blob: 7b7156140fabe1e0ebc97f25c950b608ecf7ff33 [file] [log] [blame]
 #include "os.h" #include #include RSApriv* rsafill(mpint *n, mpint *e, mpint *d, mpint *p, mpint *q) { mpint *c2, *kq, *kp, *x; RSApriv *rsa; /* make sure we're not being hoodwinked */ if(!probably_prime(p, 10) || !probably_prime(q, 10)){ werrstr("rsafill: p or q not prime"); return nil; } x = mpnew(0); mpmul(p, q, x); if(mpcmp(n, x) != 0){ werrstr("rsafill: n != p*q"); mpfree(x); return nil; } c2 = mpnew(0); mpsub(p, mpone, c2); mpsub(q, mpone, x); mpmul(c2, x, x); mpmul(e, d, c2); mpmod(c2, x, x); if(mpcmp(x, mpone) != 0){ werrstr("rsafill: e*d != 1 mod (p-1)*(q-1)"); mpfree(x); mpfree(c2); return nil; } /* compute chinese remainder coefficient */ mpinvert(p, q, c2); /* for crt a**k mod p == (a**(k mod p-1)) mod p */ kq = mpnew(0); kp = mpnew(0); mpsub(p, mpone, x); mpmod(d, x, kp); mpsub(q, mpone, x); mpmod(d, x, kq); rsa = rsaprivalloc(); rsa->pub.ek = mpcopy(e); rsa->pub.n = mpcopy(n); rsa->dk = mpcopy(d); rsa->kp = kp; rsa->kq = kq; rsa->p = mpcopy(p); rsa->q = mpcopy(q); rsa->c2 = c2; mpfree(x); return rsa; }