Mercurial > dropbear
view libtomcrypt/src/mac/pelican/pelican.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" /** @file pelican.c Pelican MAC, initialize state, by Tom St Denis */ #ifdef LTC_PELICAN #define __LTC_AES_TAB_C__ #define ENCRYPT_ONLY #define PELI_TAB #include "../../ciphers/aes/aes_tab.c" /** Initialize a Pelican state @param pelmac The Pelican state to initialize @param key The secret key @param keylen The length of the secret key (octets) @return CRYPT_OK if successful */ int pelican_init(pelican_state *pelmac, const unsigned char *key, unsigned long keylen) { int err; LTC_ARGCHK(pelmac != NULL); LTC_ARGCHK(key != NULL); #ifdef LTC_FAST if (16 % sizeof(LTC_FAST_TYPE)) { return CRYPT_INVALID_ARG; } #endif if ((err = aes_setup(key, keylen, 0, &pelmac->K)) != CRYPT_OK) { return err; } zeromem(pelmac->state, 16); aes_ecb_encrypt(pelmac->state, pelmac->state, &pelmac->K); pelmac->buflen = 0; return CRYPT_OK; } static void _four_rounds(pelican_state *pelmac) { ulong32 s0, s1, s2, s3, t0, t1, t2, t3; int r; LOAD32H(s0, pelmac->state ); LOAD32H(s1, pelmac->state + 4); LOAD32H(s2, pelmac->state + 8); LOAD32H(s3, pelmac->state + 12); for (r = 0; r < 4; r++) { t0 = Te0(byte(s0, 3)) ^ Te1(byte(s1, 2)) ^ Te2(byte(s2, 1)) ^ Te3(byte(s3, 0)); t1 = Te0(byte(s1, 3)) ^ Te1(byte(s2, 2)) ^ Te2(byte(s3, 1)) ^ Te3(byte(s0, 0)); t2 = Te0(byte(s2, 3)) ^ Te1(byte(s3, 2)) ^ Te2(byte(s0, 1)) ^ Te3(byte(s1, 0)); t3 = Te0(byte(s3, 3)) ^ Te1(byte(s0, 2)) ^ Te2(byte(s1, 1)) ^ Te3(byte(s2, 0)); s0 = t0; s1 = t1; s2 = t2; s3 = t3; } STORE32H(s0, pelmac->state ); STORE32H(s1, pelmac->state + 4); STORE32H(s2, pelmac->state + 8); STORE32H(s3, pelmac->state + 12); } /** Process a block of text through Pelican @param pelmac The Pelican MAC state @param in The input @param inlen The length input (octets) @return CRYPT_OK on success */ int pelican_process(pelican_state *pelmac, const unsigned char *in, unsigned long inlen) { LTC_ARGCHK(pelmac != NULL); LTC_ARGCHK(in != NULL); /* check range */ if (pelmac->buflen < 0 || pelmac->buflen > 15) { return CRYPT_INVALID_ARG; } #ifdef LTC_FAST if (pelmac->buflen == 0) { while (inlen & ~15) { int x; for (x = 0; x < 16; x += sizeof(LTC_FAST_TYPE)) { *(LTC_FAST_TYPE_PTR_CAST((unsigned char *)pelmac->state + x)) ^= *(LTC_FAST_TYPE_PTR_CAST((unsigned char *)in + x)); } _four_rounds(pelmac); in += 16; inlen -= 16; } } #endif while (inlen--) { pelmac->state[pelmac->buflen++] ^= *in++; if (pelmac->buflen == 16) { _four_rounds(pelmac); pelmac->buflen = 0; } } return CRYPT_OK; } /** Terminate Pelican MAC @param pelmac The Pelican MAC state @param out [out] The TAG @return CRYPT_OK on sucess */ int pelican_done(pelican_state *pelmac, unsigned char *out) { LTC_ARGCHK(pelmac != NULL); LTC_ARGCHK(out != NULL); /* check range */ if (pelmac->buflen < 0 || pelmac->buflen > 16) { return CRYPT_INVALID_ARG; } if (pelmac->buflen == 16) { _four_rounds(pelmac); pelmac->buflen = 0; } pelmac->state[pelmac->buflen++] ^= 0x80; aes_ecb_encrypt(pelmac->state, out, &pelmac->K); aes_done(&pelmac->K); return CRYPT_OK; } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */