Mercurial > dropbear
view ecc.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 | d68d61e7056a |
children |
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#ifndef DROPBEAR_DROPBEAR_ECC_H #define DROPBEAR_DROPBEAR_ECC_H #include "includes.h" #include "buffer.h" #if DROPBEAR_ECC struct dropbear_ecc_curve { int ltc_size; /* to match the byte sizes in ltc_ecc_sets[] */ const ltc_ecc_set_type *dp; /* curve domain parameters */ const struct ltc_hash_descriptor *hash_desc; const char *name; }; extern struct dropbear_ecc_curve ecc_curve_nistp256; extern struct dropbear_ecc_curve ecc_curve_nistp384; extern struct dropbear_ecc_curve ecc_curve_nistp521; extern struct dropbear_ecc_curve *dropbear_ecc_curves[]; void dropbear_ecc_fill_dp(void); struct dropbear_ecc_curve* curve_for_dp(const ltc_ecc_set_type *dp); /* "pubkey" refers to a point, but LTC uses ecc_key structure for both public and private keys */ void buf_put_ecc_raw_pubkey_string(buffer *buf, ecc_key *key); ecc_key * buf_get_ecc_raw_pubkey(buffer *buf, const struct dropbear_ecc_curve *curve); int buf_get_ecc_privkey_string(buffer *buf, ecc_key *key); mp_int * dropbear_ecc_shared_secret(ecc_key *pub_key, const ecc_key *priv_key); #endif #endif /* DROPBEAR_DROPBEAR_ECC_H */