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Diffstat (limited to 'utils/custom_mutators/example.c')
| -rw-r--r-- | utils/custom_mutators/example.c | 376 |
1 files changed, 0 insertions, 376 deletions
diff --git a/utils/custom_mutators/example.c b/utils/custom_mutators/example.c deleted file mode 100644 index 23add128..00000000 --- a/utils/custom_mutators/example.c +++ /dev/null @@ -1,376 +0,0 @@ -/* - New Custom Mutator for AFL++ - Written by Khaled Yakdan <yakdan@code-intelligence.de> - Andrea Fioraldi <andreafioraldi@gmail.com> - Shengtuo Hu <h1994st@gmail.com> - Dominik Maier <mail@dmnk.co> -*/ - -// You need to use -I /path/to/AFLplusplus/include -#include "custom_mutator_helpers.h" - -#include <stdint.h> -#include <stdlib.h> -#include <string.h> -#include <stdio.h> - -#define DATA_SIZE (100) - -static const char *commands[] = { - - "GET", - "PUT", - "DEL", - -}; - -typedef struct my_mutator { - - afl_t *afl; - - // any additional data here! - size_t trim_size_current; - int trimmming_steps; - int cur_step; - - // Reused buffers: - BUF_VAR(u8, fuzz); - BUF_VAR(u8, data); - BUF_VAR(u8, havoc); - BUF_VAR(u8, trim); - BUF_VAR(u8, post_process); - -} my_mutator_t; - -/** - * Initialize this custom mutator - * - * @param[in] afl a pointer to the internal state object. Can be ignored for - * now. - * @param[in] seed A seed for this mutator - the same seed should always mutate - * in the same way. - * @return Pointer to the data object this custom mutator instance should use. - * There may be multiple instances of this mutator in one afl-fuzz run! - * Return NULL on error. - */ -my_mutator_t *afl_custom_init(afl_t *afl, unsigned int seed) { - - srand(seed); // needed also by surgical_havoc_mutate() - - my_mutator_t *data = calloc(1, sizeof(my_mutator_t)); - if (!data) { - - perror("afl_custom_init alloc"); - return NULL; - - } - - data->afl = afl; - - return data; - -} - -/** - * Perform custom mutations on a given input - * - * (Optional for now. Required in the future) - * - * @param[in] data pointer returned in afl_custom_init for this fuzz case - * @param[in] buf Pointer to input data to be mutated - * @param[in] buf_size Size of input data - * @param[out] out_buf the buffer we will work on. we can reuse *buf. NULL on - * error. - * @param[in] add_buf Buffer containing the additional test case - * @param[in] add_buf_size Size of the additional test case - * @param[in] max_size Maximum size of the mutated output. The mutation must not - * produce data larger than max_size. - * @return Size of the mutated output. - */ -size_t afl_custom_fuzz(my_mutator_t *data, uint8_t *buf, size_t buf_size, - u8 **out_buf, uint8_t *add_buf, - size_t add_buf_size, // add_buf can be NULL - size_t max_size) { - - // Make sure that the packet size does not exceed the maximum size expected by - // the fuzzer - size_t mutated_size = DATA_SIZE <= max_size ? DATA_SIZE : max_size; - - // maybe_grow is optimized to be quick for reused buffers. - u8 *mutated_out = maybe_grow(BUF_PARAMS(data, fuzz), mutated_size); - if (!mutated_out) { - - *out_buf = NULL; - perror("custom mutator allocation (maybe_grow)"); - return 0; /* afl-fuzz will very likely error out after this. */ - - } - - // Randomly select a command string to add as a header to the packet - memcpy(mutated_out, commands[rand() % 3], 3); - - // Mutate the payload of the packet - int i; - for (i = 0; i < 8; ++i) { - - // Randomly perform one of the (no len modification) havoc mutations - surgical_havoc_mutate(mutated_out, 3, mutated_size); - - } - - *out_buf = mutated_out; - return mutated_size; - -} - -/** - * A post-processing function to use right before AFL writes the test case to - * disk in order to execute the target. - * - * (Optional) If this functionality is not needed, simply don't define this - * function. - * - * @param[in] data pointer returned in afl_custom_init for this fuzz case - * @param[in] buf Buffer containing the test case to be executed - * @param[in] buf_size Size of the test case - * @param[out] out_buf Pointer to the buffer containing the test case after - * processing. External library should allocate memory for out_buf. - * The buf pointer may be reused (up to the given buf_size); - * @return Size of the output buffer after processing or the needed amount. - * A return of 0 indicates an error. - */ -size_t afl_custom_post_process(my_mutator_t *data, uint8_t *buf, - size_t buf_size, uint8_t **out_buf) { - - uint8_t *post_process_buf = - maybe_grow(BUF_PARAMS(data, post_process), buf_size + 5); - if (!post_process_buf) { - - perror("custom mutator realloc failed."); - *out_buf = NULL; - return 0; - - } - - memcpy(post_process_buf + 5, buf, buf_size); - post_process_buf[0] = 'A'; - post_process_buf[1] = 'F'; - post_process_buf[2] = 'L'; - post_process_buf[3] = '+'; - post_process_buf[4] = '+'; - - *out_buf = post_process_buf; - - return buf_size + 5; - -} - -/** - * This method is called at the start of each trimming operation and receives - * the initial buffer. It should return the amount of iteration steps possible - * on this input (e.g. if your input has n elements and you want to remove - * them one by one, return n, if you do a binary search, return log(n), - * and so on...). - * - * If your trimming algorithm doesn't allow you to determine the amount of - * (remaining) steps easily (esp. while running), then you can alternatively - * return 1 here and always return 0 in post_trim until you are finished and - * no steps remain. In that case, returning 1 in post_trim will end the - * trimming routine. The whole current index/max iterations stuff is only used - * to show progress. - * - * (Optional) - * - * @param data pointer returned in afl_custom_init for this fuzz case - * @param buf Buffer containing the test case - * @param buf_size Size of the test case - * @return The amount of possible iteration steps to trim the input. - * negative on error. - */ -int32_t afl_custom_init_trim(my_mutator_t *data, uint8_t *buf, - size_t buf_size) { - - // We simply trim once - data->trimmming_steps = 1; - - data->cur_step = 0; - - if (!maybe_grow(BUF_PARAMS(data, trim), buf_size)) { - - perror("init_trim grow"); - return -1; - - } - - memcpy(data->trim_buf, buf, buf_size); - - data->trim_size_current = buf_size; - - return data->trimmming_steps; - -} - -/** - * This method is called for each trimming operation. It doesn't have any - * arguments because we already have the initial buffer from init_trim and we - * can memorize the current state in *data. This can also save - * reparsing steps for each iteration. It should return the trimmed input - * buffer, where the returned data must not exceed the initial input data in - * length. Returning anything that is larger than the original data (passed - * to init_trim) will result in a fatal abort of AFLFuzz. - * - * (Optional) - * - * @param[in] data pointer returned in afl_custom_init for this fuzz case - * @param[out] out_buf Pointer to the buffer containing the trimmed test case. - * External library should allocate memory for out_buf. - * AFL++ will not release the memory after saving the test case. - * Keep a ref in *data. - * *out_buf = NULL is treated as error. - * @return Pointer to the size of the trimmed test case - */ -size_t afl_custom_trim(my_mutator_t *data, uint8_t **out_buf) { - - *out_buf = data->trim_buf; - - // Remove the last byte of the trimming input - return data->trim_size_current - 1; - -} - -/** - * This method is called after each trim operation to inform you if your - * trimming step was successful or not (in terms of coverage). If you receive - * a failure here, you should reset your input to the last known good state. - * - * (Optional) - * - * @param[in] data pointer returned in afl_custom_init for this fuzz case - * @param success Indicates if the last trim operation was successful. - * @return The next trim iteration index (from 0 to the maximum amount of - * steps returned in init_trim). negative ret on failure. - */ -int32_t afl_custom_post_trim(my_mutator_t *data, int success) { - - if (success) { - - ++data->cur_step; - return data->cur_step; - - } - - return data->trimmming_steps; - -} - -/** - * Perform a single custom mutation on a given input. - * This mutation is stacked with the other muatations in havoc. - * - * (Optional) - * - * @param[in] data pointer returned in afl_custom_init for this fuzz case - * @param[in] buf Pointer to the input data to be mutated and the mutated - * output - * @param[in] buf_size Size of input data - * @param[out] out_buf The output buffer. buf can be reused, if the content - * fits. *out_buf = NULL is treated as error. - * @param[in] max_size Maximum size of the mutated output. The mutation must - * not produce data larger than max_size. - * @return Size of the mutated output. - */ -size_t afl_custom_havoc_mutation(my_mutator_t *data, u8 *buf, size_t buf_size, - u8 **out_buf, size_t max_size) { - - if (buf_size == 0) { - - *out_buf = maybe_grow(BUF_PARAMS(data, havoc), 1); - if (!*out_buf) { - - perror("custom havoc: maybe_grow"); - return 0; - - } - - **out_buf = rand() % 256; - buf_size = 1; - - } else { - - // We reuse buf here. It's legal and faster. - *out_buf = buf; - - } - - size_t victim = rand() % buf_size; - (*out_buf)[victim] += rand() % 10; - - return buf_size; - -} - -/** - * Return the probability (in percentage) that afl_custom_havoc_mutation - * is called in havoc. By default it is 6 %. - * - * (Optional) - * - * @param[in] data pointer returned in afl_custom_init for this fuzz case - * @return The probability (0-100). - */ -uint8_t afl_custom_havoc_mutation_probability(my_mutator_t *data) { - - return 5; // 5 % - -} - -/** - * Determine whether the fuzzer should fuzz the queue entry or not. - * - * (Optional) - * - * @param[in] data pointer returned in afl_custom_init for this fuzz case - * @param filename File name of the test case in the queue entry - * @return Return True(1) if the fuzzer will fuzz the queue entry, and - * False(0) otherwise. - */ -uint8_t afl_custom_queue_get(my_mutator_t *data, const uint8_t *filename) { - - return 1; - -} - -/** - * Allow for additional analysis (e.g. calling a different tool that does a - * different kind of coverage and saves this for the custom mutator). - * - * (Optional) - * - * @param data pointer returned in afl_custom_init for this fuzz case - * @param filename_new_queue File name of the new queue entry - * @param filename_orig_queue File name of the original queue entry - */ -void afl_custom_queue_new_entry(my_mutator_t * data, - const uint8_t *filename_new_queue, - const uint8_t *filename_orig_queue) { - - /* Additional analysis on the original or new test case */ - -} - -/** - * Deinitialize everything - * - * @param data The data ptr from afl_custom_init - */ -void afl_custom_deinit(my_mutator_t *data) { - - free(data->post_process_buf); - free(data->havoc_buf); - free(data->data_buf); - free(data->fuzz_buf); - free(data->trim_buf); - free(data); - -} - |