Mercurial > dropbear
view libtomcrypt/src/pk/rsa/rsa_export.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 rsa_export.c Export RSA PKCS keys, Tom St Denis */ #ifdef LTC_MRSA /** This will export either an RSAPublicKey or RSAPrivateKey [defined in PKCS #1 v2.1] @param out [out] Destination of the packet @param outlen [in/out] The max size and resulting size of the packet @param type The type of exported key (PK_PRIVATE or PK_PUBLIC) @param key The RSA key to export @return CRYPT_OK if successful */ int rsa_export(unsigned char *out, unsigned long *outlen, int type, rsa_key *key) { unsigned long zero=0; int err; LTC_ARGCHK(out != NULL); LTC_ARGCHK(outlen != NULL); LTC_ARGCHK(key != NULL); /* type valid? */ if (!(key->type == PK_PRIVATE) && (type == PK_PRIVATE)) { return CRYPT_PK_INVALID_TYPE; } if (type == PK_PRIVATE) { /* private key */ /* output is Version, n, e, d, p, q, d mod (p-1), d mod (q - 1), 1/q mod p */ return der_encode_sequence_multi(out, outlen, LTC_ASN1_SHORT_INTEGER, 1UL, &zero, LTC_ASN1_INTEGER, 1UL, key->N, LTC_ASN1_INTEGER, 1UL, key->e, LTC_ASN1_INTEGER, 1UL, key->d, LTC_ASN1_INTEGER, 1UL, key->p, LTC_ASN1_INTEGER, 1UL, key->q, LTC_ASN1_INTEGER, 1UL, key->dP, LTC_ASN1_INTEGER, 1UL, key->dQ, LTC_ASN1_INTEGER, 1UL, key->qP, LTC_ASN1_EOL, 0UL, NULL); } else { /* public key */ unsigned long tmplen, *ptmplen; unsigned char* tmp = NULL; if (type & PK_STD) { tmplen = (unsigned long)(mp_count_bits(key->N) / 8) * 2 + 8; tmp = XMALLOC(tmplen); ptmplen = &tmplen; if (tmp == NULL) { return CRYPT_MEM; } } else { tmp = out; ptmplen = outlen; } err = der_encode_sequence_multi(tmp, ptmplen, LTC_ASN1_INTEGER, 1UL, key->N, LTC_ASN1_INTEGER, 1UL, key->e, LTC_ASN1_EOL, 0UL, NULL); if ((err != CRYPT_OK) || !(type & PK_STD)) { goto finish; } err = der_encode_subject_public_key_info(out, outlen, PKA_RSA, tmp, tmplen, LTC_ASN1_NULL, NULL, 0); finish: if (tmp != out) XFREE(tmp); return err; } } #endif /* LTC_MRSA */ /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */