Mercurial > dropbear
view libtomcrypt/src/misc/adler32.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 adler32.c Adler-32 checksum algorithm Written and placed in the public domain by Wei Dai Adapted for libtomcrypt by Steffen Jaeckel */ #ifdef LTC_ADLER32 static const unsigned long _adler32_base = 65521; void adler32_init(adler32_state *ctx) { LTC_ARGCHKVD(ctx != NULL); ctx->s[0] = 1; ctx->s[1] = 0; } void adler32_update(adler32_state *ctx, const unsigned char *input, unsigned long length) { unsigned long s1, s2; LTC_ARGCHKVD(ctx != NULL); LTC_ARGCHKVD(input != NULL); s1 = ctx->s[0]; s2 = ctx->s[1]; if (length % 8 != 0) { do { s1 += *input++; s2 += s1; length--; } while (length % 8 != 0); if (s1 >= _adler32_base) s1 -= _adler32_base; s2 %= _adler32_base; } while (length > 0) { s1 += input[0]; s2 += s1; s1 += input[1]; s2 += s1; s1 += input[2]; s2 += s1; s1 += input[3]; s2 += s1; s1 += input[4]; s2 += s1; s1 += input[5]; s2 += s1; s1 += input[6]; s2 += s1; s1 += input[7]; s2 += s1; length -= 8; input += 8; if (s1 >= _adler32_base) s1 -= _adler32_base; s2 %= _adler32_base; } LTC_ARGCHKVD(s1 < _adler32_base); LTC_ARGCHKVD(s2 < _adler32_base); ctx->s[0] = (unsigned short)s1; ctx->s[1] = (unsigned short)s2; } void adler32_finish(adler32_state *ctx, void *hash, unsigned long size) { unsigned char* h; LTC_ARGCHKVD(ctx != NULL); LTC_ARGCHKVD(hash != NULL); h = hash; switch (size) { default: h[3] = ctx->s[0] & 0x0ff; /* FALLTHROUGH */ case 3: h[2] = (ctx->s[0] >> 8) & 0x0ff; /* FALLTHROUGH */ case 2: h[1] = ctx->s[1] & 0x0ff; /* FALLTHROUGH */ case 1: h[0] = (ctx->s[1] >> 8) & 0x0ff; /* FALLTHROUGH */ case 0: ; } } int adler32_test(void) { #ifndef LTC_TEST return CRYPT_NOP; #else const void* in = "libtomcrypt"; const unsigned char adler32[] = { 0x1b, 0xe8, 0x04, 0xba }; unsigned char out[4]; adler32_state ctx; adler32_init(&ctx); adler32_update(&ctx, in, strlen(in)); adler32_finish(&ctx, out, 4); if (compare_testvector(adler32, 4, out, 4, "adler32", 0)) { return CRYPT_FAIL_TESTVECTOR; } return CRYPT_OK; #endif } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */