1 /*
2 * Copyright (C) 2008, 2009 Internet Systems Consortium, Inc. ("ISC")
3 *
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
9 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
10 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
11 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
12 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
13 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
14 * PERFORMANCE OF THIS SOFTWARE.
15 */
16
17 /* $Id: base32.c,v 1.6 2009/10/21 01:22:29 each Exp $ */
18
19 /*! \file */
20
21 #include <config.h>
22
23 #include <isc/base32.h>
24 #include <isc/buffer.h>
25 #include <isc/lex.h>
26 #include <isc/region.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 /*!
39 * These static functions are also present in lib/dns/rdata.c. I'm not
40 * sure where they should go. -- bwelling
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 /*@}*/
49
50 static const char base32[] =
51 "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567=abcdefghijklmnopqrstuvwxyz234567";
52 static const char base32hex[] =
53 "0123456789ABCDEFGHIJKLMNOPQRSTUV=0123456789abcdefghijklmnopqrstuv";
54
55 static isc_result_t
base32_totext(isc_region_t * source,int wordlength,const char * wordbreak,isc_buffer_t * target,const char base[])56 base32_totext(isc_region_t *source, int wordlength, const char *wordbreak,
57 isc_buffer_t *target, const char base[])
58 {
59 char buf[9];
60 unsigned int loops = 0;
61
62 if (wordlength >= 0 && wordlength < 8)
63 wordlength = 8;
64
65 memset(buf, 0, sizeof(buf));
66 while (source->length > 0) {
67 buf[0] = base[((source->base[0]>>3)&0x1f)]; /* 5 + */
68 if (source->length == 1) {
69 buf[1] = base[(source->base[0]<<2)&0x1c];
70 buf[2] = buf[3] = buf[4] = '=';
71 buf[5] = buf[6] = buf[7] = '=';
72 RETERR(str_totext(buf, target));
73 break;
74 }
75 buf[1] = base[((source->base[0]<<2)&0x1c)| /* 3 = 8 */
76 ((source->base[1]>>6)&0x03)]; /* 2 + */
77 buf[2] = base[((source->base[1]>>1)&0x1f)]; /* 5 + */
78 if (source->length == 2) {
79 buf[3] = base[(source->base[1]<<4)&0x10];
80 buf[4] = buf[5] = buf[6] = buf[7] = '=';
81 RETERR(str_totext(buf, target));
82 break;
83 }
84 buf[3] = base[((source->base[1]<<4)&0x10)| /* 1 = 8 */
85 ((source->base[2]>>4)&0x0f)]; /* 4 + */
86 if (source->length == 3) {
87 buf[4] = base[(source->base[2]<<1)&0x1e];
88 buf[5] = buf[6] = buf[7] = '=';
89 RETERR(str_totext(buf, target));
90 break;
91 }
92 buf[4] = base[((source->base[2]<<1)&0x1e)| /* 4 = 8 */
93 ((source->base[3]>>7)&0x01)]; /* 1 + */
94 buf[5] = base[((source->base[3]>>2)&0x1f)]; /* 5 + */
95 if (source->length == 4) {
96 buf[6] = base[(source->base[3]<<3)&0x18];
97 buf[7] = '=';
98 RETERR(str_totext(buf, target));
99 break;
100 }
101 buf[6] = base[((source->base[3]<<3)&0x18)| /* 2 = 8 */
102 ((source->base[4]>>5)&0x07)]; /* 3 + */
103 buf[7] = base[source->base[4]&0x1f]; /* 5 = 8 */
104 RETERR(str_totext(buf, target));
105 isc_region_consume(source, 5);
106
107 loops++;
108 if (source->length != 0 && wordlength >= 0 &&
109 (int)((loops + 1) * 8) >= wordlength)
110 {
111 loops = 0;
112 RETERR(str_totext(wordbreak, target));
113 }
114 }
115 if (source->length > 0)
116 isc_region_consume(source, source->length);
117 return (ISC_R_SUCCESS);
118 }
119
120 isc_result_t
isc_base32_totext(isc_region_t * source,int wordlength,const char * wordbreak,isc_buffer_t * target)121 isc_base32_totext(isc_region_t *source, int wordlength,
122 const char *wordbreak, isc_buffer_t *target)
123 {
124 return (base32_totext(source, wordlength, wordbreak, target, base32));
125 }
126
127 isc_result_t
isc_base32hex_totext(isc_region_t * source,int wordlength,const char * wordbreak,isc_buffer_t * target)128 isc_base32hex_totext(isc_region_t *source, int wordlength,
129 const char *wordbreak, isc_buffer_t *target)
130 {
131 return (base32_totext(source, wordlength, wordbreak, target,
132 base32hex));
133 }
134
135 /*%
136 * State of a base32 decoding process in progress.
137 */
138 typedef struct {
139 int length; /*%< Desired length of binary data or -1 */
140 isc_buffer_t *target; /*%< Buffer for resulting binary data */
141 int digits; /*%< Number of buffered base32 digits */
142 isc_boolean_t seen_end; /*%< True if "=" end marker seen */
143 int val[8];
144 const char *base; /*%< Which encoding we are using */
145 int seen_32; /*%< Number of significant bytes if non zero */
146 } base32_decode_ctx_t;
147
148 static inline void
base32_decode_init(base32_decode_ctx_t * ctx,int length,const char base[],isc_buffer_t * target)149 base32_decode_init(base32_decode_ctx_t *ctx, int length,
150 const char base[], isc_buffer_t *target)
151 {
152 ctx->digits = 0;
153 ctx->seen_end = ISC_FALSE;
154 ctx->seen_32 = 0;
155 ctx->length = length;
156 ctx->target = target;
157 ctx->base = base;
158 }
159
160 static inline isc_result_t
base32_decode_char(base32_decode_ctx_t * ctx,int c)161 base32_decode_char(base32_decode_ctx_t *ctx, int c) {
162 char *s;
163 unsigned int last;
164
165 if (ctx->seen_end)
166 return (ISC_R_BADBASE32);
167 if ((s = strchr(ctx->base, c)) == NULL)
168 return (ISC_R_BADBASE32);
169 last = s - ctx->base;
170 /*
171 * Handle lower case.
172 */
173 if (last > 32)
174 last -= 33;
175 /*
176 * Check that padding is contiguous.
177 */
178 if (last != 32 && ctx->seen_32 != 0)
179 return (ISC_R_BADBASE32);
180 /*
181 * Check that padding starts at the right place and that
182 * bits that should be zero are.
183 * Record how many significant bytes in answer (seen_32).
184 */
185 if (last == 32 && ctx->seen_32 == 0)
186 switch (ctx->digits) {
187 case 0:
188 case 1:
189 return (ISC_R_BADBASE32);
190 case 2:
191 if ((ctx->val[1]&0x03) != 0)
192 return (ISC_R_BADBASE32);
193 ctx->seen_32 = 1;
194 break;
195 case 3:
196 return (ISC_R_BADBASE32);
197 case 4:
198 if ((ctx->val[3]&0x0f) != 0)
199 return (ISC_R_BADBASE32);
200 ctx->seen_32 = 3;
201 break;
202 case 5:
203 if ((ctx->val[4]&0x01) != 0)
204 return (ISC_R_BADBASE32);
205 ctx->seen_32 = 3;
206 break;
207 case 6:
208 return (ISC_R_BADBASE32);
209 case 7:
210 if ((ctx->val[6]&0x07) != 0)
211 return (ISC_R_BADBASE32);
212 ctx->seen_32 = 4;
213 break;
214 }
215 /*
216 * Zero fill pad values.
217 */
218 ctx->val[ctx->digits++] = (last == 32) ? 0 : last;
219
220 if (ctx->digits == 8) {
221 int n = 5;
222 unsigned char buf[5];
223
224 if (ctx->seen_32 != 0) {
225 ctx->seen_end = ISC_TRUE;
226 n = ctx->seen_32;
227 }
228 buf[0] = (ctx->val[0]<<3)|(ctx->val[1]>>2);
229 buf[1] = (ctx->val[1]<<6)|(ctx->val[2]<<1)|(ctx->val[3]>>4);
230 buf[2] = (ctx->val[3]<<4)|(ctx->val[4]>>1);
231 buf[3] = (ctx->val[4]<<7)|(ctx->val[5]<<2)|(ctx->val[6]>>3);
232 buf[4] = (ctx->val[6]<<5)|(ctx->val[7]);
233 RETERR(mem_tobuffer(ctx->target, buf, n));
234 if (ctx->length >= 0) {
235 if (n > ctx->length)
236 return (ISC_R_BADBASE32);
237 else
238 ctx->length -= n;
239 }
240 ctx->digits = 0;
241 }
242 return (ISC_R_SUCCESS);
243 }
244
245 static inline isc_result_t
base32_decode_finish(base32_decode_ctx_t * ctx)246 base32_decode_finish(base32_decode_ctx_t *ctx) {
247 if (ctx->length > 0)
248 return (ISC_R_UNEXPECTEDEND);
249 if (ctx->digits != 0)
250 return (ISC_R_BADBASE32);
251 return (ISC_R_SUCCESS);
252 }
253
254 static isc_result_t
base32_tobuffer(isc_lex_t * lexer,const char base[],isc_buffer_t * target,int length)255 base32_tobuffer(isc_lex_t *lexer, const char base[], isc_buffer_t *target,
256 int length)
257 {
258 base32_decode_ctx_t ctx;
259 isc_textregion_t *tr;
260 isc_token_t token;
261 isc_boolean_t eol;
262
263 base32_decode_init(&ctx, length, base, target);
264
265 while (!ctx.seen_end && (ctx.length != 0)) {
266 unsigned int i;
267
268 if (length > 0)
269 eol = ISC_FALSE;
270 else
271 eol = ISC_TRUE;
272 RETERR(isc_lex_getmastertoken(lexer, &token,
273 isc_tokentype_string, eol));
274 if (token.type != isc_tokentype_string)
275 break;
276 tr = &token.value.as_textregion;
277 for (i = 0; i < tr->length; i++)
278 RETERR(base32_decode_char(&ctx, tr->base[i]));
279 }
280 if (ctx.length < 0 && !ctx.seen_end)
281 isc_lex_ungettoken(lexer, &token);
282 RETERR(base32_decode_finish(&ctx));
283 return (ISC_R_SUCCESS);
284 }
285
286 isc_result_t
isc_base32_tobuffer(isc_lex_t * lexer,isc_buffer_t * target,int length)287 isc_base32_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) {
288 return (base32_tobuffer(lexer, base32, target, length));
289 }
290
291 isc_result_t
isc_base32hex_tobuffer(isc_lex_t * lexer,isc_buffer_t * target,int length)292 isc_base32hex_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) {
293 return (base32_tobuffer(lexer, base32hex, target, length));
294 }
295
296 static isc_result_t
base32_decodestring(const char * cstr,const char base[],isc_buffer_t * target)297 base32_decodestring(const char *cstr, const char base[], isc_buffer_t *target) {
298 base32_decode_ctx_t ctx;
299
300 base32_decode_init(&ctx, -1, base, target);
301 for (;;) {
302 int c = *cstr++;
303 if (c == '\0')
304 break;
305 if (c == ' ' || c == '\t' || c == '\n' || c== '\r')
306 continue;
307 RETERR(base32_decode_char(&ctx, c));
308 }
309 RETERR(base32_decode_finish(&ctx));
310 return (ISC_R_SUCCESS);
311 }
312
313 isc_result_t
isc_base32_decodestring(const char * cstr,isc_buffer_t * target)314 isc_base32_decodestring(const char *cstr, isc_buffer_t *target) {
315 return (base32_decodestring(cstr, base32, target));
316 }
317
318 isc_result_t
isc_base32hex_decodestring(const char * cstr,isc_buffer_t * target)319 isc_base32hex_decodestring(const char *cstr, isc_buffer_t *target) {
320 return (base32_decodestring(cstr, base32hex, target));
321 }
322
323 static isc_result_t
base32_decoderegion(isc_region_t * source,const char base[],isc_buffer_t * target)324 base32_decoderegion(isc_region_t *source, const char base[], isc_buffer_t *target) {
325 base32_decode_ctx_t ctx;
326
327 base32_decode_init(&ctx, -1, base, target);
328 while (source->length != 0) {
329 int c = *source->base;
330 RETERR(base32_decode_char(&ctx, c));
331 isc_region_consume(source, 1);
332 }
333 RETERR(base32_decode_finish(&ctx));
334 return (ISC_R_SUCCESS);
335 }
336
337 isc_result_t
isc_base32_decoderegion(isc_region_t * source,isc_buffer_t * target)338 isc_base32_decoderegion(isc_region_t *source, isc_buffer_t *target) {
339 return (base32_decoderegion(source, base32, target));
340 }
341
342 isc_result_t
isc_base32hex_decoderegion(isc_region_t * source,isc_buffer_t * target)343 isc_base32hex_decoderegion(isc_region_t *source, isc_buffer_t *target) {
344 return (base32_decoderegion(source, base32hex, target));
345 }
346
347 static isc_result_t
str_totext(const char * source,isc_buffer_t * target)348 str_totext(const char *source, isc_buffer_t *target) {
349 unsigned int l;
350 isc_region_t region;
351
352 isc_buffer_availableregion(target, ®ion);
353 l = strlen(source);
354
355 if (l > region.length)
356 return (ISC_R_NOSPACE);
357
358 memcpy(region.base, source, l);
359 isc_buffer_add(target, l);
360 return (ISC_R_SUCCESS);
361 }
362
363 static isc_result_t
mem_tobuffer(isc_buffer_t * target,void * base,unsigned int length)364 mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length) {
365 isc_region_t tr;
366
367 isc_buffer_availableregion(target, &tr);
368 if (length > tr.length)
369 return (ISC_R_NOSPACE);
370 memcpy(tr.base, base, length);
371 isc_buffer_add(target, length);
372 return (ISC_R_SUCCESS);
373 }
374