Example #1
0
def checkvalid(s, m, pk):
    if len(s) != 64: raise Exception("signature length is wrong")
    if len(pk) != 32: raise Exception("public-key length is wrong")
    R = bytes_to_element(s[:32])
    A = bytes_to_element(pk)
    S = bytes_to_scalar(s[32:])
    h = Hint(s[:32] + pk + m)
    v1 = Base.scalarmult(S)
    v2 = R.add(A.scalarmult(h))
    return v1==v2
Example #2
0
def checkvalid(s, m, pk):
    if len(s) != 64: raise Exception("signature length is wrong")
    if len(pk) != 32: raise Exception("public-key length is wrong")
    R = bytes_to_element(s[:32])
    A = bytes_to_element(pk)
    S = bytes_to_scalar(s[32:])
    h = Hint(s[:32] + pk + m)
    v1 = Base.scalarmult(S)
    v2 = R.add(A.scalarmult(h))
    return v1==v2
Example #3
0
def checkpk(pk, ext_pk):
    if len(pk) != 32:
        raise Exception("Public-key length is wrong")

    A = bytes_to_element(pk)
    if A != ext_pk:
        raise Exception("Wrong public key extracted")
Example #4
0
def extractpk(s, m):
    if len(s) != 64:
        raise Exception("Signature length is wrong")
    R = bytes_to_element(s[:32])
    S = bytes_to_scalar(s[32:])
    h = Hint(s[:32] + m)
    h_inv = inv2(h)
    R_neg = R.scalarmult(L-1)
    v1 = Base.scalarmult(S)
    v2 = v1.add(R_neg)
    A = v2.scalarmult(h_inv)
    return A
Example #5
0
    def test_bytes_to_element(self):
        b = encodepoint((0, 1))  # order 1, aka Zero
        self.assertRaises(ValueError, bytes_to_element, b)
        p = bytes_to_unknown_group_element(b)
        self.assertFalse(isinstance(p, Element))
        self.assertIs(p, Zero)

        b = encodepoint((0, -1 % Q))  # order 2
        self.assertRaises(ValueError, bytes_to_element, b)
        p = bytes_to_unknown_group_element(b)
        self.assertFalse(isinstance(p, Element))

        # (..,26) is in the right group
        b = b"\x1a" + b"\x00" * 31
        p = bytes_to_element(b)
        self.assertTrue(isinstance(p, Element))
Example #6
0
    def test_bytes_to_element(self):
        b = encodepoint((0,1)) # order 1, aka Zero
        self.assertRaises(ValueError, bytes_to_element, b)
        p = bytes_to_unknown_group_element(b)
        self.assertFalse(isinstance(p, Element))
        self.assertIs(p, Zero)

        b = encodepoint((0,-1%Q)) # order 2
        self.assertRaises(ValueError, bytes_to_element, b)
        p = bytes_to_unknown_group_element(b)
        self.assertFalse(isinstance(p, Element))

        # (..,26) is in the right group
        b = b"\x1a" + b"\x00"*31
        p = bytes_to_element(b)
        self.assertTrue(isinstance(p, Element))
Example #7
0
def dh_finish(x, Y_s):
    Y = bytes_to_element(Y_s)
    XY = Y.scalarmult(x)
    return sha256(XY.to_bytes()).digest()
Example #8
0
File: dh.py Project: levic92/PyRai
def dh_finish(x, Y_s):
    Y = bytes_to_element(Y_s)
    XY = Y.scalarmult(x)
    return blake2b(XY.to_bytes()).digest()
Example #9
0
def _finish(start_data, Y_s, blinding):
    (a, pw_scalar) = start_data
    Y = bytes_to_element(Y_s)  # rejects zero and non-group
    Z = Y.add(blinding.scalarmult(-pw_scalar)).scalarmult(a)
    return Z.to_bytes()
Example #10
0
def dh_finish(x: int, Y_s: bytes) -> bytes:
    Y = bytes_to_element(Y_s)
    XY = Y.scalarmult(x)
    return sha256(XY.to_bytes()).digest()
Example #11
0
def _finish(start_data, Y_s, blinding):
    (a, pw_scalar) = start_data
    Y = bytes_to_element(Y_s) # rejects zero and non-group
    Z = Y.add(blinding.scalarmult(-pw_scalar)).scalarmult(a)
    return Z.to_bytes()