length_ptr)
 194 {
 195         void *ret;
 196
 197         if ((ret = buffer_get_string_ret(buffer, length_ptr)) == NULL)
 198                 fatal("buffer_get_string: buffer error");
 199         return (ret);
 200 }
 201
 202 void *
 203 buffer_get_string_ptr(Buffer *buffer, u_int *length_ptr)
 204 {
 205         void *ptr;
 206         u_int len;
 207
 208         len = buffer_get_int(buffer);
 209         if (len > 256 * 1024)
 210                 fatal("buffer_get_string_ptr: bad string length %u", len);
 211         ptr = buffer_ptr(buffer);
 212         buffer_consume(buffer, len);
 213         if (length_ptr)
 214                 *length_ptr = len;
 215         return (ptr);
 216 }
 217
 218 /*
 219  * Stores and arbitrary binary string in the buffer.
 220  */
 221 void
 222 buffer_put_string(Buffer *buffer, const void *buf, u_int len)
 223 {
 224         buffer_put_int(buffer, len);
 225         buffer_append(buffer, buf, len);
 226 }
 227 void
 228 buffer_put_cstring(Buffer *buffer, const char *s)
 229 {
 230         if (s == NULL)
 231                 fatal("buffer_put_cstring: s == NULL");
 232         buffer_put_string(buffer, s, strlen(s));
 233 }
 234
 235 /*
 236  * Returns a character from the buffer (0 - 255).
 237  */
 238 int
 239 buffer_get_char_ret(char *ret, Buffer *buffer)
 240 {
 241         if (buffer_get_ret(buffer, ret, 1) == -1) {
 242                 error("buffer_get_char_ret: buffer_get_ret failed");
 243                 return (-1);
 244         }
 245         return (0);
 246 }
 247
 248 int
 249 buffer_get_char(Buffer *buffer)
 250 {
 251         char ch;
 252
 253         if (buffer_get_char_ret(&ch, buffer) == -1)
 254                 fatal("buffer_get_char: buffer error");
 255         return (u_char) ch;
 256 }
 257
 258 /*
 259  * Stores a character in the buffer.
 260  */
 261 void
 262 buffer_put_char(Buffer *buffer, int value)
 263 {
 264         char ch = value;
 265
 266         buffer_append(buffer, &ch, 1);
 267 }