tomcrypt/dsa_import.c
2010-06-16 12:38:11 +02:00

60 lines
1.4 KiB
C

/* 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.
*
* Tom St Denis, tomstdenis@iahu.ca, http://libtomcrypt.org
*/
#include "mycrypt.h"
#ifdef MDSA
int dsa_import(const unsigned char *in, unsigned long inlen, dsa_key *key)
{
unsigned long x, y;
int err;
_ARGCHK(in != NULL);
_ARGCHK(key != NULL);
/* check length */
if ((1+2+PACKET_SIZE) > inlen) {
return CRYPT_INVALID_PACKET;
}
/* check type */
if ((err = packet_valid_header((unsigned char *)in, PACKET_SECT_DSA, PACKET_SUB_KEY)) != CRYPT_OK) {
return err;
}
y = PACKET_SIZE;
/* init key */
if (mp_init_multi(&key->p, &key->g, &key->q, &key->x, &key->y, NULL) != MP_OKAY) {
return CRYPT_MEM;
}
/* read type/qord */
key->type = in[y++];
key->qord = ((unsigned)in[y]<<8)|((unsigned)in[y+1]);
y += 2;
/* input publics */
INPUT_BIGNUM(&key->g,in,x,y, inlen);
INPUT_BIGNUM(&key->p,in,x,y, inlen);
INPUT_BIGNUM(&key->q,in,x,y, inlen);
INPUT_BIGNUM(&key->y,in,x,y, inlen);
if (key->type == PK_PRIVATE) {
INPUT_BIGNUM(&key->x,in,x,y, inlen);
}
return CRYPT_OK;
error:
mp_clear_multi(&key->p, &key->g, &key->q, &key->x, &key->y, NULL);
return err;
}
#endif