Mercurial > dropbear
view crypto_desc.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 | 3f4cdf839a1a |
children |
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#include "includes.h" #include "dbutil.h" #include "crypto_desc.h" #include "ltc_prng.h" #include "ecc.h" #include "dbrandom.h" #if DROPBEAR_LTC_PRNG int dropbear_ltc_prng = -1; #endif /* Wrapper for libtommath */ static mp_err dropbear_rand_source(void* out, size_t size) { genrandom((unsigned char*)out, (unsigned int)size); return MP_OKAY; } /* Register the compiled in ciphers. * This should be run before using any of the ciphers/hashes */ void crypto_init() { const struct ltc_cipher_descriptor *regciphers[] = { #if DROPBEAR_AES &aes_desc, #endif #if DROPBEAR_3DES &des3_desc, #endif NULL }; const struct ltc_hash_descriptor *reghashes[] = { #if DROPBEAR_SHA1_HMAC &sha1_desc, #endif #if DROPBEAR_MD5_HMAC &md5_desc, #endif #if DROPBEAR_SHA256 &sha256_desc, #endif #if DROPBEAR_SHA384 &sha384_desc, #endif #if DROPBEAR_SHA512 &sha512_desc, #endif NULL }; int i; for (i = 0; regciphers[i] != NULL; i++) { if (register_cipher(regciphers[i]) == -1) { dropbear_exit("Error registering crypto"); } } for (i = 0; reghashes[i] != NULL; i++) { if (register_hash(reghashes[i]) == -1) { dropbear_exit("Error registering crypto"); } } #if DROPBEAR_LTC_PRNG dropbear_ltc_prng = register_prng(&dropbear_prng_desc); if (dropbear_ltc_prng == -1) { dropbear_exit("Error registering crypto"); } #endif mp_rand_source(dropbear_rand_source); #if DROPBEAR_ECC ltc_mp = ltm_desc; dropbear_ecc_fill_dp(); #endif }