1 /*
2 * Copyright (C) 2004, 2005, 2007, 2008 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 1.20 2008/09/25 04:02:39 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
isc_hex_totext(isc_region_t * source,int wordlength,const char * wordbreak,isc_buffer_t * target)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
hex_decode_init(hex_decode_ctx_t * ctx,int length,isc_buffer_t * target)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
hex_decode_char(hex_decode_ctx_t * ctx,int c)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
hex_decode_finish(hex_decode_ctx_t * ctx)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
isc_hex_tobuffer(isc_lex_t * lexer,isc_buffer_t * target,int length)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
isc_hex_decodestring(const char * cstr,isc_buffer_t * target)159 isc_hex_decodestring(const 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
str_totext(const char * source,isc_buffer_t * target)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, ®ion);
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
mem_tobuffer(isc_buffer_t * target,void * base,unsigned int length)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 }
202