1 /* 2 * Copyright (c) 2014-2020 Pavel Kalvoda <me@pavelkalvoda.com> 3 * 4 * libcbor is free software; you can redistribute it and/or modify 5 * it under the terms of the MIT license. See LICENSE for details. 6 */ 7 8 #include <cjson/cJSON.h> 9 #include <stdio.h> 10 #include <string.h> 11 12 #include "cbor.h" 13 14 void usage(void) { 15 printf("Usage: cbor2cjson [input file]\n"); 16 exit(1); 17 } 18 19 cJSON* cbor_to_cjson(cbor_item_t* item) { 20 switch (cbor_typeof(item)) { 21 case CBOR_TYPE_UINT: 22 return cJSON_CreateNumber(cbor_get_int(item)); 23 case CBOR_TYPE_NEGINT: 24 return cJSON_CreateNumber(-1 - cbor_get_int(item)); 25 case CBOR_TYPE_BYTESTRING: 26 // cJSON only handles null-terminated string -- binary data would have to 27 // be escaped 28 return cJSON_CreateString("Unsupported CBOR item: Bytestring"); 29 case CBOR_TYPE_STRING: 30 if (cbor_string_is_definite(item)) { 31 // cJSON only handles null-terminated string 32 char* null_terminated_string = malloc(cbor_string_length(item) + 1); 33 memcpy(null_terminated_string, cbor_string_handle(item), 34 cbor_string_length(item)); 35 null_terminated_string[cbor_string_length(item)] = 0; 36 cJSON* result = cJSON_CreateString(null_terminated_string); 37 free(null_terminated_string); 38 return result; 39 } 40 return cJSON_CreateString("Unsupported CBOR item: Chunked string"); 41 case CBOR_TYPE_ARRAY: { 42 cJSON* result = cJSON_CreateArray(); 43 for (size_t i = 0; i < cbor_array_size(item); i++) { 44 cJSON_AddItemToArray(result, 45 cbor_to_cjson(cbor_move(cbor_array_get(item, i)))); 46 } 47 return result; 48 } 49 case CBOR_TYPE_MAP: { 50 cJSON* result = cJSON_CreateObject(); 51 for (size_t i = 0; i < cbor_map_size(item); i++) { 52 char* key = malloc(128); 53 snprintf(key, 128, "Surrogate key %zu", i); 54 // JSON only support string keys 55 if (cbor_isa_string(cbor_map_handle(item)[i].key) && 56 cbor_string_is_definite(cbor_map_handle(item)[i].key)) { 57 size_t key_length = cbor_string_length(cbor_map_handle(item)[i].key); 58 if (key_length > 127) key_length = 127; 59 // Null-terminated madness 60 memcpy(key, cbor_string_handle(cbor_map_handle(item)[i].key), 61 key_length); 62 key[key_length] = 0; 63 } 64 65 cJSON_AddItemToObject(result, key, 66 cbor_to_cjson(cbor_map_handle(item)[i].value)); 67 free(key); 68 } 69 return result; 70 } 71 case CBOR_TYPE_TAG: 72 return cJSON_CreateString("Unsupported CBOR item: Tag"); 73 case CBOR_TYPE_FLOAT_CTRL: 74 if (cbor_float_ctrl_is_ctrl(item)) { 75 if (cbor_is_bool(item)) return cJSON_CreateBool(cbor_get_bool(item)); 76 if (cbor_is_null(item)) return cJSON_CreateNull(); 77 return cJSON_CreateString("Unsupported CBOR item: Control value"); 78 } 79 return cJSON_CreateNumber(cbor_float_get_float(item)); 80 } 81 82 return cJSON_CreateNull(); 83 } 84 85 /* 86 * Reads CBOR data from a file and outputs JSON using cJSON 87 * $ ./examples/cbor2cjson examples/data/nested_array.cbor 88 */ 89 90 int main(int argc, char* argv[]) { 91 if (argc != 2) usage(); 92 FILE* f = fopen(argv[1], "rb"); 93 if (f == NULL) usage(); 94 fseek(f, 0, SEEK_END); 95 size_t length = (size_t)ftell(f); 96 fseek(f, 0, SEEK_SET); 97 unsigned char* buffer = malloc(length); 98 fread(buffer, length, 1, f); 99 100 /* Assuming `buffer` contains `length` bytes of input data */ 101 struct cbor_load_result result; 102 cbor_item_t* item = cbor_load(buffer, length, &result); 103 free(buffer); 104 105 if (result.error.code != CBOR_ERR_NONE) { 106 printf( 107 "There was an error while reading the input near byte %zu (read %zu " 108 "bytes in total): ", 109 result.error.position, result.read); 110 exit(1); 111 } 112 113 cJSON* cjson_item = cbor_to_cjson(item); 114 char* json_string = cJSON_Print(cjson_item); 115 printf("%s\n", json_string); 116 free(json_string); 117 fflush(stdout); 118 119 /* Deallocate the result */ 120 cbor_decref(&item); 121 cJSON_Delete(cjson_item); 122 123 fclose(f); 124 } 125