Added internal python-only implementation of Ed25519

This commit is contained in:
Mark Qvist 2022-06-08 19:47:09 +02:00
parent 34efbc6100
commit e0b795b4d0
12 changed files with 845 additions and 37 deletions

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@ -0,0 +1,41 @@
import os
from .pure25519 import ed25519_oop as ed25519
class Ed25519PrivateKey:
def __init__(self, seed):
self.seed = seed
self.sk = ed25519.SigningKey(self.seed)
#self.vk = self.sk.get_verifying_key()
@classmethod
def generate(cls):
return cls.from_private_bytes(os.urandom(32))
@classmethod
def from_private_bytes(cls, data):
return cls(seed=data)
def private_bytes(self):
return self.seed
def public_key(self):
return Ed25519PublicKey.from_public_bytes(self.sk.vk_s)
def sign(self, message):
return self.sk.sign(message)
class Ed25519PublicKey:
def __init__(self, seed):
self.seed = seed
self.vk = ed25519.VerifyingKey(self.seed)
@classmethod
def from_public_bytes(cls, data):
return cls(data)
def public_bytes(self):
return self.vk.to_bytes()
def verify(self, signature, message):
self.vk.verify(signature, message)

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@ -1,14 +1,20 @@
import hashlib import hashlib
"""
The SHA primitives are abstracted here to allow platform-
aware hardware acceleration in the future. Currently only
uses Python's internal SHA-256 implementation. All SHA-256
calls in RNS end up here.
"""
def sha256(data): def sha256(data):
"""
The SHA-256 primitive is abstracted here to allow platform-
aware hardware acceleration in the future. Currently only
uses Python's internal SHA-256 implementation. All SHA-256
calls in RNS end up here.
"""
digest = hashlib.sha256() digest = hashlib.sha256()
digest.update(data) digest.update(data)
return digest.digest() return digest.digest()
def sha512(data):
digest = hashlib.sha512()
digest.update(data)
return digest.digest()

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@ -2,6 +2,9 @@ from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey, Ed25519PublicKey from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey, Ed25519PublicKey
from cryptography.hazmat.primitives.asymmetric.x25519 import X25519PrivateKey, X25519PublicKey from cryptography.hazmat.primitives.asymmetric.x25519 import X25519PrivateKey, X25519PublicKey
# These proxy classes exist to create a uniform API accross
# cryptography primitive providers.
class X25519PrivateKeyProxy: class X25519PrivateKeyProxy:
def __init__(self, real): def __init__(self, real):
self.real = real self.real = real
@ -40,4 +43,48 @@ class X25519PublicKeyProxy:
return self.real.public_bytes( return self.real.public_bytes(
encoding=serialization.Encoding.Raw, encoding=serialization.Encoding.Raw,
format=serialization.PublicFormat.Raw format=serialization.PublicFormat.Raw
) )
class Ed25519PrivateKeyProxy:
def __init__(self, real):
self.real = real
@classmethod
def generate(cls):
return cls(Ed25519PrivateKey.generate())
@classmethod
def from_private_bytes(cls, data):
return cls(Ed25519PrivateKey.from_private_bytes(data))
def private_bytes(self):
return self.real.private_bytes(
encoding=serialization.Encoding.Raw,
format=serialization.PrivateFormat.Raw,
encryption_algorithm=serialization.NoEncryption()
)
def public_key(self):
return Ed25519PublicKeyProxy(self.real.public_key())
def sign(self, message):
return self.real.sign(message)
class Ed25519PublicKeyProxy:
def __init__(self, real):
self.real = real
@classmethod
def from_public_bytes(cls, data):
return cls(Ed25519PublicKey.from_public_bytes(data))
def public_bytes(self):
return self.real.public_bytes(
encoding=serialization.Encoding.Raw,
format=serialization.PublicFormat.Raw
)
def verify(self, signature, message):
self.real.verify(signature, message)

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@ -10,13 +10,13 @@ import RNS.Cryptography.Provider as cp
if cp.PROVIDER == cp.PROVIDER_INTERNAL: if cp.PROVIDER == cp.PROVIDER_INTERNAL:
from RNS.Cryptography.X25519 import X25519PrivateKey, X25519PublicKey from RNS.Cryptography.X25519 import X25519PrivateKey, X25519PublicKey
from RNS.Cryptography.Ed25519 import Ed25519PrivateKey, Ed25519PublicKey
# TODO: Use internal Ed25519
from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey, Ed25519PublicKey
elif cp.PROVIDER == cp.PROVIDER_PYCA: elif cp.PROVIDER == cp.PROVIDER_PYCA:
from RNS.Cryptography.Proxies import X25519PrivateKeyProxy as X25519PrivateKey from RNS.Cryptography.Proxies import X25519PrivateKeyProxy as X25519PrivateKey
from RNS.Cryptography.Proxies import X25519PublicKeyProxy as X25519PublicKey from RNS.Cryptography.Proxies import X25519PublicKeyProxy as X25519PublicKey
from RNS.Cryptography.Proxies import Ed25519PrivateKeyProxy as Ed25519PrivateKey
from RNS.Cryptography.Proxies import Ed25519PublicKeyProxy as Ed25519PublicKey
modules = glob.glob(os.path.dirname(__file__)+"/*.py") modules = glob.glob(os.path.dirname(__file__)+"/*.py")
__all__ = [ os.path.basename(f)[:-3] for f in modules if not f.endswith('__init__.py')] __all__ = [ os.path.basename(f)[:-3] for f in modules if not f.endswith('__init__.py')]

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# MIT License
#
# Copyright (c) 2015 Brian Warner and other contributors
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
from . import eddsa
class BadSignatureError(Exception):
pass
SECRETKEYBYTES = 64
PUBLICKEYBYTES = 32
SIGNATUREKEYBYTES = 64
def publickey(seed32):
assert len(seed32) == 32
vk32 = eddsa.publickey(seed32)
return vk32, seed32+vk32
def sign(msg, skvk):
assert len(skvk) == 64
sk = skvk[:32]
vk = skvk[32:]
sig = eddsa.signature(msg, sk, vk)
return sig+msg
def open(sigmsg, vk):
assert len(vk) == 32
sig = sigmsg[:64]
msg = sigmsg[64:]
try:
valid = eddsa.checkvalid(sig, msg, vk)
except ValueError as e:
raise BadSignatureError(e)
except Exception as e:
if str(e) == "decoding point that is not on curve":
raise BadSignatureError(e)
raise
if not valid:
raise BadSignatureError()
return msg

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@ -0,0 +1,368 @@
# MIT License
#
# Copyright (c) 2015 Brian Warner and other contributors
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
import binascii, hashlib, itertools
Q = 2**255 - 19
L = 2**252 + 27742317777372353535851937790883648493
def inv(x):
return pow(x, Q-2, Q)
d = -121665 * inv(121666)
I = pow(2,(Q-1)//4,Q)
def xrecover(y):
xx = (y*y-1) * inv(d*y*y+1)
x = pow(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]
# Extended Coordinates: x=X/Z, y=Y/Z, x*y=T/Z
# http://www.hyperelliptic.org/EFD/g1p/auto-twisted-extended-1.html
def xform_affine_to_extended(pt):
(x, y) = pt
return (x%Q, y%Q, 1, (x*y)%Q) # (X,Y,Z,T)
def xform_extended_to_affine(pt):
(x, y, z, _) = pt
return ((x*inv(z))%Q, (y*inv(z))%Q)
def double_element(pt): # extended->extended
# dbl-2008-hwcd
(X1, Y1, Z1, _) = pt
A = (X1*X1)
B = (Y1*Y1)
C = (2*Z1*Z1)
D = (-A) % Q
J = (X1+Y1) % Q
E = (J*J-A-B) % Q
G = (D+B) % Q
F = (G-C) % Q
H = (D-B) % Q
X3 = (E*F) % Q
Y3 = (G*H) % Q
Z3 = (F*G) % Q
T3 = (E*H) % Q
return (X3, Y3, Z3, T3)
def add_elements(pt1, pt2): # extended->extended
# add-2008-hwcd-3 . Slightly slower than add-2008-hwcd-4, but -3 is
# unified, so it's safe for general-purpose addition
(X1, Y1, Z1, T1) = pt1
(X2, Y2, Z2, T2) = pt2
A = ((Y1-X1)*(Y2-X2)) % Q
B = ((Y1+X1)*(Y2+X2)) % Q
C = T1*(2*d)*T2 % Q
D = Z1*2*Z2 % Q
E = (B-A) % Q
F = (D-C) % Q
G = (D+C) % Q
H = (B+A) % Q
X3 = (E*F) % Q
Y3 = (G*H) % Q
T3 = (E*H) % Q
Z3 = (F*G) % Q
return (X3, Y3, Z3, T3)
def scalarmult_element_safe_slow(pt, n):
# this form is slightly slower, but tolerates arbitrary points, including
# those which are not in the main 1*L subgroup. This includes points of
# order 1 (the neutral element Zero), 2, 4, and 8.
assert n >= 0
if n==0:
return xform_affine_to_extended((0,1))
_ = double_element(scalarmult_element_safe_slow(pt, n>>1))
return add_elements(_, pt) if n&1 else _
def _add_elements_nonunfied(pt1, pt2): # extended->extended
# add-2008-hwcd-4 : NOT unified, only for pt1!=pt2. About 10% faster than
# the (unified) add-2008-hwcd-3, and safe to use inside scalarmult if you
# aren't using points of order 1/2/4/8
(X1, Y1, Z1, T1) = pt1
(X2, Y2, Z2, T2) = pt2
A = ((Y1-X1)*(Y2+X2)) % Q
B = ((Y1+X1)*(Y2-X2)) % Q
C = (Z1*2*T2) % Q
D = (T1*2*Z2) % Q
E = (D+C) % Q
F = (B-A) % Q
G = (B+A) % Q
H = (D-C) % Q
X3 = (E*F) % Q
Y3 = (G*H) % Q
Z3 = (F*G) % Q
T3 = (E*H) % Q
return (X3, Y3, Z3, T3)
def scalarmult_element(pt, n): # extended->extended
# This form only works properly when given points that are a member of
# the main 1*L subgroup. It will give incorrect answers when called with
# the points of order 1/2/4/8, including point Zero. (it will also work
# properly when given points of order 2*L/4*L/8*L)
assert n >= 0
if n==0:
return xform_affine_to_extended((0,1))
_ = double_element(scalarmult_element(pt, n>>1))
return _add_elements_nonunfied(_, pt) if n&1 else _
# points are encoded as 32-bytes little-endian, b255 is sign, b2b1b0 are 0
def encodepoint(P):
x = P[0]
y = P[1]
# MSB of output equals x.b0 (=x&1)
# rest of output is little-endian y
assert 0 <= y < (1<<255) # always < 0x7fff..ff
if x & 1:
y += 1<<255
return binascii.unhexlify("%064x" % y)[::-1]
def isoncurve(P):
x = P[0]
y = P[1]
return (-x*x + y*y - 1 - d*x*x*y*y) % Q == 0
class NotOnCurve(Exception):
pass
def decodepoint(s):
unclamped = int(binascii.hexlify(s[:32][::-1]), 16)
clamp = (1 << 255) - 1
y = unclamped & clamp # clear MSB
x = xrecover(y)
if bool(x & 1) != bool(unclamped & (1<<255)): x = Q-x
P = [x,y]
if not isoncurve(P): raise NotOnCurve("decoding point that is not on curve")
return P
# scalars are encoded as 32-bytes little-endian
def bytes_to_scalar(s):
assert len(s) == 32, len(s)
return int(binascii.hexlify(s[::-1]), 16)
def bytes_to_clamped_scalar(s):
# Ed25519 private keys clamp the scalar to ensure two things:
# 1: integer value is in L/2 .. L, to avoid small-logarithm
# non-wraparaound
# 2: low-order 3 bits are zero, so a small-subgroup attack won't learn
# any information
# set the top two bits to 01, and the bottom three to 000
a_unclamped = bytes_to_scalar(s)
AND_CLAMP = (1<<254) - 1 - 7
OR_CLAMP = (1<<254)
a_clamped = (a_unclamped & AND_CLAMP) | OR_CLAMP
return a_clamped
def random_scalar(entropy_f): # 0..L-1 inclusive
# reduce the bias to a safe level by generating 256 extra bits
oversized = int(binascii.hexlify(entropy_f(32+32)), 16)
return oversized % L
def password_to_scalar(pw):
oversized = hashlib.sha512(pw).digest()
return int(binascii.hexlify(oversized), 16) % L
def scalar_to_bytes(y):
y = y % L
assert 0 <= y < 2**256
return binascii.unhexlify("%064x" % y)[::-1]
# Elements, of various orders
def is_extended_zero(XYTZ):
# catch Zero
(X, Y, Z, T) = XYTZ
Y = Y % Q
Z = Z % Q
if X==0 and Y==Z and Y!=0:
return True
return False
class ElementOfUnknownGroup:
# This is used for points of order 2,4,8,2*L,4*L,8*L
def __init__(self, XYTZ):
assert isinstance(XYTZ, tuple)
assert len(XYTZ) == 4
self.XYTZ = XYTZ
def add(self, other):
if not isinstance(other, ElementOfUnknownGroup):
raise TypeError("elements can only be added to other elements")
sum_XYTZ = add_elements(self.XYTZ, other.XYTZ)
if is_extended_zero(sum_XYTZ):
return Zero
return ElementOfUnknownGroup(sum_XYTZ)
def scalarmult(self, s):
if isinstance(s, ElementOfUnknownGroup):
raise TypeError("elements cannot be multiplied together")
assert s >= 0
product = scalarmult_element_safe_slow(self.XYTZ, s)
return ElementOfUnknownGroup(product)
def to_bytes(self):
return encodepoint(xform_extended_to_affine(self.XYTZ))
def __eq__(self, other):
return self.to_bytes() == other.to_bytes()
def __ne__(self, other):
return not self == other
class Element(ElementOfUnknownGroup):
# this only holds elements in the main 1*L subgroup. It never holds Zero,
# or elements of order 1/2/4/8, or 2*L/4*L/8*L.
def add(self, other):
if not isinstance(other, ElementOfUnknownGroup):
raise TypeError("elements can only be added to other elements")
sum_element = ElementOfUnknownGroup.add(self, other)
if sum_element is Zero:
return sum_element
if isinstance(other, Element):
# adding two subgroup elements results in another subgroup
# element, or Zero, and we've already excluded Zero
return Element(sum_element.XYTZ)
# not necessarily a subgroup member, so assume not
return sum_element
def scalarmult(self, s):
if isinstance(s, ElementOfUnknownGroup):
raise TypeError("elements cannot be multiplied together")
# scalarmult of subgroup members can be done modulo the subgroup
# order, and using the faster non-unified function.
s = s % L
# scalarmult(s=0) gets you Zero
if s == 0:
return Zero
# scalarmult(s=1) gets you self, which is a subgroup member
# scalarmult(s<grouporder) gets you a different subgroup member
return Element(scalarmult_element(self.XYTZ, s))
# negation and subtraction only make sense for the main subgroup
def negate(self):
# slow. Prefer e.scalarmult(-pw) to e.scalarmult(pw).negate()
return Element(scalarmult_element(self.XYTZ, L-2))
def subtract(self, other):
return self.add(other.negate())
class _ZeroElement(ElementOfUnknownGroup):
def add(self, other):
return other # zero+anything = anything
def scalarmult(self, s):
return self # zero*anything = zero
def negate(self):
return self # -zero = zero
def subtract(self, other):
return self.add(other.negate())
Base = Element(xform_affine_to_extended(B))
Zero = _ZeroElement(xform_affine_to_extended((0,1))) # the neutral (identity) element
_zero_bytes = Zero.to_bytes()
def arbitrary_element(seed): # unknown DL
# TODO: if we don't need uniformity, maybe use just sha256 here?
hseed = hashlib.sha512(seed).digest()
y = int(binascii.hexlify(hseed), 16) % Q
# we try successive Y values until we find a valid point
for plus in itertools.count(0):
y_plus = (y + plus) % Q
x = xrecover(y_plus)
Pa = [x,y_plus] # no attempt to use both "positive" and "negative" X
# only about 50% of Y coordinates map to valid curve points (I think
# the other half give you points on the "twist").
if not isoncurve(Pa):
continue
P = ElementOfUnknownGroup(xform_affine_to_extended(Pa))
# even if the point is on our curve, it may not be in our particular
# (order=L) subgroup. The curve has order 8*L, so an arbitrary point
# could have order 1,2,4,8,1*L,2*L,4*L,8*L (everything which divides
# the group order).
# [I MAY BE COMPLETELY WRONG ABOUT THIS, but my brief statistical
# tests suggest it's not too far off] There are phi(x) points with
# order x, so:
# 1 element of order 1: [(x=0,y=1)=Zero]
# 1 element of order 2 [(x=0,y=-1)]
# 2 elements of order 4
# 4 elements of order 8
# L-1 elements of order L (including Base)
# L-1 elements of order 2*L
# 2*(L-1) elements of order 4*L
# 4*(L-1) elements of order 8*L
# So 50% of random points will have order 8*L, 25% will have order
# 4*L, 13% order 2*L, and 13% will have our desired order 1*L (and a
# vanishingly small fraction will have 1/2/4/8). If we multiply any
# of the 8*L points by 2, we're sure to get an 4*L point (and
# multiplying a 4*L point by 2 gives us a 2*L point, and so on).
# Multiplying a 1*L point by 2 gives us a different 1*L point. So
# multiplying by 8 gets us from almost any point into a uniform point
# on the correct 1*L subgroup.
P8 = P.scalarmult(8)
# if we got really unlucky and picked one of the 8 low-order points,
# multiplying by 8 will get us to the identity (Zero), which we check
# for explicitly.
if is_extended_zero(P8.XYTZ):
continue
# Test that we're finally in the right group. We want to scalarmult
# by L, and we want to *not* use the trick in Group.scalarmult()
# which does x%L, because that would bypass the check we care about.
# P is still an _ElementOfUnknownGroup, which doesn't use x%L because
# that's not correct for points outside the main group.
assert is_extended_zero(P8.scalarmult(L).XYTZ)
return Element(P8.XYTZ)
# never reached
def bytes_to_unknown_group_element(bytes):
# this accepts all elements, including Zero and wrong-subgroup ones
if bytes == _zero_bytes:
return Zero
XYTZ = xform_affine_to_extended(decodepoint(bytes))
return ElementOfUnknownGroup(XYTZ)
def bytes_to_element(bytes):
# this strictly only accepts elements in the right subgroup
P = bytes_to_unknown_group_element(bytes)
if P is Zero:
raise ValueError("element was Zero")
if not is_extended_zero(P.scalarmult(L).XYTZ):
raise ValueError("element is not in the right group")
# the point is in the expected 1*L subgroup, not in the 2/4/8 groups,
# or in the 2*L/4*L/8*L groups. Promote it to a correct-group Element.
return Element(P.XYTZ)

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@ -0,0 +1,213 @@
# MIT License
#
# Copyright (c) 2015 Brian Warner and other contributors
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
import os
import base64
from . import _ed25519
BadSignatureError = _ed25519.BadSignatureError
def create_keypair(entropy=os.urandom):
SEEDLEN = int(_ed25519.SECRETKEYBYTES/2)
assert SEEDLEN == 32
seed = entropy(SEEDLEN)
sk = SigningKey(seed)
vk = sk.get_verifying_key()
return sk, vk
class BadPrefixError(Exception):
pass
def remove_prefix(s_bytes, prefix):
assert(type(s_bytes) == type(prefix))
if s_bytes[:len(prefix)] != prefix:
raise BadPrefixError("did not see expected '%s' prefix" % (prefix,))
return s_bytes[len(prefix):]
def to_ascii(s_bytes, prefix="", encoding="base64"):
"""Return a version-prefixed ASCII representation of the given binary
string. 'encoding' indicates how to do the encoding, and can be one of:
* base64
* base32
* base16 (or hex)
This function handles bytes, not bits, so it does not append any trailing
'=' (unlike standard base64.b64encode). It also lowercases the base32
output.
'prefix' will be prepended to the encoded form, and is useful for
distinguishing the purpose and version of the binary string. E.g. you
could prepend 'pub0-' to a VerifyingKey string to allow the receiving
code to raise a useful error if someone pasted in a signature string by
mistake.
"""
assert isinstance(s_bytes, bytes)
if not isinstance(prefix, bytes):
prefix = prefix.encode('ascii')
if encoding == "base64":
s_ascii = base64.b64encode(s_bytes).decode('ascii').rstrip("=")
elif encoding == "base32":
s_ascii = base64.b32encode(s_bytes).decode('ascii').rstrip("=").lower()
elif encoding in ("base16", "hex"):
s_ascii = base64.b16encode(s_bytes).decode('ascii').lower()
else:
raise NotImplementedError
return prefix+s_ascii.encode('ascii')
def from_ascii(s_ascii, prefix="", encoding="base64"):
"""This is the opposite of to_ascii. It will throw BadPrefixError if
the prefix is not found.
"""
if isinstance(s_ascii, bytes):
s_ascii = s_ascii.decode('ascii')
if isinstance(prefix, bytes):
prefix = prefix.decode('ascii')
s_ascii = remove_prefix(s_ascii.strip(), prefix)
if encoding == "base64":
s_ascii += "="*((4 - len(s_ascii)%4)%4)
s_bytes = base64.b64decode(s_ascii)
elif encoding == "base32":
s_ascii += "="*((8 - len(s_ascii)%8)%8)
s_bytes = base64.b32decode(s_ascii.upper())
elif encoding in ("base16", "hex"):
s_bytes = base64.b16decode(s_ascii.upper())
else:
raise NotImplementedError
return s_bytes
class SigningKey(object):
# this can only be used to reconstruct a key created by create_keypair().
def __init__(self, sk_s, prefix="", encoding=None):
assert isinstance(sk_s, bytes)
if not isinstance(prefix, bytes):
prefix = prefix.encode('ascii')
sk_s = remove_prefix(sk_s, prefix)
if encoding is not None:
sk_s = from_ascii(sk_s, encoding=encoding)
if len(sk_s) == 32:
# create from seed
vk_s, sk_s = _ed25519.publickey(sk_s)
else:
if len(sk_s) != 32+32:
raise ValueError("SigningKey takes 32-byte seed or 64-byte string")
self.sk_s = sk_s # seed+pubkey
self.vk_s = sk_s[32:] # just pubkey
def to_bytes(self, prefix=""):
if not isinstance(prefix, bytes):
prefix = prefix.encode('ascii')
return prefix+self.sk_s
def to_ascii(self, prefix="", encoding=None):
assert encoding
if not isinstance(prefix, bytes):
prefix = prefix.encode('ascii')
return to_ascii(self.to_seed(), prefix, encoding)
def to_seed(self, prefix=""):
if not isinstance(prefix, bytes):
prefix = prefix.encode('ascii')
return prefix+self.sk_s[:32]
def __eq__(self, them):
if not isinstance(them, object): return False
return (them.__class__ == self.__class__
and them.sk_s == self.sk_s)
def get_verifying_key(self):
return VerifyingKey(self.vk_s)
def sign(self, msg, prefix="", encoding=None):
assert isinstance(msg, bytes)
if not isinstance(prefix, bytes):
prefix = prefix.encode('ascii')
sig_and_msg = _ed25519.sign(msg, self.sk_s)
# the response is R+S+msg
sig_R = sig_and_msg[0:32]
sig_S = sig_and_msg[32:64]
msg_out = sig_and_msg[64:]
sig_out = sig_R + sig_S
assert msg_out == msg
if encoding:
return to_ascii(sig_out, prefix, encoding)
return prefix+sig_out
class VerifyingKey(object):
def __init__(self, vk_s, prefix="", encoding=None):
if not isinstance(prefix, bytes):
prefix = prefix.encode('ascii')
if not isinstance(vk_s, bytes):
vk_s = vk_s.encode('ascii')
assert isinstance(vk_s, bytes)
vk_s = remove_prefix(vk_s, prefix)
if encoding is not None:
vk_s = from_ascii(vk_s, encoding=encoding)
assert len(vk_s) == 32
self.vk_s = vk_s
def to_bytes(self, prefix=""):
if not isinstance(prefix, bytes):
prefix = prefix.encode('ascii')
return prefix+self.vk_s
def to_ascii(self, prefix="", encoding=None):
assert encoding
if not isinstance(prefix, bytes):
prefix = prefix.encode('ascii')
return to_ascii(self.vk_s, prefix, encoding)
def __eq__(self, them):
if not isinstance(them, object): return False
return (them.__class__ == self.__class__
and them.vk_s == self.vk_s)
def verify(self, sig, msg, prefix="", encoding=None):
if not isinstance(sig, bytes):
sig = sig.encode('ascii')
if not isinstance(prefix, bytes):
prefix = prefix.encode('ascii')
assert isinstance(sig, bytes)
assert isinstance(msg, bytes)
if encoding:
sig = from_ascii(sig, prefix, encoding)
else:
sig = remove_prefix(sig, prefix)
assert len(sig) == 64
sig_R = sig[:32]
sig_S = sig[32:]
sig_and_msg = sig_R + sig_S + msg
# this might raise BadSignatureError
msg2 = _ed25519.open(sig_and_msg, self.vk_s)
assert msg2 == msg
def selftest():
message = b"crypto libraries should always test themselves at powerup"
sk = SigningKey(b"priv0-VIsfn5OFGa09Un2MR6Hm7BQ5++xhcQskU2OGXG8jSJl4cWLZrRrVcSN2gVYMGtZT+3354J5jfmqAcuRSD9KIyg",
prefix="priv0-", encoding="base64")
vk = VerifyingKey(b"pub0-eHFi2a0a1XEjdoFWDBrWU/t9+eCeY35qgHLkUg/SiMo",
prefix="pub0-", encoding="base64")
assert sk.get_verifying_key() == vk
sig = sk.sign(message, prefix="sig0-", encoding="base64")
assert sig == b"sig0-E/QrwtSF52x8+q0l4ahA7eJbRKc777ClKNg217Q0z4fiYMCdmAOI+rTLVkiFhX6k3D+wQQfKdJYMxaTUFfv1DQ", sig
vk.verify(sig, message, prefix="sig0-", encoding="base64")
selftest()

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@ -0,0 +1,94 @@
# MIT License
#
# Copyright (c) 2015 Brian Warner and other contributors
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
from RNS.Cryptography.Hashes import sha512
from .basic import (bytes_to_clamped_scalar,
bytes_to_scalar, scalar_to_bytes,
bytes_to_element, Base)
import hashlib, binascii
def H(m):
return sha512(m)
def publickey(seed):
# turn first half of SHA512(seed) into scalar, then into point
assert len(seed) == 32
a = bytes_to_clamped_scalar(H(seed)[:32])
A = Base.scalarmult(a)
return A.to_bytes()
def Hint(m):
h = H(m)
return int(binascii.hexlify(h[::-1]), 16)
def signature(m,sk,pk):
assert len(sk) == 32 # seed
assert len(pk) == 32
h = H(sk[:32])
a_bytes, inter = h[:32], h[32:]
a = bytes_to_clamped_scalar(a_bytes)
r = Hint(inter + m)
R = Base.scalarmult(r)
R_bytes = R.to_bytes()
S = r + Hint(R_bytes + pk + m) * a
return R_bytes + scalar_to_bytes(S)
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
# wrappers
import os
def create_signing_key():
seed = os.urandom(32)
return seed
def create_verifying_key(signing_key):
return publickey(signing_key)
def sign(skbytes, msg):
"""Return just the signature, given the message and just the secret
key."""
if len(skbytes) != 32:
raise ValueError("Bad signing key length %d" % len(skbytes))
vkbytes = create_verifying_key(skbytes)
sig = signature(msg, skbytes, vkbytes)
return sig
def verify(vkbytes, sig, msg):
if len(vkbytes) != 32:
raise ValueError("Bad verifying key length %d" % len(vkbytes))
if len(sig) != 64:
raise ValueError("Bad signature length %d" % len(sig))
rc = checkvalid(sig, msg, vkbytes)
if not rc:
raise ValueError("rc != 0", rc)
return True

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@ -28,10 +28,8 @@ import atexit
import hashlib import hashlib
from .vendor import umsgpack as umsgpack from .vendor import umsgpack as umsgpack
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey, Ed25519PublicKey
from RNS.Cryptography import X25519PrivateKey, X25519PublicKey from RNS.Cryptography import X25519PrivateKey, X25519PublicKey, Ed25519PrivateKey, Ed25519PublicKey
from RNS.Cryptography import Fernet from RNS.Cryptography import Fernet
@ -294,20 +292,13 @@ class Identity:
self.prv_bytes = self.prv.private_bytes() self.prv_bytes = self.prv.private_bytes()
self.sig_prv = Ed25519PrivateKey.generate() self.sig_prv = Ed25519PrivateKey.generate()
self.sig_prv_bytes = self.sig_prv.private_bytes( self.sig_prv_bytes = self.sig_prv.private_bytes()
encoding=serialization.Encoding.Raw,
format=serialization.PrivateFormat.Raw,
encryption_algorithm=serialization.NoEncryption()
)
self.pub = self.prv.public_key() self.pub = self.prv.public_key()
self.pub_bytes = self.pub.public_bytes() self.pub_bytes = self.pub.public_bytes()
self.sig_pub = self.sig_prv.public_key() self.sig_pub = self.sig_prv.public_key()
self.sig_pub_bytes = self.sig_pub.public_bytes( self.sig_pub_bytes = self.sig_pub.public_bytes()
encoding=serialization.Encoding.Raw,
format=serialization.PublicFormat.Raw
)
self.update_hashes() self.update_hashes()
@ -342,10 +333,7 @@ class Identity:
self.pub_bytes = self.pub.public_bytes() self.pub_bytes = self.pub.public_bytes()
self.sig_pub = self.sig_prv.public_key() self.sig_pub = self.sig_prv.public_key()
self.sig_pub_bytes = self.sig_pub.public_bytes( self.sig_pub_bytes = self.sig_pub.public_bytes()
encoding=serialization.Encoding.Raw,
format=serialization.PublicFormat.Raw
)
self.update_hashes() self.update_hashes()

View File

@ -20,11 +20,7 @@
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE. # SOFTWARE.
from cryptography.hazmat.primitives import hashes from RNS.Cryptography import X25519PrivateKey, X25519PublicKey, Ed25519PrivateKey, Ed25519PublicKey
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey, Ed25519PublicKey
from RNS.Cryptography import X25519PrivateKey, X25519PublicKey
from RNS.Cryptography import Fernet from RNS.Cryptography import Fernet
from time import sleep from time import sleep
@ -180,10 +176,7 @@ class Link:
self.pub_bytes = self.pub.public_bytes() self.pub_bytes = self.pub.public_bytes()
self.sig_pub = self.sig_prv.public_key() self.sig_pub = self.sig_prv.public_key()
self.sig_pub_bytes = self.sig_pub.public_bytes( self.sig_pub_bytes = self.sig_pub.public_bytes()
encoding=serialization.Encoding.Raw,
format=serialization.PublicFormat.Raw
)
if peer_pub_bytes == None: if peer_pub_bytes == None:
self.peer_pub = None self.peer_pub = None

View File

@ -1 +1 @@
__version__ = "0.3.7" __version__ = "0.3.8"