1 | /* |
2 | * Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved. |
3 | * |
4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
5 | * this file except in compliance with the License. You can obtain a copy |
6 | * in the file LICENSE in the source distribution or at |
7 | * https://www.openssl.org/source/license.html |
8 | */ |
9 | |
10 | #include "internal/cryptlib.h" |
11 | #include "internal/packet.h" |
12 | #include <openssl/sslerr.h> |
13 | |
14 | #define DEFAULT_BUF_SIZE 256 |
15 | |
16 | int WPACKET_allocate_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes) |
17 | { |
18 | if (!WPACKET_reserve_bytes(pkt, len, allocbytes)) |
19 | return 0; |
20 | |
21 | pkt->written += len; |
22 | pkt->curr += len; |
23 | return 1; |
24 | } |
25 | |
26 | int WPACKET_sub_allocate_bytes__(WPACKET *pkt, size_t len, |
27 | unsigned char **allocbytes, size_t lenbytes) |
28 | { |
29 | if (!WPACKET_start_sub_packet_len__(pkt, lenbytes) |
30 | || !WPACKET_allocate_bytes(pkt, len, allocbytes) |
31 | || !WPACKET_close(pkt)) |
32 | return 0; |
33 | |
34 | return 1; |
35 | } |
36 | |
37 | #define GETBUF(p) (((p)->staticbuf != NULL) \ |
38 | ? (p)->staticbuf \ |
39 | : ((p)->buf != NULL \ |
40 | ? (unsigned char *)(p)->buf->data \ |
41 | : NULL)) |
42 | |
43 | int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes) |
44 | { |
45 | /* Internal API, so should not fail */ |
46 | if (!ossl_assert(pkt->subs != NULL && len != 0)) |
47 | return 0; |
48 | |
49 | if (pkt->maxsize - pkt->written < len) |
50 | return 0; |
51 | |
52 | if (pkt->buf != NULL && (pkt->buf->length - pkt->written < len)) { |
53 | size_t newlen; |
54 | size_t reflen; |
55 | |
56 | reflen = (len > pkt->buf->length) ? len : pkt->buf->length; |
57 | |
58 | if (reflen > SIZE_MAX / 2) { |
59 | newlen = SIZE_MAX; |
60 | } else { |
61 | newlen = reflen * 2; |
62 | if (newlen < DEFAULT_BUF_SIZE) |
63 | newlen = DEFAULT_BUF_SIZE; |
64 | } |
65 | if (BUF_MEM_grow(pkt->buf, newlen) == 0) |
66 | return 0; |
67 | } |
68 | if (allocbytes != NULL) |
69 | *allocbytes = WPACKET_get_curr(pkt); |
70 | |
71 | return 1; |
72 | } |
73 | |
74 | int WPACKET_sub_reserve_bytes__(WPACKET *pkt, size_t len, |
75 | unsigned char **allocbytes, size_t lenbytes) |
76 | { |
77 | if (!WPACKET_reserve_bytes(pkt, lenbytes + len, allocbytes)) |
78 | return 0; |
79 | |
80 | if (*allocbytes != NULL) |
81 | *allocbytes += lenbytes; |
82 | |
83 | return 1; |
84 | } |
85 | |
86 | static size_t maxmaxsize(size_t lenbytes) |
87 | { |
88 | if (lenbytes >= sizeof(size_t) || lenbytes == 0) |
89 | return SIZE_MAX; |
90 | |
91 | return ((size_t)1 << (lenbytes * 8)) - 1 + lenbytes; |
92 | } |
93 | |
94 | static int wpacket_intern_init_len(WPACKET *pkt, size_t lenbytes) |
95 | { |
96 | unsigned char *lenchars; |
97 | |
98 | pkt->curr = 0; |
99 | pkt->written = 0; |
100 | |
101 | if ((pkt->subs = OPENSSL_zalloc(sizeof(*pkt->subs))) == NULL) { |
102 | SSLerr(SSL_F_WPACKET_INTERN_INIT_LEN, ERR_R_MALLOC_FAILURE); |
103 | return 0; |
104 | } |
105 | |
106 | if (lenbytes == 0) |
107 | return 1; |
108 | |
109 | pkt->subs->pwritten = lenbytes; |
110 | pkt->subs->lenbytes = lenbytes; |
111 | |
112 | if (!WPACKET_allocate_bytes(pkt, lenbytes, &lenchars)) { |
113 | OPENSSL_free(pkt->subs); |
114 | pkt->subs = NULL; |
115 | return 0; |
116 | } |
117 | pkt->subs->packet_len = 0; |
118 | |
119 | return 1; |
120 | } |
121 | |
122 | int WPACKET_init_static_len(WPACKET *pkt, unsigned char *buf, size_t len, |
123 | size_t lenbytes) |
124 | { |
125 | size_t max = maxmaxsize(lenbytes); |
126 | |
127 | /* Internal API, so should not fail */ |
128 | if (!ossl_assert(buf != NULL && len > 0)) |
129 | return 0; |
130 | |
131 | pkt->staticbuf = buf; |
132 | pkt->buf = NULL; |
133 | pkt->maxsize = (max < len) ? max : len; |
134 | |
135 | return wpacket_intern_init_len(pkt, lenbytes); |
136 | } |
137 | |
138 | int WPACKET_init_len(WPACKET *pkt, BUF_MEM *buf, size_t lenbytes) |
139 | { |
140 | /* Internal API, so should not fail */ |
141 | if (!ossl_assert(buf != NULL)) |
142 | return 0; |
143 | |
144 | pkt->staticbuf = NULL; |
145 | pkt->buf = buf; |
146 | pkt->maxsize = maxmaxsize(lenbytes); |
147 | |
148 | return wpacket_intern_init_len(pkt, lenbytes); |
149 | } |
150 | |
151 | int WPACKET_init(WPACKET *pkt, BUF_MEM *buf) |
152 | { |
153 | return WPACKET_init_len(pkt, buf, 0); |
154 | } |
155 | |
156 | int WPACKET_init_null(WPACKET *pkt, size_t lenbytes) |
157 | { |
158 | pkt->staticbuf = NULL; |
159 | pkt->buf = NULL; |
160 | pkt->maxsize = maxmaxsize(lenbytes); |
161 | |
162 | return wpacket_intern_init_len(pkt, 0); |
163 | } |
164 | |
165 | int WPACKET_set_flags(WPACKET *pkt, unsigned int flags) |
166 | { |
167 | /* Internal API, so should not fail */ |
168 | if (!ossl_assert(pkt->subs != NULL)) |
169 | return 0; |
170 | |
171 | pkt->subs->flags = flags; |
172 | |
173 | return 1; |
174 | } |
175 | |
176 | /* Store the |value| of length |len| at location |data| */ |
177 | static int put_value(unsigned char *data, size_t value, size_t len) |
178 | { |
179 | if (data == NULL) |
180 | return 1; |
181 | |
182 | for (data += len - 1; len > 0; len--) { |
183 | *data = (unsigned char)(value & 0xff); |
184 | data--; |
185 | value >>= 8; |
186 | } |
187 | |
188 | /* Check whether we could fit the value in the assigned number of bytes */ |
189 | if (value > 0) |
190 | return 0; |
191 | |
192 | return 1; |
193 | } |
194 | |
195 | |
196 | /* |
197 | * Internal helper function used by WPACKET_close(), WPACKET_finish() and |
198 | * WPACKET_fill_lengths() to close a sub-packet and write out its length if |
199 | * necessary. If |doclose| is 0 then it goes through the motions of closing |
200 | * (i.e. it fills in all the lengths), but doesn't actually close anything. |
201 | */ |
202 | static int wpacket_intern_close(WPACKET *pkt, WPACKET_SUB *sub, int doclose) |
203 | { |
204 | size_t packlen = pkt->written - sub->pwritten; |
205 | |
206 | if (packlen == 0 |
207 | && (sub->flags & WPACKET_FLAGS_NON_ZERO_LENGTH) != 0) |
208 | return 0; |
209 | |
210 | if (packlen == 0 |
211 | && sub->flags & WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH) { |
212 | /* We can't handle this case. Return an error */ |
213 | if (!doclose) |
214 | return 0; |
215 | |
216 | /* Deallocate any bytes allocated for the length of the WPACKET */ |
217 | if ((pkt->curr - sub->lenbytes) == sub->packet_len) { |
218 | pkt->written -= sub->lenbytes; |
219 | pkt->curr -= sub->lenbytes; |
220 | } |
221 | |
222 | /* Don't write out the packet length */ |
223 | sub->packet_len = 0; |
224 | sub->lenbytes = 0; |
225 | } |
226 | |
227 | /* Write out the WPACKET length if needed */ |
228 | if (sub->lenbytes > 0) { |
229 | unsigned char *buf = GETBUF(pkt); |
230 | |
231 | if (buf != NULL |
232 | && !put_value(&buf[sub->packet_len], packlen, |
233 | sub->lenbytes)) |
234 | return 0; |
235 | } |
236 | |
237 | if (doclose) { |
238 | pkt->subs = sub->parent; |
239 | OPENSSL_free(sub); |
240 | } |
241 | |
242 | return 1; |
243 | } |
244 | |
245 | int WPACKET_fill_lengths(WPACKET *pkt) |
246 | { |
247 | WPACKET_SUB *sub; |
248 | |
249 | if (!ossl_assert(pkt->subs != NULL)) |
250 | return 0; |
251 | |
252 | for (sub = pkt->subs; sub != NULL; sub = sub->parent) { |
253 | if (!wpacket_intern_close(pkt, sub, 0)) |
254 | return 0; |
255 | } |
256 | |
257 | return 1; |
258 | } |
259 | |
260 | int WPACKET_close(WPACKET *pkt) |
261 | { |
262 | /* |
263 | * Internal API, so should not fail - but we do negative testing of this |
264 | * so no assert (otherwise the tests fail) |
265 | */ |
266 | if (pkt->subs == NULL || pkt->subs->parent == NULL) |
267 | return 0; |
268 | |
269 | return wpacket_intern_close(pkt, pkt->subs, 1); |
270 | } |
271 | |
272 | int WPACKET_finish(WPACKET *pkt) |
273 | { |
274 | int ret; |
275 | |
276 | /* |
277 | * Internal API, so should not fail - but we do negative testing of this |
278 | * so no assert (otherwise the tests fail) |
279 | */ |
280 | if (pkt->subs == NULL || pkt->subs->parent != NULL) |
281 | return 0; |
282 | |
283 | ret = wpacket_intern_close(pkt, pkt->subs, 1); |
284 | if (ret) { |
285 | OPENSSL_free(pkt->subs); |
286 | pkt->subs = NULL; |
287 | } |
288 | |
289 | return ret; |
290 | } |
291 | |
292 | int WPACKET_start_sub_packet_len__(WPACKET *pkt, size_t lenbytes) |
293 | { |
294 | WPACKET_SUB *sub; |
295 | unsigned char *lenchars; |
296 | |
297 | /* Internal API, so should not fail */ |
298 | if (!ossl_assert(pkt->subs != NULL)) |
299 | return 0; |
300 | |
301 | if ((sub = OPENSSL_zalloc(sizeof(*sub))) == NULL) { |
302 | SSLerr(SSL_F_WPACKET_START_SUB_PACKET_LEN__, ERR_R_MALLOC_FAILURE); |
303 | return 0; |
304 | } |
305 | |
306 | sub->parent = pkt->subs; |
307 | pkt->subs = sub; |
308 | sub->pwritten = pkt->written + lenbytes; |
309 | sub->lenbytes = lenbytes; |
310 | |
311 | if (lenbytes == 0) { |
312 | sub->packet_len = 0; |
313 | return 1; |
314 | } |
315 | |
316 | sub->packet_len = pkt->written; |
317 | |
318 | if (!WPACKET_allocate_bytes(pkt, lenbytes, &lenchars)) |
319 | return 0; |
320 | |
321 | return 1; |
322 | } |
323 | |
324 | int WPACKET_start_sub_packet(WPACKET *pkt) |
325 | { |
326 | return WPACKET_start_sub_packet_len__(pkt, 0); |
327 | } |
328 | |
329 | int WPACKET_put_bytes__(WPACKET *pkt, unsigned int val, size_t size) |
330 | { |
331 | unsigned char *data; |
332 | |
333 | /* Internal API, so should not fail */ |
334 | if (!ossl_assert(size <= sizeof(unsigned int)) |
335 | || !WPACKET_allocate_bytes(pkt, size, &data) |
336 | || !put_value(data, val, size)) |
337 | return 0; |
338 | |
339 | return 1; |
340 | } |
341 | |
342 | int WPACKET_set_max_size(WPACKET *pkt, size_t maxsize) |
343 | { |
344 | WPACKET_SUB *sub; |
345 | size_t lenbytes; |
346 | |
347 | /* Internal API, so should not fail */ |
348 | if (!ossl_assert(pkt->subs != NULL)) |
349 | return 0; |
350 | |
351 | /* Find the WPACKET_SUB for the top level */ |
352 | for (sub = pkt->subs; sub->parent != NULL; sub = sub->parent) |
353 | continue; |
354 | |
355 | lenbytes = sub->lenbytes; |
356 | if (lenbytes == 0) |
357 | lenbytes = sizeof(pkt->maxsize); |
358 | |
359 | if (maxmaxsize(lenbytes) < maxsize || maxsize < pkt->written) |
360 | return 0; |
361 | |
362 | pkt->maxsize = maxsize; |
363 | |
364 | return 1; |
365 | } |
366 | |
367 | int WPACKET_memset(WPACKET *pkt, int ch, size_t len) |
368 | { |
369 | unsigned char *dest; |
370 | |
371 | if (len == 0) |
372 | return 1; |
373 | |
374 | if (!WPACKET_allocate_bytes(pkt, len, &dest)) |
375 | return 0; |
376 | |
377 | if (dest != NULL) |
378 | memset(dest, ch, len); |
379 | |
380 | return 1; |
381 | } |
382 | |
383 | int WPACKET_memcpy(WPACKET *pkt, const void *src, size_t len) |
384 | { |
385 | unsigned char *dest; |
386 | |
387 | if (len == 0) |
388 | return 1; |
389 | |
390 | if (!WPACKET_allocate_bytes(pkt, len, &dest)) |
391 | return 0; |
392 | |
393 | if (dest != NULL) |
394 | memcpy(dest, src, len); |
395 | |
396 | return 1; |
397 | } |
398 | |
399 | int WPACKET_sub_memcpy__(WPACKET *pkt, const void *src, size_t len, |
400 | size_t lenbytes) |
401 | { |
402 | if (!WPACKET_start_sub_packet_len__(pkt, lenbytes) |
403 | || !WPACKET_memcpy(pkt, src, len) |
404 | || !WPACKET_close(pkt)) |
405 | return 0; |
406 | |
407 | return 1; |
408 | } |
409 | |
410 | int WPACKET_get_total_written(WPACKET *pkt, size_t *written) |
411 | { |
412 | /* Internal API, so should not fail */ |
413 | if (!ossl_assert(written != NULL)) |
414 | return 0; |
415 | |
416 | *written = pkt->written; |
417 | |
418 | return 1; |
419 | } |
420 | |
421 | int WPACKET_get_length(WPACKET *pkt, size_t *len) |
422 | { |
423 | /* Internal API, so should not fail */ |
424 | if (!ossl_assert(pkt->subs != NULL && len != NULL)) |
425 | return 0; |
426 | |
427 | *len = pkt->written - pkt->subs->pwritten; |
428 | |
429 | return 1; |
430 | } |
431 | |
432 | unsigned char *WPACKET_get_curr(WPACKET *pkt) |
433 | { |
434 | unsigned char *buf = GETBUF(pkt); |
435 | |
436 | if (buf == NULL) |
437 | return NULL; |
438 | |
439 | return buf + pkt->curr; |
440 | } |
441 | |
442 | int WPACKET_is_null_buf(WPACKET *pkt) |
443 | { |
444 | return pkt->buf == NULL && pkt->staticbuf == NULL; |
445 | } |
446 | |
447 | void WPACKET_cleanup(WPACKET *pkt) |
448 | { |
449 | WPACKET_SUB *sub, *parent; |
450 | |
451 | for (sub = pkt->subs; sub != NULL; sub = parent) { |
452 | parent = sub->parent; |
453 | OPENSSL_free(sub); |
454 | } |
455 | pkt->subs = NULL; |
456 | } |
457 | |