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 /* fallthrough */
440 case 3: dst[4] = b32[(src[2] & 0x0f) << 1 | c];
441
442 /* ........ .......3 3333.... ........ ........ */
443 c = src[2] >> 4 ;
444 /* fallthrough */
445 case 2: dst[3] = b32[(src[1] & 0x01) << 4 | c];
446
447 /* ........ ..22222. ........ ........ ........ */
448 dst[2] = b32[(src[1] & 0x3e) >> 1];
449
450 /* .....111 11...... ........ ........ ........ */
451 c = src[1] >> 6 ;
452 /* fallthrough */
453 case 1: dst[1] = b32[(src[0] & 0x07) << 2 | c];
454
455 /* 00000... ........ ........ ........ ........ */
456 dst[0] = b32[ src[0] >> 3];
457 }
458 /* Add padding */
459 if (add_padding) {
460 switch (src_sz) {
461 case 1: dst[2] = '=';
462 dst[3] = '=';
463 /* fallthrough */
464 case 2: dst[4] = '=';
465 /* fallthrough */
466 case 3: dst[5] = '=';
467 dst[6] = '=';
468 /* fallthrough */
469 case 4: dst[7] = '=';
470 }
471 }
472 return (int)ret_sz;
473 }
474
475 int
sldns_b32_ntop(const uint8_t * src,size_t src_sz,char * dst,size_t dst_sz)476 sldns_b32_ntop(const uint8_t* src, size_t src_sz, char* dst, size_t dst_sz)
477 {
478 return sldns_b32_ntop_base(src, src_sz, dst, dst_sz, 0, 1);
479 }
480
481 int
sldns_b32_ntop_extended_hex(const uint8_t * src,size_t src_sz,char * dst,size_t dst_sz)482 sldns_b32_ntop_extended_hex(const uint8_t* src, size_t src_sz,
483 char* dst, size_t dst_sz)
484 {
485 return sldns_b32_ntop_base(src, src_sz, dst, dst_sz, 1, 1);
486 }
487
sldns_b32_pton_calculate_size(size_t src_text_length)488 size_t sldns_b32_pton_calculate_size(size_t src_text_length)
489 {
490 return src_text_length * 5 / 8;
491 }
492
493 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)494 sldns_b32_pton_base(const char* src, size_t src_sz, uint8_t* dst, size_t dst_sz,
495 int extended_hex, int check_padding)
496 {
497 size_t i = 0;
498 char ch = '\0';
499 uint8_t buf[8];
500 uint8_t* start = dst;
501
502 while (src_sz) {
503 /* Collect 8 characters in buf (if possible) */
504 for (i = 0; i < 8; i++) {
505
506 do {
507 ch = *src++;
508 --src_sz;
509
510 } while (isspace((unsigned char)ch) && src_sz > 0);
511
512 if (ch == '=' || ch == '\0')
513 break;
514
515 else if (extended_hex)
516
517 if (ch >= '0' && ch <= '9')
518 buf[i] = (uint8_t)ch - '0';
519 else if (ch >= 'a' && ch <= 'v')
520 buf[i] = (uint8_t)ch - 'a' + 10;
521 else if (ch >= 'A' && ch <= 'V')
522 buf[i] = (uint8_t)ch - 'A' + 10;
523 else
524 return -1;
525
526 else if (ch >= 'a' && ch <= 'z')
527 buf[i] = (uint8_t)ch - 'a';
528 else if (ch >= 'A' && ch <= 'Z')
529 buf[i] = (uint8_t)ch - 'A';
530 else if (ch >= '2' && ch <= '7')
531 buf[i] = (uint8_t)ch - '2' + 26;
532 else
533 return -1;
534 }
535 /* Less that 8 characters. We're done. */
536 if (i < 8)
537 break;
538
539 /* Enough space available at the destination? */
540 if (dst_sz < 5)
541 return -1;
542
543 /* 00000... ........ ........ ........ ........ */
544 /* .....111 11...... ........ ........ ........ */
545 dst[0] = buf[0] << 3 | buf[1] >> 2;
546
547 /* .....111 11...... ........ ........ ........ */
548 /* ........ ..22222. ........ ........ ........ */
549 /* ........ .......3 3333.... ........ ........ */
550 dst[1] = buf[1] << 6 | buf[2] << 1 | buf[3] >> 4;
551
552 /* ........ .......3 3333.... ........ ........ */
553 /* ........ ........ ....4444 4....... ........ */
554 dst[2] = buf[3] << 4 | buf[4] >> 1;
555
556 /* ........ ........ ....4444 4....... ........ */
557 /* ........ ........ ........ .55555.. ........ */
558 /* ........ ........ ........ ......66 666..... */
559 dst[3] = buf[4] << 7 | buf[5] << 2 | buf[6] >> 3;
560
561 /* ........ ........ ........ ......66 666..... */
562 /* ........ ........ ........ ........ ...77777 */
563 dst[4] = buf[6] << 5 | buf[7];
564
565 dst += 5;
566 dst_sz -= 5;
567 }
568 /* Not ending on a eight byte boundary? */
569 if (i > 0 && i < 8) {
570
571 /* Enough space available at the destination? */
572 if (dst_sz < (i + 1) / 2)
573 return -1;
574
575 switch (i) {
576 case 7: /* ........ ........ ........ ......66 666..... */
577 /* ........ ........ ........ .55555.. ........ */
578 /* ........ ........ ....4444 4....... ........ */
579 dst[3] = buf[4] << 7 | buf[5] << 2 | buf[6] >> 3;
580 /* fallthrough */
581
582 case 5: /* ........ ........ ....4444 4....... ........ */
583 /* ........ .......3 3333.... ........ ........ */
584 dst[2] = buf[3] << 4 | buf[4] >> 1;
585 /* fallthrough */
586
587 case 4: /* ........ .......3 3333.... ........ ........ */
588 /* ........ ..22222. ........ ........ ........ */
589 /* .....111 11...... ........ ........ ........ */
590 dst[1] = buf[1] << 6 | buf[2] << 1 | buf[3] >> 4;
591 /* fallthrough */
592
593 case 2: /* .....111 11...... ........ ........ ........ */
594 /* 00000... ........ ........ ........ ........ */
595 dst[0] = buf[0] << 3 | buf[1] >> 2;
596
597 break;
598
599 default:
600 return -1;
601 }
602 dst += (i + 1) / 2;
603
604 if (check_padding) {
605 /* Check remaining padding characters */
606 if (ch != '=')
607 return -1;
608
609 /* One down, 8 - i - 1 more to come... */
610 for (i = 8 - i - 1; i > 0; i--) {
611
612 do {
613 if (src_sz == 0)
614 return -1;
615 ch = *src++;
616 src_sz--;
617
618 } while (isspace((unsigned char)ch));
619
620 if (ch != '=')
621 return -1;
622 }
623 }
624 }
625 return dst - start;
626 }
627
628 int
sldns_b32_pton(const char * src,size_t src_sz,uint8_t * dst,size_t dst_sz)629 sldns_b32_pton(const char* src, size_t src_sz, uint8_t* dst, size_t dst_sz)
630 {
631 return sldns_b32_pton_base(src, src_sz, dst, dst_sz, 0, 1);
632 }
633
634 int
sldns_b32_pton_extended_hex(const char * src,size_t src_sz,uint8_t * dst,size_t dst_sz)635 sldns_b32_pton_extended_hex(const char* src, size_t src_sz,
636 uint8_t* dst, size_t dst_sz)
637 {
638 return sldns_b32_pton_base(src, src_sz, dst, dst_sz, 1, 1);
639 }
640
sldns_b64_ntop_calculate_size(size_t srcsize)641 size_t sldns_b64_ntop_calculate_size(size_t srcsize)
642 {
643 return ((((srcsize + 2) / 3) * 4) + 1);
644 }
645
646 /* RFC 1521, section 5.2.
647 *
648 * The encoding process represents 24-bit groups of input bits as output
649 * strings of 4 encoded characters. Proceeding from left to right, a
650 * 24-bit input group is formed by concatenating 3 8-bit input groups.
651 * These 24 bits are then treated as 4 concatenated 6-bit groups, each
652 * of which is translated into a single digit in the base64 alphabet.
653 *
654 * This routine does not insert spaces or linebreaks after 76 characters.
655 */
sldns_b64_ntop_base(uint8_t const * src,size_t srclength,char * target,size_t targsize,int base64url,int padding)656 static int sldns_b64_ntop_base(uint8_t const *src, size_t srclength,
657 char *target, size_t targsize, int base64url, int padding)
658 {
659 char* b64;
660 const char pad64 = '=';
661 size_t i = 0, o = 0;
662 if(base64url)
663 b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123"
664 "456789-_";
665 else
666 b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123"
667 "456789+/";
668 if(targsize < sldns_b64_ntop_calculate_size(srclength))
669 return -1;
670 /* whole chunks: xxxxxxyy yyyyzzzz zzwwwwww */
671 while(i+3 <= srclength) {
672 if(o+4 > targsize) return -1;
673 target[o] = b64[src[i] >> 2];
674 target[o+1] = b64[ ((src[i]&0x03)<<4) | (src[i+1]>>4) ];
675 target[o+2] = b64[ ((src[i+1]&0x0f)<<2) | (src[i+2]>>6) ];
676 target[o+3] = b64[ (src[i+2]&0x3f) ];
677 i += 3;
678 o += 4;
679 }
680 /* remainder */
681 switch(srclength - i) {
682 case 2:
683 /* two at end, converted into A B C = */
684 target[o] = b64[src[i] >> 2];
685 target[o+1] = b64[ ((src[i]&0x03)<<4) | (src[i+1]>>4) ];
686 target[o+2] = b64[ ((src[i+1]&0x0f)<<2) ];
687 if(padding) {
688 target[o+3] = pad64;
689 /* i += 2; */
690 o += 4;
691 } else {
692 o += 3;
693 }
694 break;
695 case 1:
696 /* one at end, converted into A B = = */
697 target[o] = b64[src[i] >> 2];
698 target[o+1] = b64[ ((src[i]&0x03)<<4) ];
699 if(padding) {
700 target[o+2] = pad64;
701 target[o+3] = pad64;
702 /* i += 1; */
703 o += 4;
704 } else {
705 o += 2;
706 }
707 break;
708 case 0:
709 default:
710 /* nothing */
711 break;
712 }
713 /* assert: i == srclength */
714 if(o+1 > targsize) return -1;
715 target[o] = 0;
716 return (int)o;
717 }
718
sldns_b64_ntop(uint8_t const * src,size_t srclength,char * target,size_t targsize)719 int sldns_b64_ntop(uint8_t const *src, size_t srclength, char *target,
720 size_t targsize)
721 {
722 return sldns_b64_ntop_base(src, srclength, target, targsize,
723 0 /* no base64url */, 1 /* padding */);
724 }
725
sldns_b64url_ntop(uint8_t const * src,size_t srclength,char * target,size_t targsize)726 int sldns_b64url_ntop(uint8_t const *src, size_t srclength, char *target,
727 size_t targsize)
728 {
729 return sldns_b64_ntop_base(src, srclength, target, targsize,
730 1 /* base64url */, 0 /* no padding */);
731 }
732
sldns_b64_pton_calculate_size(size_t srcsize)733 size_t sldns_b64_pton_calculate_size(size_t srcsize)
734 {
735 return (((((srcsize + 3) / 4) * 3)) + 1);
736 }
737
738 /* 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)739 static int sldns_b64_pton_base(char const *src, size_t srcsize, uint8_t *target,
740 size_t targsize, int base64url)
741 {
742 const uint8_t pad64 = 64; /* is 64th in the b64 array */
743 const char* s = src;
744 uint8_t in[4];
745 size_t o = 0, incount = 0;
746 int check_padding = (srcsize) ? 0 : 1;
747
748 while(*s && (check_padding || srcsize)) {
749 /* skip any character that is not base64 */
750 /* conceptually we do:
751 const char* b64 = pad'=' is appended to array
752 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
753 const char* d = strchr(b64, *s++);
754 and use d-b64;
755 */
756 char d = *s++;
757 srcsize--;
758 if(d <= 'Z' && d >= 'A')
759 d -= 'A';
760 else if(d <= 'z' && d >= 'a')
761 d = d - 'a' + 26;
762 else if(d <= '9' && d >= '0')
763 d = d - '0' + 52;
764 else if(!base64url && d == '+')
765 d = 62;
766 else if(base64url && d == '-')
767 d = 62;
768 else if(!base64url && d == '/')
769 d = 63;
770 else if(base64url && d == '_')
771 d = 63;
772 else if(d == '=') {
773 if(!check_padding)
774 continue;
775 d = 64;
776 } else continue;
777
778 in[incount++] = (uint8_t)d;
779 /* work on block of 4, unless padding is not used and there are
780 * less than 4 chars left */
781 if(incount != 4 && (check_padding || srcsize))
782 continue;
783 assert(!check_padding || incount==4);
784 /* process whole block of 4 characters into 3 output bytes */
785 if((incount == 2 ||
786 (incount == 4 && in[3] == pad64 && in[2] == pad64))) { /* A B = = */
787 if(o+1 > targsize)
788 return -1;
789 target[o] = (in[0]<<2) | ((in[1]&0x30)>>4);
790 o += 1;
791 break; /* we are done */
792 } else if(incount == 3 ||
793 (incount == 4 && in[3] == pad64)) { /* A B C = */
794 if(o+2 > targsize)
795 return -1;
796 target[o] = (in[0]<<2) | ((in[1]&0x30)>>4);
797 target[o+1]= ((in[1]&0x0f)<<4) | ((in[2]&0x3c)>>2);
798 o += 2;
799 break; /* we are done */
800 } else {
801 if(incount != 4 || o+3 > targsize)
802 return -1;
803 /* write xxxxxxyy yyyyzzzz zzwwwwww */
804 target[o] = (in[0]<<2) | ((in[1]&0x30)>>4);
805 target[o+1]= ((in[1]&0x0f)<<4) | ((in[2]&0x3c)>>2);
806 target[o+2]= ((in[2]&0x03)<<6) | in[3];
807 o += 3;
808 }
809 incount = 0;
810 }
811 return (int)o;
812 }
813
sldns_b64_pton(char const * src,uint8_t * target,size_t targsize)814 int sldns_b64_pton(char const *src, uint8_t *target, size_t targsize)
815 {
816 return sldns_b64_pton_base(src, 0, target, targsize, 0);
817 }
818
sldns_b64url_pton(char const * src,size_t srcsize,uint8_t * target,size_t targsize)819 int sldns_b64url_pton(char const *src, size_t srcsize, uint8_t *target,
820 size_t targsize)
821 {
822 if(!srcsize) {
823 return 0;
824 }
825 return sldns_b64_pton_base(src, srcsize, target, targsize, 1);
826 }
827
sldns_b64_contains_nonurl(char const * src,size_t srcsize)828 int sldns_b64_contains_nonurl(char const *src, size_t srcsize)
829 {
830 const char* s = src;
831 while(*s && srcsize) {
832 char d = *s++;
833 srcsize--;
834 /* the '+' and the '/' and padding '=' is not allowed in b64
835 * url encoding */
836 if(d == '+' || d == '/' || d == '=') {
837 return 1;
838 }
839 }
840 return 0;
841 }
842