1 // Copyright 2015 The Weave Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef UW_LIBUWEAVE_SRC_MACAROON_ENCODING_ 6 #define UW_LIBUWEAVE_SRC_MACAROON_ENCODING_ 7 8 /* 9 * Utility functions to encode and decode canonical CBOR representations for 10 * cryptographic use, such as signatures. We only need to support a very small 11 * subset of the CBOR standard, since only these are used in our cryptographic 12 * designs. The supported data types are: unsigned integers (maximum 32 bits), 13 * byte strings, text strings, and arrays. 14 */ 15 16 #include <stdbool.h> 17 #include <stddef.h> 18 #include <stdint.h> 19 20 #define UW_MACAROON_ENCODING_MAX_UINT_CBOR_LEN 5 21 22 /** 23 * Gets the number of bytes that is occupied by the first data item in the give 24 * CBOR string. 25 */ 26 bool uw_macaroon_encoding_get_item_len_(const uint8_t* cbor, 27 size_t cbor_len, 28 size_t* first_item_len); 29 30 bool uw_macaroon_encoding_encode_uint_(const uint32_t unsigned_int, 31 uint8_t* buffer, 32 size_t buffer_size, 33 size_t* resulting_cbor_len); 34 bool uw_macaroon_encoding_encode_array_len_(const uint32_t array_len, 35 uint8_t* buffer, 36 size_t buffer_size, 37 size_t* resulting_cbor_len); 38 bool uw_macaroon_encoding_encode_byte_str_(const uint8_t* str, 39 size_t str_len, 40 uint8_t* buffer, 41 size_t buffer_size, 42 size_t* resulting_cbor_len); 43 bool uw_macaroon_encoding_encode_text_str_(const uint8_t* str, 44 size_t str_len, 45 uint8_t* buffer, 46 size_t buffer_size, 47 size_t* resulting_cbor_len); 48 49 /** Only encode the header (major type and length) of the byte string */ 50 bool uw_macaroon_encoding_encode_byte_str_len_(size_t str_len, 51 uint8_t* buffer, 52 size_t buffer_size, 53 size_t* resulting_cbor_len); 54 55 bool uw_macaroon_encoding_decode_uint_(const uint8_t* cbor, 56 size_t cbor_len, 57 uint32_t* unsigned_int); 58 bool uw_macaroon_encoding_decode_array_len_(const uint8_t* cbor, 59 size_t cbor_len, 60 uint32_t* array_len); 61 bool uw_macaroon_encoding_decode_byte_str_(const uint8_t* cbor, 62 size_t cbor_len, 63 const uint8_t** str, 64 size_t* str_len); 65 bool uw_macaroon_encoding_decode_text_str_(const uint8_t* cbor, 66 size_t cbor_len, 67 const uint8_t** str, 68 size_t* str_len); 69 70 #endif // UW_LIBUWEAVE_SRC_MACAROON_ENCODING_ 71