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 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133
|
/* der2rsa.c
*
* Decoding of keys in PKCS#1 format.
*/
/* nettle, low-level cryptographics library
*
* Copyright (C) 2005 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
#include "rsa.h"
#include "bignum.h"
#include "asn1.h"
#define GET(i, x, l) \
(asn1_der_iterator_next((i)) == ASN1_ITERATOR_PRIMITIVE \
&& (i)->type == ASN1_INTEGER \
&& asn1_der_get_bignum((i), (x), (l)) \
&& mpz_sgn((x)) > 0)
int
rsa_public_key_from_der_iterator(struct rsa_public_key *pub,
unsigned limit,
struct asn1_der_iterator *i)
{
/* RSAPublicKey ::= SEQUENCE {
modulus INTEGER, -- n
publicExponent INTEGER -- e
}
*/
return (i->type == ASN1_SEQUENCE
&& asn1_der_decode_constructed_last(i) == ASN1_ITERATOR_PRIMITIVE
&& asn1_der_get_bignum(i, pub->n, limit)
&& mpz_sgn(pub->n) > 0
&& GET(i, pub->e, limit)
&& asn1_der_iterator_next(i) == ASN1_ITERATOR_END
&& rsa_public_key_prepare(pub));
}
int
rsa_private_key_from_der_iterator(struct rsa_public_key *pub,
struct rsa_private_key *priv,
unsigned limit,
struct asn1_der_iterator *i)
{
/* RSAPrivateKey ::= SEQUENCE {
version Version,
modulus INTEGER, -- n
publicExponent INTEGER, -- e
privateExponent INTEGER, -- d
prime1 INTEGER, -- p
prime2 INTEGER, -- q
exponent1 INTEGER, -- d mod (p-1)
exponent2 INTEGER, -- d mod (q-1)
coefficient INTEGER, -- (inverse of q) mod p
otherPrimeInfos OtherPrimeInfos OPTIONAL
}
*/
uint32_t version;
if (i->type != ASN1_SEQUENCE)
return 0;
if (asn1_der_decode_constructed_last(i) == ASN1_ITERATOR_PRIMITIVE
&& i->type == ASN1_INTEGER
&& asn1_der_get_uint32(i, &version)
&& version <= 1
&& GET(i, pub->n, limit)
&& GET(i, pub->e, limit)
&& rsa_public_key_prepare(pub)
&& GET(i, priv->d, limit)
&& GET(i, priv->p, limit)
&& GET(i, priv->q, limit)
&& GET(i, priv->a, limit)
&& GET(i, priv->b, limit)
&& GET(i, priv->c, limit)
&& rsa_private_key_prepare(priv))
{
if (version == 1)
{
/* otherPrimeInfos must be present. We ignore the contents */
if (!(asn1_der_iterator_next(i) == ASN1_ITERATOR_CONSTRUCTED
&& i->type == ASN1_SEQUENCE))
return 0;
}
return (asn1_der_iterator_next(i) == ASN1_ITERATOR_END);
}
return 0;
}
int
rsa_keypair_from_der(struct rsa_public_key *pub,
struct rsa_private_key *priv,
unsigned limit,
unsigned length, const uint8_t *data)
{
struct asn1_der_iterator i;
enum asn1_iterator_result res;
res = asn1_der_iterator_first(&i, length, data);
if (res != ASN1_ITERATOR_CONSTRUCTED)
return 0;
if (priv)
return rsa_private_key_from_der_iterator(pub, priv, limit, &i);
else
return rsa_public_key_from_der_iterator(pub, limit, &i);
}
|