view fuzz/fuzz-harness.c @ 1790:42745af83b7d

Introduce extra delay before closing unauthenticated sessions To make it harder for attackers, introduce a delay to keep an unauthenticated session open a bit longer, thus blocking a connection slot until after the delay. Without this, while there is a limit on the amount of attempts an attacker can make at the same time (MAX_UNAUTH_PER_IP), the time taken by dropbear to handle one attempt is still short and thus for each of the allowed parallel attempts many attempts can be chained one after the other. The attempt rate is then: "MAX_UNAUTH_PER_IP / <process time of one attempt>". With the delay, this rate becomes: "MAX_UNAUTH_PER_IP / UNAUTH_CLOSE_DELAY".
author Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
date Wed, 15 Feb 2017 13:53:04 +0100
parents 8179eabe16c9
children fd00aeff38fd
line wrap: on
line source

#include "includes.h"
#include "buffer.h"
#include "dbutil.h"

extern int LLVMFuzzerTestOneInput(const unsigned char *data, size_t size);

int main(int argc, char ** argv) {
    int i;
    buffer *input = buf_new(100000);

    for (i = 1; i < argc; i++) {
#if DEBUG_TRACE
        if (strcmp(argv[i], "-v") == 0) {
            debug_trace = 1;
            TRACE(("debug printing on"))
        }
#endif
    }

    int old_fuzz_wrapfds = 0;
    for (i = 1; i < argc; i++) {
        if (argv[i][0] == '-') {
            /* ignore arguments */
            continue;
        }

        char* fn = argv[i];
        buf_setlen(input, 0);
        buf_readfile(input, fn);
        buf_setpos(input, 0);

		/* Run twice to catch problems with statefulness */
        fuzz.wrapfds = old_fuzz_wrapfds;
        printf("Running %s once \n", fn);
        LLVMFuzzerTestOneInput(input->data, input->len);
        printf("Running %s twice \n", fn);
        LLVMFuzzerTestOneInput(input->data, input->len);
        printf("Done %s\n", fn);

        /* Disable wrapfd so it won't interfere with buf_readfile() above */
        old_fuzz_wrapfds = fuzz.wrapfds;
        fuzz.wrapfds = 0;
    }

    printf("Finished\n");

    return 0;
}

// Just to let it link
size_t LLVMFuzzerMutate(uint8_t *UNUSED(Data), size_t UNUSED(Size), size_t UNUSED(MaxSize)) {
    printf("standalone fuzzer harness shouldn't call LLVMFuzzerMutate");
    abort();
    return 0;
}