void dec_gost(char *set_hash,char *in,char **out,int n_blocks){
gost_ctx *c=(gost_ctx *)malloc(sizeof(gost_ctx));
gost_subst_block *b=NULL;
gost_init(c,b);
gost_key(c,(byte *)set_hash);
*out=NULL;
*out=(char *)malloc(n_blocks*8);
gost_dec(c,(byte *)in,(byte *) *out,n_blocks);
}
int keyUnwrapCryptoPro(gost_ctx *ctx,const unsigned char *keyExchangeKey,
const unsigned char *wrappedKey, unsigned char *sessionKey)
{
unsigned char kek_ukm[32],cek_mac[4];
keyDiversifyCryptoPro(ctx,keyExchangeKey,wrappedKey
/* First 8 bytes of wrapped Key is ukm */
,kek_ukm);
gost_key(ctx,kek_ukm);
gost_dec(ctx,wrappedKey+8,sessionKey,4);
gost_mac_iv(ctx,32,wrappedKey,sessionKey,32,cek_mac);
if (memcmp(cek_mac,wrappedKey+40,4))
{
return 0;
}
return 1;
}
