1 /*
2 * parseutil.c - parse utilities for string and wire conversion
3 *
4 * (c) NLnet Labs, 2004-2006
5 *
6 * See the file LICENSE for the license
7 */
8 /**
9 * \file
10 *
11 * Utility functions for parsing, base32(DNS variant) and base64 encoding
12 * and decoding, Hex, Time units, Escape codes.
13 */
14
15 #include "config.h"
16 #include "sldns/parseutil.h"
17 #include <sys/time.h>
18 #include <time.h>
19 #include <ctype.h>
20
21 sldns_lookup_table *
sldns_lookup_by_name(sldns_lookup_table * table,const char * name)22 sldns_lookup_by_name(sldns_lookup_table *table, const char *name)
23 {
24 while (table->name != NULL) {
25 if (strcasecmp(name, table->name) == 0)
26 return table;
27 table++;
28 }
29 return NULL;
30 }
31
32 sldns_lookup_table *
sldns_lookup_by_id(sldns_lookup_table * table,int id)33 sldns_lookup_by_id(sldns_lookup_table *table, int id)
34 {
35 while (table->name != NULL) {
36 if (table->id == id)
37 return table;
38 table++;
39 }
40 return NULL;
41 }
42
43 /* Number of days per month (except for February in leap years). */
44 static const int mdays[] = {
45 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
46 };
47
48 #define LDNS_MOD(x,y) (((x) % (y) < 0) ? ((x) % (y) + (y)) : ((x) % (y)))
49 #define LDNS_DIV(x,y) (((x) % (y) < 0) ? ((x) / (y) - 1 ) : ((x) / (y)))
50
51 static int
is_leap_year(int year)52 is_leap_year(int year)
53 {
54 return LDNS_MOD(year, 4) == 0 && (LDNS_MOD(year, 100) != 0
55 || LDNS_MOD(year, 400) == 0);
56 }
57
58 static int
leap_days(int y1,int y2)59 leap_days(int y1, int y2)
60 {
61 --y1;
62 --y2;
63 return (LDNS_DIV(y2, 4) - LDNS_DIV(y1, 4)) -
64 (LDNS_DIV(y2, 100) - LDNS_DIV(y1, 100)) +
65 (LDNS_DIV(y2, 400) - LDNS_DIV(y1, 400));
66 }
67
68 /*
69 * Code adapted from Python 2.4.1 sources (Lib/calendar.py).
70 */
71 time_t
sldns_mktime_from_utc(const struct tm * tm)72 sldns_mktime_from_utc(const struct tm *tm)
73 {
74 int year = 1900 + tm->tm_year;
75 time_t days = 365 * ((time_t) year - 1970) + leap_days(1970, year);
76 time_t hours;
77 time_t minutes;
78 time_t seconds;
79 int i;
80
81 for (i = 0; i < tm->tm_mon; ++i) {
82 days += mdays[i];
83 }
84 if (tm->tm_mon > 1 && is_leap_year(year)) {
85 ++days;
86 }
87 days += tm->tm_mday - 1;
88
89 hours = days * 24 + tm->tm_hour;
90 minutes = hours * 60 + tm->tm_min;
91 seconds = minutes * 60 + tm->tm_sec;
92
93 return seconds;
94 }
95
96 #if SIZEOF_TIME_T <= 4
97
98 static void
sldns_year_and_yday_from_days_since_epoch(int64_t days,struct tm * result)99 sldns_year_and_yday_from_days_since_epoch(int64_t days, struct tm *result)
100 {
101 int year = 1970;
102 int new_year;
103
104 while (days < 0 || days >= (int64_t) (is_leap_year(year) ? 366 : 365)) {
105 new_year = year + (int) LDNS_DIV(days, 365);
106 days -= (new_year - year) * 365;
107 days -= leap_days(year, new_year);
108 year = new_year;
109 }
110 result->tm_year = year;
111 result->tm_yday = (int) days;
112 }
113
114 /* Number of days per month in a leap year. */
115 static const int leap_year_mdays[] = {
116 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
117 };
118
119 static void
sldns_mon_and_mday_from_year_and_yday(struct tm * result)120 sldns_mon_and_mday_from_year_and_yday(struct tm *result)
121 {
122 int idays = result->tm_yday;
123 const int *mon_lengths = is_leap_year(result->tm_year) ?
124 leap_year_mdays : mdays;
125
126 result->tm_mon = 0;
127 while (idays >= mon_lengths[result->tm_mon]) {
128 idays -= mon_lengths[result->tm_mon++];
129 }
130 result->tm_mday = idays + 1;
131 }
132
133 static void
sldns_wday_from_year_and_yday(struct tm * result)134 sldns_wday_from_year_and_yday(struct tm *result)
135 {
136 result->tm_wday = 4 /* 1-1-1970 was a thursday */
137 + LDNS_MOD((result->tm_year - 1970), 7) * LDNS_MOD(365, 7)
138 + leap_days(1970, result->tm_year)
139 + result->tm_yday;
140 result->tm_wday = LDNS_MOD(result->tm_wday, 7);
141 if (result->tm_wday < 0) {
142 result->tm_wday += 7;
143 }
144 }
145
146 static struct tm *
sldns_gmtime64_r(int64_t clock,struct tm * result)147 sldns_gmtime64_r(int64_t clock, struct tm *result)
148 {
149 result->tm_isdst = 0;
150 result->tm_sec = (int) LDNS_MOD(clock, 60);
151 clock = LDNS_DIV(clock, 60);
152 result->tm_min = (int) LDNS_MOD(clock, 60);
153 clock = LDNS_DIV(clock, 60);
154 result->tm_hour = (int) LDNS_MOD(clock, 24);
155 clock = LDNS_DIV(clock, 24);
156
157 sldns_year_and_yday_from_days_since_epoch(clock, result);
158 sldns_mon_and_mday_from_year_and_yday(result);
159 sldns_wday_from_year_and_yday(result);
160 result->tm_year -= 1900;
161
162 return result;
163 }
164
165 #endif /* SIZEOF_TIME_T <= 4 */
166
167 static int64_t
sldns_serial_arithmetics_time(int32_t time,time_t now)168 sldns_serial_arithmetics_time(int32_t time, time_t now)
169 {
170 int32_t offset = (int32_t)((uint32_t) time - (uint32_t) now);
171 return (int64_t) now + offset;
172 }
173
174 struct tm *
sldns_serial_arithmetics_gmtime_r(int32_t time,time_t now,struct tm * result)175 sldns_serial_arithmetics_gmtime_r(int32_t time, time_t now, struct tm *result)
176 {
177 #if SIZEOF_TIME_T <= 4
178 int64_t secs_since_epoch = sldns_serial_arithmetics_time(time, now);
179 return sldns_gmtime64_r(secs_since_epoch, result);
180 #else
181 time_t secs_since_epoch = sldns_serial_arithmetics_time(time, now);
182 return gmtime_r(&secs_since_epoch, result);
183 #endif
184 }
185
186 int
sldns_hexdigit_to_int(char ch)187 sldns_hexdigit_to_int(char ch)
188 {
189 switch (ch) {
190 case '0': return 0;
191 case '1': return 1;
192 case '2': return 2;
193 case '3': return 3;
194 case '4': return 4;
195 case '5': return 5;
196 case '6': return 6;
197 case '7': return 7;
198 case '8': return 8;
199 case '9': return 9;
200 case 'a': case 'A': return 10;
201 case 'b': case 'B': return 11;
202 case 'c': case 'C': return 12;
203 case 'd': case 'D': return 13;
204 case 'e': case 'E': return 14;
205 case 'f': case 'F': return 15;
206 default:
207 return -1;
208 }
209 }
210
211 uint32_t
sldns_str2period(const char * nptr,const char ** endptr)212 sldns_str2period(const char *nptr, const char **endptr)
213 {
214 int sign = 0;
215 uint32_t i = 0;
216 uint32_t seconds = 0;
217
218 for(*endptr = nptr; **endptr; (*endptr)++) {
219 switch (**endptr) {
220 case ' ':
221 case '\t':
222 break;
223 case '-':
224 if(sign == 0) {
225 sign = -1;
226 } else {
227 return seconds;
228 }
229 break;
230 case '+':
231 if(sign == 0) {
232 sign = 1;
233 } else {
234 return seconds;
235 }
236 break;
237 case 's':
238 case 'S':
239 seconds += i;
240 i = 0;
241 break;
242 case 'm':
243 case 'M':
244 seconds += i * 60;
245 i = 0;
246 break;
247 case 'h':
248 case 'H':
249 seconds += i * 60 * 60;
250 i = 0;
251 break;
252 case 'd':
253 case 'D':
254 seconds += i * 60 * 60 * 24;
255 i = 0;
256 break;
257 case 'w':
258 case 'W':
259 seconds += i * 60 * 60 * 24 * 7;
260 i = 0;
261 break;
262 case '0':
263 case '1':
264 case '2':
265 case '3':
266 case '4':
267 case '5':
268 case '6':
269 case '7':
270 case '8':
271 case '9':
272 i *= 10;
273 i += (**endptr - '0');
274 break;
275 default:
276 seconds += i;
277 /* disregard signedness */
278 return seconds;
279 }
280 }
281 seconds += i;
282 /* disregard signedness */
283 return seconds;
284 }
285
286 int
sldns_parse_escape(uint8_t * ch_p,const char ** str_p)287 sldns_parse_escape(uint8_t *ch_p, const char** str_p)
288 {
289 uint16_t val;
290
291 if ((*str_p)[0] && isdigit((unsigned char)(*str_p)[0]) &&
292 (*str_p)[1] && isdigit((unsigned char)(*str_p)[1]) &&
293 (*str_p)[2] && isdigit((unsigned char)(*str_p)[2])) {
294
295 val = (uint16_t)(((*str_p)[0] - '0') * 100 +
296 ((*str_p)[1] - '0') * 10 +
297 ((*str_p)[2] - '0'));
298
299 if (val > 255) {
300 goto error;
301 }
302 *ch_p = (uint8_t)val;
303 *str_p += 3;
304 return 1;
305
306 } else if ((*str_p)[0] && !isdigit((unsigned char)(*str_p)[0])) {
307
308 *ch_p = (uint8_t)*(*str_p)++;
309 return 1;
310 }
311 error:
312 *str_p = NULL;
313 return 0; /* LDNS_WIREPARSE_ERR_SYNTAX_BAD_ESCAPE */
314 }
315
316 /** parse one character, with escape codes */
317 int
sldns_parse_char(uint8_t * ch_p,const char ** str_p)318 sldns_parse_char(uint8_t *ch_p, const char** str_p)
319 {
320 switch (**str_p) {
321
322 case '\0': return 0;
323
324 case '\\': *str_p += 1;
325 return sldns_parse_escape(ch_p, str_p);
326
327 default: *ch_p = (uint8_t)*(*str_p)++;
328 return 1;
329 }
330 }
331
sldns_b32_ntop_calculate_size(size_t src_data_length)332 size_t sldns_b32_ntop_calculate_size(size_t src_data_length)
333 {
334 return src_data_length == 0 ? 0 : ((src_data_length - 1) / 5 + 1) * 8;
335 }
336
sldns_b32_ntop_calculate_size_no_padding(size_t src_data_length)337 size_t sldns_b32_ntop_calculate_size_no_padding(size_t src_data_length)
338 {
339 return ((src_data_length + 3) * 8 / 5) - 4;
340 }
341
342 static int
sldns_b32_ntop_base(const uint8_t * src,size_t src_sz,char * dst,size_t dst_sz,int extended_hex,int add_padding)343 sldns_b32_ntop_base(const uint8_t* src, size_t src_sz, char* dst, size_t dst_sz,
344 int extended_hex, int add_padding)
345 {
346 size_t ret_sz;
347 const char* b32 = extended_hex ? "0123456789abcdefghijklmnopqrstuv"
348 : "abcdefghijklmnopqrstuvwxyz234567";
349
350 size_t c = 0; /* c is used to carry partial base32 character over
351 * byte boundaries for sizes with a remainder.
352 * (i.e. src_sz % 5 != 0)
353 */
354
355 ret_sz = add_padding ? sldns_b32_ntop_calculate_size(src_sz)
356 : sldns_b32_ntop_calculate_size_no_padding(src_sz);
357
358 /* Do we have enough space? */
359 if (dst_sz < ret_sz + 1)
360 return -1;
361
362 /* We know the size; terminate the string */
363 dst[ret_sz] = '\0';
364
365 /* First process all chunks of five */
366 while (src_sz >= 5) {
367 /* 00000... ........ ........ ........ ........ */
368 dst[0] = b32[(src[0] ) >> 3];
369
370 /* .....111 11...... ........ ........ ........ */
371 dst[1] = b32[(src[0] & 0x07) << 2 | src[1] >> 6];
372
373 /* ........ ..22222. ........ ........ ........ */
374 dst[2] = b32[(src[1] & 0x3e) >> 1];
375
376 /* ........ .......3 3333.... ........ ........ */
377 dst[3] = b32[(src[1] & 0x01) << 4 | src[2] >> 4];
378
379 /* ........ ........ ....4444 4....... ........ */
380 dst[4] = b32[(src[2] & 0x0f) << 1 | src[3] >> 7];
381
382 /* ........ ........ ........ .55555.. ........ */
383 dst[5] = b32[(src[3] & 0x7c) >> 2];
384
385 /* ........ ........ ........ ......66 666..... */
386 dst[6] = b32[(src[3] & 0x03) << 3 | src[4] >> 5];
387
388 /* ........ ........ ........ ........ ...77777 */
389 dst[7] = b32[(src[4] & 0x1f) ];
390
391 src_sz -= 5;
392 src += 5;
393 dst += 8;
394 }
395 /* Process what remains */
396 switch (src_sz) {
397 case 4: /* ........ ........ ........ ......66 666..... */
398 dst[6] = b32[(src[3] & 0x03) << 3];
399
400 /* ........ ........ ........ .55555.. ........ */
401 dst[5] = b32[(src[3] & 0x7c) >> 2];
402
403 /* ........ ........ ....4444 4....... ........ */
404 c = src[3] >> 7 ;
405 /* fallthrough */
406 case 3: dst[4] = b32[(src[2] & 0x0f) << 1 | c];
407
408 /* ........ .......3 3333.... ........ ........ */
409 c = src[2] >> 4 ;
410 /* fallthrough */
411 case 2: dst[3] = b32[(src[1] & 0x01) << 4 | c];
412
413 /* ........ ..22222. ........ ........ ........ */
414 dst[2] = b32[(src[1] & 0x3e) >> 1];
415
416 /* .....111 11...... ........ ........ ........ */
417 c = src[1] >> 6 ;
418 /* fallthrough */
419 case 1: dst[1] = b32[(src[0] & 0x07) << 2 | c];
420
421 /* 00000... ........ ........ ........ ........ */
422 dst[0] = b32[ src[0] >> 3];
423 }
424 /* Add padding */
425 if (add_padding) {
426 switch (src_sz) {
427 case 1: dst[2] = '=';
428 dst[3] = '=';
429 /* fallthrough */
430 case 2: dst[4] = '=';
431 /* fallthrough */
432 case 3: dst[5] = '=';
433 dst[6] = '=';
434 /* fallthrough */
435 case 4: dst[7] = '=';
436 }
437 }
438 return (int)ret_sz;
439 }
440
441 int
sldns_b32_ntop(const uint8_t * src,size_t src_sz,char * dst,size_t dst_sz)442 sldns_b32_ntop(const uint8_t* src, size_t src_sz, char* dst, size_t dst_sz)
443 {
444 return sldns_b32_ntop_base(src, src_sz, dst, dst_sz, 0, 1);
445 }
446
447 int
sldns_b32_ntop_extended_hex(const uint8_t * src,size_t src_sz,char * dst,size_t dst_sz)448 sldns_b32_ntop_extended_hex(const uint8_t* src, size_t src_sz,
449 char* dst, size_t dst_sz)
450 {
451 return sldns_b32_ntop_base(src, src_sz, dst, dst_sz, 1, 1);
452 }
453
sldns_b32_pton_calculate_size(size_t src_text_length)454 size_t sldns_b32_pton_calculate_size(size_t src_text_length)
455 {
456 return src_text_length * 5 / 8;
457 }
458
459 static int
sldns_b32_pton_base(const char * src,size_t src_sz,uint8_t * dst,size_t dst_sz,int extended_hex,int check_padding)460 sldns_b32_pton_base(const char* src, size_t src_sz, uint8_t* dst, size_t dst_sz,
461 int extended_hex, int check_padding)
462 {
463 size_t i = 0;
464 char ch = '\0';
465 uint8_t buf[8];
466 uint8_t* start = dst;
467
468 while (src_sz) {
469 /* Collect 8 characters in buf (if possible) */
470 for (i = 0; i < 8; i++) {
471
472 do {
473 ch = *src++;
474 --src_sz;
475
476 } while (isspace((unsigned char)ch) && src_sz > 0);
477
478 if (ch == '=' || ch == '\0')
479 break;
480
481 else if (extended_hex)
482
483 if (ch >= '0' && ch <= '9')
484 buf[i] = (uint8_t)ch - '0';
485 else if (ch >= 'a' && ch <= 'v')
486 buf[i] = (uint8_t)ch - 'a' + 10;
487 else if (ch >= 'A' && ch <= 'V')
488 buf[i] = (uint8_t)ch - 'A' + 10;
489 else
490 return -1;
491
492 else if (ch >= 'a' && ch <= 'z')
493 buf[i] = (uint8_t)ch - 'a';
494 else if (ch >= 'A' && ch <= 'Z')
495 buf[i] = (uint8_t)ch - 'A';
496 else if (ch >= '2' && ch <= '7')
497 buf[i] = (uint8_t)ch - '2' + 26;
498 else
499 return -1;
500 }
501 /* Less that 8 characters. We're done. */
502 if (i < 8)
503 break;
504
505 /* Enough space available at the destination? */
506 if (dst_sz < 5)
507 return -1;
508
509 /* 00000... ........ ........ ........ ........ */
510 /* .....111 11...... ........ ........ ........ */
511 dst[0] = buf[0] << 3 | buf[1] >> 2;
512
513 /* .....111 11...... ........ ........ ........ */
514 /* ........ ..22222. ........ ........ ........ */
515 /* ........ .......3 3333.... ........ ........ */
516 dst[1] = buf[1] << 6 | buf[2] << 1 | buf[3] >> 4;
517
518 /* ........ .......3 3333.... ........ ........ */
519 /* ........ ........ ....4444 4....... ........ */
520 dst[2] = buf[3] << 4 | buf[4] >> 1;
521
522 /* ........ ........ ....4444 4....... ........ */
523 /* ........ ........ ........ .55555.. ........ */
524 /* ........ ........ ........ ......66 666..... */
525 dst[3] = buf[4] << 7 | buf[5] << 2 | buf[6] >> 3;
526
527 /* ........ ........ ........ ......66 666..... */
528 /* ........ ........ ........ ........ ...77777 */
529 dst[4] = buf[6] << 5 | buf[7];
530
531 dst += 5;
532 dst_sz -= 5;
533 }
534 /* Not ending on a eight byte boundary? */
535 if (i > 0 && i < 8) {
536
537 /* Enough space available at the destination? */
538 if (dst_sz < (i + 1) / 2)
539 return -1;
540
541 switch (i) {
542 case 7: /* ........ ........ ........ ......66 666..... */
543 /* ........ ........ ........ .55555.. ........ */
544 /* ........ ........ ....4444 4....... ........ */
545 dst[3] = buf[4] << 7 | buf[5] << 2 | buf[6] >> 3;
546 /* fallthrough */
547
548 case 5: /* ........ ........ ....4444 4....... ........ */
549 /* ........ .......3 3333.... ........ ........ */
550 dst[2] = buf[3] << 4 | buf[4] >> 1;
551 /* fallthrough */
552
553 case 4: /* ........ .......3 3333.... ........ ........ */
554 /* ........ ..22222. ........ ........ ........ */
555 /* .....111 11...... ........ ........ ........ */
556 dst[1] = buf[1] << 6 | buf[2] << 1 | buf[3] >> 4;
557 /* fallthrough */
558
559 case 2: /* .....111 11...... ........ ........ ........ */
560 /* 00000... ........ ........ ........ ........ */
561 dst[0] = buf[0] << 3 | buf[1] >> 2;
562
563 break;
564
565 default:
566 return -1;
567 }
568 dst += (i + 1) / 2;
569
570 if (check_padding) {
571 /* Check remaining padding characters */
572 if (ch != '=')
573 return -1;
574
575 /* One down, 8 - i - 1 more to come... */
576 for (i = 8 - i - 1; i > 0; i--) {
577
578 do {
579 if (src_sz == 0)
580 return -1;
581 ch = *src++;
582 src_sz--;
583
584 } while (isspace((unsigned char)ch));
585
586 if (ch != '=')
587 return -1;
588 }
589 }
590 }
591 return dst - start;
592 }
593
594 int
sldns_b32_pton(const char * src,size_t src_sz,uint8_t * dst,size_t dst_sz)595 sldns_b32_pton(const char* src, size_t src_sz, uint8_t* dst, size_t dst_sz)
596 {
597 return sldns_b32_pton_base(src, src_sz, dst, dst_sz, 0, 1);
598 }
599
600 int
sldns_b32_pton_extended_hex(const char * src,size_t src_sz,uint8_t * dst,size_t dst_sz)601 sldns_b32_pton_extended_hex(const char* src, size_t src_sz,
602 uint8_t* dst, size_t dst_sz)
603 {
604 return sldns_b32_pton_base(src, src_sz, dst, dst_sz, 1, 1);
605 }
606
sldns_b64_ntop_calculate_size(size_t srcsize)607 size_t sldns_b64_ntop_calculate_size(size_t srcsize)
608 {
609 return ((((srcsize + 2) / 3) * 4) + 1);
610 }
611
612 /* RFC 1521, section 5.2.
613 *
614 * The encoding process represents 24-bit groups of input bits as output
615 * strings of 4 encoded characters. Proceeding from left to right, a
616 * 24-bit input group is formed by concatenating 3 8-bit input groups.
617 * These 24 bits are then treated as 4 concatenated 6-bit groups, each
618 * of which is translated into a single digit in the base64 alphabet.
619 *
620 * This routine does not insert spaces or linebreaks after 76 characters.
621 */
sldns_b64_ntop_base(uint8_t const * src,size_t srclength,char * target,size_t targsize,int base64url,int padding)622 static int sldns_b64_ntop_base(uint8_t const *src, size_t srclength,
623 char *target, size_t targsize, int base64url, int padding)
624 {
625 char* b64;
626 const char pad64 = '=';
627 size_t i = 0, o = 0;
628 if(base64url)
629 b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123"
630 "456789-_";
631 else
632 b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123"
633 "456789+/";
634 if(targsize < sldns_b64_ntop_calculate_size(srclength))
635 return -1;
636 /* whole chunks: xxxxxxyy yyyyzzzz zzwwwwww */
637 while(i+3 <= srclength) {
638 if(o+4 > targsize) return -1;
639 target[o] = b64[src[i] >> 2];
640 target[o+1] = b64[ ((src[i]&0x03)<<4) | (src[i+1]>>4) ];
641 target[o+2] = b64[ ((src[i+1]&0x0f)<<2) | (src[i+2]>>6) ];
642 target[o+3] = b64[ (src[i+2]&0x3f) ];
643 i += 3;
644 o += 4;
645 }
646 /* remainder */
647 switch(srclength - i) {
648 case 2:
649 /* two at end, converted into A B C = */
650 target[o] = b64[src[i] >> 2];
651 target[o+1] = b64[ ((src[i]&0x03)<<4) | (src[i+1]>>4) ];
652 target[o+2] = b64[ ((src[i+1]&0x0f)<<2) ];
653 if(padding) {
654 target[o+3] = pad64;
655 /* i += 2; */
656 o += 4;
657 } else {
658 o += 3;
659 }
660 break;
661 case 1:
662 /* one at end, converted into A B = = */
663 target[o] = b64[src[i] >> 2];
664 target[o+1] = b64[ ((src[i]&0x03)<<4) ];
665 if(padding) {
666 target[o+2] = pad64;
667 target[o+3] = pad64;
668 /* i += 1; */
669 o += 4;
670 } else {
671 o += 2;
672 }
673 break;
674 case 0:
675 default:
676 /* nothing */
677 break;
678 }
679 /* assert: i == srclength */
680 if(o+1 > targsize) return -1;
681 target[o] = 0;
682 return (int)o;
683 }
684
sldns_b64_ntop(uint8_t const * src,size_t srclength,char * target,size_t targsize)685 int sldns_b64_ntop(uint8_t const *src, size_t srclength, char *target,
686 size_t targsize)
687 {
688 return sldns_b64_ntop_base(src, srclength, target, targsize,
689 0 /* no base64url */, 1 /* padding */);
690 }
691
sldns_b64url_ntop(uint8_t const * src,size_t srclength,char * target,size_t targsize)692 int sldns_b64url_ntop(uint8_t const *src, size_t srclength, char *target,
693 size_t targsize)
694 {
695 return sldns_b64_ntop_base(src, srclength, target, targsize,
696 1 /* base64url */, 0 /* no padding */);
697 }
698
sldns_b64_pton_calculate_size(size_t srcsize)699 size_t sldns_b64_pton_calculate_size(size_t srcsize)
700 {
701 return (((((srcsize + 3) / 4) * 3)) + 1);
702 }
703
704 /* padding not required if srcsize is set */
sldns_b64_pton_base(char const * src,size_t srcsize,uint8_t * target,size_t targsize,int base64url)705 static int sldns_b64_pton_base(char const *src, size_t srcsize, uint8_t *target,
706 size_t targsize, int base64url)
707 {
708 const uint8_t pad64 = 64; /* is 64th in the b64 array */
709 const char* s = src;
710 uint8_t in[4];
711 size_t o = 0, incount = 0;
712 int check_padding = (srcsize) ? 0 : 1;
713
714 while(*s && (check_padding || srcsize)) {
715 /* skip any character that is not base64 */
716 /* conceptually we do:
717 const char* b64 = pad'=' is appended to array
718 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
719 const char* d = strchr(b64, *s++);
720 and use d-b64;
721 */
722 char d = *s++;
723 srcsize--;
724 if(d <= 'Z' && d >= 'A')
725 d -= 'A';
726 else if(d <= 'z' && d >= 'a')
727 d = d - 'a' + 26;
728 else if(d <= '9' && d >= '0')
729 d = d - '0' + 52;
730 else if(!base64url && d == '+')
731 d = 62;
732 else if(base64url && d == '-')
733 d = 62;
734 else if(!base64url && d == '/')
735 d = 63;
736 else if(base64url && d == '_')
737 d = 63;
738 else if(d == '=') {
739 if(!check_padding)
740 continue;
741 d = 64;
742 } else continue;
743
744 in[incount++] = (uint8_t)d;
745 /* work on block of 4, unless padding is not used and there are
746 * less than 4 chars left */
747 if(incount != 4 && (check_padding || srcsize))
748 continue;
749 assert(!check_padding || incount==4);
750 /* process whole block of 4 characters into 3 output bytes */
751 if((incount == 2 ||
752 (incount == 4 && in[3] == pad64 && in[2] == pad64))) { /* A B = = */
753 if(o+1 > targsize)
754 return -1;
755 target[o] = (in[0]<<2) | ((in[1]&0x30)>>4);
756 o += 1;
757 break; /* we are done */
758 } else if(incount == 3 ||
759 (incount == 4 && in[3] == pad64)) { /* A B C = */
760 if(o+2 > targsize)
761 return -1;
762 target[o] = (in[0]<<2) | ((in[1]&0x30)>>4);
763 target[o+1]= ((in[1]&0x0f)<<4) | ((in[2]&0x3c)>>2);
764 o += 2;
765 break; /* we are done */
766 } else {
767 if(incount != 4 || o+3 > targsize)
768 return -1;
769 /* write xxxxxxyy yyyyzzzz zzwwwwww */
770 target[o] = (in[0]<<2) | ((in[1]&0x30)>>4);
771 target[o+1]= ((in[1]&0x0f)<<4) | ((in[2]&0x3c)>>2);
772 target[o+2]= ((in[2]&0x03)<<6) | in[3];
773 o += 3;
774 }
775 incount = 0;
776 }
777 return (int)o;
778 }
779
sldns_b64_pton(char const * src,uint8_t * target,size_t targsize)780 int sldns_b64_pton(char const *src, uint8_t *target, size_t targsize)
781 {
782 return sldns_b64_pton_base(src, 0, target, targsize, 0);
783 }
784
sldns_b64url_pton(char const * src,size_t srcsize,uint8_t * target,size_t targsize)785 int sldns_b64url_pton(char const *src, size_t srcsize, uint8_t *target,
786 size_t targsize)
787 {
788 if(!srcsize) {
789 return 0;
790 }
791 return sldns_b64_pton_base(src, srcsize, target, targsize, 1);
792 }
793
sldns_b64_contains_nonurl(char const * src,size_t srcsize)794 int sldns_b64_contains_nonurl(char const *src, size_t srcsize)
795 {
796 const char* s = src;
797 while(*s && srcsize) {
798 char d = *s++;
799 srcsize--;
800 /* the '+' and the '/' and padding '=' is not allowed in b64
801 * url encoding */
802 if(d == '+' || d == '/' || d == '=') {
803 return 1;
804 }
805 }
806 return 0;
807 }
808