view fuzz/fuzzer-pubkey.c @ 1861:2b3a8026a6ce

Add re-exec for server This allows ASLR to re-randomize the address space for every connection, preventing some vulnerabilities from being exploitable by repeated probing. Overhead (memory and time) is yet to be confirmed. At present this is only enabled on Linux. Other BSD platforms with fexecve() would probably also work though have not been tested.
author Matt Johnston <matt@ucc.asn.au>
date Sun, 30 Jan 2022 10:14:56 +0800
parents 97ad26e397a5
children
line wrap: on
line source

#include "fuzz.h"
#include "session.h"
#include "fuzz-wrapfd.h"
#include "debug.h"

static void setup_fuzzer(void) {
	fuzz_common_setup();
}

int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
	static int once = 0;
	if (!once) {
		setup_fuzzer();
		once = 1;
	}

	if (fuzz_set_input(Data, Size) == DROPBEAR_FAILURE) {
		return 0;
	}

	m_malloc_set_epoch(1);

	if (setjmp(fuzz.jmp) == 0) {
		buffer *line = buf_getstringbuf(fuzz.input);
		buffer *keyblob = buf_getstringbuf(fuzz.input);

		unsigned int algolen;
		char* algoname = buf_getstring(keyblob, &algolen);

		if (signature_type_from_name(algoname, algolen) == DROPBEAR_SIGNATURE_NONE) {
			dropbear_exit("fuzzer imagined a bogus algorithm");
		}

		int ret = fuzz_checkpubkey_line(line, 5, "/home/me/authorized_keys",
			algoname, algolen,
			keyblob->data, keyblob->len);

		if (ret == DROPBEAR_SUCCESS) {
			/* fuzz_checkpubkey_line() should have cleaned up for failure */
			svr_pubkey_options_cleanup();
		}

		buf_free(line);
		buf_free(keyblob);
		m_free(algoname);
		m_malloc_free_epoch(1, 0);
	} else {
		m_malloc_free_epoch(1, 1);
		TRACE(("dropbear_exit longjmped"))
		/* dropbear_exit jumped here */
	}

	return 0;
}