Mercurial > dropbear
view libtomcrypt/src/encauth/ccm/ccm_init.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.h" #ifdef LTC_CCM_MODE /** Initialize a CCM state @param ccm The CCM state to initialize @param cipher The index of the cipher to use @param key The secret key @param keylen The length of the secret key @param ptlen The length of the plain/cipher text that will be processed @param taglen The max length of the MAC tag @param aadlen The length of the AAD @return CRYPT_OK on success */ int ccm_init(ccm_state *ccm, int cipher, const unsigned char *key, int keylen, int ptlen, int taglen, int aadlen) { int err; LTC_ARGCHK(ccm != NULL); LTC_ARGCHK(key != NULL); LTC_ARGCHK(taglen != 0); XMEMSET(ccm, 0, sizeof(ccm_state)); /* check cipher input */ if ((err = cipher_is_valid(cipher)) != CRYPT_OK) { return err; } if (cipher_descriptor[cipher].block_length != 16) { return CRYPT_INVALID_CIPHER; } /* make sure the taglen is even and <= 16 */ ccm->taglen = taglen; ccm->taglen &= ~1; if (ccm->taglen > 16) { ccm->taglen = 16; } /* can't use < 4 */ if (ccm->taglen < 4) { return CRYPT_INVALID_ARG; } /* schedule key */ if ((err = cipher_descriptor[cipher].setup(key, keylen, 0, &ccm->K)) != CRYPT_OK) { return err; } ccm->cipher = cipher; /* let's get the L value */ ccm->ptlen = ptlen; ccm->L = 0; while (ptlen) { ++ccm->L; ptlen >>= 8; } if (ccm->L <= 1) { ccm->L = 2; } ccm->aadlen = aadlen; return CRYPT_OK; } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */