1 /* 2 Copyright (c) 2021 Fraunhofer AISEC. See the COPYRIGHT 3 file at the top-level directory of this distribution. 4 5 Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or 6 http://www.apache.org/licenses/LICENSE-2.0> or the MIT license 7 <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your 8 option. This file may not be copied, modified, or distributed 9 except according to those terms. 10 */ 11 12 #ifndef COAP_H 13 #define COAP_H 14 15 #include <stdint.h> 16 17 #include "common/byte_array.h" 18 #include "common/oscore_edhoc_error.h" 19 20 #define MAX_PIV_LEN 5 21 #define MAX_KID_CONTEXT_LEN \ 22 8 /*This implementation supports Context IDs up to 8 byte*/ 23 #define MAX_KID_LEN 7 24 #define MAX_AAD_LEN 30 25 #define MAX_INFO_LEN 50 26 27 /* Mask and offset for first byte in CoAP/OSCORE header*/ 28 #define HEADER_LEN 4 29 #define HEADER_VERSION_MASK 0xC0 30 #define HEADER_VERSION_OFFSET 6 31 #define HEADER_TYPE_MASK 0x30 32 #define HEADER_TYPE_OFFSET 4 33 #define HEADER_CODE_MASK 0x0F 34 #define HEADER_CODE_OFFSET 0 35 36 /* Mask and offset for first byte in compressed OSCORE option*/ 37 #define COMP_OSCORE_OPT_KIDC_H_MASK 0x10 38 #define COMP_OSCORE_OPT_KIDC_H_OFFSET 4 39 #define COMP_OSCORE_OPT_KID_K_MASK 0x08 40 #define COMP_OSCORE_OPT_KID_K_OFFSET 3 41 #define COMP_OSCORE_OPT_PIV_N_MASK 0x07 42 #define COMP_OSCORE_OPT_PIV_N_OFFSET 0 43 44 #define OSCORE_OPT_VALUE_LEN \ 45 (2 + MAX_PIV_LEN + MAX_KID_CONTEXT_LEN + MAX_KID_LEN) 46 47 #define MAX_OPTION_COUNT 20 48 49 50 #define TYPE_CON 0x00 51 #define TYPE_NON 0x01 52 #define TYPE_ACK 0x02 53 #define TYPE_RST 0x03 54 55 #define CODE_CLASS_MASK 0xe0 56 #define CODE_DETAIL_MASK 0x1f 57 #define CODE_EMPTY 0x00 58 #define CODE_REQ_POST 0x02 59 #define CODE_RESP_CHANGED 0x44 60 61 #define REQUEST_CLASS 0 62 63 /* all CoAP instances are preceeded with 'o_' to show correspondence to 64 * OSCORE and prevent conflicts with networking CoAP libraries 65 */ 66 struct o_coap_header { 67 uint8_t ver; 68 uint8_t type; 69 uint8_t TKL; 70 uint8_t code; 71 uint16_t MID; 72 }; 73 74 struct o_coap_option { 75 uint16_t delta; 76 uint8_t len; 77 uint8_t *value; 78 uint8_t option_number; 79 }; 80 81 struct oscore_option { 82 uint16_t delta; 83 uint8_t len; 84 uint8_t *value; 85 uint8_t buf[OSCORE_OPT_VALUE_LEN]; 86 uint8_t option_number; 87 }; 88 89 struct o_coap_packet { 90 struct o_coap_header header; 91 uint8_t *token; 92 uint8_t options_cnt; 93 struct o_coap_option options[MAX_OPTION_COUNT]; 94 uint32_t payload_len; 95 uint8_t *payload; 96 }; 97 98 struct compressed_oscore_option { 99 uint8_t h; /*flag bit for KID_context*/ 100 uint8_t k; /*flag bit for KID*/ 101 uint8_t n; /*bytes number of PIV*/ 102 struct byte_array piv; /*same as sender sequence number*/ 103 struct byte_array kid_context; 104 struct byte_array kid; 105 }; 106 107 struct piv_kid_context { 108 struct byte_array partial_iv; 109 struct byte_array kid; 110 struct byte_array kid_context; 111 }; 112 113 /** 114 * @brief Covert a byte array to a OSCORE/CoAP struct 115 * @param in: pointer input message packet, in byte string format 116 * @param out: pointer to output OSCORE packet 117 * @return err 118 */ 119 enum err buf2coap(struct byte_array *in, struct o_coap_packet *out); 120 121 /** 122 * @brief Converts a CoAP/OSCORE packet to a byte string 123 * @param in: input CoAP/OSCORE packet 124 * @param out_byte_string: byte string containing the OSCORE packet 125 * @param out_byte_string_len: length of the byte string 126 * @return err 127 */ 128 enum err coap2buf(struct o_coap_packet *in, uint8_t *out_byte_string, 129 uint32_t *out_byte_string_len); 130 131 /** 132 * @brief Convert input options into byte string 133 * @param options: input pointer to an array of options 134 * @param options_cnt: count number of input options 135 * @param out_byte_string: output pointer to options byte string 136 * @return err 137 * 138 */ 139 enum err options_into_byte_string(struct o_coap_option *options, 140 uint8_t options_cnt, 141 struct byte_array *out_byte_string); 142 #endif 143
