commit 98c4e218b8cccd25e3bf003a348704e3bc9b1344 Author: Nick Mathewson nickm@torproject.org Date: Fri Oct 16 10:31:13 2020 -0400

Update slow_ed25519.py to work with python 3. --- src/test/slow_ed25519.py | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/src/test/slow_ed25519.py b/src/test/slow_ed25519.py index be4eeab857..df1456b811 100644 --- a/src/test/slow_ed25519.py +++ b/src/test/slow_ed25519.py @@ -24,7 +24,7 @@ def H(m):

def expmod(b,e,m): if e == 0: return 1 - t = expmod(b,e/2,m)**2 % m + t = expmod(b,e//2,m)**2 % m if e & 1: t = (t*b) % m return t

@@ -32,11 +32,11 @@ def inv(x): return expmod(x,q-2,q)

d = -121665 * inv(121666) -I = expmod(2,(q-1)/4,q) +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) + 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 @@ -56,23 +56,23 @@ def edwards(P,Q):

def scalarmult(P,e): if e == 0: return [0,1] - Q = scalarmult(P,e/2) + Q = scalarmult(P,e//2) Q = edwards(Q,Q) if e & 1: Q = edwards(Q,P) return Q

def encodeint(y): bits = [(y >> i) & 1 for i in range(b)] - return ''.join([chr(sum([bits[i * 8 + j] << j for j in range(8)])) for i in range(b/8)]) + return bytes(sum([bits[i * 8 + j] << j for j in range(8)]) for i in range(b//8))

def encodepoint(P): x = P[0] y = P[1] bits = [(y >> i) & 1 for i in range(b - 1)] + [x & 1] - return ''.join([chr(sum([bits[i * 8 + j] << j for j in range(8)])) for i in range(b/8)]) + return bytes([(sum([bits[i * 8 + j] << j for j in range(8)])) for i in range(b//8)])

def bit(h,i): - return (ord(h[i/8]) >> (i%8)) & 1 + return (h[i//8] >> (i%8)) & 1

def publickey(sk): h = H(sk) @@ -87,7 +87,7 @@ def Hint(m): def signature(m,sk,pk): h = H(sk) a = 2**(b-2) + sum(2**i * bit(h,i) for i in range(3,b-2)) - r = Hint(''.join([h[i] for i in range(b/8,b/4)]) + m) + r = Hint(bytes([h[i] for i in range(b//8,b//4)]) + m) R = scalarmult(B,r) S = (r + Hint(encodepoint(R) + pk + m) * a) % l return encodepoint(R) + encodeint(S) @@ -109,12 +109,11 @@ def decodepoint(s): return P

def checkvalid(s,m,pk): - if len(s) != b/4: raise Exception("signature length is wrong") - if len(pk) != b/8: raise Exception("public-key length is wrong") - R = decodepoint(s[0:b/8]) + if len(s) != b//4: raise Exception("signature length is wrong") + if len(pk) != b//8: raise Exception("public-key length is wrong") + R = decodepoint(s[0:b//8]) A = decodepoint(pk) - S = decodeint(s[b/8:b/4]) + S = decodeint(s[b//8:b//4]) h = Hint(encodepoint(R) + pk + m) if scalarmult(B,S) != edwards(R,scalarmult(A,h)): raise Exception("signature does not pass verification") -