Mercurial > dropbear
view libtomcrypt/src/encauth/chachapoly/chacha20poly1305_setiv.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 |
line wrap: on
line source
/* 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" #ifdef LTC_CHACHA20POLY1305_MODE /** Set IV + counter data to the ChaCha20Poly1305 state and reset the context @param st The ChaCha20Poly1305 state @param iv The IV data to add @param ivlen The length of the IV (must be 12 or 8) @return CRYPT_OK on success */ int chacha20poly1305_setiv(chacha20poly1305_state *st, const unsigned char *iv, unsigned long ivlen) { chacha_state tmp_st; int i, err; unsigned char polykey[32]; LTC_ARGCHK(st != NULL); LTC_ARGCHK(iv != NULL); LTC_ARGCHK(ivlen == 12 || ivlen == 8); /* set IV for chacha20 */ if (ivlen == 12) { /* IV 96bit */ if ((err = chacha_ivctr32(&st->chacha, iv, ivlen, 1)) != CRYPT_OK) return err; } else { /* IV 64bit */ if ((err = chacha_ivctr64(&st->chacha, iv, ivlen, 1)) != CRYPT_OK) return err; } /* copy chacha20 key to temporary state */ for(i = 0; i < 12; i++) tmp_st.input[i] = st->chacha.input[i]; tmp_st.rounds = 20; /* set IV */ if (ivlen == 12) { /* IV 32bit */ if ((err = chacha_ivctr32(&tmp_st, iv, ivlen, 0)) != CRYPT_OK) return err; } else { /* IV 64bit */ if ((err = chacha_ivctr64(&tmp_st, iv, ivlen, 0)) != CRYPT_OK) return err; } /* (re)generate new poly1305 key */ if ((err = chacha_keystream(&tmp_st, polykey, 32)) != CRYPT_OK) return err; /* (re)initialise poly1305 */ if ((err = poly1305_init(&st->poly, polykey, 32)) != CRYPT_OK) return err; st->ctlen = 0; st->aadlen = 0; st->aadflg = 1; return CRYPT_OK; } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */