view fuzz-wrapfd.h @ 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 a6da10ac64b5
children 685b47d8faf7
line wrap: on
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#ifndef FUZZ_WRAPFD_H
#define FUZZ_WRAPFD_H

#include "buffer.h"

enum wrapfd_mode {
    UNUSED = 0,
    COMMONBUF, // using the common buffer
    DUMMY, // reads return fixed output, of random length
};

// buf is a common buffer read by all wrapped FDs. doesn't take ownership of buf
void wrapfd_setup(buffer *buf);
void wrapfd_setseed(uint32_t seed);
int wrapfd_new_fuzzinput(void);
int wrapfd_new_dummy(void);

// called via #defines for read/write/select
int wrapfd_read(int fd, void *out, size_t count);
int wrapfd_write(int fd, const void* in, size_t count);
int wrapfd_select(int nfds, fd_set *readfds, fd_set *writefds, 
    fd_set *exceptfds, struct timeval *timeout);
int wrapfd_close(int fd);

#endif // FUZZ_WRAPFD_H