Subversion Repositories planix.SVN

#include "os.h"

#include <mp.h>

#include <libsec.h>

mpint*

egdecrypt(EGpriv *priv, mpint *in, mpint *out)

{

	EGpub *pub = &priv->pub;

	mpint *gamma, *delta;

	mpint *p = pub->p;

	int plen = mpsignif(p)+1;

	int shift = ((plen+Dbits-1)/Dbits)*Dbits;

	if(out == nil)

		out = mpnew(0);

	gamma = mpnew(0);

	delta = mpnew(0);

	mpright(in, shift, gamma);

	mpleft(gamma, shift, delta);

	mpsub(in, delta, delta);	

	mpexp(gamma, priv->secret, p, out);

	mpinvert(out, p, gamma);

	mpmul(gamma, delta, out);

	mpmod(out, p, out);

	mpfree(gamma);

	mpfree(delta);

	return out;

}