sexp2rsa.c 2.81 KB
Newer Older
Niels Möller's avatar
Niels Möller committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
/* sexp2rsa.h
 *
 */

/* nettle, low-level cryptographics library
 *
 * Copyright (C) 2002 Niels Mller
 *  
 * The nettle library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at your
 * option) any later version.
 * 
 * The nettle library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 * License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with the nettle library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

#if HAVE_CONFIG_H
#include "config.h"
#endif

29
#if WITH_PUBLIC_KEY
Niels Möller's avatar
Niels Möller committed
30 31 32 33 34 35 36 37 38 39 40

#include "rsa.h"

#include "bignum.h"
#include "sexp.h"

#include <string.h>

static int
get_value(mpz_t x, struct sexp_iterator *i)
{
41
  if (i->type == SEXP_ATOM
Niels Möller's avatar
Niels Möller committed
42 43 44 45 46 47 48 49 50 51 52
      && !i->display)
    {
      nettle_mpz_set_str_256(x, i->atom_length, i->atom);
      return 1;
    }
  else
    return 0;
}

#define GET(x, v) do { if (!get_value(x, v)) return 0; } while(0)

53 54 55 56 57 58 59 60 61
/* FIXME: Pass in a maximum key size, to avoid denial-of-service
 * problems. */

/* Iterator should point past the algorithm tag, e.g.
 *
 *   (public-key (rsa (n |xxxx|) (e |xxxx|))
 *                    ^ here
 */

Niels Möller's avatar
Niels Möller committed
62
int
63 64 65
rsa_keypair_from_sexp_alist(struct rsa_public_key *pub,
			    struct rsa_private_key *priv,
			    struct sexp_iterator *i)
Niels Möller's avatar
Niels Möller committed
66
{
67
  static const uint8_t *names[8]
Niels Möller's avatar
Niels Möller committed
68 69
    = { "n", "e", "d", "p", "q", "a", "b", "c" };
  struct sexp_iterator values[8];
70
  unsigned nvalues = priv ? 8 : 2;
Niels Möller's avatar
Niels Möller committed
71
  
72
  if (!sexp_iterator_assoc(i, nvalues, names, values))
Niels Möller's avatar
Niels Möller committed
73 74 75 76 77 78 79 80 81 82
    return 0;

  if (priv)
    {
      GET(priv->d, &values[2]);
      GET(priv->p, &values[3]);
      GET(priv->q, &values[4]);
      GET(priv->a, &values[5]);
      GET(priv->b, &values[6]);
      GET(priv->c, &values[7]);
83 84 85

      if (!rsa_prepare_private_key(priv))
	return 0;
Niels Möller's avatar
Niels Möller committed
86 87 88 89 90 91
    }

  if (pub)
    {
      GET(pub->n, &values[0]);
      GET(pub->e, &values[1]);
92 93 94

      if (!rsa_prepare_public_key(pub))
	return 0;
Niels Möller's avatar
Niels Möller committed
95
    }
96
  
Niels Möller's avatar
Niels Möller committed
97 98 99
  return 1;
}

100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
int
rsa_keypair_from_sexp(struct rsa_public_key *pub,
		      struct rsa_private_key *priv,
		      unsigned length, const uint8_t *expr)
{
  struct sexp_iterator i;
  static const uint8_t *names[3]
    = { "rsa", "rsa-pkcs1", "rsa-pkcs1-sha1" };

  if (!sexp_iterator_first(&i, length, expr))
    return 0;
  
  if (!sexp_iterator_check_type(&i, priv ? "private-key" : "public-key"))
    return 0;

  if (!sexp_iterator_check_types(&i, 3, names))
    return 0;

  return rsa_keypair_from_sexp_alist(pub, priv, &i);
}

121
#endif /* WITH_PUBLIC_KEY */