1 // SPDX-License-Identifier: MIT
2 /*
3 * Copyright (C) 2016 The Android Open Source Project
4 */
5
6 #include "avb_util.h"
7
8 #include <stdarg.h>
9
avb_be32toh(uint32_t in)10 uint32_t avb_be32toh(uint32_t in) {
11 uint8_t* d = (uint8_t*)∈
12 uint32_t ret;
13 ret = ((uint32_t)d[0]) << 24;
14 ret |= ((uint32_t)d[1]) << 16;
15 ret |= ((uint32_t)d[2]) << 8;
16 ret |= ((uint32_t)d[3]);
17 return ret;
18 }
19
avb_be64toh(uint64_t in)20 uint64_t avb_be64toh(uint64_t in) {
21 uint8_t* d = (uint8_t*)∈
22 uint64_t ret;
23 ret = ((uint64_t)d[0]) << 56;
24 ret |= ((uint64_t)d[1]) << 48;
25 ret |= ((uint64_t)d[2]) << 40;
26 ret |= ((uint64_t)d[3]) << 32;
27 ret |= ((uint64_t)d[4]) << 24;
28 ret |= ((uint64_t)d[5]) << 16;
29 ret |= ((uint64_t)d[6]) << 8;
30 ret |= ((uint64_t)d[7]);
31 return ret;
32 }
33
34 /* Converts a 32-bit unsigned integer from host to big-endian byte order. */
avb_htobe32(uint32_t in)35 uint32_t avb_htobe32(uint32_t in) {
36 union {
37 uint32_t word;
38 uint8_t bytes[4];
39 } ret;
40 ret.bytes[0] = (in >> 24) & 0xff;
41 ret.bytes[1] = (in >> 16) & 0xff;
42 ret.bytes[2] = (in >> 8) & 0xff;
43 ret.bytes[3] = in & 0xff;
44 return ret.word;
45 }
46
47 /* Converts a 64-bit unsigned integer from host to big-endian byte order. */
avb_htobe64(uint64_t in)48 uint64_t avb_htobe64(uint64_t in) {
49 union {
50 uint64_t word;
51 uint8_t bytes[8];
52 } ret;
53 ret.bytes[0] = (in >> 56) & 0xff;
54 ret.bytes[1] = (in >> 48) & 0xff;
55 ret.bytes[2] = (in >> 40) & 0xff;
56 ret.bytes[3] = (in >> 32) & 0xff;
57 ret.bytes[4] = (in >> 24) & 0xff;
58 ret.bytes[5] = (in >> 16) & 0xff;
59 ret.bytes[6] = (in >> 8) & 0xff;
60 ret.bytes[7] = in & 0xff;
61 return ret.word;
62 }
63
avb_safe_memcmp(const void * s1,const void * s2,size_t n)64 int avb_safe_memcmp(const void* s1, const void* s2, size_t n) {
65 const unsigned char* us1 = s1;
66 const unsigned char* us2 = s2;
67 int result = 0;
68
69 if (0 == n) {
70 return 0;
71 }
72
73 /*
74 * Code snippet without data-dependent branch due to Nate Lawson
75 * (nate@root.org) of Root Labs.
76 */
77 while (n--) {
78 result |= *us1++ ^ *us2++;
79 }
80
81 return result != 0;
82 }
83
avb_safe_add_to(uint64_t * value,uint64_t value_to_add)84 bool avb_safe_add_to(uint64_t* value, uint64_t value_to_add) {
85 uint64_t original_value;
86
87 avb_assert(value != NULL);
88
89 original_value = *value;
90
91 *value += value_to_add;
92 if (*value < original_value) {
93 avb_error("Overflow when adding values.\n");
94 return false;
95 }
96
97 return true;
98 }
99
avb_safe_add(uint64_t * out_result,uint64_t a,uint64_t b)100 bool avb_safe_add(uint64_t* out_result, uint64_t a, uint64_t b) {
101 uint64_t dummy;
102 if (out_result == NULL) {
103 out_result = &dummy;
104 }
105 *out_result = a;
106 return avb_safe_add_to(out_result, b);
107 }
108
avb_validate_utf8(const uint8_t * data,size_t num_bytes)109 bool avb_validate_utf8(const uint8_t* data, size_t num_bytes) {
110 size_t n;
111 unsigned int num_cc;
112
113 for (n = 0, num_cc = 0; n < num_bytes; n++) {
114 uint8_t c = data[n];
115
116 if (num_cc > 0) {
117 if ((c & (0x80 | 0x40)) == 0x80) {
118 /* 10xx xxxx */
119 } else {
120 goto fail;
121 }
122 num_cc--;
123 } else {
124 if (c < 0x80) {
125 num_cc = 0;
126 } else if ((c & (0x80 | 0x40 | 0x20)) == (0x80 | 0x40)) {
127 /* 110x xxxx */
128 num_cc = 1;
129 } else if ((c & (0x80 | 0x40 | 0x20 | 0x10)) == (0x80 | 0x40 | 0x20)) {
130 /* 1110 xxxx */
131 num_cc = 2;
132 } else if ((c & (0x80 | 0x40 | 0x20 | 0x10 | 0x08)) ==
133 (0x80 | 0x40 | 0x20 | 0x10)) {
134 /* 1111 0xxx */
135 num_cc = 3;
136 } else {
137 goto fail;
138 }
139 }
140 }
141
142 if (num_cc != 0) {
143 goto fail;
144 }
145
146 return true;
147
148 fail:
149 return false;
150 }
151
avb_str_concat(char * buf,size_t buf_size,const char * str1,size_t str1_len,const char * str2,size_t str2_len)152 bool avb_str_concat(char* buf,
153 size_t buf_size,
154 const char* str1,
155 size_t str1_len,
156 const char* str2,
157 size_t str2_len) {
158 uint64_t combined_len;
159
160 if (!avb_safe_add(&combined_len, str1_len, str2_len)) {
161 avb_error("Overflow when adding string sizes.\n");
162 return false;
163 }
164
165 if (combined_len > buf_size - 1) {
166 avb_error("Insufficient buffer space.\n");
167 return false;
168 }
169
170 avb_memcpy(buf, str1, str1_len);
171 avb_memcpy(buf + str1_len, str2, str2_len);
172 buf[combined_len] = '\0';
173
174 return true;
175 }
176
avb_malloc(size_t size)177 void* avb_malloc(size_t size) {
178 void* ret = avb_malloc_(size);
179 if (ret == NULL) {
180 avb_error("Failed to allocate memory.\n");
181 return NULL;
182 }
183 return ret;
184 }
185
avb_calloc(size_t size)186 void* avb_calloc(size_t size) {
187 void* ret = avb_malloc(size);
188 if (ret == NULL) {
189 return NULL;
190 }
191
192 avb_memset(ret, '\0', size);
193 return ret;
194 }
195
avb_strdup(const char * str)196 char* avb_strdup(const char* str) {
197 size_t len = avb_strlen(str);
198 char* ret = avb_malloc(len + 1);
199 if (ret == NULL) {
200 return NULL;
201 }
202
203 avb_memcpy(ret, str, len);
204 ret[len] = '\0';
205
206 return ret;
207 }
208
avb_strstr(const char * haystack,const char * needle)209 const char* avb_strstr(const char* haystack, const char* needle) {
210 size_t n, m;
211
212 /* Look through |haystack| and check if the first character of
213 * |needle| matches. If so, check the rest of |needle|.
214 */
215 for (n = 0; haystack[n] != '\0'; n++) {
216 if (haystack[n] != needle[0]) {
217 continue;
218 }
219
220 for (m = 1;; m++) {
221 if (needle[m] == '\0') {
222 return haystack + n;
223 }
224
225 if (haystack[n + m] != needle[m]) {
226 break;
227 }
228 }
229 }
230
231 return NULL;
232 }
233
avb_strv_find_str(const char * const * strings,const char * str,size_t str_size)234 const char* avb_strv_find_str(const char* const* strings,
235 const char* str,
236 size_t str_size) {
237 size_t n;
238 for (n = 0; strings[n] != NULL; n++) {
239 if (avb_strlen(strings[n]) == str_size &&
240 avb_memcmp(strings[n], str, str_size) == 0) {
241 return strings[n];
242 }
243 }
244 return NULL;
245 }
246
avb_replace(const char * str,const char * search,const char * replace)247 char* avb_replace(const char* str, const char* search, const char* replace) {
248 char* ret = NULL;
249 size_t ret_len = 0;
250 size_t search_len, replace_len;
251 const char* str_after_last_replace;
252
253 search_len = avb_strlen(search);
254 replace_len = avb_strlen(replace);
255
256 str_after_last_replace = str;
257 while (*str != '\0') {
258 const char* s;
259 size_t num_before;
260 size_t num_new;
261
262 s = avb_strstr(str, search);
263 if (s == NULL) {
264 break;
265 }
266
267 num_before = s - str;
268
269 if (ret == NULL) {
270 num_new = num_before + replace_len + 1;
271 ret = avb_malloc(num_new);
272 if (ret == NULL) {
273 goto out;
274 }
275 avb_memcpy(ret, str, num_before);
276 avb_memcpy(ret + num_before, replace, replace_len);
277 ret[num_new - 1] = '\0';
278 ret_len = num_new - 1;
279 } else {
280 char* new_str;
281 num_new = ret_len + num_before + replace_len + 1;
282 new_str = avb_malloc(num_new);
283 if (new_str == NULL) {
284 goto out;
285 }
286 avb_memcpy(new_str, ret, ret_len);
287 avb_memcpy(new_str + ret_len, str, num_before);
288 avb_memcpy(new_str + ret_len + num_before, replace, replace_len);
289 new_str[num_new - 1] = '\0';
290 avb_free(ret);
291 ret = new_str;
292 ret_len = num_new - 1;
293 }
294
295 str = s + search_len;
296 str_after_last_replace = str;
297 }
298
299 if (ret == NULL) {
300 ret = avb_strdup(str_after_last_replace);
301 if (ret == NULL) {
302 goto out;
303 }
304 } else {
305 size_t num_remaining = avb_strlen(str_after_last_replace);
306 size_t num_new = ret_len + num_remaining + 1;
307 char* new_str = avb_malloc(num_new);
308 if (new_str == NULL) {
309 goto out;
310 }
311 avb_memcpy(new_str, ret, ret_len);
312 avb_memcpy(new_str + ret_len, str_after_last_replace, num_remaining);
313 new_str[num_new - 1] = '\0';
314 avb_free(ret);
315 ret = new_str;
316 ret_len = num_new - 1;
317 }
318
319 out:
320 return ret;
321 }
322
323 /* We only support a limited amount of strings in avb_strdupv(). */
324 #define AVB_STRDUPV_MAX_NUM_STRINGS 32
325
avb_strdupv(const char * str,...)326 char* avb_strdupv(const char* str, ...) {
327 va_list ap;
328 const char* strings[AVB_STRDUPV_MAX_NUM_STRINGS];
329 size_t lengths[AVB_STRDUPV_MAX_NUM_STRINGS];
330 size_t num_strings, n;
331 uint64_t total_length;
332 char *ret = NULL, *dest;
333
334 num_strings = 0;
335 total_length = 0;
336 va_start(ap, str);
337 do {
338 size_t str_len = avb_strlen(str);
339 strings[num_strings] = str;
340 lengths[num_strings] = str_len;
341 if (!avb_safe_add_to(&total_length, str_len)) {
342 avb_fatal("Overflow while determining total length.\n");
343 break;
344 }
345 num_strings++;
346 if (num_strings == AVB_STRDUPV_MAX_NUM_STRINGS) {
347 avb_fatal("Too many strings passed.\n");
348 break;
349 }
350 str = va_arg(ap, const char*);
351 } while (str != NULL);
352 va_end(ap);
353
354 ret = avb_malloc(total_length + 1);
355 if (ret == NULL) {
356 goto out;
357 }
358
359 dest = ret;
360 for (n = 0; n < num_strings; n++) {
361 avb_memcpy(dest, strings[n], lengths[n]);
362 dest += lengths[n];
363 }
364 *dest = '\0';
365 avb_assert(dest == ret + total_length);
366
367 out:
368 return ret;
369 }
370
avb_basename(const char * str)371 const char* avb_basename(const char* str) {
372 int64_t n;
373 size_t len;
374
375 len = avb_strlen(str);
376 if (len >= 2) {
377 for (n = len - 2; n >= 0; n--) {
378 if (str[n] == '/') {
379 return str + n + 1;
380 }
381 }
382 }
383 return str;
384 }
385
avb_uppercase(char * str)386 void avb_uppercase(char* str) {
387 size_t i;
388 for (i = 0; str[i] != '\0'; ++i) {
389 if (str[i] <= 0x7A && str[i] >= 0x61) {
390 str[i] -= 0x20;
391 }
392 }
393 }
394
avb_bin2hex(const uint8_t * data,size_t data_len)395 char* avb_bin2hex(const uint8_t* data, size_t data_len) {
396 const char hex_digits[17] = "0123456789abcdef";
397 char* hex_data;
398 size_t n;
399
400 hex_data = avb_malloc(data_len * 2 + 1);
401 if (hex_data == NULL) {
402 return NULL;
403 }
404
405 for (n = 0; n < data_len; n++) {
406 hex_data[n * 2] = hex_digits[data[n] >> 4];
407 hex_data[n * 2 + 1] = hex_digits[data[n] & 0x0f];
408 }
409 hex_data[n * 2] = '\0';
410 return hex_data;
411 }
412