Mercurial > dropbear
view libtomcrypt/tests/prng_test.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_test.h> #ifdef LTC_PRNG_ENABLE_LTC_RNG static unsigned long my_test_rng_read; static unsigned long my_test_rng(unsigned char *buf, unsigned long len, void (*callback)(void)) { unsigned long n; LTC_UNUSED_PARAM(callback); for (n = 0; n < len; ++n) { buf[n] = 4; } my_test_rng_read += n; return n; } #endif int prng_test(void) { int err = CRYPT_NOP; int x; unsigned char buf[4096] = { 0 }; unsigned long n, one; prng_state nprng; #ifdef LTC_PRNG_ENABLE_LTC_RNG unsigned long before; unsigned long (*previous)(unsigned char *, unsigned long , void (*)(void)) = ltc_rng; ltc_rng = my_test_rng; before = my_test_rng_read; if ((err = rng_make_prng(128, find_prng("yarrow"), &yarrow_prng, NULL)) != CRYPT_OK) { fprintf(stderr, "rng_make_prng with 'my_test_rng' failed: %s\n", error_to_string(err)); exit(EXIT_FAILURE); } if (before == my_test_rng_read) { fprintf(stderr, "somehow there was no read from the ltc_rng! %lu == %lu\n", before, my_test_rng_read); exit(EXIT_FAILURE); } ltc_rng = previous; #endif /* test prngs (test, import/export) */ for (x = 0; prng_descriptor[x].name != NULL; x++) { if(strstr(prng_descriptor[x].name, "no_prng") == prng_descriptor[x].name) continue; err = CRYPT_OK; DOX(prng_descriptor[x].test(), prng_descriptor[x].name); DOX(prng_descriptor[x].start(&nprng), prng_descriptor[x].name); DOX(prng_descriptor[x].add_entropy((unsigned char *)"helloworld12", 12, &nprng), prng_descriptor[x].name); DOX(prng_descriptor[x].ready(&nprng), prng_descriptor[x].name); n = sizeof(buf); if (strcmp(prng_descriptor[x].name, "sprng")) { one = 1; if (prng_descriptor[x].pexport(buf, &one, &nprng) != CRYPT_BUFFER_OVERFLOW) { fprintf(stderr, "Error testing pexport with a short buffer (%s)\n", prng_descriptor[x].name); return CRYPT_ERROR; } } DOX(prng_descriptor[x].pexport(buf, &n, &nprng), prng_descriptor[x].name); prng_descriptor[x].done(&nprng); DOX(prng_descriptor[x].pimport(buf, n, &nprng), prng_descriptor[x].name); DOX(prng_descriptor[x].pimport(buf, 4096, &nprng), prng_descriptor[x].name); /* try to import larger data */ DOX(prng_descriptor[x].ready(&nprng), prng_descriptor[x].name); if (prng_descriptor[x].read(buf, 100, &nprng) != 100) { fprintf(stderr, "Error reading from imported PRNG (%s)!\n", prng_descriptor[x].name); return CRYPT_ERROR; } prng_descriptor[x].done(&nprng); } return err; } /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */