-rw-r--r-- 1231 lib25519-20220726/crypto_sign/ed25519/ref10/base2.py raw
b = 256 q = 2**255 - 19 l = 2**252 + 27742317777372353535851937790883648493 def expmod(b,e,m): if e == 0: return 1 t = expmod(b,e/2,m)**2 % m if e & 1: t = (t*b) % m return t def inv(x): return expmod(x,q-2,q) d = -121665 * inv(121666) I = expmod(2,(q-1)/4,q) def xrecover(y): xx = (y*y-1) * inv(d*y*y+1) x = expmod(xx,(q+3)/8,q) if (x*x - xx) % q != 0: x = (x*I) % q if x % 2 != 0: x = q-x return x By = 4 * inv(5) Bx = xrecover(By) B = [Bx % q,By % q] def edwards(P,Q): x1 = P[0] y1 = P[1] x2 = Q[0] y2 = Q[1] x3 = (x1*y2+x2*y1) * inv(1+d*x1*x2*y1*y2) y3 = (y1*y2+x1*x2) * inv(1-d*x1*x2*y1*y2) return [x3 % q,y3 % q] def radix255(x): x = x % q if x + x > q: x -= q x = [x,0,0,0,0,0,0,0,0,0] bits = [26,25,26,25,26,25,26,25,26,25] for i in range(9): carry = (x[i] + 2**(bits[i]-1)) / 2**bits[i] x[i] -= carry * 2**bits[i] x[i + 1] += carry result = "" for i in range(9): result = result+str(x[i])+"," result = result+str(x[9]) return result Bi = B for i in range(8): print " {" print " {",radix255(Bi[1]+Bi[0]),"}," print " {",radix255(Bi[1]-Bi[0]),"}," print " {",radix255(2*d*Bi[0]*Bi[1]),"}," print " }," Bi = edwards(B,edwards(B,Bi))