/src/boringssl/crypto/asn1/a_int.cc
Line | Count | Source |
1 | | // Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. |
2 | | // |
3 | | // Licensed under the Apache License, Version 2.0 (the "License"); |
4 | | // you may not use this file except in compliance with the License. |
5 | | // You may obtain a copy of the License at |
6 | | // |
7 | | // https://www.apache.org/licenses/LICENSE-2.0 |
8 | | // |
9 | | // Unless required by applicable law or agreed to in writing, software |
10 | | // distributed under the License is distributed on an "AS IS" BASIS, |
11 | | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
12 | | // See the License for the specific language governing permissions and |
13 | | // limitations under the License. |
14 | | |
15 | | #include <openssl/asn1.h> |
16 | | |
17 | | #include <assert.h> |
18 | | #include <limits.h> |
19 | | #include <string.h> |
20 | | |
21 | | #include <openssl/bytestring.h> |
22 | | #include <openssl/err.h> |
23 | | #include <openssl/mem.h> |
24 | | #include <openssl/span.h> |
25 | | |
26 | | #include "../internal.h" |
27 | | #include "internal.h" |
28 | | |
29 | | |
30 | | using namespace bssl; |
31 | | |
32 | 64 | ASN1_INTEGER *ASN1_INTEGER_dup(const ASN1_INTEGER *x) { |
33 | 64 | return ASN1_STRING_dup(x); |
34 | 64 | } |
35 | | |
36 | 37 | int ASN1_INTEGER_cmp(const ASN1_INTEGER *x, const ASN1_INTEGER *y) { |
37 | | // Compare signs. |
38 | 37 | int neg = x->type & V_ASN1_NEG; |
39 | 37 | if (neg != (y->type & V_ASN1_NEG)) { |
40 | 2 | return neg ? -1 : 1; |
41 | 2 | } |
42 | | |
43 | 35 | int ret = ASN1_STRING_cmp(x, y); |
44 | 35 | if (neg) { |
45 | | // This could be `-ret`, but `ASN1_STRING_cmp` is not forbidden from |
46 | | // returning `INT_MIN`. |
47 | 17 | if (ret < 0) { |
48 | 10 | return 1; |
49 | 10 | } else if (ret > 0) { |
50 | 6 | return -1; |
51 | 6 | } else { |
52 | 1 | return 0; |
53 | 1 | } |
54 | 17 | } |
55 | | |
56 | 18 | return ret; |
57 | 35 | } |
58 | | |
59 | | // negate_twos_complement negates `len` bytes from `buf` in-place, interpreted |
60 | | // as a signed, big-endian two's complement value. |
61 | 135k | static void negate_twos_complement(uint8_t *buf, size_t len) { |
62 | 135k | uint8_t borrow = 0; |
63 | 6.70M | for (size_t i = len - 1; i < len; i--) { |
64 | 6.56M | uint8_t t = buf[i]; |
65 | 6.56M | buf[i] = 0u - borrow - t; |
66 | 6.56M | borrow |= t != 0; |
67 | 6.56M | } |
68 | 135k | } |
69 | | |
70 | 31.5k | static int is_all_zeros(const uint8_t *in, size_t len) { |
71 | 70.3k | for (size_t i = 0; i < len; i++) { |
72 | 65.7k | if (in[i] != 0) { |
73 | 26.9k | return 0; |
74 | 26.9k | } |
75 | 65.7k | } |
76 | 4.60k | return 1; |
77 | 31.5k | } |
78 | | |
79 | | int bssl::asn1_marshal_integer(CBB *out, const ASN1_INTEGER *in, |
80 | 143k | CBS_ASN1_TAG tag) { |
81 | 143k | int len = i2c_ASN1_INTEGER(in, nullptr); |
82 | 143k | if (len <= 0) { |
83 | 0 | return 0; |
84 | 0 | } |
85 | 143k | tag = tag == 0 ? CBS_ASN1_INTEGER : tag; |
86 | 143k | CBB child; |
87 | 143k | uint8_t *ptr; |
88 | 143k | return CBB_add_asn1(out, &child, tag) && // |
89 | 143k | CBB_add_space(&child, &ptr, static_cast<size_t>(len)) && // |
90 | 143k | i2c_ASN1_INTEGER(in, &ptr) == len && // |
91 | 143k | CBB_flush(out); |
92 | 143k | } |
93 | | |
94 | 307k | int i2c_ASN1_INTEGER(const ASN1_INTEGER *in, unsigned char **outp) { |
95 | 307k | if (in == nullptr) { |
96 | 0 | return 0; |
97 | 0 | } |
98 | | |
99 | | // `ASN1_INTEGER`s should be represented minimally, but it is possible to |
100 | | // construct invalid ones. Skip leading zeros so this does not produce an |
101 | | // invalid encoding or break invariants. |
102 | 307k | CBS cbs; |
103 | 307k | CBS_init(&cbs, in->data, in->length); |
104 | 307k | while (CBS_len(&cbs) > 0 && CBS_data(&cbs)[0] == 0) { |
105 | 0 | CBS_skip(&cbs, 1); |
106 | 0 | } |
107 | | |
108 | 307k | int is_negative = (in->type & V_ASN1_NEG) != 0; |
109 | 307k | size_t pad; |
110 | 307k | CBS copy = cbs; |
111 | 307k | uint8_t msb; |
112 | 307k | if (!CBS_get_u8(©, &msb)) { |
113 | | // Zero is represented as a single byte. |
114 | 15.1k | is_negative = 0; |
115 | 15.1k | pad = 1; |
116 | 292k | } else if (is_negative) { |
117 | | // 0x80...01 through 0xff...ff have a two's complement of 0x7f...ff |
118 | | // through 0x00...01 and need an extra byte to be negative. |
119 | | // 0x01...00 through 0x80...00 have a two's complement of 0xfe...ff |
120 | | // through 0x80...00 and can be negated as-is. |
121 | 156k | pad = msb > 0x80 || |
122 | 83.7k | (msb == 0x80 && !is_all_zeros(CBS_data(©), CBS_len(©))); |
123 | 156k | } else { |
124 | | // If the high bit is set, the signed representation needs an extra |
125 | | // byte to be positive. |
126 | 135k | pad = (msb & 0x80) != 0; |
127 | 135k | } |
128 | | |
129 | 307k | if (CBS_len(&cbs) > INT_MAX - pad) { |
130 | 0 | OPENSSL_PUT_ERROR(ASN1, ERR_R_OVERFLOW); |
131 | 0 | return 0; |
132 | 0 | } |
133 | 307k | int len = (int)(pad + CBS_len(&cbs)); |
134 | 307k | assert(len > 0); |
135 | 307k | if (outp == nullptr) { |
136 | 153k | return len; |
137 | 153k | } |
138 | | |
139 | 153k | if (pad) { |
140 | 54.5k | (*outp)[0] = 0; |
141 | 54.5k | } |
142 | 153k | OPENSSL_memcpy(*outp + pad, CBS_data(&cbs), CBS_len(&cbs)); |
143 | 153k | if (is_negative) { |
144 | 78.2k | negate_twos_complement(*outp, len); |
145 | 78.2k | assert((*outp)[0] >= 0x80); |
146 | 78.2k | } else { |
147 | 75.3k | assert((*outp)[0] < 0x80); |
148 | 75.3k | } |
149 | 153k | *outp += len; |
150 | 153k | return len; |
151 | 153k | } |
152 | | |
153 | | static int asn1_parse_integer_contents(Span<const uint8_t> in, |
154 | 293k | ASN1_INTEGER *out) { |
155 | 293k | CBS cbs = in; |
156 | 293k | int is_negative; |
157 | 293k | if (!CBS_is_valid_asn1_integer(&cbs, &is_negative)) { |
158 | 366 | OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_INTEGER); |
159 | 366 | return 0; |
160 | 366 | } |
161 | | |
162 | | // Convert to `ASN1_INTEGER`'s sign-and-magnitude representation. First, |
163 | | // determine the size needed for a minimal result. |
164 | 293k | if (is_negative) { |
165 | | // 0xff00...01 through 0xff7f..ff have a two's complement of 0x00ff...ff |
166 | | // through 0x000100...001 and need one leading zero removed. 0x8000...00 |
167 | | // through 0xff00...00 have a two's complement of 0x8000...00 through |
168 | | // 0x0100...00 and will be minimally-encoded as-is. |
169 | 57.6k | if (CBS_len(&cbs) > 0 && CBS_data(&cbs)[0] == 0xff && |
170 | 28.1k | !is_all_zeros(CBS_data(&cbs) + 1, CBS_len(&cbs) - 1)) { |
171 | 25.4k | CBS_skip(&cbs, 1); |
172 | 25.4k | } |
173 | 235k | } else { |
174 | | // Remove the leading zero byte, if any. |
175 | 235k | if (CBS_len(&cbs) > 0 && CBS_data(&cbs)[0] == 0x00) { |
176 | 143k | CBS_skip(&cbs, 1); |
177 | 143k | } |
178 | 235k | } |
179 | | |
180 | 293k | if (!ASN1_STRING_set(out, CBS_data(&cbs), CBS_len(&cbs))) { |
181 | 0 | return 0; |
182 | 0 | } |
183 | | |
184 | 293k | if (is_negative) { |
185 | 57.6k | out->type = V_ASN1_NEG_INTEGER; |
186 | 57.6k | negate_twos_complement(out->data, out->length); |
187 | 235k | } else { |
188 | 235k | out->type = V_ASN1_INTEGER; |
189 | 235k | } |
190 | | |
191 | | // The value should be minimally-encoded. |
192 | 293k | assert(out->length == 0 || out->data[0] != 0); |
193 | | // Zero is not negative. |
194 | 293k | assert(!is_negative || out->length > 0); |
195 | 293k | return 1; |
196 | 293k | } |
197 | | |
198 | 295k | int bssl::asn1_parse_integer(CBS *cbs, ASN1_INTEGER *out, CBS_ASN1_TAG tag) { |
199 | 295k | tag = tag == 0 ? CBS_ASN1_INTEGER : tag; |
200 | 295k | CBS child; |
201 | 295k | if (!CBS_get_asn1(cbs, &child, tag)) { |
202 | 2.09k | OPENSSL_PUT_ERROR(ASN1, ASN1_R_DECODE_ERROR); |
203 | 2.09k | return 0; |
204 | 2.09k | } |
205 | 293k | return asn1_parse_integer_contents(child, out); |
206 | 295k | } |
207 | | |
208 | | int bssl::asn1_parse_enumerated(CBS *cbs, ASN1_ENUMERATED *out, |
209 | 71.5k | CBS_ASN1_TAG tag) { |
210 | 71.5k | tag = tag == 0 ? CBS_ASN1_ENUMERATED : tag; |
211 | 71.5k | if (!asn1_parse_integer(cbs, out, tag)) { |
212 | 889 | return 0; |
213 | 889 | } |
214 | | // Fix the type value. |
215 | 70.6k | out->type = |
216 | 70.6k | (out->type & V_ASN1_NEG) ? V_ASN1_NEG_ENUMERATED : V_ASN1_ENUMERATED; |
217 | 70.6k | return 1; |
218 | 71.5k | } |
219 | | |
220 | | ASN1_INTEGER *c2i_ASN1_INTEGER(ASN1_INTEGER **out, const unsigned char **inp, |
221 | 0 | long len) { |
222 | 0 | if (len < 0) { |
223 | 0 | OPENSSL_PUT_ERROR(ASN1, ASN1_R_STRING_TOO_SHORT); |
224 | 0 | return nullptr; |
225 | 0 | } |
226 | | |
227 | 0 | ASN1_INTEGER *ret = nullptr; |
228 | 0 | if (out == nullptr || *out == nullptr) { |
229 | 0 | ret = ASN1_INTEGER_new(); |
230 | 0 | if (ret == nullptr) { |
231 | 0 | return nullptr; |
232 | 0 | } |
233 | 0 | } else { |
234 | 0 | ret = *out; |
235 | 0 | } |
236 | | |
237 | 0 | if (!asn1_parse_integer_contents(Span(*inp, len), ret)) { |
238 | 0 | if (ret != nullptr && (out == nullptr || *out != ret)) { |
239 | 0 | ASN1_INTEGER_free(ret); |
240 | 0 | } |
241 | 0 | return nullptr; |
242 | 0 | } |
243 | | |
244 | 0 | *inp += len; |
245 | 0 | if (out != nullptr) { |
246 | 0 | *out = ret; |
247 | 0 | } |
248 | 0 | return ret; |
249 | |
|
250 | 0 | } |
251 | | |
252 | 0 | int ASN1_INTEGER_set_int64(ASN1_INTEGER *a, int64_t v) { |
253 | 0 | if (v >= 0) { |
254 | 0 | return ASN1_INTEGER_set_uint64(a, (uint64_t)v); |
255 | 0 | } |
256 | | |
257 | 0 | if (!ASN1_INTEGER_set_uint64(a, 0 - (uint64_t)v)) { |
258 | 0 | return 0; |
259 | 0 | } |
260 | | |
261 | 0 | a->type = V_ASN1_NEG_INTEGER; |
262 | 0 | return 1; |
263 | 0 | } |
264 | | |
265 | 0 | int ASN1_ENUMERATED_set_int64(ASN1_ENUMERATED *a, int64_t v) { |
266 | 0 | if (v >= 0) { |
267 | 0 | return ASN1_ENUMERATED_set_uint64(a, (uint64_t)v); |
268 | 0 | } |
269 | | |
270 | 0 | if (!ASN1_ENUMERATED_set_uint64(a, 0 - (uint64_t)v)) { |
271 | 0 | return 0; |
272 | 0 | } |
273 | | |
274 | 0 | a->type = V_ASN1_NEG_ENUMERATED; |
275 | 0 | return 1; |
276 | 0 | } |
277 | | |
278 | 0 | int ASN1_INTEGER_set(ASN1_INTEGER *a, long v) { |
279 | 0 | static_assert(sizeof(long) <= sizeof(int64_t), "long fits in int64_t"); |
280 | 0 | return ASN1_INTEGER_set_int64(a, v); |
281 | 0 | } |
282 | | |
283 | 0 | int ASN1_ENUMERATED_set(ASN1_ENUMERATED *a, long v) { |
284 | 0 | static_assert(sizeof(long) <= sizeof(int64_t), "long fits in int64_t"); |
285 | 0 | return ASN1_ENUMERATED_set_int64(a, v); |
286 | 0 | } |
287 | | |
288 | 0 | static int asn1_string_set_uint64(ASN1_STRING *out, uint64_t v, int type) { |
289 | 0 | uint8_t buf[sizeof(uint64_t)]; |
290 | 0 | CRYPTO_store_u64_be(buf, v); |
291 | 0 | size_t leading_zeros; |
292 | 0 | for (leading_zeros = 0; leading_zeros < sizeof(buf); leading_zeros++) { |
293 | 0 | if (buf[leading_zeros] != 0) { |
294 | 0 | break; |
295 | 0 | } |
296 | 0 | } |
297 | |
|
298 | 0 | if (!ASN1_STRING_set(out, buf + leading_zeros, sizeof(buf) - leading_zeros)) { |
299 | 0 | return 0; |
300 | 0 | } |
301 | 0 | out->type = type; |
302 | 0 | return 1; |
303 | 0 | } |
304 | | |
305 | 0 | int ASN1_INTEGER_set_uint64(ASN1_INTEGER *out, uint64_t v) { |
306 | 0 | return asn1_string_set_uint64(out, v, V_ASN1_INTEGER); |
307 | 0 | } |
308 | | |
309 | 0 | int ASN1_ENUMERATED_set_uint64(ASN1_ENUMERATED *out, uint64_t v) { |
310 | 0 | return asn1_string_set_uint64(out, v, V_ASN1_ENUMERATED); |
311 | 0 | } |
312 | | |
313 | | static int asn1_string_get_abs_uint64(uint64_t *out, const ASN1_STRING *a, |
314 | 3.97k | int type) { |
315 | 3.97k | if ((a->type & ~V_ASN1_NEG) != type) { |
316 | 0 | OPENSSL_PUT_ERROR(ASN1, ASN1_R_WRONG_INTEGER_TYPE); |
317 | 0 | return 0; |
318 | 0 | } |
319 | 3.97k | uint8_t buf[sizeof(uint64_t)] = {0}; |
320 | 3.97k | if (a->length > (int)sizeof(buf)) { |
321 | 2.01k | OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_INTEGER); |
322 | 2.01k | return 0; |
323 | 2.01k | } |
324 | 1.96k | OPENSSL_memcpy(buf + sizeof(buf) - a->length, a->data, a->length); |
325 | 1.96k | *out = CRYPTO_load_u64_be(buf); |
326 | 1.96k | return 1; |
327 | 3.97k | } |
328 | | |
329 | | static int asn1_string_get_uint64(uint64_t *out, const ASN1_STRING *a, |
330 | 2.88k | int type) { |
331 | 2.88k | if (!asn1_string_get_abs_uint64(out, a, type)) { |
332 | 1.67k | return 0; |
333 | 1.67k | } |
334 | 1.20k | if (a->type & V_ASN1_NEG) { |
335 | 394 | OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_INTEGER); |
336 | 394 | return 0; |
337 | 394 | } |
338 | 810 | return 1; |
339 | 1.20k | } |
340 | | |
341 | 2.88k | int ASN1_INTEGER_get_uint64(uint64_t *out, const ASN1_INTEGER *a) { |
342 | 2.88k | return asn1_string_get_uint64(out, a, V_ASN1_INTEGER); |
343 | 2.88k | } |
344 | | |
345 | 0 | int ASN1_ENUMERATED_get_uint64(uint64_t *out, const ASN1_ENUMERATED *a) { |
346 | 0 | return asn1_string_get_uint64(out, a, V_ASN1_ENUMERATED); |
347 | 0 | } |
348 | | |
349 | 1.09k | static int asn1_string_get_int64(int64_t *out, const ASN1_STRING *a, int type) { |
350 | 1.09k | uint64_t v; |
351 | 1.09k | if (!asn1_string_get_abs_uint64(&v, a, type)) { |
352 | 339 | return 0; |
353 | 339 | } |
354 | 758 | int64_t i64; |
355 | 758 | int fits_in_i64; |
356 | | // Check `v != 0` to handle manually-constructed negative zeros. |
357 | 758 | if ((a->type & V_ASN1_NEG) && v != 0) { |
358 | 437 | i64 = (int64_t)(0u - v); |
359 | 437 | fits_in_i64 = i64 < 0; |
360 | 437 | } else { |
361 | 321 | i64 = (int64_t)v; |
362 | 321 | fits_in_i64 = i64 >= 0; |
363 | 321 | } |
364 | 758 | if (!fits_in_i64) { |
365 | 228 | OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_INTEGER); |
366 | 228 | return 0; |
367 | 228 | } |
368 | 530 | *out = i64; |
369 | 530 | return 1; |
370 | 758 | } |
371 | | |
372 | 0 | int ASN1_INTEGER_get_int64(int64_t *out, const ASN1_INTEGER *a) { |
373 | 0 | return asn1_string_get_int64(out, a, V_ASN1_INTEGER); |
374 | 0 | } |
375 | | |
376 | 0 | int ASN1_ENUMERATED_get_int64(int64_t *out, const ASN1_ENUMERATED *a) { |
377 | 0 | return asn1_string_get_int64(out, a, V_ASN1_ENUMERATED); |
378 | 0 | } |
379 | | |
380 | 1.09k | static long asn1_string_get_long(const ASN1_STRING *a, int type) { |
381 | 1.09k | if (a == nullptr) { |
382 | 0 | return 0; |
383 | 0 | } |
384 | | |
385 | 1.09k | int64_t v; |
386 | 1.09k | if (!asn1_string_get_int64(&v, a, type) || // |
387 | 567 | v < LONG_MIN || v > LONG_MAX) { |
388 | | // This function's return value does not distinguish overflow from -1. |
389 | 567 | ERR_clear_error(); |
390 | 567 | return -1; |
391 | 567 | } |
392 | | |
393 | 530 | return (long)v; |
394 | 1.09k | } |
395 | | |
396 | 17 | long ASN1_INTEGER_get(const ASN1_INTEGER *a) { |
397 | 17 | return asn1_string_get_long(a, V_ASN1_INTEGER); |
398 | 17 | } |
399 | | |
400 | 1.08k | long ASN1_ENUMERATED_get(const ASN1_ENUMERATED *a) { |
401 | 1.08k | return asn1_string_get_long(a, V_ASN1_ENUMERATED); |
402 | 1.08k | } |
403 | | |
404 | | static ASN1_STRING *bn_to_asn1_string(const BIGNUM *bn, ASN1_STRING *ai, |
405 | 12.3k | int type) { |
406 | 12.3k | ASN1_INTEGER *ret; |
407 | 12.3k | if (ai == nullptr) { |
408 | 12.3k | ret = ASN1_STRING_type_new(type); |
409 | 12.3k | } else { |
410 | 0 | ret = ai; |
411 | 0 | } |
412 | 12.3k | int len; |
413 | 12.3k | if (ret == nullptr) { |
414 | 0 | OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); |
415 | 0 | goto err; |
416 | 0 | } |
417 | | |
418 | 12.3k | if (BN_is_negative(bn) && !BN_is_zero(bn)) { |
419 | 517 | ret->type = type | V_ASN1_NEG; |
420 | 11.8k | } else { |
421 | 11.8k | ret->type = type; |
422 | 11.8k | } |
423 | | |
424 | 12.3k | len = BN_num_bytes(bn); |
425 | 12.3k | if (!ASN1_STRING_set(ret, nullptr, len) || |
426 | 12.3k | !BN_bn2bin_padded(ret->data, len, bn)) { |
427 | 0 | goto err; |
428 | 0 | } |
429 | 12.3k | return ret; |
430 | | |
431 | 0 | err: |
432 | 0 | if (ret != ai) { |
433 | 0 | ASN1_STRING_free(ret); |
434 | 0 | } |
435 | 0 | return nullptr; |
436 | 12.3k | } |
437 | | |
438 | 12.3k | ASN1_INTEGER *BN_to_ASN1_INTEGER(const BIGNUM *bn, ASN1_INTEGER *ai) { |
439 | 12.3k | return bn_to_asn1_string(bn, ai, V_ASN1_INTEGER); |
440 | 12.3k | } |
441 | | |
442 | 0 | ASN1_ENUMERATED *BN_to_ASN1_ENUMERATED(const BIGNUM *bn, ASN1_ENUMERATED *ai) { |
443 | 0 | return bn_to_asn1_string(bn, ai, V_ASN1_ENUMERATED); |
444 | 0 | } |
445 | | |
446 | 2.03k | static BIGNUM *asn1_string_to_bn(const ASN1_STRING *ai, BIGNUM *bn, int type) { |
447 | 2.03k | if ((ai->type & ~V_ASN1_NEG) != type) { |
448 | 0 | OPENSSL_PUT_ERROR(ASN1, ASN1_R_WRONG_INTEGER_TYPE); |
449 | 0 | return nullptr; |
450 | 0 | } |
451 | | |
452 | 2.03k | BIGNUM *ret; |
453 | 2.03k | if ((ret = BN_bin2bn(ai->data, ai->length, bn)) == nullptr) { |
454 | 0 | OPENSSL_PUT_ERROR(ASN1, ASN1_R_BN_LIB); |
455 | 2.03k | } else if (ai->type & V_ASN1_NEG) { |
456 | 1.20k | BN_set_negative(ret, 1); |
457 | 1.20k | } |
458 | 2.03k | return ret; |
459 | 2.03k | } |
460 | | |
461 | 1.00k | BIGNUM *ASN1_INTEGER_to_BN(const ASN1_INTEGER *ai, BIGNUM *bn) { |
462 | 1.00k | return asn1_string_to_bn(ai, bn, V_ASN1_INTEGER); |
463 | 1.00k | } |
464 | | |
465 | 1.02k | BIGNUM *ASN1_ENUMERATED_to_BN(const ASN1_ENUMERATED *ai, BIGNUM *bn) { |
466 | 1.02k | return asn1_string_to_bn(ai, bn, V_ASN1_ENUMERATED); |
467 | 1.02k | } |