Mercurial > dropbear
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 |
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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