Mercurial > dropbear
view libtomcrypt/src/modes/f8/f8_test_mode.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 | 6dba84798cd5 |
children |
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/* LibTomCrypt, modular cryptographic library -- Tom St Denis * * LibTomCrypt is a library that provides various cryptographic * algorithms in a highly modular and flexible manner. * * The library is free for all purposes without any express * guarantee it works. */ #include "tomcrypt.h" /** @file f8_test_mode.c F8 implementation, test, Tom St Denis */ #ifdef LTC_F8_MODE int f8_test_mode(void) { #ifndef LTC_TEST return CRYPT_NOP; #else static const unsigned char key[16] = { 0x23, 0x48, 0x29, 0x00, 0x84, 0x67, 0xbe, 0x18, 0x6c, 0x3d, 0xe1, 0x4a, 0xae, 0x72, 0xd6, 0x2c }; static const unsigned char salt[4] = { 0x32, 0xf2, 0x87, 0x0d }; static const unsigned char IV[16] = { 0x00, 0x6e, 0x5c, 0xba, 0x50, 0x68, 0x1d, 0xe5, 0x5c, 0x62, 0x15, 0x99, 0xd4, 0x62, 0x56, 0x4a }; static const unsigned char pt[39] = { 0x70, 0x73, 0x65, 0x75, 0x64, 0x6f, 0x72, 0x61, 0x6e, 0x64, 0x6f, 0x6d, 0x6e, 0x65, 0x73, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68, 0x65, 0x20, 0x6e, 0x65, 0x78, 0x74, 0x20, 0x62, 0x65, 0x73, 0x74, 0x20, 0x74, 0x68, 0x69, 0x6e, 0x67 }; static const unsigned char ct[39] = { 0x01, 0x9c, 0xe7, 0xa2, 0x6e, 0x78, 0x54, 0x01, 0x4a, 0x63, 0x66, 0xaa, 0x95, 0xd4, 0xee, 0xfd, 0x1a, 0xd4, 0x17, 0x2a, 0x14, 0xf9, 0xfa, 0xf4, 0x55, 0xb7, 0xf1, 0xd4, 0xb6, 0x2b, 0xd0, 0x8f, 0x56, 0x2c, 0x0e, 0xef, 0x7c, 0x48, 0x02 }; unsigned char buf[39]; symmetric_F8 f8; int err, idx; idx = find_cipher("aes"); if (idx == -1) { idx = find_cipher("rijndael"); if (idx == -1) return CRYPT_NOP; } /* initialize the context */ if ((err = f8_start(idx, IV, key, sizeof(key), salt, sizeof(salt), 0, &f8)) != CRYPT_OK) { return err; } /* encrypt block */ if ((err = f8_encrypt(pt, buf, sizeof(pt), &f8)) != CRYPT_OK) { f8_done(&f8); return err; } f8_done(&f8); /* compare */ if (compare_testvector(buf, sizeof(ct), ct, sizeof(ct), "f8", 0)) { return CRYPT_FAIL_TESTVECTOR; } return CRYPT_OK; #endif } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */