39 lines
806 B
C
39 lines
806 B
C
#include "os.h"
|
|
#include <mp.h>
|
|
#include <libsec.h>
|
|
|
|
mpint*
|
|
egencrypt(EGpub *pub, mpint *in, mpint *out)
|
|
{
|
|
mpint *m, *k, *gamma, *delta, *pm1;
|
|
mpint *p = pub->p, *alpha = pub->alpha;
|
|
int plen = mpsignif(p);
|
|
int shift = ((plen+Dbits)/Dbits)*Dbits;
|
|
// in libcrypt version, (int)(LENGTH(pub->p)*sizeof(NumType)*CHARBITS);
|
|
|
|
if(out == nil)
|
|
out = mpnew(0);
|
|
pm1 = mpnew(0);
|
|
m = mpnew(0);
|
|
gamma = mpnew(0);
|
|
delta = mpnew(0);
|
|
mpmod(in, p, m);
|
|
while(1){
|
|
k = mprand(plen, genrandom, nil);
|
|
if((mpcmp(mpone, k) <= 0) && (mpcmp(k, pm1) < 0))
|
|
break;
|
|
}
|
|
mpexp(alpha, k, p, gamma);
|
|
mpexp(pub->key, k, p, delta);
|
|
mpmul(m, delta, delta);
|
|
mpmod(delta, p, delta);
|
|
mpleft(gamma, shift, out);
|
|
mpadd(delta, out, out);
|
|
mpfree(pm1);
|
|
mpfree(m);
|
|
mpfree(k);
|
|
mpfree(gamma);
|
|
mpfree(delta);
|
|
return out;
|
|
}
|