diff options
Diffstat (limited to 'src/crypto/shen_ed25519_ref/ref10/base.py')
-rw-r--r-- | src/crypto/shen_ed25519_ref/ref10/base.py | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/src/crypto/shen_ed25519_ref/ref10/base.py b/src/crypto/shen_ed25519_ref/ref10/base.py new file mode 100644 index 000000000..84accc858 --- /dev/null +++ b/src/crypto/shen_ed25519_ref/ref10/base.py @@ -0,0 +1,65 @@ +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(32): + print "{" + Bij = Bi + for j in range(8): + print " {" + print " {",radix255(Bij[1]+Bij[0]),"}," + print " {",radix255(Bij[1]-Bij[0]),"}," + print " {",radix255(2*d*Bij[0]*Bij[1]),"}," + Bij = edwards(Bij,Bi) + print " }," + print "}," + for k in range(8): + Bi = edwards(Bi,Bi) |