| 2 | #include <stdio.h> |
| 3 | |
| 4 | int cert_field_get(const uint8_t *data, uint32_t length, uint16_t *field_type, const uint8_t **contents, uint32_t *field_size) { |
| 5 | uint16_t field_id; |
| 6 | uint32_t field_len; |
| 7 | uint32_t additional_len; |
| 8 | |
| 9 | /* sanity checks. */ |
| 10 | if (data == NULL) { |
| 11 | return 1; |
| 12 | } |
| 13 | if (field_type == NULL && contents == NULL && field_size == NULL) { |
| 14 | return 1; |
| 15 | } |
| 16 | if (length < 2) { |
| 17 | return 1; |
| 18 | } |
| 19 | |
| 20 | /* retrieve field id and number of additional bytes we need to read for the field's size */ |
| 21 | field_id = (((uint16_t)data[0]) << 8) | data[1]; |
| 22 | if (field_id == 0xFFFF) { |
| 23 | return 1; |
| 24 | } |
| 25 | |
| 26 | switch (field_id & 0xF) { |
| 27 | case 0xD: additional_len = 1; break; |
| 28 | case 0xE: additional_len = 2; break; |
| 29 | case 0xF: additional_len = 4; break; |
| 30 | default: additional_len = 0; break; |
| 31 | } |
| 32 | |
| 33 | if (length < 2 + additional_len) { |
| 34 | return 1; |
| 35 | } |
| 36 | |
| 37 | /* retrieve data size of field. */ |
| 38 | switch (field_id & 0xF) { |
| 39 | case 0xD: |
| 40 | field_len = (uint32_t)data[2]; |
| 41 | break; |
| 42 | |
| 43 | case 0xE: |
| 44 | field_len = (((uint32_t)data[2]) << 8) | data[3]; |
| 45 | break; |
| 46 | |
| 47 | case 0xF: |
| 48 | field_len = (((uint32_t)data[2]) << 24) | (((uint32_t)data[3]) << 16) | (((uint32_t)data[4]) << 8) | data[5]; |
| 49 | break; |
| 50 | |
| 51 | default: |
| 52 | field_len = field_id & 0xF; |
| 53 | break; |
| 54 | } |
| 55 | |
| 56 | if (length < 2 + additional_len + field_len) { |
| 57 | return 1; |
| 58 | } |
| 59 | |
| 60 | if (field_type != NULL) { |
| 61 | /* don't mask out the size indication, it may be useful to the user. */ |
no outgoing calls
no test coverage detected