Mercurial > dropbear
view libtomcrypt/src/mac/xcbc/xcbc_file.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 | e9dba7abd939 |
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 xcbc_file.c XCBC support, process a file, Tom St Denis */ #ifdef LTC_XCBC /** XCBC a file @param cipher The index of the cipher desired @param key The secret key @param keylen The length of the secret key (octets) @param filename The name of the file you wish to XCBC @param out [out] Where the authentication tag is to be stored @param outlen [in/out] The max size and resulting size of the authentication tag @return CRYPT_OK if successful, CRYPT_NOP if file support has been disabled */ int xcbc_file(int cipher, const unsigned char *key, unsigned long keylen, const char *filename, unsigned char *out, unsigned long *outlen) { #ifdef LTC_NO_FILE LTC_UNUSED_PARAM(cipher); LTC_UNUSED_PARAM(key); LTC_UNUSED_PARAM(keylen); LTC_UNUSED_PARAM(filename); LTC_UNUSED_PARAM(out); LTC_UNUSED_PARAM(outlen); return CRYPT_NOP; #else size_t x; int err; xcbc_state xcbc; FILE *in; unsigned char *buf; LTC_ARGCHK(key != NULL); LTC_ARGCHK(filename != NULL); LTC_ARGCHK(out != NULL); LTC_ARGCHK(outlen != NULL); if ((buf = XMALLOC(LTC_FILE_READ_BUFSIZE)) == NULL) { return CRYPT_MEM; } if ((err = xcbc_init(&xcbc, cipher, key, keylen)) != CRYPT_OK) { goto LBL_ERR; } in = fopen(filename, "rb"); if (in == NULL) { err = CRYPT_FILE_NOTFOUND; goto LBL_ERR; } do { x = fread(buf, 1, LTC_FILE_READ_BUFSIZE, in); if ((err = xcbc_process(&xcbc, buf, (unsigned long)x)) != CRYPT_OK) { fclose(in); goto LBL_CLEANBUF; } } while (x == LTC_FILE_READ_BUFSIZE); if (fclose(in) != 0) { err = CRYPT_ERROR; goto LBL_CLEANBUF; } err = xcbc_done(&xcbc, out, outlen); LBL_CLEANBUF: zeromem(buf, LTC_FILE_READ_BUFSIZE); LBL_ERR: #ifdef LTC_CLEAN_STACK zeromem(&xcbc, sizeof(xcbc_state)); #endif XFREE(buf); return err; #endif } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */