1 #include "os.h"
2 #include <mp.h>
3 #include <libsec.h>
4
5 mpint*
egencrypt(EGpub * pub,mpint * in,mpint * out)6 egencrypt(EGpub *pub, mpint *in, mpint *out)
7 {
8 mpint *m, *k, *gamma, *delta, *pm1;
9 mpint *p = pub->p, *alpha = pub->alpha;
10 int plen = mpsignif(p);
11 int shift = ((plen+Dbits)/Dbits)*Dbits;
12 // in libcrypt version, (int)(LENGTH(pub->p)*sizeof(NumType)*CHARBITS);
13
14 if(out == nil)
15 out = mpnew(0);
16 pm1 = mpnew(0);
17 m = mpnew(0);
18 gamma = mpnew(0);
19 delta = mpnew(0);
20 mpmod(in, p, m);
21 while(1){
22 k = mprand(plen, genrandom, nil);
23 if((mpcmp(mpone, k) <= 0) && (mpcmp(k, pm1) < 0))
24 break;
25 }
26 mpexp(alpha, k, p, gamma);
27 mpexp(pub->key, k, p, delta);
28 mpmul(m, delta, delta);
29 mpmod(delta, p, delta);
30 mpleft(gamma, shift, out);
31 mpadd(delta, out, out);
32 mpfree(pm1);
33 mpfree(m);
34 mpfree(k);
35 mpfree(gamma);
36 mpfree(delta);
37 return out;
38 }
39