xref: /dragonfly/contrib/ldns/util.c (revision bcb3e04d)
1 /*
2  * util.c
3  *
4  * some general memory functions
5  *
6  * a Net::DNS like library for C
7  *
8  * (c) NLnet Labs, 2004-2006
9  *
10  * See the file LICENSE for the license
11  */
12 
13 #include <ldns/config.h>
14 
15 #include <ldns/rdata.h>
16 #include <ldns/rr.h>
17 #include <ldns/util.h>
18 #include <strings.h>
19 #include <stdlib.h>
20 #include <stdio.h>
21 #include <sys/time.h>
22 #include <time.h>
23 
24 #ifdef HAVE_SSL
25 #include <openssl/rand.h>
26 #endif
27 
28 /* put this here tmp. for debugging */
29 void
30 xprintf_rdf(ldns_rdf *rd)
31 {
32 	/* assume printable string */
33 	fprintf(stderr, "size\t:%u\n", (unsigned int)ldns_rdf_size(rd));
34 	fprintf(stderr, "type\t:%u\n", (unsigned int)ldns_rdf_get_type(rd));
35 	fprintf(stderr, "data\t:[%.*s]\n", (int)ldns_rdf_size(rd),
36 			(char*)ldns_rdf_data(rd));
37 }
38 
39 void
40 xprintf_rr(ldns_rr *rr)
41 {
42 	/* assume printable string */
43 	uint16_t count, i;
44 
45 	count = ldns_rr_rd_count(rr);
46 
47 	for(i = 0; i < count; i++) {
48 		fprintf(stderr, "print rd %u\n", (unsigned int) i);
49 		xprintf_rdf(rr->_rdata_fields[i]);
50 	}
51 }
52 
53 void xprintf_hex(uint8_t *data, size_t len)
54 {
55 	size_t i;
56 	for (i = 0; i < len; i++) {
57 		if (i > 0 && i % 20 == 0) {
58 			printf("\t; %u - %u\n", (unsigned int) i - 19, (unsigned int) i);
59 		}
60 		printf("%02x ", (unsigned int) data[i]);
61 	}
62 	printf("\n");
63 }
64 
65 ldns_lookup_table *
66 ldns_lookup_by_name(ldns_lookup_table *table, const char *name)
67 {
68 	while (table->name != NULL) {
69 		if (strcasecmp(name, table->name) == 0)
70 			return table;
71 		table++;
72 	}
73 	return NULL;
74 }
75 
76 ldns_lookup_table *
77 ldns_lookup_by_id(ldns_lookup_table *table, int id)
78 {
79 	while (table->name != NULL) {
80 		if (table->id == id)
81 			return table;
82 		table++;
83 	}
84 	return NULL;
85 }
86 
87 int
88 ldns_get_bit(uint8_t bits[], size_t index)
89 {
90 	/*
91 	 * The bits are counted from left to right, so bit #0 is the
92 	 * left most bit.
93 	 */
94 	return (int) (bits[index / 8] & (1 << (7 - index % 8)));
95 }
96 
97 int
98 ldns_get_bit_r(uint8_t bits[], size_t index)
99 {
100 	/*
101 	 * The bits are counted from right to left, so bit #0 is the
102 	 * right most bit.
103 	 */
104 	return (int) bits[index / 8] & (1 << (index % 8));
105 }
106 
107 void
108 ldns_set_bit(uint8_t *byte, int bit_nr, bool value)
109 {
110 	if (bit_nr >= 0 && bit_nr < 8) {
111 		if (value) {
112 			*byte = *byte | (0x01 << bit_nr);
113 		} else {
114 			*byte = *byte & !(0x01 << bit_nr);
115 		}
116 	}
117 }
118 
119 int
120 ldns_hexdigit_to_int(char ch)
121 {
122 	switch (ch) {
123 	case '0': return 0;
124 	case '1': return 1;
125 	case '2': return 2;
126 	case '3': return 3;
127 	case '4': return 4;
128 	case '5': return 5;
129 	case '6': return 6;
130 	case '7': return 7;
131 	case '8': return 8;
132 	case '9': return 9;
133 	case 'a': case 'A': return 10;
134 	case 'b': case 'B': return 11;
135 	case 'c': case 'C': return 12;
136 	case 'd': case 'D': return 13;
137 	case 'e': case 'E': return 14;
138 	case 'f': case 'F': return 15;
139 	default:
140 		return -1;
141 	}
142 }
143 
144 char
145 ldns_int_to_hexdigit(int i)
146 {
147 	switch (i) {
148 	case 0: return '0';
149 	case 1: return '1';
150 	case 2: return '2';
151 	case 3: return '3';
152 	case 4: return '4';
153 	case 5: return '5';
154 	case 6: return '6';
155 	case 7: return '7';
156 	case 8: return '8';
157 	case 9: return '9';
158 	case 10: return 'a';
159 	case 11: return 'b';
160 	case 12: return 'c';
161 	case 13: return 'd';
162 	case 14: return 'e';
163 	case 15: return 'f';
164 	default:
165 		abort();
166 	}
167 }
168 
169 int
170 ldns_hexstring_to_data(uint8_t *data, const char *str)
171 {
172 	size_t i;
173 
174 	if (!str || !data) {
175 		return -1;
176 	}
177 
178 	if (strlen(str) % 2 != 0) {
179 		return -2;
180 	}
181 
182 	for (i = 0; i < strlen(str) / 2; i++) {
183 		data[i] =
184 			16 * (uint8_t) ldns_hexdigit_to_int(str[i*2]) +
185 			(uint8_t) ldns_hexdigit_to_int(str[i*2 + 1]);
186 	}
187 
188 	return (int) i;
189 }
190 
191 const char *
192 ldns_version(void)
193 {
194 	return (char*)LDNS_VERSION;
195 }
196 
197 /* Number of days per month (except for February in leap years). */
198 static const int mdays[] = {
199 	31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
200 };
201 
202 static int
203 is_leap_year(int year)
204 {
205 	return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
206 }
207 
208 static int
209 leap_days(int y1, int y2)
210 {
211 	--y1;
212 	--y2;
213 	return (y2/4 - y1/4) - (y2/100 - y1/100) + (y2/400 - y1/400);
214 }
215 
216 /*
217  * Code adapted from Python 2.4.1 sources (Lib/calendar.py).
218  */
219 time_t
220 mktime_from_utc(const struct tm *tm)
221 {
222 	int year = 1900 + tm->tm_year;
223 	time_t days = 365 * ((time_t) year - 1970) + leap_days(1970, year);
224 	time_t hours;
225 	time_t minutes;
226 	time_t seconds;
227 	int i;
228 
229 	for (i = 0; i < tm->tm_mon; ++i) {
230 		days += mdays[i];
231 	}
232 	if (tm->tm_mon > 1 && is_leap_year(year)) {
233 		++days;
234 	}
235 	days += tm->tm_mday - 1;
236 
237 	hours = days * 24 + tm->tm_hour;
238 	minutes = hours * 60 + tm->tm_min;
239 	seconds = minutes * 60 + tm->tm_sec;
240 
241 	return seconds;
242 }
243 
244 /**
245  * Init the random source
246  * applications should call this if they need entropy data within ldns
247  * If openSSL is available, it is automatically seeded from /dev/urandom
248  * or /dev/random
249  *
250  * If you need more entropy, or have no openssl available, this function
251  * MUST be called at the start of the program
252  *
253  * If openssl *is* available, this function just adds more entropy
254  **/
255 int
256 ldns_init_random(FILE *fd, unsigned int size)
257 {
258 	/* if fp is given, seed srandom with data from file
259 	   otherwise use /dev/urandom */
260 	FILE *rand_f;
261 	uint8_t *seed;
262 	size_t read = 0;
263 	unsigned int seed_i;
264 	struct timeval tv;
265 	struct timezone tz;
266 
267 	/* we'll need at least sizeof(unsigned int) bytes for the
268 	   standard prng seed */
269 	if (size < (unsigned int) sizeof(seed_i)){
270 		size = (unsigned int) sizeof(seed_i);
271 	}
272 
273 	seed = LDNS_XMALLOC(uint8_t, size);
274 
275 	if (!fd) {
276 		if ((rand_f = fopen("/dev/urandom", "r")) == NULL) {
277 			/* no readable /dev/urandom, try /dev/random */
278 			if ((rand_f = fopen("/dev/random", "r")) == NULL) {
279 				/* no readable /dev/random either, and no entropy
280 				   source given. we'll have to improvise */
281 				for (read = 0; read < size; read++) {
282 					gettimeofday(&tv, &tz);
283 					seed[read] = (uint8_t) (tv.tv_usec % 256);
284 				}
285 			} else {
286 				read = fread(seed, 1, size, rand_f);
287 			}
288 		} else {
289 			read = fread(seed, 1, size, rand_f);
290 		}
291 	} else {
292 		rand_f = fd;
293 		read = fread(seed, 1, size, rand_f);
294 	}
295 
296 	if (read < size) {
297 		LDNS_FREE(seed);
298 		return 1;
299 	} else {
300 #ifdef HAVE_SSL
301 		/* Seed the OpenSSL prng (most systems have it seeded
302 		   automatically, in that case this call just adds entropy */
303 		RAND_seed(seed, (int) size);
304 #else
305 		/* Seed the standard prng, only uses the first
306 		 * unsigned sizeof(unsiged int) bytes found in the entropy pool
307 		 */
308 		memcpy(&seed_i, seed, sizeof(seed_i));
309 		srandom(seed_i);
310 #endif
311 		LDNS_FREE(seed);
312 	}
313 
314 	if (!fd) {
315 		fclose(rand_f);
316 	}
317 
318 	return 0;
319 }
320 
321 /*
322  * BubbleBabble code taken from OpenSSH
323  * Copyright (c) 2001 Carsten Raskgaard.  All rights reserved.
324  */
325 char *
326 ldns_bubblebabble(uint8_t *data, size_t len)
327 {
328 	char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' };
329 	char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm',
330 	    'n', 'p', 'r', 's', 't', 'v', 'z', 'x' };
331 	size_t i, j = 0, rounds, seed = 1;
332 	char *retval;
333 
334 	rounds = (len / 2) + 1;
335 	retval = LDNS_XMALLOC(char, rounds * 6);
336 	retval[j++] = 'x';
337 	for (i = 0; i < rounds; i++) {
338 		size_t idx0, idx1, idx2, idx3, idx4;
339 		if ((i + 1 < rounds) || (len % 2 != 0)) {
340 			idx0 = (((((size_t)(data[2 * i])) >> 6) & 3) +
341 			    seed) % 6;
342 			idx1 = (((size_t)(data[2 * i])) >> 2) & 15;
343 			idx2 = ((((size_t)(data[2 * i])) & 3) +
344 			    (seed / 6)) % 6;
345 			retval[j++] = vowels[idx0];
346 			retval[j++] = consonants[idx1];
347 			retval[j++] = vowels[idx2];
348 			if ((i + 1) < rounds) {
349 				idx3 = (((size_t)(data[(2 * i) + 1])) >> 4) & 15;
350 				idx4 = (((size_t)(data[(2 * i) + 1]))) & 15;
351 				retval[j++] = consonants[idx3];
352 				retval[j++] = '-';
353 				retval[j++] = consonants[idx4];
354 				seed = ((seed * 5) +
355 				    ((((size_t)(data[2 * i])) * 7) +
356 				    ((size_t)(data[(2 * i) + 1])))) % 36;
357 			}
358 		} else {
359 			idx0 = seed % 6;
360 			idx1 = 16;
361 			idx2 = seed / 6;
362 			retval[j++] = vowels[idx0];
363 			retval[j++] = consonants[idx1];
364 			retval[j++] = vowels[idx2];
365 		}
366 	}
367 	retval[j++] = 'x';
368 	retval[j++] = '\0';
369 	return retval;
370 }
371