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,int * overflow)212 sldns_str2period(const char *nptr, const char **endptr, int* overflow)
213 {
214 int sign = 0;
215 uint32_t i = 0;
216 uint32_t seconds = 0;
217 const uint32_t maxint = 0xffffffff;
218 *overflow = 0;
219
220 for(*endptr = nptr; **endptr; (*endptr)++) {
221 switch (**endptr) {
222 case ' ':
223 case '\t':
224 break;
225 case '-':
226 if(sign == 0) {
227 sign = -1;
228 } else {
229 return seconds;
230 }
231 break;
232 case '+':
233 if(sign == 0) {
234 sign = 1;
235 } else {
236 return seconds;
237 }
238 break;
239 case 's':
240 case 'S':
241 if(seconds > maxint-i) {
242 *overflow = 1;
243 return 0;
244 }
245 seconds += i;
246 i = 0;
247 break;
248 case 'm':
249 case 'M':
250 if(i > maxint/60 || seconds > maxint-(i*60)) {
251 *overflow = 1;
252 return 0;
253 }
254 seconds += i * 60;
255 i = 0;
256 break;
257 case 'h':
258 case 'H':
259 if(i > maxint/(60*60) || seconds > maxint-(i*60*60)) {
260 *overflow = 1;
261 return 0;
262 }
263 seconds += i * 60 * 60;
264 i = 0;
265 break;
266 case 'd':
267 case 'D':
268 if(i > maxint/(60*60*24) || seconds > maxint-(i*60*60*24)) {
269 *overflow = 1;
270 return 0;
271 }
272 seconds += i * 60 * 60 * 24;
273 i = 0;
274 break;
275 case 'w':
276 case 'W':
277 if(i > maxint/(60*60*24*7) || seconds > maxint-(i*60*60*24*7)) {
278 *overflow = 1;
279 return 0;
280 }
281 seconds += i * 60 * 60 * 24 * 7;
282 i = 0;
283 break;
284 case '0':
285 case '1':
286 case '2':
287 case '3':
288 case '4':
289 case '5':
290 case '6':
291 case '7':
292 case '8':
293 case '9':
294 if(i > maxint/10 || i*10 > maxint - (**endptr - '0')) {
295 *overflow = 1;
296 return 0;
297 }
298 i *= 10;
299 i += (**endptr - '0');
300 break;
301 default:
302 if(seconds > maxint-i) {
303 *overflow = 1;
304 return 0;
305 }
306 seconds += i;
307 /* disregard signedness */
308 return seconds;
309 }
310 }
311 if(seconds > maxint-i) {
312 *overflow = 1;
313 return 0;
314 }
315 seconds += i;
316 /* disregard signedness */
317 return seconds;
318 }
319
320 int
sldns_parse_escape(uint8_t * ch_p,const char ** str_p)321 sldns_parse_escape(uint8_t *ch_p, const char** str_p)
322 {
323 uint16_t val;
324
325 if ((*str_p)[0] && isdigit((unsigned char)(*str_p)[0]) &&
326 (*str_p)[1] && isdigit((unsigned char)(*str_p)[1]) &&
327 (*str_p)[2] && isdigit((unsigned char)(*str_p)[2])) {
328
329 val = (uint16_t)(((*str_p)[0] - '0') * 100 +
330 ((*str_p)[1] - '0') * 10 +
331 ((*str_p)[2] - '0'));
332
333 if (val > 255) {
334 goto error;
335 }
336 *ch_p = (uint8_t)val;
337 *str_p += 3;
338 return 1;
339
340 } else if ((*str_p)[0] && !isdigit((unsigned char)(*str_p)[0])) {
341
342 *ch_p = (uint8_t)*(*str_p)++;
343 return 1;
344 }
345 error:
346 *str_p = NULL;
347 return 0; /* LDNS_WIREPARSE_ERR_SYNTAX_BAD_ESCAPE */
348 }
349
350 /** parse one character, with escape codes */
351 int
sldns_parse_char(uint8_t * ch_p,const char ** str_p)352 sldns_parse_char(uint8_t *ch_p, const char** str_p)
353 {
354 switch (**str_p) {
355
356 case '\0': return 0;
357
358 case '\\': *str_p += 1;
359 return sldns_parse_escape(ch_p, str_p);
360
361 default: *ch_p = (uint8_t)*(*str_p)++;
362 return 1;
363 }
364 }
365
sldns_b32_ntop_calculate_size(size_t src_data_length)366 size_t sldns_b32_ntop_calculate_size(size_t src_data_length)
367 {
368 return src_data_length == 0 ? 0 : ((src_data_length - 1) / 5 + 1) * 8;
369 }
370
sldns_b32_ntop_calculate_size_no_padding(size_t src_data_length)371 size_t sldns_b32_ntop_calculate_size_no_padding(size_t src_data_length)
372 {
373 return ((src_data_length + 3) * 8 / 5) - 4;
374 }
375
376 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)377 sldns_b32_ntop_base(const uint8_t* src, size_t src_sz, char* dst, size_t dst_sz,
378 int extended_hex, int add_padding)
379 {
380 size_t ret_sz;
381 const char* b32 = extended_hex ? "0123456789abcdefghijklmnopqrstuv"
382 : "abcdefghijklmnopqrstuvwxyz234567";
383
384 size_t c = 0; /* c is used to carry partial base32 character over
385 * byte boundaries for sizes with a remainder.
386 * (i.e. src_sz % 5 != 0)
387 */
388
389 ret_sz = add_padding ? sldns_b32_ntop_calculate_size(src_sz)
390 : sldns_b32_ntop_calculate_size_no_padding(src_sz);
391
392 /* Do we have enough space? */
393 if (dst_sz < ret_sz + 1)
394 return -1;
395
396 /* We know the size; terminate the string */
397 dst[ret_sz] = '\0';
398
399 /* First process all chunks of five */
400 while (src_sz >= 5) {
401 /* 00000... ........ ........ ........ ........ */
402 dst[0] = b32[(src[0] ) >> 3];
403
404 /* .....111 11...... ........ ........ ........ */
405 dst[1] = b32[(src[0] & 0x07) << 2 | src[1] >> 6];
406
407 /* ........ ..22222. ........ ........ ........ */
408 dst[2] = b32[(src[1] & 0x3e) >> 1];
409
410 /* ........ .......3 3333.... ........ ........ */
411 dst[3] = b32[(src[1] & 0x01) << 4 | src[2] >> 4];
412
413 /* ........ ........ ....4444 4....... ........ */
414 dst[4] = b32[(src[2] & 0x0f) << 1 | src[3] >> 7];
415
416 /* ........ ........ ........ .55555.. ........ */
417 dst[5] = b32[(src[3] & 0x7c) >> 2];
418
419 /* ........ ........ ........ ......66 666..... */
420 dst[6] = b32[(src[3] & 0x03) << 3 | src[4] >> 5];
421
422 /* ........ ........ ........ ........ ...77777 */
423 dst[7] = b32[(src[4] & 0x1f) ];
424
425 src_sz -= 5;
426 src += 5;
427 dst += 8;
428 }
429 /* Process what remains */
430 switch (src_sz) {
431 case 4: /* ........ ........ ........ ......66 666..... */
432 dst[6] = b32[(src[3] & 0x03) << 3];
433
434 /* ........ ........ ........ .55555.. ........ */
435 dst[5] = b32[(src[3] & 0x7c) >> 2];
436
437 /* ........ ........ ....4444 4....... ........ */
438 c = src[3] >> 7 ;
439 ATTR_FALLTHROUGH
440 /* fallthrough */
441 case 3: dst[4] = b32[(src[2] & 0x0f) << 1 | c];
442
443 /* ........ .......3 3333.... ........ ........ */
444 c = src[2] >> 4 ;
445 ATTR_FALLTHROUGH
446 /* fallthrough */
447 case 2: dst[3] = b32[(src[1] & 0x01) << 4 | c];
448
449 /* ........ ..22222. ........ ........ ........ */
450 dst[2] = b32[(src[1] & 0x3e) >> 1];
451
452 /* .....111 11...... ........ ........ ........ */
453 c = src[1] >> 6 ;
454 ATTR_FALLTHROUGH
455 /* fallthrough */
456 case 1: dst[1] = b32[(src[0] & 0x07) << 2 | c];
457
458 /* 00000... ........ ........ ........ ........ */
459 dst[0] = b32[ src[0] >> 3];
460 }
461 /* Add padding */
462 if (add_padding) {
463 switch (src_sz) {
464 case 1: dst[2] = '=';
465 dst[3] = '=';
466 ATTR_FALLTHROUGH
467 /* fallthrough */
468 case 2: dst[4] = '=';
469 ATTR_FALLTHROUGH
470 /* fallthrough */
471 case 3: dst[5] = '=';
472 dst[6] = '=';
473 ATTR_FALLTHROUGH
474 /* fallthrough */
475 case 4: dst[7] = '=';
476 }
477 }
478 return (int)ret_sz;
479 }
480
481 int
sldns_b32_ntop(const uint8_t * src,size_t src_sz,char * dst,size_t dst_sz)482 sldns_b32_ntop(const uint8_t* src, size_t src_sz, char* dst, size_t dst_sz)
483 {
484 return sldns_b32_ntop_base(src, src_sz, dst, dst_sz, 0, 1);
485 }
486
487 int
sldns_b32_ntop_extended_hex(const uint8_t * src,size_t src_sz,char * dst,size_t dst_sz)488 sldns_b32_ntop_extended_hex(const uint8_t* src, size_t src_sz,
489 char* dst, size_t dst_sz)
490 {
491 return sldns_b32_ntop_base(src, src_sz, dst, dst_sz, 1, 1);
492 }
493
sldns_b32_pton_calculate_size(size_t src_text_length)494 size_t sldns_b32_pton_calculate_size(size_t src_text_length)
495 {
496 return src_text_length * 5 / 8;
497 }
498
499 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)500 sldns_b32_pton_base(const char* src, size_t src_sz, uint8_t* dst, size_t dst_sz,
501 int extended_hex, int check_padding)
502 {
503 size_t i = 0;
504 char ch = '\0';
505 uint8_t buf[8];
506 uint8_t* start = dst;
507
508 while (src_sz) {
509 /* Collect 8 characters in buf (if possible) */
510 for (i = 0; i < 8; i++) {
511
512 do {
513 ch = *src++;
514 --src_sz;
515
516 } while (isspace((unsigned char)ch) && src_sz > 0);
517
518 if (ch == '=' || ch == '\0')
519 break;
520
521 else if (extended_hex)
522
523 if (ch >= '0' && ch <= '9')
524 buf[i] = (uint8_t)ch - '0';
525 else if (ch >= 'a' && ch <= 'v')
526 buf[i] = (uint8_t)ch - 'a' + 10;
527 else if (ch >= 'A' && ch <= 'V')
528 buf[i] = (uint8_t)ch - 'A' + 10;
529 else
530 return -1;
531
532 else if (ch >= 'a' && ch <= 'z')
533 buf[i] = (uint8_t)ch - 'a';
534 else if (ch >= 'A' && ch <= 'Z')
535 buf[i] = (uint8_t)ch - 'A';
536 else if (ch >= '2' && ch <= '7')
537 buf[i] = (uint8_t)ch - '2' + 26;
538 else
539 return -1;
540 }
541 /* Less that 8 characters. We're done. */
542 if (i < 8)
543 break;
544
545 /* Enough space available at the destination? */
546 if (dst_sz < 5)
547 return -1;
548
549 /* 00000... ........ ........ ........ ........ */
550 /* .....111 11...... ........ ........ ........ */
551 dst[0] = buf[0] << 3 | buf[1] >> 2;
552
553 /* .....111 11...... ........ ........ ........ */
554 /* ........ ..22222. ........ ........ ........ */
555 /* ........ .......3 3333.... ........ ........ */
556 dst[1] = buf[1] << 6 | buf[2] << 1 | buf[3] >> 4;
557
558 /* ........ .......3 3333.... ........ ........ */
559 /* ........ ........ ....4444 4....... ........ */
560 dst[2] = buf[3] << 4 | buf[4] >> 1;
561
562 /* ........ ........ ....4444 4....... ........ */
563 /* ........ ........ ........ .55555.. ........ */
564 /* ........ ........ ........ ......66 666..... */
565 dst[3] = buf[4] << 7 | buf[5] << 2 | buf[6] >> 3;
566
567 /* ........ ........ ........ ......66 666..... */
568 /* ........ ........ ........ ........ ...77777 */
569 dst[4] = buf[6] << 5 | buf[7];
570
571 dst += 5;
572 dst_sz -= 5;
573 }
574 /* Not ending on a eight byte boundary? */
575 if (i > 0 && i < 8) {
576
577 /* Enough space available at the destination? */
578 if (dst_sz < (i + 1) / 2)
579 return -1;
580
581 switch (i) {
582 case 7: /* ........ ........ ........ ......66 666..... */
583 /* ........ ........ ........ .55555.. ........ */
584 /* ........ ........ ....4444 4....... ........ */
585 dst[3] = buf[4] << 7 | buf[5] << 2 | buf[6] >> 3;
586 ATTR_FALLTHROUGH
587 /* fallthrough */
588
589 case 5: /* ........ ........ ....4444 4....... ........ */
590 /* ........ .......3 3333.... ........ ........ */
591 dst[2] = buf[3] << 4 | buf[4] >> 1;
592 ATTR_FALLTHROUGH
593 /* fallthrough */
594
595 case 4: /* ........ .......3 3333.... ........ ........ */
596 /* ........ ..22222. ........ ........ ........ */
597 /* .....111 11...... ........ ........ ........ */
598 dst[1] = buf[1] << 6 | buf[2] << 1 | buf[3] >> 4;
599 ATTR_FALLTHROUGH
600 /* fallthrough */
601
602 case 2: /* .....111 11...... ........ ........ ........ */
603 /* 00000... ........ ........ ........ ........ */
604 dst[0] = buf[0] << 3 | buf[1] >> 2;
605
606 break;
607
608 default:
609 return -1;
610 }
611 dst += (i + 1) / 2;
612
613 if (check_padding) {
614 /* Check remaining padding characters */
615 if (ch != '=')
616 return -1;
617
618 /* One down, 8 - i - 1 more to come... */
619 for (i = 8 - i - 1; i > 0; i--) {
620
621 do {
622 if (src_sz == 0)
623 return -1;
624 ch = *src++;
625 src_sz--;
626
627 } while (isspace((unsigned char)ch));
628
629 if (ch != '=')
630 return -1;
631 }
632 }
633 }
634 return dst - start;
635 }
636
637 int
sldns_b32_pton(const char * src,size_t src_sz,uint8_t * dst,size_t dst_sz)638 sldns_b32_pton(const char* src, size_t src_sz, uint8_t* dst, size_t dst_sz)
639 {
640 return sldns_b32_pton_base(src, src_sz, dst, dst_sz, 0, 1);
641 }
642
643 int
sldns_b32_pton_extended_hex(const char * src,size_t src_sz,uint8_t * dst,size_t dst_sz)644 sldns_b32_pton_extended_hex(const char* src, size_t src_sz,
645 uint8_t* dst, size_t dst_sz)
646 {
647 return sldns_b32_pton_base(src, src_sz, dst, dst_sz, 1, 1);
648 }
649
sldns_b64_ntop_calculate_size(size_t srcsize)650 size_t sldns_b64_ntop_calculate_size(size_t srcsize)
651 {
652 return ((((srcsize + 2) / 3) * 4) + 1);
653 }
654
655 /* RFC 1521, section 5.2.
656 *
657 * The encoding process represents 24-bit groups of input bits as output
658 * strings of 4 encoded characters. Proceeding from left to right, a
659 * 24-bit input group is formed by concatenating 3 8-bit input groups.
660 * These 24 bits are then treated as 4 concatenated 6-bit groups, each
661 * of which is translated into a single digit in the base64 alphabet.
662 *
663 * This routine does not insert spaces or linebreaks after 76 characters.
664 */
sldns_b64_ntop_base(uint8_t const * src,size_t srclength,char * target,size_t targsize,int base64url,int padding)665 static int sldns_b64_ntop_base(uint8_t const *src, size_t srclength,
666 char *target, size_t targsize, int base64url, int padding)
667 {
668 char* b64;
669 const char pad64 = '=';
670 size_t i = 0, o = 0;
671 if(base64url)
672 b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123"
673 "456789-_";
674 else
675 b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123"
676 "456789+/";
677 if(targsize < sldns_b64_ntop_calculate_size(srclength))
678 return -1;
679 /* whole chunks: xxxxxxyy yyyyzzzz zzwwwwww */
680 while(i+3 <= srclength) {
681 if(o+4 > targsize) return -1;
682 target[o] = b64[src[i] >> 2];
683 target[o+1] = b64[ ((src[i]&0x03)<<4) | (src[i+1]>>4) ];
684 target[o+2] = b64[ ((src[i+1]&0x0f)<<2) | (src[i+2]>>6) ];
685 target[o+3] = b64[ (src[i+2]&0x3f) ];
686 i += 3;
687 o += 4;
688 }
689 /* remainder */
690 switch(srclength - i) {
691 case 2:
692 /* two at end, converted into A B C = */
693 target[o] = b64[src[i] >> 2];
694 target[o+1] = b64[ ((src[i]&0x03)<<4) | (src[i+1]>>4) ];
695 target[o+2] = b64[ ((src[i+1]&0x0f)<<2) ];
696 if(padding) {
697 target[o+3] = pad64;
698 /* i += 2; */
699 o += 4;
700 } else {
701 o += 3;
702 }
703 break;
704 case 1:
705 /* one at end, converted into A B = = */
706 target[o] = b64[src[i] >> 2];
707 target[o+1] = b64[ ((src[i]&0x03)<<4) ];
708 if(padding) {
709 target[o+2] = pad64;
710 target[o+3] = pad64;
711 /* i += 1; */
712 o += 4;
713 } else {
714 o += 2;
715 }
716 break;
717 case 0:
718 default:
719 /* nothing */
720 break;
721 }
722 /* assert: i == srclength */
723 if(o+1 > targsize) return -1;
724 target[o] = 0;
725 return (int)o;
726 }
727
sldns_b64_ntop(uint8_t const * src,size_t srclength,char * target,size_t targsize)728 int sldns_b64_ntop(uint8_t const *src, size_t srclength, char *target,
729 size_t targsize)
730 {
731 return sldns_b64_ntop_base(src, srclength, target, targsize,
732 0 /* no base64url */, 1 /* padding */);
733 }
734
sldns_b64url_ntop(uint8_t const * src,size_t srclength,char * target,size_t targsize)735 int sldns_b64url_ntop(uint8_t const *src, size_t srclength, char *target,
736 size_t targsize)
737 {
738 return sldns_b64_ntop_base(src, srclength, target, targsize,
739 1 /* base64url */, 0 /* no padding */);
740 }
741
sldns_b64_pton_calculate_size(size_t srcsize)742 size_t sldns_b64_pton_calculate_size(size_t srcsize)
743 {
744 return (((((srcsize + 3) / 4) * 3)) + 1);
745 }
746
747 /* 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)748 static int sldns_b64_pton_base(char const *src, size_t srcsize, uint8_t *target,
749 size_t targsize, int base64url)
750 {
751 const uint8_t pad64 = 64; /* is 64th in the b64 array */
752 const char* s = src;
753 uint8_t in[4];
754 size_t o = 0, incount = 0;
755 int check_padding = (srcsize) ? 0 : 1;
756
757 while(*s && (check_padding || srcsize)) {
758 /* skip any character that is not base64 */
759 /* conceptually we do:
760 const char* b64 = pad'=' is appended to array
761 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
762 const char* d = strchr(b64, *s++);
763 and use d-b64;
764 */
765 char d = *s++;
766 srcsize--;
767 if(d <= 'Z' && d >= 'A')
768 d -= 'A';
769 else if(d <= 'z' && d >= 'a')
770 d = d - 'a' + 26;
771 else if(d <= '9' && d >= '0')
772 d = d - '0' + 52;
773 else if(!base64url && d == '+')
774 d = 62;
775 else if(base64url && d == '-')
776 d = 62;
777 else if(!base64url && d == '/')
778 d = 63;
779 else if(base64url && d == '_')
780 d = 63;
781 else if(d == '=') {
782 if(!check_padding)
783 continue;
784 d = 64;
785 } else continue;
786
787 in[incount++] = (uint8_t)d;
788 /* work on block of 4, unless padding is not used and there are
789 * less than 4 chars left */
790 if(incount != 4 && (check_padding || srcsize))
791 continue;
792 assert(!check_padding || incount==4);
793 /* process whole block of 4 characters into 3 output bytes */
794 if((incount == 2 ||
795 (incount == 4 && in[3] == pad64 && in[2] == pad64))) { /* A B = = */
796 if(o+1 > targsize)
797 return -1;
798 target[o] = (in[0]<<2) | ((in[1]&0x30)>>4);
799 o += 1;
800 break; /* we are done */
801 } else if(incount == 3 ||
802 (incount == 4 && in[3] == pad64)) { /* A B C = */
803 if(o+2 > targsize)
804 return -1;
805 target[o] = (in[0]<<2) | ((in[1]&0x30)>>4);
806 target[o+1]= ((in[1]&0x0f)<<4) | ((in[2]&0x3c)>>2);
807 o += 2;
808 break; /* we are done */
809 } else {
810 if(incount != 4 || o+3 > targsize)
811 return -1;
812 /* write xxxxxxyy yyyyzzzz zzwwwwww */
813 target[o] = (in[0]<<2) | ((in[1]&0x30)>>4);
814 target[o+1]= ((in[1]&0x0f)<<4) | ((in[2]&0x3c)>>2);
815 target[o+2]= ((in[2]&0x03)<<6) | in[3];
816 o += 3;
817 }
818 incount = 0;
819 }
820 return (int)o;
821 }
822
sldns_b64_pton(char const * src,uint8_t * target,size_t targsize)823 int sldns_b64_pton(char const *src, uint8_t *target, size_t targsize)
824 {
825 return sldns_b64_pton_base(src, 0, target, targsize, 0);
826 }
827
sldns_b64url_pton(char const * src,size_t srcsize,uint8_t * target,size_t targsize)828 int sldns_b64url_pton(char const *src, size_t srcsize, uint8_t *target,
829 size_t targsize)
830 {
831 if(!srcsize) {
832 return 0;
833 }
834 return sldns_b64_pton_base(src, srcsize, target, targsize, 1);
835 }
836
sldns_b64_contains_nonurl(char const * src,size_t srcsize)837 int sldns_b64_contains_nonurl(char const *src, size_t srcsize)
838 {
839 const char* s = src;
840 while(*s && srcsize) {
841 char d = *s++;
842 srcsize--;
843 /* the '+' and the '/' and padding '=' is not allowed in b64
844 * url encoding */
845 if(d == '+' || d == '/' || d == '=') {
846 return 1;
847 }
848 }
849 return 0;
850 }
851