Mercurial > dropbear
view libtomcrypt/tests/prng_test.c @ 1930:299f4f19ba19
Add /usr/sbin and /sbin to default root PATH
When dropbear is used in a very restricted environment (such as in a
initrd), the default user shell is often also very restricted
and doesn't take care of setting the PATH so the user ends up
with the PATH set by dropbear. Unfortunately, dropbear always
sets "/usr/bin:/bin" as default PATH even for the root user
which should have /usr/sbin and /sbin too.
For a concrete instance of this problem, see the "Remote Unlocking"
section in this tutorial: https://paxswill.com/blog/2013/11/04/encrypted-raspberry-pi/
It speaks of a bug in the initramfs script because it's written "blkid"
instead of "/sbin/blkid"... this is just because the scripts from the
initramfs do not expect to have a PATH without the sbin directories and
because dropbear is not setting the PATH appropriately for the root user.
I'm thus suggesting to use the attached patch to fix this misbehaviour (I
did not test it, but it's easy enough). It might seem anecdotic but
multiple Kali users have been bitten by this.
From https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=903403
author | Raphael Hertzog <hertzog@debian.org> |
---|---|
date | Mon, 09 Jul 2018 16:27:53 +0200 |
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: $Format:%ai$ */