ref: 0a5f81a44230cbd562b6d71a0a5be018e24a5ba6
dir: /sys/src/libsec/port/egencrypt.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; }