diff options
Diffstat (limited to 'test/ossfuzz')
| -rw-r--r-- | test/ossfuzz/json_load_dump_fuzzer.cc | 101 |
1 files changed, 93 insertions, 8 deletions
diff --git a/test/ossfuzz/json_load_dump_fuzzer.cc b/test/ossfuzz/json_load_dump_fuzzer.cc index 09f52d2..bc3844e 100644 --- a/test/ossfuzz/json_load_dump_fuzzer.cc +++ b/test/ossfuzz/json_load_dump_fuzzer.cc @@ -1,13 +1,44 @@ #include <stdint.h> +#include <stdlib.h> #include <sys/types.h> +#include <inttypes.h> #include "jansson.h" +static int enable_diags; + +#define FUZZ_DEBUG(FMT, ...) \ + if (enable_diags) \ + { \ + fprintf(stderr, FMT, ##__VA_ARGS__); \ + fprintf(stderr, "\n"); \ + } + + +static int json_dump_counter(const char *buffer, size_t size, void *data) +{ + uint64_t *counter = reinterpret_cast<uint64_t *>(data); + *counter += size; + return 0; +} + + +#define NUM_COMMAND_BYTES (sizeof(size_t) + sizeof(size_t) + 1) + +#define FUZZ_DUMP_CALLBACK 0x00 +#define FUZZ_DUMP_STRING 0x01 + extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { json_error_t error; + unsigned char dump_mode; + + // Enable or disable diagnostics based on the FUZZ_VERBOSE environment flag. + enable_diags = (getenv("FUZZ_VERBOSE") != NULL); - if (size < sizeof(size_t) + sizeof(size_t)) + FUZZ_DEBUG("Input data length: %zd", size); + + if (size < NUM_COMMAND_BYTES) { return 0; } @@ -15,12 +46,53 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) // Use the first sizeof(size_t) bytes as load flags. size_t load_flags = *(const size_t*)data; data += sizeof(size_t); - size -= sizeof(size_t); + + FUZZ_DEBUG("load_flags: 0x%zx\n" + "& JSON_REJECT_DUPLICATES = 0x%zx\n" + "& JSON_DECODE_ANY = 0x%zx\n" + "& JSON_DISABLE_EOF_CHECK = 0x%zx\n" + "& JSON_DECODE_INT_AS_REAL = 0x%zx\n" + "& JSON_ALLOW_NUL = 0x%zx\n", + load_flags, + load_flags & JSON_REJECT_DUPLICATES, + load_flags & JSON_DECODE_ANY, + load_flags & JSON_DISABLE_EOF_CHECK, + load_flags & JSON_DECODE_INT_AS_REAL, + load_flags & JSON_ALLOW_NUL); // Use the next sizeof(size_t) bytes as dump flags. size_t dump_flags = *(const size_t*)data; data += sizeof(size_t); - size -= sizeof(size_t); + + FUZZ_DEBUG("dump_flags: 0x%zx\n" + "& JSON_MAX_INDENT = 0x%zx\n" + "& JSON_COMPACT = 0x%zx\n" + "& JSON_ENSURE_ASCII = 0x%zx\n" + "& JSON_SORT_KEYS = 0x%zx\n" + "& JSON_PRESERVE_ORDER = 0x%zx\n" + "& JSON_ENCODE_ANY = 0x%zx\n" + "& JSON_ESCAPE_SLASH = 0x%zx\n" + "& JSON_REAL_PRECISION = 0x%zx\n" + "& JSON_EMBED = 0x%zx\n", + dump_flags, + dump_flags & JSON_MAX_INDENT, + dump_flags & JSON_COMPACT, + dump_flags & JSON_ENSURE_ASCII, + dump_flags & JSON_SORT_KEYS, + dump_flags & JSON_PRESERVE_ORDER, + dump_flags & JSON_ENCODE_ANY, + dump_flags & JSON_ESCAPE_SLASH, + ((dump_flags >> 11) & 0x1F) << 11, + dump_flags & JSON_EMBED); + + // Use the next byte as the dump mode. + dump_mode = data[0]; + data++; + + FUZZ_DEBUG("dump_mode: 0x%x", (unsigned int)dump_mode); + + // Remove the command bytes from the size total. + size -= NUM_COMMAND_BYTES; // Attempt to load the remainder of the data with the given load flags. const char* text = reinterpret_cast<const char *>(data); @@ -31,11 +103,24 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) return 0; } - // Attempt to dump the loaded json object with the given dump flags. - char* out = json_dumps(jobj, dump_flags); - if (out) + if (dump_mode & FUZZ_DUMP_STRING) + { + // Dump as a string. Remove indents so that we don't run out of memory. + char *out = json_dumps(jobj, dump_flags & ~JSON_MAX_INDENT); + if (out != NULL) + { + free(out); + } + } + else { - free(out); + // Default is callback mode. + // + // Attempt to dump the loaded json object with the given dump flags. + uint64_t counter = 0; + + json_dump_callback(jobj, json_dump_counter, &counter, dump_flags); + FUZZ_DEBUG("Counter function counted %" PRIu64 " bytes.", counter); } if (jobj) @@ -44,4 +129,4 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) } return 0; -}
\ No newline at end of file +} |