view libtomcrypt/src/pk/rsa/rsa_set.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"


#ifdef LTC_MRSA

/**
  Import RSA key from raw numbers

  @param N       RSA's N
  @param Nlen    RSA's N's length
  @param e       RSA's e
  @param elen    RSA's e's length
  @param d       RSA's d  (only private key, NULL for public key)
  @param dlen    RSA's d's length
  @param key     [out] the destination for the imported key
  @return CRYPT_OK if successful
*/
int rsa_set_key(const unsigned char *N,  unsigned long Nlen,
                const unsigned char *e,  unsigned long elen,
                const unsigned char *d,  unsigned long dlen,
                rsa_key *key)
{
   int err;

   LTC_ARGCHK(key         != NULL);
   LTC_ARGCHK(N           != NULL);
   LTC_ARGCHK(e           != NULL);
   LTC_ARGCHK(ltc_mp.name != NULL);

   err = mp_init_multi(&key->e, &key->d, &key->N, &key->dQ, &key->dP, &key->qP, &key->p, &key->q, NULL);
   if (err != CRYPT_OK) return err;

   if ((err = mp_read_unsigned_bin(key->N , (unsigned char *)N , Nlen)) != CRYPT_OK)    { goto LBL_ERR; }
   if ((err = mp_read_unsigned_bin(key->e , (unsigned char *)e , elen)) != CRYPT_OK)    { goto LBL_ERR; }
   if (d && dlen) {
      if ((err = mp_read_unsigned_bin(key->d , (unsigned char *)d , dlen)) != CRYPT_OK) { goto LBL_ERR; }
      key->type = PK_PRIVATE;
   }
   else {
      key->type = PK_PUBLIC;
   }
   return CRYPT_OK;

LBL_ERR:
   rsa_free(key);
   return err;
}

/**
  Import factors of an RSA key from raw numbers

  Only for private keys.

  @param p       RSA's p
  @param plen    RSA's p's length
  @param q       RSA's q
  @param qlen    RSA's q's length
  @param key     [out] the destination for the imported key
  @return CRYPT_OK if successful
*/
int rsa_set_factors(const unsigned char *p,  unsigned long plen,
                    const unsigned char *q,  unsigned long qlen,
                    rsa_key *key)
{
   int err;

   LTC_ARGCHK(key         != NULL);
   LTC_ARGCHK(p           != NULL);
   LTC_ARGCHK(q           != NULL);
   LTC_ARGCHK(ltc_mp.name != NULL);

   if (key->type != PK_PRIVATE) return CRYPT_PK_TYPE_MISMATCH;

   if ((err = mp_read_unsigned_bin(key->p , (unsigned char *)p , plen)) != CRYPT_OK) { goto LBL_ERR; }
   if ((err = mp_read_unsigned_bin(key->q , (unsigned char *)q , qlen)) != CRYPT_OK) { goto LBL_ERR; }
   return CRYPT_OK;

LBL_ERR:
   rsa_free(key);
   return err;
}

/**
  Import CRT parameters of an RSA key from raw numbers

  Only for private keys.

  @param dP      RSA's dP
  @param dPlen   RSA's dP's length
  @param dQ      RSA's dQ
  @param dQlen   RSA's dQ's length
  @param qP      RSA's qP
  @param qPlen   RSA's qP's length
  @param key     [out] the destination for the imported key
  @return CRYPT_OK if successful
*/
int rsa_set_crt_params(const unsigned char *dP, unsigned long dPlen,
                       const unsigned char *dQ, unsigned long dQlen,
                       const unsigned char *qP, unsigned long qPlen,
                       rsa_key *key)
{
   int err;

   LTC_ARGCHK(key         != NULL);
   LTC_ARGCHK(dP          != NULL);
   LTC_ARGCHK(dQ          != NULL);
   LTC_ARGCHK(qP          != NULL);
   LTC_ARGCHK(ltc_mp.name != NULL);

   if (key->type != PK_PRIVATE) return CRYPT_PK_TYPE_MISMATCH;

   if ((err = mp_read_unsigned_bin(key->dP, (unsigned char *)dP, dPlen)) != CRYPT_OK) { goto LBL_ERR; }
   if ((err = mp_read_unsigned_bin(key->dQ, (unsigned char *)dQ, dQlen)) != CRYPT_OK) { goto LBL_ERR; }
   if ((err = mp_read_unsigned_bin(key->qP, (unsigned char *)qP, qPlen)) != CRYPT_OK) { goto LBL_ERR; }
   return CRYPT_OK;

LBL_ERR:
   rsa_free(key);
   return err;
}

#endif /* LTC_MRSA */

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