Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 1 | /* Copyright (c) 2015, Google Inc. |
| 2 | * |
| 3 | * Permission to use, copy, modify, and/or distribute this software for any |
| 4 | * purpose with or without fee is hereby granted, provided that the above |
| 5 | * copyright notice and this permission notice appear in all copies. |
| 6 | * |
| 7 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| 8 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| 9 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
| 10 | * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 11 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION |
| 12 | * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN |
| 13 | * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ |
| 14 | |
| 15 | #include <openssl/bn.h> |
| 16 | |
| 17 | #include <openssl/bytestring.h> |
| 18 | #include <openssl/err.h> |
| 19 | |
| 20 | |
David Benjamin | 4969cc9 | 2016-04-22 15:02:23 -0400 | [diff] [blame] | 21 | int BN_parse_asn1_unsigned(CBS *cbs, BIGNUM *ret) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 22 | CBS child; |
| 23 | if (!CBS_get_asn1(cbs, &child, CBS_ASN1_INTEGER) || |
| 24 | CBS_len(&child) == 0) { |
| 25 | OPENSSL_PUT_ERROR(BN, BN_R_BAD_ENCODING); |
| 26 | return 0; |
| 27 | } |
| 28 | |
| 29 | if (CBS_data(&child)[0] & 0x80) { |
| 30 | OPENSSL_PUT_ERROR(BN, BN_R_NEGATIVE_NUMBER); |
| 31 | return 0; |
| 32 | } |
| 33 | |
| 34 | /* INTEGERs must be minimal. */ |
| 35 | if (CBS_data(&child)[0] == 0x00 && |
| 36 | CBS_len(&child) > 1 && |
| 37 | !(CBS_data(&child)[1] & 0x80)) { |
| 38 | OPENSSL_PUT_ERROR(BN, BN_R_BAD_ENCODING); |
| 39 | return 0; |
| 40 | } |
| 41 | |
| 42 | return BN_bin2bn(CBS_data(&child), CBS_len(&child), ret) != NULL; |
| 43 | } |
| 44 | |
David Benjamin | 4969cc9 | 2016-04-22 15:02:23 -0400 | [diff] [blame] | 45 | int BN_parse_asn1_unsigned_buggy(CBS *cbs, BIGNUM *ret) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 46 | CBS child; |
| 47 | if (!CBS_get_asn1(cbs, &child, CBS_ASN1_INTEGER) || |
| 48 | CBS_len(&child) == 0) { |
| 49 | OPENSSL_PUT_ERROR(BN, BN_R_BAD_ENCODING); |
| 50 | return 0; |
| 51 | } |
| 52 | |
| 53 | /* This function intentionally does not reject negative numbers or non-minimal |
| 54 | * encodings. Estonian IDs issued between September 2014 to September 2015 are |
| 55 | * broken. See https://crbug.com/532048 and https://crbug.com/534766. |
| 56 | * |
| 57 | * TODO(davidben): Remove this code and callers in March 2016. */ |
| 58 | return BN_bin2bn(CBS_data(&child), CBS_len(&child), ret) != NULL; |
| 59 | } |
| 60 | |
David Benjamin | 4969cc9 | 2016-04-22 15:02:23 -0400 | [diff] [blame] | 61 | int BN_marshal_asn1(CBB *cbb, const BIGNUM *bn) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 62 | /* Negative numbers are unsupported. */ |
| 63 | if (BN_is_negative(bn)) { |
| 64 | OPENSSL_PUT_ERROR(BN, BN_R_NEGATIVE_NUMBER); |
| 65 | return 0; |
| 66 | } |
| 67 | |
| 68 | CBB child; |
David Benjamin | 4969cc9 | 2016-04-22 15:02:23 -0400 | [diff] [blame] | 69 | if (!CBB_add_asn1(cbb, &child, CBS_ASN1_INTEGER) || |
| 70 | /* The number must be padded with a leading zero if the high bit would |
| 71 | * otherwise be set or if |bn| is zero. */ |
| 72 | (BN_num_bits(bn) % 8 == 0 && !CBB_add_u8(&child, 0x00)) || |
| 73 | !BN_bn2cbb_padded(&child, BN_num_bytes(bn), bn) || |
| 74 | !CBB_flush(cbb)) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 75 | OPENSSL_PUT_ERROR(BN, BN_R_ENCODE_ERROR); |
| 76 | return 0; |
| 77 | } |
| 78 | |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 79 | return 1; |
| 80 | } |