Mercurial > dropbear
view libtomcrypt/src/misc/error_to_string.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 error_to_string.c Convert error codes to ASCII strings, Tom St Denis */ static const char * const err_2_str[] = { "CRYPT_OK", "CRYPT_ERROR", "Non-fatal 'no-operation' requested.", "Invalid key size.", "Invalid number of rounds for block cipher.", "Algorithm failed test vectors.", "Buffer overflow.", "Invalid input packet.", "Invalid number of bits for a PRNG.", "Error reading the PRNG.", "Invalid cipher specified.", "Invalid hash specified.", "Invalid PRNG specified.", "Out of memory.", "Invalid PK key or key type specified for function.", "A private PK key is required.", "Invalid argument provided.", "File Not Found", "Invalid PK type.", "An overflow of a value was detected/prevented.", "UNUSED1.", "The input was longer than expected.", "Invalid sized parameter.", "Invalid size for prime.", "Invalid padding.", "Hash applied to too many bits.", }; /** Convert an LTC error code to ASCII @param err The error code @return A pointer to the ASCII NUL terminated string for the error or "Invalid error code." if the err code was not valid. */ const char *error_to_string(int err) { if (err < 0 || err >= (int)(sizeof(err_2_str)/sizeof(err_2_str[0]))) { return "Invalid error code."; } else { return err_2_str[err]; } } /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */