view libtomcrypt/src/pk/dh/dh_export.c @ 1499:2d450c1056e3

options: Complete the transition to numeric toggles (`#if') For the sake of review, this commit alters only the code; the affiliated comments within the source files also need to be updated, but doing so now would obscure the operational changes that have been made here. * All on/off options have been switched to the numeric `#if' variant; that is the only way to make this `default_options.h.in' thing work in a reasonable manner. * There is now some very minor compile-time checking of the user's choice of options. * NO_FAST_EXPTMOD doesn't seem to be used, so it has been removed. * ENABLE_USER_ALGO_LIST was supposed to be renamed DROPBEAR_USER_ALGO_LIST, and this commit completes that work. * DROPBEAR_FUZZ seems to be a relatively new, as-yet undocumented option, which was added by the following commit: commit 6e0b539e9ca0b5628c6c5a3d118ad6a2e79e8039 Author: Matt Johnston <[email protected]> Date: Tue May 23 22:29:21 2017 +0800 split out checkpubkey_line() separately It has now been added to `sysoptions.h' and defined as `0' by default. * The configuration option `DROPBEAR_PASSWORD_ENV' is no longer listed in `default_options.h.in'; it is no longer meant to be set by the user, and is instead left to be defined in `sysoptions.h' (where it was already being defined) as merely the name of the environment variable in question: DROPBEAR_PASSWORD To enable or disable use of that environment variable, the user must now toggle `DROPBEAR_USE_DROPBEAR_PASSWORD'. * The sFTP support is now toggled by setting `DROPBEAR_SFTPSERVER', and the path of the sFTP server program is set independently through the usual SFTPSERVER_PATH.
author Michael Witten <mfwitten@gmail.com>
date Thu, 20 Jul 2017 19:38:26 +0000
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_MDH

/**
  Export a DH key to a binary packet
  @param out    [out] The destination for the key
  @param outlen [in/out] The max size and resulting size of the DH key
  @param type   Which type of key (PK_PRIVATE or PK_PUBLIC)
  @param key    The key you wish to export
  @return CRYPT_OK if successful
*/
int dh_export(unsigned char *out, unsigned long *outlen, int type, dh_key *key)
{
   unsigned char flags[1];
   int err;
   unsigned long version = 0;

   LTC_ARGCHK(out    != NULL);
   LTC_ARGCHK(outlen != NULL);
   LTC_ARGCHK(key    != NULL);

   if (type == PK_PRIVATE) {
      /* export x - private key */
      flags[0] = 1;
      err = der_encode_sequence_multi(out, outlen,
                                LTC_ASN1_SHORT_INTEGER, 1UL, &version,
                                LTC_ASN1_BIT_STRING,    1UL, flags,
                                LTC_ASN1_INTEGER,       1UL, key->prime,
                                LTC_ASN1_INTEGER,       1UL, key->base,
                                LTC_ASN1_INTEGER,       1UL, key->x,
                                LTC_ASN1_EOL,           0UL, NULL);
   }
   else {
      /* export y - public key */
      flags[0] = 0;
      err = der_encode_sequence_multi(out, outlen,
                                LTC_ASN1_SHORT_INTEGER, 1UL, &version,
                                LTC_ASN1_BIT_STRING,    1UL, flags,
                                LTC_ASN1_INTEGER,       1UL, key->prime,
                                LTC_ASN1_INTEGER,       1UL, key->base,
                                LTC_ASN1_INTEGER,       1UL, key->y,
                                LTC_ASN1_EOL,           0UL, NULL);
   }

   return err;
}

#endif /* LTC_MDH */

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/* commit time: $Format:%ai$ */