Mercurial > dropbear
view libtomcrypt/src/pk/rsa/rsa_decrypt_key.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 rsa_decrypt_key.c RSA PKCS #1 Decryption, Tom St Denis and Andreas Lange */ #ifdef LTC_MRSA /** PKCS #1 decrypt then v1.5 or OAEP depad @param in The ciphertext @param inlen The length of the ciphertext (octets) @param out [out] The plaintext @param outlen [in/out] The max size and resulting size of the plaintext (octets) @param lparam The system "lparam" value @param lparamlen The length of the lparam value (octets) @param hash_idx The index of the hash desired @param padding Type of padding (LTC_PKCS_1_OAEP or LTC_PKCS_1_V1_5) @param stat [out] Result of the decryption, 1==valid, 0==invalid @param key The corresponding private RSA key @return CRYPT_OK if succcessul (even if invalid) */ int rsa_decrypt_key_ex(const unsigned char *in, unsigned long inlen, unsigned char *out, unsigned long *outlen, const unsigned char *lparam, unsigned long lparamlen, int hash_idx, int padding, int *stat, rsa_key *key) { unsigned long modulus_bitlen, modulus_bytelen, x; int err; unsigned char *tmp; LTC_ARGCHK(out != NULL); LTC_ARGCHK(outlen != NULL); LTC_ARGCHK(key != NULL); LTC_ARGCHK(stat != NULL); /* default to invalid */ *stat = 0; /* valid padding? */ if ((padding != LTC_PKCS_1_V1_5) && (padding != LTC_PKCS_1_OAEP)) { return CRYPT_PK_INVALID_PADDING; } if (padding == LTC_PKCS_1_OAEP) { /* valid hash ? */ if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) { return err; } } /* get modulus len in bits */ modulus_bitlen = mp_count_bits( (key->N)); /* outlen must be at least the size of the modulus */ modulus_bytelen = mp_unsigned_bin_size( (key->N)); if (modulus_bytelen != inlen) { return CRYPT_INVALID_PACKET; } /* allocate ram */ tmp = XMALLOC(inlen); if (tmp == NULL) { return CRYPT_MEM; } /* rsa decode the packet */ x = inlen; if ((err = ltc_mp.rsa_me(in, inlen, tmp, &x, PK_PRIVATE, key)) != CRYPT_OK) { XFREE(tmp); return err; } if (padding == LTC_PKCS_1_OAEP) { /* now OAEP decode the packet */ err = pkcs_1_oaep_decode(tmp, x, lparam, lparamlen, modulus_bitlen, hash_idx, out, outlen, stat); } else { /* now PKCS #1 v1.5 depad the packet */ err = pkcs_1_v1_5_decode(tmp, x, LTC_PKCS_1_EME, modulus_bitlen, out, outlen, stat); } XFREE(tmp); return err; } #endif /* LTC_MRSA */ /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */