contrib/bind-9.5.2/lib/isc/hex.c

   1 /*
   2  * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2000-2003  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and/or distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: hex.c,v 1.18 2007/06/19 23:47:17 tbox Exp $ */
  19
  20 /*! \file */
  21
  22 #include <config.h>
  23
  24 #include <ctype.h>
  25
  26 #include <isc/buffer.h>
  27 #include <isc/hex.h>
  28 #include <isc/lex.h>
  29 #include <isc/string.h>
  30 #include <isc/util.h>
  31
  32 #define RETERR(x) do { \
  33         isc_result_t _r = (x); \
  34         if (_r != ISC_R_SUCCESS) \
  35                 return (_r); \
  36         } while (0)
  37
  38
  39 /*
  40  * BEW: These static functions are copied from lib/dns/rdata.c.
  41  */
  42 static isc_result_t
  43 str_totext(const char *source, isc_buffer_t *target);
  44
  45 static isc_result_t
  46 mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length);
  47
  48 static const char hex[] = "0123456789ABCDEF";
  49
  50 isc_result_t
  51 isc_hex_totext(isc_region_t *source, int wordlength,
  52                const char *wordbreak, isc_buffer_t *target)
  53 {
  54         char buf[3];
  55         unsigned int loops = 0;
  56
  57         if (wordlength < 2)
  58                 wordlength = 2;
  59
  60         memset(buf, 0, sizeof(buf));
  61         while (source->length > 0) {
  62                 buf[0] = hex[(source->base[0] >> 4) & 0xf];
  63                 buf[1] = hex[(source->base[0]) & 0xf];
  64                 RETERR(str_totext(buf, target));
  65                 isc_region_consume(source, 1);
  66
  67                 loops++;
  68                 if (source->length != 0 &&
  69                     (int)((loops + 1) * 2) >= wordlength)
  70                 {
  71                         loops = 0;
  72                         RETERR(str_totext(wordbreak, target));
  73                 }
  74         }
  75         return (ISC_R_SUCCESS);
  76 }
  77
  78 /*%
  79  * State of a hex decoding process in progress.
  80  */
  81 typedef struct {
  82         int length;             /*%< Desired length of binary data or -1 */
  83         isc_buffer_t *target;   /*%< Buffer for resulting binary data */
  84         int digits;             /*%< Number of buffered hex digits */
  85         int val[2];
  86 } hex_decode_ctx_t;
  87
  88 static inline void
  89 hex_decode_init(hex_decode_ctx_t *ctx, int length, isc_buffer_t *target)
  90 {
  91         ctx->digits = 0;
  92         ctx->length = length;
  93         ctx->target = target;
  94 }
  95
  96 static inline isc_result_t
  97 hex_decode_char(hex_decode_ctx_t *ctx, int c) {
  98         char *s;
  99
 100         if ((s = strchr(hex, toupper(c))) == NULL)
 101                 return (ISC_R_BADHEX);
 102         ctx->val[ctx->digits++] = s - hex;
 103         if (ctx->digits == 2) {
 104                 unsigned char num;
 105
 106                 num = (ctx->val[0] << 4) + (ctx->val[1]);
 107                 RETERR(mem_tobuffer(ctx->target, &num, 1));
 108                 if (ctx->length >= 0) {
 109                         if (ctx->length == 0)
 110                                 return (ISC_R_BADHEX);
 111                         else
 112                                 ctx->length -= 1;
 113                 }
 114                 ctx->digits = 0;
 115         }
 116         return (ISC_R_SUCCESS);
 117 }
 118
 119 static inline isc_result_t
 120 hex_decode_finish(hex_decode_ctx_t *ctx) {
 121         if (ctx->length > 0)
 122                 return (ISC_R_UNEXPECTEDEND);
 123         if (ctx->digits != 0)
 124                 return (ISC_R_BADHEX);
 125         return (ISC_R_SUCCESS);
 126 }
 127
 128 isc_result_t
 129 isc_hex_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) {
 130         hex_decode_ctx_t ctx;
 131         isc_textregion_t *tr;
 132         isc_token_t token;
 133         isc_boolean_t eol;
 134
 135         hex_decode_init(&ctx, length, target);
 136
 137         while (ctx.length != 0) {
 138                 unsigned int i;
 139
 140                 if (length > 0)
 141                         eol = ISC_FALSE;
 142                 else
 143                         eol = ISC_TRUE;
 144                 RETERR(isc_lex_getmastertoken(lexer, &token,
 145                                               isc_tokentype_string, eol));
 146                 if (token.type != isc_tokentype_string)
 147                         break;
 148                 tr = &token.value.as_textregion;
 149                 for (i = 0; i < tr->length; i++)
 150                         RETERR(hex_decode_char(&ctx, tr->base[i]));
 151         }
 152         if (ctx.length < 0)
 153                 isc_lex_ungettoken(lexer, &token);
 154         RETERR(hex_decode_finish(&ctx));
 155         return (ISC_R_SUCCESS);
 156 }
 157
 158 isc_result_t
 159 isc_hex_decodestring(char *cstr, isc_buffer_t *target) {
 160         hex_decode_ctx_t ctx;
 161
 162         hex_decode_init(&ctx, -1, target);
 163         for (;;) {
 164                 int c = *cstr++;
 165                 if (c == '\0')
 166                         break;
 167                 if (c == ' ' || c == '\t' || c == '\n' || c== '\r')
 168                         continue;
 169                 RETERR(hex_decode_char(&ctx, c));
 170         }
 171         RETERR(hex_decode_finish(&ctx));
 172         return (ISC_R_SUCCESS);
 173 }
 174
 175 static isc_result_t
 176 str_totext(const char *source, isc_buffer_t *target) {
 177         unsigned int l;
 178         isc_region_t region;
 179
 180         isc_buffer_availableregion(target, &region);
 181         l = strlen(source);
 182
 183         if (l > region.length)
 184                 return (ISC_R_NOSPACE);
 185
 186         memcpy(region.base, source, l);
 187         isc_buffer_add(target, l);
 188         return (ISC_R_SUCCESS);
 189 }
 190
 191 static isc_result_t
 192 mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length) {
 193         isc_region_t tr;
 194
 195         isc_buffer_availableregion(target, &tr);
 196         if (length > tr.length)
 197                 return (ISC_R_NOSPACE);
 198         memcpy(tr.base, base, length);
 199         isc_buffer_add(target, length);
 200         return (ISC_R_SUCCESS);
 201 }