contrib/bind-9.2.4rc7/lib/isc/hex.c

   1 /*
   2  * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2000-2002  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and 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 1.8.2.3 2004/03/09 06:11:46 marka Exp $ */
  19
  20 #include <config.h>
  21
  22 #include <ctype.h>
  23
  24 #include <isc/buffer.h>
  25 #include <isc/hex.h>
  26 #include <isc/lex.h>
  27 #include <isc/string.h>
  28 #include <isc/util.h>
  29
  30 #define RETERR(x) do { \
  31         isc_result_t _r = (x); \
  32         if (_r != ISC_R_SUCCESS) \
  33                 return (_r); \
  34         } while (0)
  35
  36
  37 /*
  38  * BEW: These static functions are copied from lib/dns/rdata.c.
  39  */
  40 static isc_result_t
  41 str_totext(const char *source, isc_buffer_t *target);
  42
  43 static isc_result_t
  44 mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length);
  45
  46 static const char hex[] = "0123456789ABCDEF";
  47
  48 isc_result_t
  49 isc_hex_totext(isc_region_t *source, int wordlength,
  50                const char *wordbreak, isc_buffer_t *target)
  51 {
  52         char buf[3];
  53         unsigned int loops = 0;
  54
  55         if (wordlength < 2)
  56                 wordlength = 2;
  57
  58         memset(buf, 0, sizeof buf);
  59         while (source->length > 0) {
  60                 buf[0] = hex[(source->base[0] >> 4) & 0xf];
  61                 buf[1] = hex[(source->base[0]) & 0xf];
  62                 RETERR(str_totext(buf, target));
  63                 isc_region_consume(source, 1);
  64
  65                 loops++;
  66                 if (source->length != 0 &&
  67                     (int)((loops + 1) * 2) >= wordlength)
  68                 {
  69                         loops = 0;
  70                         RETERR(str_totext(wordbreak, target));
  71                 }
  72         }
  73         return (ISC_R_SUCCESS);
  74 }
  75
  76 /*
  77  * State of a hex decoding process in progress.
  78  */
  79 typedef struct {
  80         int length;             /* Desired length of binary data or -1 */
  81         isc_buffer_t *target;   /* Buffer for resulting binary data */
  82         int digits;             /* Number of buffered hex digits */
  83         int val[2];
  84 } hex_decode_ctx_t;
  85
  86 static inline void
  87 hex_decode_init(hex_decode_ctx_t *ctx, int length, isc_buffer_t *target)
  88 {
  89         ctx->digits = 0;
  90         ctx->length = length;
  91         ctx->target = target;
  92 }
  93
  94 static inline isc_result_t
  95 hex_decode_char(hex_decode_ctx_t *ctx, int c) {
  96         char *s;
  97
  98         if ((s = strchr(hex, toupper(c))) == NULL)
  99                 return (ISC_R_BADHEX);
 100         ctx->val[ctx->digits++] = s - hex;
 101         if (ctx->digits == 2) {
 102                 unsigned char num;
 103
 104                 num = (ctx->val[0] << 4) + (ctx->val[1]);
 105                 RETERR(mem_tobuffer(ctx->target, &num, 1));
 106                 if (ctx->length >= 0) {
 107                         if (ctx->length == 0)
 108                                 return (ISC_R_BADHEX);
 109                         else
 110                                 ctx->length -= 1;
 111                 }
 112                 ctx->digits = 0;
 113         }
 114         return (ISC_R_SUCCESS);
 115 }
 116
 117 static inline isc_result_t
 118 hex_decode_finish(hex_decode_ctx_t *ctx) {
 119         if (ctx->length > 0)
 120                 return (ISC_R_UNEXPECTEDEND);
 121         if (ctx->digits != 0)
 122                 return (ISC_R_BADHEX);
 123         return (ISC_R_SUCCESS);
 124 }
 125
 126 isc_result_t
 127 isc_hex_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) {
 128         hex_decode_ctx_t ctx;
 129         isc_textregion_t *tr;
 130         isc_token_t token;
 131         isc_boolean_t eol;
 132
 133         hex_decode_init(&ctx, length, target);
 134
 135         while (ctx.length != 0) {
 136                 unsigned int i;
 137
 138                 if (length > 0)
 139                         eol = ISC_FALSE;
 140                 else
 141                         eol = ISC_TRUE;
 142                 RETERR(isc_lex_getmastertoken(lexer, &token,
 143                                               isc_tokentype_string, eol));
 144                 if (token.type != isc_tokentype_string)
 145                         break;
 146                 tr = &token.value.as_textregion;
 147                 for (i = 0 ;i < tr->length; i++)
 148                         RETERR(hex_decode_char(&ctx, tr->base[i]));
 149         }
 150         if (ctx.length < 0)
 151                 isc_lex_ungettoken(lexer, &token);
 152         RETERR(hex_decode_finish(&ctx));
 153         return (ISC_R_SUCCESS);
 154 }
 155
 156 isc_result_t
 157 isc_hex_decodestring(char *cstr, isc_buffer_t *target) {
 158         hex_decode_ctx_t ctx;
 159
 160         hex_decode_init(&ctx, -1, target);
 161         for (;;) {
 162                 int c = *cstr++;
 163                 if (c == '\0')
 164                         break;
 165                 if (c == ' ' || c == '\t' || c == '\n' || c== '\r')
 166                         continue;
 167                 RETERR(hex_decode_char(&ctx, c));
 168         }
 169         RETERR(hex_decode_finish(&ctx));
 170         return (ISC_R_SUCCESS);
 171 }
 172
 173 static isc_result_t
 174 str_totext(const char *source, isc_buffer_t *target) {
 175         unsigned int l;
 176         isc_region_t region;
 177
 178         isc_buffer_availableregion(target, &region);
 179         l = strlen(source);
 180
 181         if (l > region.length)
 182                 return (ISC_R_NOSPACE);
 183
 184         memcpy(region.base, source, l);
 185         isc_buffer_add(target, l);
 186         return (ISC_R_SUCCESS);
 187 }
 188
 189 static isc_result_t
 190 mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length) {
 191         isc_region_t tr;
 192
 193         isc_buffer_availableregion(target, &tr);
 194         if (length > tr.length)
 195                 return (ISC_R_NOSPACE);
 196         memcpy(tr.base, base, length);
 197         isc_buffer_add(target, length);
 198         return (ISC_R_SUCCESS);
 199 }