Mercurial > dropbear
view libtomcrypt/src/mac/pmac/pmac_done.c @ 1861:2b3a8026a6ce
Add re-exec for server
This allows ASLR to re-randomize the address
space for every connection, preventing some
vulnerabilities from being exploitable by
repeated probing.
Overhead (memory and time) is yet to be confirmed.
At present this is only enabled on Linux. Other BSD platforms
with fexecve() would probably also work though have not been tested.
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Sun, 30 Jan 2022 10:14:56 +0800 |
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 pmac_done.c PMAC implementation, terminate a session, by Tom St Denis */ #ifdef LTC_PMAC int pmac_done(pmac_state *state, unsigned char *out, unsigned long *outlen) { int err, x; LTC_ARGCHK(state != NULL); LTC_ARGCHK(out != NULL); if ((err = cipher_is_valid(state->cipher_idx)) != CRYPT_OK) { return err; } if ((state->buflen > (int)sizeof(state->block)) || (state->buflen < 0) || (state->block_len > (int)sizeof(state->block)) || (state->buflen > state->block_len)) { return CRYPT_INVALID_ARG; } /* handle padding. If multiple xor in L/x */ if (state->buflen == state->block_len) { /* xor Lr against the checksum */ for (x = 0; x < state->block_len; x++) { state->checksum[x] ^= state->block[x] ^ state->Lr[x]; } } else { /* otherwise xor message bytes then the 0x80 byte */ for (x = 0; x < state->buflen; x++) { state->checksum[x] ^= state->block[x]; } state->checksum[x] ^= 0x80; } /* encrypt it */ if ((err = cipher_descriptor[state->cipher_idx].ecb_encrypt(state->checksum, state->checksum, &state->key)) != CRYPT_OK) { return err; } cipher_descriptor[state->cipher_idx].done(&state->key); /* store it */ for (x = 0; x < state->block_len && x < (int)*outlen; x++) { out[x] = state->checksum[x]; } *outlen = x; #ifdef LTC_CLEAN_STACK zeromem(state, sizeof(*state)); #endif return CRYPT_OK; } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */