view libtomcrypt/src/pk/rsa/rsa_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 e9dba7abd939
line wrap: on
line source

/* 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 = (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 */

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