-rw-r--r-- 567 lib25519-20240928/crypto_mGnP/ed25519/ref10/d2.py raw
q = 2**255 - 19 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) 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 d = -121665 * inv(121666) print radix255(d*2)