This commit is contained in:
lz_db
2025-11-16 12:31:03 +08:00
commit 0fab423a18
1451 changed files with 743213 additions and 0 deletions

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from .keys import SigningKey, VerifyingKey, BadSignatureError, BadDigestError
from .curves import NIST192p, NIST224p, NIST256p, NIST384p, NIST521p, SECP256k1
# This code comes from http://github.com/warner/python-ecdsa
#from ._version import get_versions
__version__ = 'ccxt' # custom ccxt version
#del get_versions
__all__ = ["curves", "der", "ecdsa", "ellipticcurve", "keys", "numbertheory",
"util"]
_hush_pyflakes = [SigningKey, VerifyingKey, BadSignatureError, BadDigestError,
NIST192p, NIST224p, NIST256p, NIST384p, NIST521p, SECP256k1]
del _hush_pyflakes

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# This file helps to compute a version number in source trees obtained from
# git-archive tarball (such as those provided by githubs download-from-tag
# feature). Distribution tarballs (built by setup.py sdist) and build
# directories (produced by setup.py build) will contain a much shorter file
# that just contains the computed version number.
# This file is released into the public domain. Generated by
# versioneer-0.17 (https://github.com/warner/python-versioneer)
"""Git implementation of _version.py."""
import errno
import os
import re
import subprocess
import sys
def get_keywords():
"""Get the keywords needed to look up the version information."""
# these strings will be replaced by git during git-archive.
# setup.py/versioneer.py will grep for the variable names, so they must
# each be defined on a line of their own. _version.py will just call
# get_keywords().
git_refnames = "$Format:%d$"
git_full = "$Format:%H$"
git_date = "$Format:%ci$"
keywords = {"refnames": git_refnames, "full": git_full, "date": git_date}
return keywords
class VersioneerConfig:
"""Container for Versioneer configuration parameters."""
def get_config():
"""Create, populate and return the VersioneerConfig() object."""
# these strings are filled in when 'setup.py versioneer' creates
# _version.py
cfg = VersioneerConfig()
cfg.VCS = "git"
cfg.style = "pep440"
cfg.tag_prefix = "python-ecdsa-"
cfg.parentdir_prefix = "ecdsa-"
cfg.versionfile_source = "ecdsa/_version.py"
cfg.verbose = False
return cfg
class NotThisMethod(Exception):
"""Exception raised if a method is not valid for the current scenario."""
LONG_VERSION_PY = {}
HANDLERS = {}
def register_vcs_handler(vcs, method): # decorator
"""Decorator to mark a method as the handler for a particular VCS."""
def decorate(f):
"""Store f in HANDLERS[vcs][method]."""
if vcs not in HANDLERS:
HANDLERS[vcs] = {}
HANDLERS[vcs][method] = f
return f
return decorate
def run_command(commands, args, cwd=None, verbose=False, hide_stderr=False,
env=None):
"""Call the given command(s)."""
assert isinstance(commands, list)
p = None
for c in commands:
try:
dispcmd = str([c] + args)
# remember shell=False, so use git.cmd on windows, not just git
p = subprocess.Popen([c] + args, cwd=cwd, env=env,
stdout=subprocess.PIPE,
stderr=(subprocess.PIPE if hide_stderr
else None))
break
except EnvironmentError:
e = sys.exc_info()[1]
if e.errno == errno.ENOENT:
continue
if verbose:
print("unable to run %s" % dispcmd)
print(e)
return None, None
else:
if verbose:
print("unable to find command, tried %s" % (commands,))
return None, None
stdout = p.communicate()[0].strip()
if sys.version_info[0] >= 3:
stdout = stdout.decode()
if p.returncode != 0:
if verbose:
print("unable to run %s (error)" % dispcmd)
print("stdout was %s" % stdout)
return None, p.returncode
return stdout, p.returncode
def versions_from_parentdir(parentdir_prefix, root, verbose):
"""Try to determine the version from the parent directory name.
Source tarballs conventionally unpack into a directory that includes both
the project name and a version string. We will also support searching up
two directory levels for an appropriately named parent directory
"""
rootdirs = []
for i in range(3):
dirname = os.path.basename(root)
if dirname.startswith(parentdir_prefix):
return {"version": dirname[len(parentdir_prefix):],
"full-revisionid": None,
"dirty": False, "error": None, "date": None}
else:
rootdirs.append(root)
root = os.path.dirname(root) # up a level
if verbose:
print("Tried directories %s but none started with prefix %s" %
(str(rootdirs), parentdir_prefix))
raise NotThisMethod("rootdir doesn't start with parentdir_prefix")
@register_vcs_handler("git", "get_keywords")
def git_get_keywords(versionfile_abs):
"""Extract version information from the given file."""
# the code embedded in _version.py can just fetch the value of these
# keywords. When used from setup.py, we don't want to import _version.py,
# so we do it with a regexp instead. This function is not used from
# _version.py.
keywords = {}
try:
f = open(versionfile_abs, "r")
for line in f.readlines():
if line.strip().startswith("git_refnames ="):
mo = re.search(r'=\s*"(.*)"', line)
if mo:
keywords["refnames"] = mo.group(1)
if line.strip().startswith("git_full ="):
mo = re.search(r'=\s*"(.*)"', line)
if mo:
keywords["full"] = mo.group(1)
if line.strip().startswith("git_date ="):
mo = re.search(r'=\s*"(.*)"', line)
if mo:
keywords["date"] = mo.group(1)
f.close()
except EnvironmentError:
pass
return keywords
@register_vcs_handler("git", "keywords")
def git_versions_from_keywords(keywords, tag_prefix, verbose):
"""Get version information from git keywords."""
if not keywords:
raise NotThisMethod("no keywords at all, weird")
date = keywords.get("date")
if date is not None:
# git-2.2.0 added "%cI", which expands to an ISO-8601 -compliant
# datestamp. However we prefer "%ci" (which expands to an "ISO-8601
# -like" string, which we must then edit to make compliant), because
# it's been around since git-1.5.3, and it's too difficult to
# discover which version we're using, or to work around using an
# older one.
date = date.strip().replace(" ", "T", 1).replace(" ", "", 1)
refnames = keywords["refnames"].strip()
if refnames.startswith("$Format"):
if verbose:
print("keywords are unexpanded, not using")
raise NotThisMethod("unexpanded keywords, not a git-archive tarball")
refs = set([r.strip() for r in refnames.strip("()").split(",")])
# starting in git-1.8.3, tags are listed as "tag: foo-1.0" instead of
# just "foo-1.0". If we see a "tag: " prefix, prefer those.
TAG = "tag: "
tags = set([r[len(TAG):] for r in refs if r.startswith(TAG)])
if not tags:
# Either we're using git < 1.8.3, or there really are no tags. We use
# a heuristic: assume all version tags have a digit. The old git %d
# expansion behaves like git log --decorate=short and strips out the
# refs/heads/ and refs/tags/ prefixes that would let us distinguish
# between branches and tags. By ignoring refnames without digits, we
# filter out many common branch names like "release" and
# "stabilization", as well as "HEAD" and "master".
tags = set([r for r in refs if re.search(r'\d', r)])
if verbose:
print("discarding '%s', no digits" % ",".join(refs - tags))
if verbose:
print("likely tags: %s" % ",".join(sorted(tags)))
for ref in sorted(tags):
# sorting will prefer e.g. "2.0" over "2.0rc1"
if ref.startswith(tag_prefix):
r = ref[len(tag_prefix):]
if verbose:
print("picking %s" % r)
return {"version": r,
"full-revisionid": keywords["full"].strip(),
"dirty": False, "error": None,
"date": date}
# no suitable tags, so version is "0+unknown", but full hex is still there
if verbose:
print("no suitable tags, using unknown + full revision id")
return {"version": "0+unknown",
"full-revisionid": keywords["full"].strip(),
"dirty": False, "error": "no suitable tags", "date": None}
@register_vcs_handler("git", "pieces_from_vcs")
def git_pieces_from_vcs(tag_prefix, root, verbose, run_command=run_command):
"""Get version from 'git describe' in the root of the source tree.
This only gets called if the git-archive 'subst' keywords were *not*
expanded, and _version.py hasn't already been rewritten with a short
version string, meaning we're inside a checked out source tree.
"""
GITS = ["git"]
if sys.platform == "win32":
GITS = ["git.cmd", "git.exe"]
out, rc = run_command(GITS, ["rev-parse", "--git-dir"], cwd=root,
hide_stderr=True)
if rc != 0:
if verbose:
print("Directory %s not under git control" % root)
raise NotThisMethod("'git rev-parse --git-dir' returned error")
# if there is a tag matching tag_prefix, this yields TAG-NUM-gHEX[-dirty]
# if there isn't one, this yields HEX[-dirty] (no NUM)
describe_out, rc = run_command(GITS, ["describe", "--tags", "--dirty",
"--always", "--long",
"--match", "%s*" % tag_prefix],
cwd=root)
# --long was added in git-1.5.5
if describe_out is None:
raise NotThisMethod("'git describe' failed")
describe_out = describe_out.strip()
full_out, rc = run_command(GITS, ["rev-parse", "HEAD"], cwd=root)
if full_out is None:
raise NotThisMethod("'git rev-parse' failed")
full_out = full_out.strip()
pieces = {}
pieces["long"] = full_out
pieces["short"] = full_out[:7] # maybe improved later
pieces["error"] = None
# parse describe_out. It will be like TAG-NUM-gHEX[-dirty] or HEX[-dirty]
# TAG might have hyphens.
git_describe = describe_out
# look for -dirty suffix
dirty = git_describe.endswith("-dirty")
pieces["dirty"] = dirty
if dirty:
git_describe = git_describe[:git_describe.rindex("-dirty")]
# now we have TAG-NUM-gHEX or HEX
if "-" in git_describe:
# TAG-NUM-gHEX
mo = re.search(r'^(.+)-(\d+)-g([0-9a-f]+)$', git_describe)
if not mo:
# unparseable. Maybe git-describe is misbehaving?
pieces["error"] = ("unable to parse git-describe output: '%s'"
% describe_out)
return pieces
# tag
full_tag = mo.group(1)
if not full_tag.startswith(tag_prefix):
if verbose:
fmt = "tag '%s' doesn't start with prefix '%s'"
print(fmt % (full_tag, tag_prefix))
pieces["error"] = ("tag '%s' doesn't start with prefix '%s'"
% (full_tag, tag_prefix))
return pieces
pieces["closest-tag"] = full_tag[len(tag_prefix):]
# distance: number of commits since tag
pieces["distance"] = int(mo.group(2))
# commit: short hex revision ID
pieces["short"] = mo.group(3)
else:
# HEX: no tags
pieces["closest-tag"] = None
count_out, rc = run_command(GITS, ["rev-list", "HEAD", "--count"],
cwd=root)
pieces["distance"] = int(count_out) # total number of commits
# commit date: see ISO-8601 comment in git_versions_from_keywords()
date = run_command(GITS, ["show", "-s", "--format=%ci", "HEAD"],
cwd=root)[0].strip()
pieces["date"] = date.strip().replace(" ", "T", 1).replace(" ", "", 1)
return pieces
def plus_or_dot(pieces):
"""Return a + if we don't already have one, else return a ."""
if "+" in pieces.get("closest-tag", ""):
return "."
return "+"
def render_pep440(pieces):
"""Build up version string, with post-release "local version identifier".
Our goal: TAG[+DISTANCE.gHEX[.dirty]] . Note that if you
get a tagged build and then dirty it, you'll get TAG+0.gHEX.dirty
Exceptions:
1: no tags. git_describe was just HEX. 0+untagged.DISTANCE.gHEX[.dirty]
"""
if pieces["closest-tag"]:
rendered = pieces["closest-tag"]
if pieces["distance"] or pieces["dirty"]:
rendered += plus_or_dot(pieces)
rendered += "%d.g%s" % (pieces["distance"], pieces["short"])
if pieces["dirty"]:
rendered += ".dirty"
else:
# exception #1
rendered = "0+untagged.%d.g%s" % (pieces["distance"],
pieces["short"])
if pieces["dirty"]:
rendered += ".dirty"
return rendered
def render_pep440_pre(pieces):
"""TAG[.post.devDISTANCE] -- No -dirty.
Exceptions:
1: no tags. 0.post.devDISTANCE
"""
if pieces["closest-tag"]:
rendered = pieces["closest-tag"]
if pieces["distance"]:
rendered += ".post.dev%d" % pieces["distance"]
else:
# exception #1
rendered = "0.post.dev%d" % pieces["distance"]
return rendered
def render_pep440_post(pieces):
"""TAG[.postDISTANCE[.dev0]+gHEX] .
The ".dev0" means dirty. Note that .dev0 sorts backwards
(a dirty tree will appear "older" than the corresponding clean one),
but you shouldn't be releasing software with -dirty anyways.
Exceptions:
1: no tags. 0.postDISTANCE[.dev0]
"""
if pieces["closest-tag"]:
rendered = pieces["closest-tag"]
if pieces["distance"] or pieces["dirty"]:
rendered += ".post%d" % pieces["distance"]
if pieces["dirty"]:
rendered += ".dev0"
rendered += plus_or_dot(pieces)
rendered += "g%s" % pieces["short"]
else:
# exception #1
rendered = "0.post%d" % pieces["distance"]
if pieces["dirty"]:
rendered += ".dev0"
rendered += "+g%s" % pieces["short"]
return rendered
def render_pep440_old(pieces):
"""TAG[.postDISTANCE[.dev0]] .
The ".dev0" means dirty.
Eexceptions:
1: no tags. 0.postDISTANCE[.dev0]
"""
if pieces["closest-tag"]:
rendered = pieces["closest-tag"]
if pieces["distance"] or pieces["dirty"]:
rendered += ".post%d" % pieces["distance"]
if pieces["dirty"]:
rendered += ".dev0"
else:
# exception #1
rendered = "0.post%d" % pieces["distance"]
if pieces["dirty"]:
rendered += ".dev0"
return rendered
def render_git_describe(pieces):
"""TAG[-DISTANCE-gHEX][-dirty].
Like 'git describe --tags --dirty --always'.
Exceptions:
1: no tags. HEX[-dirty] (note: no 'g' prefix)
"""
if pieces["closest-tag"]:
rendered = pieces["closest-tag"]
if pieces["distance"]:
rendered += "-%d-g%s" % (pieces["distance"], pieces["short"])
else:
# exception #1
rendered = pieces["short"]
if pieces["dirty"]:
rendered += "-dirty"
return rendered
def render_git_describe_long(pieces):
"""TAG-DISTANCE-gHEX[-dirty].
Like 'git describe --tags --dirty --always -long'.
The distance/hash is unconditional.
Exceptions:
1: no tags. HEX[-dirty] (note: no 'g' prefix)
"""
if pieces["closest-tag"]:
rendered = pieces["closest-tag"]
rendered += "-%d-g%s" % (pieces["distance"], pieces["short"])
else:
# exception #1
rendered = pieces["short"]
if pieces["dirty"]:
rendered += "-dirty"
return rendered
def render(pieces, style):
"""Render the given version pieces into the requested style."""
if pieces["error"]:
return {"version": "unknown",
"full-revisionid": pieces.get("long"),
"dirty": None,
"error": pieces["error"],
"date": None}
if not style or style == "default":
style = "pep440" # the default
if style == "pep440":
rendered = render_pep440(pieces)
elif style == "pep440-pre":
rendered = render_pep440_pre(pieces)
elif style == "pep440-post":
rendered = render_pep440_post(pieces)
elif style == "pep440-old":
rendered = render_pep440_old(pieces)
elif style == "git-describe":
rendered = render_git_describe(pieces)
elif style == "git-describe-long":
rendered = render_git_describe_long(pieces)
else:
raise ValueError("unknown style '%s'" % style)
return {"version": rendered, "full-revisionid": pieces["long"],
"dirty": pieces["dirty"], "error": None,
"date": pieces.get("date")}
def get_versions():
"""Get version information or return default if unable to do so."""
# I am in _version.py, which lives at ROOT/VERSIONFILE_SOURCE. If we have
# __file__, we can work backwards from there to the root. Some
# py2exe/bbfreeze/non-CPython implementations don't do __file__, in which
# case we can only use expanded keywords.
cfg = get_config()
verbose = cfg.verbose
try:
return git_versions_from_keywords(get_keywords(), cfg.tag_prefix,
verbose)
except NotThisMethod:
pass
try:
root = os.path.realpath(__file__)
# versionfile_source is the relative path from the top of the source
# tree (where the .git directory might live) to this file. Invert
# this to find the root from __file__.
for i in cfg.versionfile_source.split('/'):
root = os.path.dirname(root)
except NameError:
return {"version": "0+unknown", "full-revisionid": None,
"dirty": None,
"error": "unable to find root of source tree",
"date": None}
try:
pieces = git_pieces_from_vcs(cfg.tag_prefix, root, verbose)
return render(pieces, cfg.style)
except NotThisMethod:
pass
try:
if cfg.parentdir_prefix:
return versions_from_parentdir(cfg.parentdir_prefix, root, verbose)
except NotThisMethod:
pass
return {"version": "0+unknown", "full-revisionid": None,
"dirty": None,
"error": "unable to compute version", "date": None}

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from __future__ import division
from . import der, ecdsa
class UnknownCurveError(Exception):
pass
def orderlen(order):
return (1+len("%x" % order))//2 # bytes
# the NIST curves
class Curve:
def __init__(self, name, curve, generator, oid, openssl_name=None):
self.name = name
self.openssl_name = openssl_name # maybe None
self.curve = curve
self.generator = generator
self.order = generator.order()
self.baselen = orderlen(self.order)
self.verifying_key_length = 2*self.baselen
self.signature_length = 2*self.baselen
self.oid = oid
self.encoded_oid = der.encode_oid(*oid)
NIST192p = Curve("NIST192p", ecdsa.curve_192,
ecdsa.generator_192,
(1, 2, 840, 10045, 3, 1, 1), "prime192v1")
NIST224p = Curve("NIST224p", ecdsa.curve_224,
ecdsa.generator_224,
(1, 3, 132, 0, 33), "secp224r1")
NIST256p = Curve("NIST256p", ecdsa.curve_256,
ecdsa.generator_256,
(1, 2, 840, 10045, 3, 1, 7), "prime256v1")
NIST384p = Curve("NIST384p", ecdsa.curve_384,
ecdsa.generator_384,
(1, 3, 132, 0, 34), "secp384r1")
NIST521p = Curve("NIST521p", ecdsa.curve_521,
ecdsa.generator_521,
(1, 3, 132, 0, 35), "secp521r1")
SECP256k1 = Curve("SECP256k1", ecdsa.curve_secp256k1,
ecdsa.generator_secp256k1,
(1, 3, 132, 0, 10), "secp256k1")
curves = [NIST192p, NIST224p, NIST256p, NIST384p, NIST521p, SECP256k1]
def find_curve(oid_curve):
for c in curves:
if c.oid == oid_curve:
return c
raise UnknownCurveError("I don't know about the curve with oid %s."
"I only know about these: %s" %
(oid_curve, [c.name for c in curves]))

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from __future__ import division
import binascii
import base64
class UnexpectedDER(Exception):
pass
def encode_constructed(tag, value):
return int.to_bytes(0xa0+tag, 1, 'big') + encode_length(len(value)) + value
def encode_integer(r):
assert r >= 0 # can't support negative numbers yet
h = ("%x" % r).encode()
if len(h) % 2:
h = b'0' + h
s = binascii.unhexlify(h)
num = s[0] if isinstance(s[0], int) else ord(s[0])
if num <= 0x7f:
return b'\x02' + int.to_bytes(len(s), 1, 'big') + s
else:
# DER integers are two's complement, so if the first byte is
# 0x80-0xff then we need an extra 0x00 byte to prevent it from
# looking negative.
return b'\x02' + int.to_bytes(len(s)+1, 1, 'big') + b'\x00' + s
def encode_bitstring(s):
return b'\x03' + encode_length(len(s)) + s
def encode_octet_string(s):
return b'\x04' + encode_length(len(s)) + s
def encode_oid(first, second, *pieces):
assert first <= 2
assert second <= 39
encoded_pieces = [int.to_bytes(40*first+second, 1, 'big')] + [encode_number(p)
for p in pieces]
body = b''.join(encoded_pieces)
return b'\x06' + encode_length(len(body)) + body
def encode_sequence(*encoded_pieces):
total_len = sum([len(p) for p in encoded_pieces])
return b'\x30' + encode_length(total_len) + b''.join(encoded_pieces)
def encode_number(n):
b128_digits = []
while n:
b128_digits.insert(0, (n & 0x7f) | 0x80)
n = n >> 7
if not b128_digits:
b128_digits.append(0)
b128_digits[-1] &= 0x7f
return b''.join([int.to_bytes(d, 1, 'big') for d in b128_digits])
def remove_constructed(string):
s0 = string[0] if isinstance(string[0], int) else ord(string[0])
if (s0 & 0xe0) != 0xa0:
raise UnexpectedDER("wanted constructed tag (0xa0-0xbf), got 0x%02x"
% s0)
tag = s0 & 0x1f
length, llen = read_length(string[1:])
body = string[1+llen:1+llen+length]
rest = string[1+llen+length:]
return tag, body, rest
def remove_sequence(string):
if not string.startswith(b'\x30'):
n = string[0] if isinstance(string[0], int) else ord(string[0])
raise UnexpectedDER("wanted sequence (0x30), got 0x%02x" % n)
length, lengthlength = read_length(string[1:])
endseq = 1+lengthlength+length
return string[1+lengthlength:endseq], string[endseq:]
def remove_octet_string(string):
if not string.startswith(b'\x04'):
n = string[0] if isinstance(string[0], int) else ord(string[0])
raise UnexpectedDER("wanted octetstring (0x04), got 0x%02x" % n)
length, llen = read_length(string[1:])
body = string[1+llen:1+llen+length]
rest = string[1+llen+length:]
return body, rest
def remove_object(string):
if not string.startswith(b'\x06'):
n = string[0] if isinstance(string[0], int) else ord(string[0])
raise UnexpectedDER("wanted object (0x06), got 0x%02x" % n)
length, lengthlength = read_length(string[1:])
body = string[1+lengthlength:1+lengthlength+length]
rest = string[1+lengthlength+length:]
numbers = []
while body:
n, ll = read_number(body)
numbers.append(n)
body = body[ll:]
n0 = numbers.pop(0)
first = n0//40
second = n0-(40*first)
numbers.insert(0, first)
numbers.insert(1, second)
return tuple(numbers), rest
def remove_integer(string):
if not string.startswith(b'\x02'):
n = string[0] if isinstance(string[0], int) else ord(string[0])
raise UnexpectedDER("wanted integer (0x02), got 0x%02x" % n)
length, llen = read_length(string[1:])
numberbytes = string[1+llen:1+llen+length]
rest = string[1+llen+length:]
nbytes = numberbytes[0] if isinstance(numberbytes[0], int) else ord(numberbytes[0])
assert nbytes < 0x80 # can't support negative numbers yet
return int(binascii.hexlify(numberbytes), 16), rest
def read_number(string):
number = 0
llen = 0
# base-128 big endian, with b7 set in all but the last byte
while True:
if llen > len(string):
raise UnexpectedDER("ran out of length bytes")
number = number << 7
d = string[llen] if isinstance(string[llen], int) else ord(string[llen])
number += (d & 0x7f)
llen += 1
if not d & 0x80:
break
return number, llen
def encode_length(l):
assert l >= 0
if l < 0x80:
return int.to_bytes(l, 1, 'big')
s = ("%x" % l).encode()
if len(s) % 2:
s = b'0' + s
s = binascii.unhexlify(s)
llen = len(s)
return int.to_bytes(0x80 | llen, 1, 'big') + s
def read_length(string):
num = string[0] if isinstance(string[0], int) else ord(string[0])
if not (num & 0x80):
# short form
return (num & 0x7f), 1
# else long-form: b0&0x7f is number of additional base256 length bytes,
# big-endian
llen = num & 0x7f
if llen > len(string)-1:
raise UnexpectedDER("ran out of length bytes")
return int(binascii.hexlify(string[1:1+llen]), 16), 1+llen
def remove_bitstring(string):
num = string[0] if isinstance(string[0], int) else ord(string[0])
if not string.startswith(b'\x03'):
raise UnexpectedDER("wanted bitstring (0x03), got 0x%02x" % num)
length, llen = read_length(string[1:])
body = string[1+llen:1+llen+length]
rest = string[1+llen+length:]
return body, rest
# SEQUENCE([1, STRING(secexp), cont[0], OBJECT(curvename), cont[1], BINTSTRING)
# signatures: (from RFC3279)
# ansi-X9-62 OBJECT IDENTIFIER ::= {
# iso(1) member-body(2) us(840) 10045 }
#
# id-ecSigType OBJECT IDENTIFIER ::= {
# ansi-X9-62 signatures(4) }
# ecdsa-with-SHA1 OBJECT IDENTIFIER ::= {
# id-ecSigType 1 }
## so 1,2,840,10045,4,1
## so 0x42, .. ..
# Ecdsa-Sig-Value ::= SEQUENCE {
# r INTEGER,
# s INTEGER }
# id-public-key-type OBJECT IDENTIFIER ::= { ansi-X9.62 2 }
#
# id-ecPublicKey OBJECT IDENTIFIER ::= { id-publicKeyType 1 }
# I think the secp224r1 identifier is (t=06,l=05,v=2b81040021)
# secp224r1 OBJECT IDENTIFIER ::= {
# iso(1) identified-organization(3) certicom(132) curve(0) 33 }
# and the secp384r1 is (t=06,l=05,v=2b81040022)
# secp384r1 OBJECT IDENTIFIER ::= {
# iso(1) identified-organization(3) certicom(132) curve(0) 34 }
def unpem(pem):
if isinstance(pem, str):
pem = pem.encode()
d = b''.join([l.strip() for l in pem.split(b'\n')
if l and not l.startswith(b'-----')])
return base64.b64decode(d)
def topem(der, name):
b64 = base64.b64encode(der)
lines = [("-----BEGIN %s-----\n" % name).encode()]
lines.extend([b64[start:start+64]+b'\n'
for start in range(0, len(b64), 64)])
lines.append(("-----END %s-----\n" % name).encode())
return b''.join(lines)

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#! /usr/bin/env python
"""
Implementation of Elliptic-Curve Digital Signatures.
Classes and methods for elliptic-curve signatures:
private keys, public keys, signatures,
NIST prime-modulus curves with modulus lengths of
192, 224, 256, 384, and 521 bits.
Example:
# (In real-life applications, you would probably want to
# protect against defects in SystemRandom.)
from random import SystemRandom
randrange = SystemRandom().randrange
# Generate a public/private key pair using the NIST Curve P-192:
g = generator_192
n = g.order()
secret = randrange( 1, n )
pubkey = Public_key( g, g * secret )
privkey = Private_key( pubkey, secret )
# Signing a hash value:
hash = randrange( 1, n )
signature = privkey.sign( hash, randrange( 1, n ) )
# Verifying a signature for a hash value:
if pubkey.verifies( hash, signature ):
print_("Demo verification succeeded.")
else:
print_("*** Demo verification failed.")
# Verification fails if the hash value is modified:
if pubkey.verifies( hash-1, signature ):
print_("**** Demo verification failed to reject tampered hash.")
else:
print_("Demo verification correctly rejected tampered hash.")
Version of 2009.05.16.
Revision history:
2005.12.31 - Initial version.
2008.11.25 - Substantial revisions introducing new classes.
2009.05.16 - Warn against using random.randrange in real applications.
2009.05.17 - Use random.SystemRandom by default.
Written in 2005 by Peter Pearson and placed in the public domain.
"""
from . import ellipticcurve
from . import numbertheory
class RSZeroError(RuntimeError):
pass
class Signature(object):
"""ECDSA signature.
"""
def __init__(self, r, s, recovery_param):
self.r = r
self.s = s
self.recovery_param = recovery_param
def recover_public_keys(self, hash, generator):
"""Returns two public keys for which the signature is valid
hash is signed hash
generator is the used generator of the signature
"""
curve = generator.curve()
n = generator.order()
r = self.r
s = self.s
e = hash
x = r
# Compute the curve point with x as x-coordinate
alpha = (pow(x, 3, curve.p()) + (curve.a() * x) + curve.b()) % curve.p()
beta = numbertheory.square_root_mod_prime(alpha, curve.p())
y = beta if beta % 2 == 0 else curve.p() - beta
# Compute the public key
R1 = ellipticcurve.Point(curve, x, y, n)
Q1 = numbertheory.inverse_mod(r, n) * (s * R1 + (-e % n) * generator)
Pk1 = Public_key(generator, Q1)
# And the second solution
R2 = ellipticcurve.Point(curve, x, -y, n)
Q2 = numbertheory.inverse_mod(r, n) * (s * R2 + (-e % n) * generator)
Pk2 = Public_key(generator, Q2)
return [Pk1, Pk2]
class Public_key(object):
"""Public key for ECDSA.
"""
def __init__(self, generator, point):
"""generator is the Point that generates the group,
point is the Point that defines the public key.
"""
self.curve = generator.curve()
self.generator = generator
self.point = point
n = generator.order()
if not n:
raise RuntimeError("Generator point must have order.")
if not n * point == ellipticcurve.INFINITY:
raise RuntimeError("Generator point order is bad.")
if point.x() < 0 or n <= point.x() or point.y() < 0 or n <= point.y():
raise RuntimeError("Generator point has x or y out of range.")
def verifies(self, hash, signature):
"""Verify that signature is a valid signature of hash.
Return True if the signature is valid.
"""
# From X9.62 J.3.1.
G = self.generator
n = G.order()
r = signature.r
s = signature.s
if r < 1 or r > n - 1:
return False
if s < 1 or s > n - 1:
return False
c = numbertheory.inverse_mod(s, n)
u1 = (hash * c) % n
u2 = (r * c) % n
xy = u1 * G + u2 * self.point
v = xy.x() % n
return v == r
class Private_key(object):
"""Private key for ECDSA.
"""
def __init__(self, public_key, secret_multiplier):
"""public_key is of class Public_key;
secret_multiplier is a large integer.
"""
self.public_key = public_key
self.secret_multiplier = secret_multiplier
def sign(self, hash, random_k):
"""Return a signature for the provided hash, using the provided
random nonce. It is absolutely vital that random_k be an unpredictable
number in the range [1, self.public_key.point.order()-1]. If
an attacker can guess random_k, he can compute our private key from a
single signature. Also, if an attacker knows a few high-order
bits (or a few low-order bits) of random_k, he can compute our private
key from many signatures. The generation of nonces with adequate
cryptographic strength is very difficult and far beyond the scope
of this comment.
May raise RuntimeError, in which case retrying with a new
random value k is in order.
"""
G = self.public_key.generator
n = G.order()
k = random_k % n
p1 = k * G
r = p1.x() % n
if r == 0:
raise RSZeroError("amazingly unlucky random number r")
s = (numbertheory.inverse_mod(k, n) *
(hash + (self.secret_multiplier * r) % n)) % n
if s == 0:
raise RSZeroError("amazingly unlucky random number s")
recovery_param = p1.y() % 2 or (2 if p1.x() == k else 0)
return Signature(r, s, recovery_param)
def int_to_string(x):
"""Convert integer x into a string of bytes, as per X9.62."""
assert x >= 0
if x == 0:
return b'\0'
result = []
while x:
ordinal = x & 0xFF
result.append(int.to_bytes(ordinal, 1, 'big'))
x >>= 8
result.reverse()
return b''.join(result)
def string_to_int(s):
"""Convert a string of bytes into an integer, as per X9.62."""
result = 0
for c in s:
if not isinstance(c, int):
c = ord(c)
result = 256 * result + c
return result
def digest_integer(m):
"""Convert an integer into a string of bytes, compute
its SHA-1 hash, and convert the result to an integer."""
#
# I don't expect this function to be used much. I wrote
# it in order to be able to duplicate the examples
# in ECDSAVS.
#
from hashlib import sha1
return string_to_int(sha1(int_to_string(m)).digest())
def point_is_valid(generator, x, y):
"""Is (x,y) a valid public key based on the specified generator?"""
# These are the tests specified in X9.62.
n = generator.order()
curve = generator.curve()
if x < 0 or n <= x or y < 0 or n <= y:
return False
if not curve.contains_point(x, y):
return False
if not n * ellipticcurve.Point(curve, x, y) == ellipticcurve.INFINITY:
return False
return True
# NIST Curve P-192:
_p = 6277101735386680763835789423207666416083908700390324961279
_r = 6277101735386680763835789423176059013767194773182842284081
# s = 0x3045ae6fc8422f64ed579528d38120eae12196d5L
# c = 0x3099d2bbbfcb2538542dcd5fb078b6ef5f3d6fe2c745de65L
_b = 0x64210519e59c80e70fa7e9ab72243049feb8deecc146b9b1
_Gx = 0x188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012
_Gy = 0x07192b95ffc8da78631011ed6b24cdd573f977a11e794811
curve_192 = ellipticcurve.CurveFp(_p, -3, _b)
generator_192 = ellipticcurve.Point(curve_192, _Gx, _Gy, _r)
# NIST Curve P-224:
_p = 26959946667150639794667015087019630673557916260026308143510066298881
_r = 26959946667150639794667015087019625940457807714424391721682722368061
# s = 0xbd71344799d5c7fcdc45b59fa3b9ab8f6a948bc5L
# c = 0x5b056c7e11dd68f40469ee7f3c7a7d74f7d121116506d031218291fbL
_b = 0xb4050a850c04b3abf54132565044b0b7d7bfd8ba270b39432355ffb4
_Gx = 0xb70e0cbd6bb4bf7f321390b94a03c1d356c21122343280d6115c1d21
_Gy = 0xbd376388b5f723fb4c22dfe6cd4375a05a07476444d5819985007e34
curve_224 = ellipticcurve.CurveFp(_p, -3, _b)
generator_224 = ellipticcurve.Point(curve_224, _Gx, _Gy, _r)
# NIST Curve P-256:
_p = 115792089210356248762697446949407573530086143415290314195533631308867097853951
_r = 115792089210356248762697446949407573529996955224135760342422259061068512044369
# s = 0xc49d360886e704936a6678e1139d26b7819f7e90L
# c = 0x7efba1662985be9403cb055c75d4f7e0ce8d84a9c5114abcaf3177680104fa0dL
_b = 0x5ac635d8aa3a93e7b3ebbd55769886bc651d06b0cc53b0f63bce3c3e27d2604b
_Gx = 0x6b17d1f2e12c4247f8bce6e563a440f277037d812deb33a0f4a13945d898c296
_Gy = 0x4fe342e2fe1a7f9b8ee7eb4a7c0f9e162bce33576b315ececbb6406837bf51f5
curve_256 = ellipticcurve.CurveFp(_p, -3, _b)
generator_256 = ellipticcurve.Point(curve_256, _Gx, _Gy, _r)
# NIST Curve P-384:
_p = 39402006196394479212279040100143613805079739270465446667948293404245721771496870329047266088258938001861606973112319
_r = 39402006196394479212279040100143613805079739270465446667946905279627659399113263569398956308152294913554433653942643
# s = 0xa335926aa319a27a1d00896a6773a4827acdac73L
# c = 0x79d1e655f868f02fff48dcdee14151ddb80643c1406d0ca10dfe6fc52009540a495e8042ea5f744f6e184667cc722483L
_b = 0xb3312fa7e23ee7e4988e056be3f82d19181d9c6efe8141120314088f5013875ac656398d8a2ed19d2a85c8edd3ec2aef
_Gx = 0xaa87ca22be8b05378eb1c71ef320ad746e1d3b628ba79b9859f741e082542a385502f25dbf55296c3a545e3872760ab7
_Gy = 0x3617de4a96262c6f5d9e98bf9292dc29f8f41dbd289a147ce9da3113b5f0b8c00a60b1ce1d7e819d7a431d7c90ea0e5f
curve_384 = ellipticcurve.CurveFp(_p, -3, _b)
generator_384 = ellipticcurve.Point(curve_384, _Gx, _Gy, _r)
# NIST Curve P-521:
_p = 6864797660130609714981900799081393217269435300143305409394463459185543183397656052122559640661454554977296311391480858037121987999716643812574028291115057151
_r = 6864797660130609714981900799081393217269435300143305409394463459185543183397655394245057746333217197532963996371363321113864768612440380340372808892707005449
# s = 0xd09e8800291cb85396cc6717393284aaa0da64baL
# c = 0x0b48bfa5f420a34949539d2bdfc264eeeeb077688e44fbf0ad8f6d0edb37bd6b533281000518e19f1b9ffbe0fe9ed8a3c2200b8f875e523868c70c1e5bf55bad637L
_b = 0x051953eb9618e1c9a1f929a21a0b68540eea2da725b99b315f3b8b489918ef109e156193951ec7e937b1652c0bd3bb1bf073573df883d2c34f1ef451fd46b503f00
_Gx = 0xc6858e06b70404e9cd9e3ecb662395b4429c648139053fb521f828af606b4d3dbaa14b5e77efe75928fe1dc127a2ffa8de3348b3c1856a429bf97e7e31c2e5bd66
_Gy = 0x11839296a789a3bc0045c8a5fb42c7d1bd998f54449579b446817afbd17273e662c97ee72995ef42640c550b9013fad0761353c7086a272c24088be94769fd16650
curve_521 = ellipticcurve.CurveFp(_p, -3, _b)
generator_521 = ellipticcurve.Point(curve_521, _Gx, _Gy, _r)
# Certicom secp256-k1
_a = 0x0000000000000000000000000000000000000000000000000000000000000000
_b = 0x0000000000000000000000000000000000000000000000000000000000000007
_p = 0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f
_Gx = 0x79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
_Gy = 0x483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8
_r = 0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141
curve_secp256k1 = ellipticcurve.CurveFp(_p, _a, _b)
generator_secp256k1 = ellipticcurve.Point(curve_secp256k1, _Gx, _Gy, _r)

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#! /usr/bin/env python
#
# Implementation of elliptic curves, for cryptographic applications.
#
# This module doesn't provide any way to choose a random elliptic
# curve, nor to verify that an elliptic curve was chosen randomly,
# because one can simply use NIST's standard curves.
#
# Notes from X9.62-1998 (draft):
# Nomenclature:
# - Q is a public key.
# The "Elliptic Curve Domain Parameters" include:
# - q is the "field size", which in our case equals p.
# - p is a big prime.
# - G is a point of prime order (5.1.1.1).
# - n is the order of G (5.1.1.1).
# Public-key validation (5.2.2):
# - Verify that Q is not the point at infinity.
# - Verify that X_Q and Y_Q are in [0,p-1].
# - Verify that Q is on the curve.
# - Verify that nQ is the point at infinity.
# Signature generation (5.3):
# - Pick random k from [1,n-1].
# Signature checking (5.4.2):
# - Verify that r and s are in [1,n-1].
#
# Version of 2008.11.25.
#
# Revision history:
# 2005.12.31 - Initial version.
# 2008.11.25 - Change CurveFp.is_on to contains_point.
#
# Written in 2005 by Peter Pearson and placed in the public domain.
from __future__ import division
from . import numbertheory
class CurveFp(object):
"""Elliptic Curve over the field of integers modulo a prime."""
def __init__(self, p, a, b):
"""The curve of points satisfying y^2 = x^3 + a*x + b (mod p)."""
self.__p = p
self.__a = a
self.__b = b
def p(self):
return self.__p
def a(self):
return self.__a
def b(self):
return self.__b
def contains_point(self, x, y):
"""Is the point (x,y) on this curve?"""
return (y * y - (x * x * x + self.__a * x + self.__b)) % self.__p == 0
def __str__(self):
return "CurveFp(p=%d, a=%d, b=%d)" % (self.__p, self.__a, self.__b)
class Point(object):
"""A point on an elliptic curve. Altering x and y is forbidding,
but they can be read by the x() and y() methods."""
def __init__(self, curve, x, y, order=None):
"""curve, x, y, order; order (optional) is the order of this point."""
self.__curve = curve
self.__x = x
self.__y = y
self.__order = order
# self.curve is allowed to be None only for INFINITY:
if self.__curve:
assert self.__curve.contains_point(x, y)
if order:
assert self * order == INFINITY
def __eq__(self, other):
"""Return True if the points are identical, False otherwise."""
if self.__curve == other.__curve \
and self.__x == other.__x \
and self.__y == other.__y:
return True
else:
return False
def __add__(self, other):
"""Add one point to another point."""
# X9.62 B.3:
if other == INFINITY:
return self
if self == INFINITY:
return other
assert self.__curve == other.__curve
if self.__x == other.__x:
if (self.__y + other.__y) % self.__curve.p() == 0:
return INFINITY
else:
return self.double()
p = self.__curve.p()
l = ((other.__y - self.__y) * \
numbertheory.inverse_mod(other.__x - self.__x, p)) % p
x3 = (l * l - self.__x - other.__x) % p
y3 = (l * (self.__x - x3) - self.__y) % p
return Point(self.__curve, x3, y3)
def __mul__(self, other):
"""Multiply a point by an integer."""
def leftmost_bit(x):
assert x > 0
result = 1
while result <= x:
result = 2 * result
return result // 2
e = other
if self.__order:
e = e % self.__order
if e == 0:
return INFINITY
if self == INFINITY:
return INFINITY
assert e > 0
# From X9.62 D.3.2:
e3 = 3 * e
negative_self = Point(self.__curve, self.__x, -self.__y, self.__order)
i = leftmost_bit(e3) // 2
result = self
# print_("Multiplying %s by %d (e3 = %d):" % (self, other, e3))
while i > 1:
result = result.double()
if (e3 & i) != 0 and (e & i) == 0:
result = result + self
if (e3 & i) == 0 and (e & i) != 0:
result = result + negative_self
# print_(". . . i = %d, result = %s" % ( i, result ))
i = i // 2
return result
def __rmul__(self, other):
"""Multiply a point by an integer."""
return self * other
def __str__(self):
if self == INFINITY:
return "infinity"
return "(%d,%d)" % (self.__x, self.__y)
def double(self):
"""Return a new point that is twice the old."""
if self == INFINITY:
return INFINITY
# X9.62 B.3:
p = self.__curve.p()
a = self.__curve.a()
l = ((3 * self.__x * self.__x + a) * \
numbertheory.inverse_mod(2 * self.__y, p)) % p
x3 = (l * l - 2 * self.__x) % p
y3 = (l * (self.__x - x3) - self.__y) % p
return Point(self.__curve, x3, y3)
def x(self):
return self.__x
def y(self):
return self.__y
def curve(self):
return self.__curve
def order(self):
return self.__order
# This one point is the Point At Infinity for all purposes:
INFINITY = Point(None, None, None)

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import binascii
from . import ecdsa
from . import der
from . import rfc6979
from .curves import NIST192p, find_curve
from .ecdsa import RSZeroError
from .util import string_to_number, number_to_string, randrange
from .util import sigencode_string, sigdecode_string
from .util import oid_ecPublicKey, encoded_oid_ecPublicKey
from hashlib import sha1
class BadSignatureError(Exception):
pass
class BadDigestError(Exception):
pass
class VerifyingKey:
def __init__(self, _error__please_use_generate=None):
if not _error__please_use_generate:
raise TypeError("Please use VerifyingKey.generate() to "
"construct me")
@classmethod
def from_public_point(klass, point, curve=NIST192p, hashfunc=sha1):
self = klass(_error__please_use_generate=True)
self.curve = curve
self.default_hashfunc = hashfunc
self.pubkey = ecdsa.Public_key(curve.generator, point)
self.pubkey.order = curve.order
return self
@classmethod
def from_string(klass, string, curve=NIST192p, hashfunc=sha1,
validate_point=True):
order = curve.order
assert (len(string) == curve.verifying_key_length), \
(len(string), curve.verifying_key_length)
xs = string[:curve.baselen]
ys = string[curve.baselen:]
assert len(xs) == curve.baselen, (len(xs), curve.baselen)
assert len(ys) == curve.baselen, (len(ys), curve.baselen)
x = string_to_number(xs)
y = string_to_number(ys)
if validate_point:
assert ecdsa.point_is_valid(curve.generator, x, y)
from . import ellipticcurve
point = ellipticcurve.Point(curve.curve, x, y, order)
return klass.from_public_point(point, curve, hashfunc)
@classmethod
def from_pem(klass, string):
return klass.from_der(der.unpem(string))
@classmethod
def from_der(klass, string):
# [[oid_ecPublicKey,oid_curve], point_str_bitstring]
s1, empty = der.remove_sequence(string)
if empty != b'':
raise der.UnexpectedDER("trailing junk after DER pubkey: %s" %
binascii.hexlify(empty))
s2, point_str_bitstring = der.remove_sequence(s1)
# s2 = oid_ecPublicKey,oid_curve
oid_pk, rest = der.remove_object(s2)
oid_curve, empty = der.remove_object(rest)
if empty != b'':
raise der.UnexpectedDER("trailing junk after DER pubkey objects: %s" %
binascii.hexlify(empty))
assert oid_pk == oid_ecPublicKey, (oid_pk, oid_ecPublicKey)
curve = find_curve(oid_curve)
point_str, empty = der.remove_bitstring(point_str_bitstring)
if empty != b'':
raise der.UnexpectedDER("trailing junk after pubkey pointstring: %s" %
binascii.hexlify(empty))
assert point_str.startswith(b'\x00\x04')
return klass.from_string(point_str[2:], curve)
@classmethod
def from_public_key_recovery(klass, signature, data, curve, hashfunc=sha1, sigdecode=sigdecode_string):
# Given a signature and corresponding message this function
# returns a list of verifying keys for this signature and message
digest = hashfunc(data).digest()
return klass.from_public_key_recovery_with_digest(signature, digest, curve, hashfunc=sha1, sigdecode=sigdecode)
@classmethod
def from_public_key_recovery_with_digest(klass, signature, digest, curve, hashfunc=sha1, sigdecode=sigdecode_string):
# Given a signature and corresponding digest this function
# returns a list of verifying keys for this signature and message
generator = curve.generator
r, s = sigdecode(signature, generator.order())
sig = ecdsa.Signature(r, s)
digest_as_number = string_to_number(digest)
pks = sig.recover_public_keys(digest_as_number, generator)
# Transforms the ecdsa.Public_key object into a VerifyingKey
verifying_keys = [klass.from_public_point(pk.point, curve, hashfunc) for pk in pks]
return verifying_keys
def to_string(self):
# VerifyingKey.from_string(vk.to_string()) == vk as long as the
# curves are the same: the curve itself is not included in the
# serialized form
order = self.pubkey.order
x_str = number_to_string(self.pubkey.point.x(), order)
y_str = number_to_string(self.pubkey.point.y(), order)
return x_str + y_str
def to_pem(self):
return der.topem(self.to_der(), "PUBLIC KEY")
def to_der(self):
order = self.pubkey.order
x_str = number_to_string(self.pubkey.point.x(), order)
y_str = number_to_string(self.pubkey.point.y(), order)
point_str = b'\x00\x04' + x_str + y_str
return der.encode_sequence(der.encode_sequence(encoded_oid_ecPublicKey,
self.curve.encoded_oid),
der.encode_bitstring(point_str))
def verify(self, signature, data, hashfunc=None, sigdecode=sigdecode_string):
hashfunc = hashfunc or self.default_hashfunc
digest = hashfunc(data).digest()
return self.verify_digest(signature, digest, sigdecode)
def verify_digest(self, signature, digest, sigdecode=sigdecode_string):
if len(digest) > self.curve.baselen:
raise BadDigestError("this curve (%s) is too short "
"for your digest (%d)" % (self.curve.name,
8 * len(digest)))
number = string_to_number(digest)
r, s = sigdecode(signature, self.pubkey.order)
sig = ecdsa.Signature(r, s)
if self.pubkey.verifies(number, sig):
return True
raise BadSignatureError
class SigningKey:
def __init__(self, _error__please_use_generate=None):
if not _error__please_use_generate:
raise TypeError("Please use SigningKey.generate() to construct me")
@classmethod
def generate(klass, curve=NIST192p, entropy=None, hashfunc=sha1):
secexp = randrange(curve.order, entropy)
return klass.from_secret_exponent(secexp, curve, hashfunc)
# to create a signing key from a short (arbitrary-length) seed, convert
# that seed into an integer with something like
# secexp=util.randrange_from_seed__X(seed, curve.order), and then pass
# that integer into SigningKey.from_secret_exponent(secexp, curve)
@classmethod
def from_secret_exponent(klass, secexp, curve=NIST192p, hashfunc=sha1):
self = klass(_error__please_use_generate=True)
self.curve = curve
self.default_hashfunc = hashfunc
self.baselen = curve.baselen
n = curve.order
assert 1 <= secexp < n
pubkey_point = curve.generator * secexp
pubkey = ecdsa.Public_key(curve.generator, pubkey_point)
pubkey.order = n
self.verifying_key = VerifyingKey.from_public_point(pubkey_point, curve,
hashfunc)
self.privkey = ecdsa.Private_key(pubkey, secexp)
self.privkey.order = n
return self
@classmethod
def from_string(klass, string, curve=NIST192p, hashfunc=sha1):
assert len(string) == curve.baselen, (len(string), curve.baselen)
secexp = string_to_number(string)
return klass.from_secret_exponent(secexp, curve, hashfunc)
@classmethod
def from_pem(klass, string, hashfunc=sha1):
# the privkey pem file has two sections: "EC PARAMETERS" and "EC
# PRIVATE KEY". The first is redundant.
if isinstance(string, str):
string = string.encode()
privkey_pem = string[string.index(b'-----BEGIN EC PRIVATE KEY-----'):]
return klass.from_der(der.unpem(privkey_pem), hashfunc)
@classmethod
def from_der(klass, string, hashfunc=sha1):
# SEQ([int(1), octetstring(privkey),cont[0], oid(secp224r1),
# cont[1],bitstring])
s, empty = der.remove_sequence(string)
if empty != b'':
raise der.UnexpectedDER("trailing junk after DER privkey: %s" %
binascii.hexlify(empty))
one, s = der.remove_integer(s)
if one != 1:
raise der.UnexpectedDER("expected '1' at start of DER privkey,"
" got %d" % one)
privkey_str, s = der.remove_octet_string(s)
tag, curve_oid_str, s = der.remove_constructed(s)
if tag != 0:
raise der.UnexpectedDER("expected tag 0 in DER privkey,"
" got %d" % tag)
curve_oid, empty = der.remove_object(curve_oid_str)
if empty != b'':
raise der.UnexpectedDER("trailing junk after DER privkey "
"curve_oid: %s" % binascii.hexlify(empty))
curve = find_curve(curve_oid)
# we don't actually care about the following fields
#
# tag, pubkey_bitstring, s = der.remove_constructed(s)
# if tag != 1:
# raise der.UnexpectedDER("expected tag 1 in DER privkey, got %d"
# % tag)
# pubkey_str = der.remove_bitstring(pubkey_bitstring)
# if empty != "":
# raise der.UnexpectedDER("trailing junk after DER privkey "
# "pubkeystr: %s" % binascii.hexlify(empty))
# our from_string method likes fixed-length privkey strings
if len(privkey_str) < curve.baselen:
privkey_str = b'\x00' * (curve.baselen - len(privkey_str)) + privkey_str
return klass.from_string(privkey_str, curve, hashfunc)
def to_string(self):
secexp = self.privkey.secret_multiplier
s = number_to_string(secexp, self.privkey.order)
return s
def to_pem(self):
# TODO: "BEGIN ECPARAMETERS"
return der.topem(self.to_der(), "EC PRIVATE KEY")
def to_der(self):
# SEQ([int(1), octetstring(privkey),cont[0], oid(secp224r1),
# cont[1],bitstring])
encoded_vk = b'\x00\x04' + self.get_verifying_key().to_string()
return der.encode_sequence(der.encode_integer(1),
der.encode_octet_string(self.to_string()),
der.encode_constructed(0, self.curve.encoded_oid),
der.encode_constructed(1, der.encode_bitstring(encoded_vk)),
)
def get_verifying_key(self):
return self.verifying_key
def sign_deterministic(self, data, hashfunc=None,
sigencode=sigencode_string,
extra_entropy=b''):
hashfunc = hashfunc or self.default_hashfunc
digest = hashfunc(data).digest()
return self.sign_digest_deterministic(
digest, hashfunc=hashfunc, sigencode=sigencode,
extra_entropy=extra_entropy)
def sign_digest_deterministic(self, digest, hashfunc=None,
sigencode=sigencode_string,
extra_entropy=b''):
"""
Calculates 'k' from data itself, removing the need for strong
random generator and producing deterministic (reproducible) signatures.
See RFC 6979 for more details.
"""
secexp = self.privkey.secret_multiplier
def simple_r_s(r, s, order, v):
return r, s, order, v
retry_gen = 0
while True:
k = rfc6979.generate_k(
self.curve.generator.order(), secexp, hashfunc, digest,
retry_gen=retry_gen, extra_entropy=extra_entropy)
try:
r, s, order, v = self.sign_digest(digest, sigencode=simple_r_s, k=k)
break
except RSZeroError:
retry_gen += 1
return sigencode(r, s, order, v)
def sign(self, data, entropy=None, hashfunc=None, sigencode=sigencode_string, k=None):
"""
hashfunc= should behave like hashlib.sha1 . The output length of the
hash (in bytes) must not be longer than the length of the curve order
(rounded up to the nearest byte), so using SHA256 with nist256p is
ok, but SHA256 with nist192p is not. (In the 2**-96ish unlikely event
of a hash output larger than the curve order, the hash will
effectively be wrapped mod n).
Use hashfunc=hashlib.sha1 to match openssl's -ecdsa-with-SHA1 mode,
or hashfunc=hashlib.sha256 for openssl-1.0.0's -ecdsa-with-SHA256.
"""
hashfunc = hashfunc or self.default_hashfunc
h = hashfunc(data).digest()
return self.sign_digest(h, entropy, sigencode, k)
def sign_digest(self, digest, entropy=None, sigencode=sigencode_string, k=None):
if len(digest) > self.curve.baselen:
raise BadDigestError("this curve (%s) is too short "
"for your digest (%d)" % (self.curve.name,
8 * len(digest)))
number = string_to_number(digest)
r, s, v = self.sign_number(number, entropy, k)
return sigencode(r, s, self.privkey.order, v)
def sign_number(self, number, entropy=None, k=None):
# returns a pair of numbers
order = self.privkey.order
# privkey.sign() may raise RuntimeError in the amazingly unlikely
# (2**-192) event that r=0 or s=0, because that would leak the key.
# We could re-try with a different 'k', but we couldn't test that
# code, so I choose to allow the signature to fail instead.
# If k is set, it is used directly. In other cases
# it is generated using entropy function
if k is not None:
_k = k
else:
_k = randrange(order, entropy)
assert 1 <= _k < order
sig = self.privkey.sign(number, _k)
return sig.r, sig.s, sig.recovery_param

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#! /usr/bin/env python
#
# Provide some simple capabilities from number theory.
#
# Version of 2008.11.14.
#
# Written in 2005 and 2006 by Peter Pearson and placed in the public domain.
# Revision history:
# 2008.11.14: Use pow(base, exponent, modulus) for modular_exp.
# Make gcd and lcm accept arbitrarly many arguments.
from __future__ import division
from functools import reduce
import math
class Error(Exception):
"""Base class for exceptions in this module."""
pass
class SquareRootError(Error):
pass
class NegativeExponentError(Error):
pass
def modular_exp(base, exponent, modulus):
"Raise base to exponent, reducing by modulus"
if exponent < 0:
raise NegativeExponentError("Negative exponents (%d) not allowed" \
% exponent)
return pow(base, exponent, modulus)
# result = 1L
# x = exponent
# b = base + 0L
# while x > 0:
# if x % 2 > 0: result = (result * b) % modulus
# x = x // 2
# b = (b * b) % modulus
# return result
def polynomial_reduce_mod(poly, polymod, p):
"""Reduce poly by polymod, integer arithmetic modulo p.
Polynomials are represented as lists of coefficients
of increasing powers of x."""
# This module has been tested only by extensive use
# in calculating modular square roots.
# Just to make this easy, require a monic polynomial:
assert polymod[-1] == 1
assert len(polymod) > 1
while len(poly) >= len(polymod):
if poly[-1] != 0:
for i in range(2, len(polymod) + 1):
poly[-i] = (poly[-i] - poly[-1] * polymod[-i]) % p
poly = poly[0:-1]
return poly
def polynomial_multiply_mod(m1, m2, polymod, p):
"""Polynomial multiplication modulo a polynomial over ints mod p.
Polynomials are represented as lists of coefficients
of increasing powers of x."""
# This is just a seat-of-the-pants implementation.
# This module has been tested only by extensive use
# in calculating modular square roots.
# Initialize the product to zero:
prod = (len(m1) + len(m2) - 1) * [0]
# Add together all the cross-terms:
for i in range(len(m1)):
for j in range(len(m2)):
prod[i + j] = (prod[i + j] + m1[i] * m2[j]) % p
return polynomial_reduce_mod(prod, polymod, p)
def polynomial_exp_mod(base, exponent, polymod, p):
"""Polynomial exponentiation modulo a polynomial over ints mod p.
Polynomials are represented as lists of coefficients
of increasing powers of x."""
# Based on the Handbook of Applied Cryptography, algorithm 2.227.
# This module has been tested only by extensive use
# in calculating modular square roots.
assert exponent < p
if exponent == 0:
return [1]
G = base
k = exponent
if k % 2 == 1:
s = G
else:
s = [1]
while k > 1:
k = k // 2
G = polynomial_multiply_mod(G, G, polymod, p)
if k % 2 == 1:
s = polynomial_multiply_mod(G, s, polymod, p)
return s
def jacobi(a, n):
"""Jacobi symbol"""
# Based on the Handbook of Applied Cryptography (HAC), algorithm 2.149.
# This function has been tested by comparison with a small
# table printed in HAC, and by extensive use in calculating
# modular square roots.
assert n >= 3
assert n % 2 == 1
a = a % n
if a == 0:
return 0
if a == 1:
return 1
a1, e = a, 0
while a1 % 2 == 0:
a1, e = a1 // 2, e + 1
if e % 2 == 0 or n % 8 == 1 or n % 8 == 7:
s = 1
else:
s = -1
if a1 == 1:
return s
if n % 4 == 3 and a1 % 4 == 3:
s = -s
return s * jacobi(n % a1, a1)
def square_root_mod_prime(a, p):
"""Modular square root of a, mod p, p prime."""
# Based on the Handbook of Applied Cryptography, algorithms 3.34 to 3.39.
# This module has been tested for all values in [0,p-1] for
# every prime p from 3 to 1229.
assert 0 <= a < p
assert 1 < p
if a == 0:
return 0
if p == 2:
return a
jac = jacobi(a, p)
if jac == -1:
raise SquareRootError("%d has no square root modulo %d" \
% (a, p))
if p % 4 == 3:
return modular_exp(a, (p + 1) // 4, p)
if p % 8 == 5:
d = modular_exp(a, (p - 1) // 4, p)
if d == 1:
return modular_exp(a, (p + 3) // 8, p)
if d == p - 1:
return (2 * a * modular_exp(4 * a, (p - 5) // 8, p)) % p
raise RuntimeError("Shouldn't get here.")
for b in range(2, p):
if jacobi(b * b - 4 * a, p) == -1:
f = (a, -b, 1)
ff = polynomial_exp_mod((0, 1), (p + 1) // 2, f, p)
assert ff[1] == 0
return ff[0]
raise RuntimeError("No b found.")
def inverse_mod(a, m):
"""Inverse of a mod m."""
if a < 0 or m <= a:
a = a % m
# From Ferguson and Schneier, roughly:
c, d = a, m
uc, vc, ud, vd = 1, 0, 0, 1
while c != 0:
q, c, d = divmod(d, c) + (c,)
uc, vc, ud, vd = ud - q * uc, vd - q * vc, uc, vc
# At this point, d is the GCD, and ud*a+vd*m = d.
# If d == 1, this means that ud is a inverse.
assert d == 1
if ud > 0:
return ud
else:
return ud + m
def gcd2(a, b):
"""Greatest common divisor using Euclid's algorithm."""
while a:
a, b = b % a, a
return b
def gcd(*a):
"""Greatest common divisor.
Usage: gcd([ 2, 4, 6 ])
or: gcd(2, 4, 6)
"""
if len(a) > 1:
return reduce(gcd2, a)
if hasattr(a[0], "__iter__"):
return reduce(gcd2, a[0])
return a[0]
def lcm2(a, b):
"""Least common multiple of two integers."""
return (a * b) // gcd(a, b)
def lcm(*a):
"""Least common multiple.
Usage: lcm([ 3, 4, 5 ])
or: lcm(3, 4, 5)
"""
if len(a) > 1:
return reduce(lcm2, a)
if hasattr(a[0], "__iter__"):
return reduce(lcm2, a[0])
return a[0]
def factorization(n):
"""Decompose n into a list of (prime,exponent) pairs."""
assert isinstance(n, int)
if n < 2:
return []
result = []
d = 2
# Test the small primes:
for d in smallprimes:
if d > n:
break
q, r = divmod(n, d)
if r == 0:
count = 1
while d <= n:
n = q
q, r = divmod(n, d)
if r != 0:
break
count = count + 1
result.append((d, count))
# If n is still greater than the last of our small primes,
# it may require further work:
if n > smallprimes[-1]:
if is_prime(n): # If what's left is prime, it's easy:
result.append((n, 1))
else: # Ugh. Search stupidly for a divisor:
d = smallprimes[-1]
while 1:
d = d + 2 # Try the next divisor.
q, r = divmod(n, d)
if q < d: # n < d*d means we're done, n = 1 or prime.
break
if r == 0: # d divides n. How many times?
count = 1
n = q
while d <= n: # As long as d might still divide n,
q, r = divmod(n, d) # see if it does.
if r != 0:
break
n = q # It does. Reduce n, increase count.
count = count + 1
result.append((d, count))
if n > 1:
result.append((n, 1))
return result
def phi(n):
"""Return the Euler totient function of n."""
assert isinstance(n, int)
if n < 3:
return 1
result = 1
ff = factorization(n)
for f in ff:
e = f[1]
if e > 1:
result = result * f[0] ** (e - 1) * (f[0] - 1)
else:
result = result * (f[0] - 1)
return result
def carmichael(n):
"""Return Carmichael function of n.
Carmichael(n) is the smallest integer x such that
m**x = 1 mod n for all m relatively prime to n.
"""
return carmichael_of_factorized(factorization(n))
def carmichael_of_factorized(f_list):
"""Return the Carmichael function of a number that is
represented as a list of (prime,exponent) pairs.
"""
if len(f_list) < 1:
return 1
result = carmichael_of_ppower(f_list[0])
for i in range(1, len(f_list)):
result = lcm(result, carmichael_of_ppower(f_list[i]))
return result
def carmichael_of_ppower(pp):
"""Carmichael function of the given power of the given prime.
"""
p, a = pp
if p == 2 and a > 2:
return 2 ** (a - 2)
else:
return (p - 1) * p ** (a - 1)
def order_mod(x, m):
"""Return the order of x in the multiplicative group mod m.
"""
# Warning: this implementation is not very clever, and will
# take a long time if m is very large.
if m <= 1:
return 0
assert gcd(x, m) == 1
z = x
result = 1
while z != 1:
z = (z * x) % m
result = result + 1
return result
def largest_factor_relatively_prime(a, b):
"""Return the largest factor of a relatively prime to b.
"""
while 1:
d = gcd(a, b)
if d <= 1:
break
b = d
while 1:
q, r = divmod(a, d)
if r > 0:
break
a = q
return a
def kinda_order_mod(x, m):
"""Return the order of x in the multiplicative group mod m',
where m' is the largest factor of m relatively prime to x.
"""
return order_mod(x, largest_factor_relatively_prime(m, x))
def is_prime(n):
"""Return True if x is prime, False otherwise.
We use the Miller-Rabin test, as given in Menezes et al. p. 138.
This test is not exact: there are composite values n for which
it returns True.
In testing the odd numbers from 10000001 to 19999999,
about 66 composites got past the first test,
5 got past the second test, and none got past the third.
Since factors of 2, 3, 5, 7, and 11 were detected during
preliminary screening, the number of numbers tested by
Miller-Rabin was (19999999 - 10000001)*(2/3)*(4/5)*(6/7)
= 4.57 million.
"""
# (This is used to study the risk of false positives:)
global miller_rabin_test_count
miller_rabin_test_count = 0
if n <= smallprimes[-1]:
if n in smallprimes:
return True
else:
return False
if gcd(n, 2 * 3 * 5 * 7 * 11) != 1:
return False
# Choose a number of iterations sufficient to reduce the
# probability of accepting a composite below 2**-80
# (from Menezes et al. Table 4.4):
t = 40
n_bits = 1 + int(math.log(n, 2))
for k, tt in ((100, 27),
(150, 18),
(200, 15),
(250, 12),
(300, 9),
(350, 8),
(400, 7),
(450, 6),
(550, 5),
(650, 4),
(850, 3),
(1300, 2),
):
if n_bits < k:
break
t = tt
# Run the test t times:
s = 0
r = n - 1
while (r % 2) == 0:
s = s + 1
r = r // 2
for i in range(t):
a = smallprimes[i]
y = modular_exp(a, r, n)
if y != 1 and y != n - 1:
j = 1
while j <= s - 1 and y != n - 1:
y = modular_exp(y, 2, n)
if y == 1:
miller_rabin_test_count = i + 1
return False
j = j + 1
if y != n - 1:
miller_rabin_test_count = i + 1
return False
return True
def next_prime(starting_value):
"Return the smallest prime larger than the starting value."
if starting_value < 2:
return 2
result = (starting_value + 1) | 1
while not is_prime(result):
result = result + 2
return result
smallprimes = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41,
43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97,
101, 103, 107, 109, 113, 127, 131, 137, 139, 149,
151, 157, 163, 167, 173, 179, 181, 191, 193, 197,
199, 211, 223, 227, 229, 233, 239, 241, 251, 257,
263, 269, 271, 277, 281, 283, 293, 307, 311, 313,
317, 331, 337, 347, 349, 353, 359, 367, 373, 379,
383, 389, 397, 401, 409, 419, 421, 431, 433, 439,
443, 449, 457, 461, 463, 467, 479, 487, 491, 499,
503, 509, 521, 523, 541, 547, 557, 563, 569, 571,
577, 587, 593, 599, 601, 607, 613, 617, 619, 631,
641, 643, 647, 653, 659, 661, 673, 677, 683, 691,
701, 709, 719, 727, 733, 739, 743, 751, 757, 761,
769, 773, 787, 797, 809, 811, 821, 823, 827, 829,
839, 853, 857, 859, 863, 877, 881, 883, 887, 907,
911, 919, 929, 937, 941, 947, 953, 967, 971, 977,
983, 991, 997, 1009, 1013, 1019, 1021, 1031, 1033,
1039, 1049, 1051, 1061, 1063, 1069, 1087, 1091, 1093,
1097, 1103, 1109, 1117, 1123, 1129, 1151, 1153, 1163,
1171, 1181, 1187, 1193, 1201, 1213, 1217, 1223, 1229]
miller_rabin_test_count = 0

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@@ -0,0 +1,100 @@
'''
RFC 6979:
Deterministic Usage of the Digital Signature Algorithm (DSA) and
Elliptic Curve Digital Signature Algorithm (ECDSA)
http://tools.ietf.org/html/rfc6979
Many thanks to Coda Hale for his implementation in Go language:
https://github.com/codahale/rfc6979
'''
import hmac
from binascii import hexlify
from .util import number_to_string, number_to_string_crop
def bit_length(num):
# http://docs.python.org/dev/library/stdtypes.html#int.bit_length
s = bin(num) # binary representation: bin(-37) --> '-0b100101'
s = s.lstrip('-0b') # remove leading zeros and minus sign
return len(s) # len('100101') --> 6
def bits2int(data, qlen):
x = int(hexlify(data), 16)
l = len(data) * 8
if l > qlen:
return x >> (l - qlen)
return x
def bits2octets(data, order):
z1 = bits2int(data, bit_length(order))
z2 = z1 - order
if z2 < 0:
z2 = z1
return number_to_string_crop(z2, order)
# https://tools.ietf.org/html/rfc6979#section-3.2
def generate_k(order, secexp, hash_func, data, retry_gen=0, extra_entropy=b''):
'''
order - order of the DSA generator used in the signature
secexp - secure exponent (private key) in numeric form
hash_func - reference to the same hash function used for generating hash
data - hash in binary form of the signing data
retry_gen - int - how many good 'k' values to skip before returning
extra_entropy - extra added data in binary form as per section-3.6 of
rfc6979
'''
qlen = bit_length(order)
holen = hash_func().digest_size
rolen = (qlen + 7) / 8
bx = number_to_string(secexp, order) + bits2octets(data, order) + \
extra_entropy
# Step B
v = b'\x01' * holen
# Step C
k = b'\x00' * holen
# Step D
k = hmac.new(k, v + b'\x00' + bx, hash_func).digest()
# Step E
v = hmac.new(k, v, hash_func).digest()
# Step F
k = hmac.new(k, v + b'\x01' + bx, hash_func).digest()
# Step G
v = hmac.new(k, v, hash_func).digest()
# Step H
while True:
# Step H1
t = b''
# Step H2
while len(t) < rolen:
v = hmac.new(k, v, hash_func).digest()
t += v
# Step H3
secret = bits2int(t, qlen)
if secret >= 1 and secret < order:
if retry_gen <= 0:
return secret
else:
retry_gen -= 1
k = hmac.new(k, v + b'\x00', hash_func).digest()
v = hmac.new(k, v, hash_func).digest()

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from __future__ import division
import os
import math
import binascii
from hashlib import sha256
from . import der
from .curves import orderlen
# RFC5480:
# The "unrestricted" algorithm identifier is:
# id-ecPublicKey OBJECT IDENTIFIER ::= {
# iso(1) member-body(2) us(840) ansi-X9-62(10045) keyType(2) 1 }
oid_ecPublicKey = (1, 2, 840, 10045, 2, 1)
encoded_oid_ecPublicKey = der.encode_oid(*oid_ecPublicKey)
def randrange(order, entropy=None):
"""Return a random integer k such that 1 <= k < order, uniformly
distributed across that range. For simplicity, this only behaves well if
'order' is fairly close (but below) a power of 256. The try-try-again
algorithm we use takes longer and longer time (on average) to complete as
'order' falls, rising to a maximum of avg=512 loops for the worst-case
(256**k)+1 . All of the standard curves behave well. There is a cutoff at
10k loops (which raises RuntimeError) to prevent an infinite loop when
something is really broken like the entropy function not working.
Note that this function is not declared to be forwards-compatible: we may
change the behavior in future releases. The entropy= argument (which
should get a callable that behaves like os.urandom) can be used to
achieve stability within a given release (for repeatable unit tests), but
should not be used as a long-term-compatible key generation algorithm.
"""
# we could handle arbitrary orders (even 256**k+1) better if we created
# candidates bit-wise instead of byte-wise, which would reduce the
# worst-case behavior to avg=2 loops, but that would be more complex. The
# change would be to round the order up to a power of 256, subtract one
# (to get 0xffff..), use that to get a byte-long mask for the top byte,
# generate the len-1 entropy bytes, generate one extra byte and mask off
# the top bits, then combine it with the rest. Requires jumping back and
# forth between strings and integers a lot.
if entropy is None:
entropy = os.urandom
assert order > 1
bytes = orderlen(order)
dont_try_forever = 10000 # gives about 2**-60 failures for worst case
while dont_try_forever > 0:
dont_try_forever -= 1
candidate = string_to_number(entropy(bytes)) + 1
if 1 <= candidate < order:
return candidate
continue
raise RuntimeError("randrange() tried hard but gave up, either something"
" is very wrong or you got realllly unlucky. Order was"
" %x" % order)
class PRNG:
# this returns a callable which, when invoked with an integer N, will
# return N pseudorandom bytes. Note: this is a short-term PRNG, meant
# primarily for the needs of randrange_from_seed__trytryagain(), which
# only needs to run it a few times per seed. It does not provide
# protection against state compromise (forward security).
def __init__(self, seed):
self.generator = self.block_generator(seed)
def __call__(self, numbytes):
a = [next(self.generator) for i in range(numbytes)]
return bytes(a)
def block_generator(self, seed):
counter = 0
while True:
for byte in sha256(("prng-%d-%s" % (counter, seed)).encode()).digest():
yield byte
counter += 1
def randrange_from_seed__overshoot_modulo(seed, order):
# hash the data, then turn the digest into a number in [1,order).
#
# We use David-Sarah Hopwood's suggestion: turn it into a number that's
# sufficiently larger than the group order, then modulo it down to fit.
# This should give adequate (but not perfect) uniformity, and simple
# code. There are other choices: try-try-again is the main one.
base = PRNG(seed)(2 * orderlen(order))
number = (int(binascii.hexlify(base), 16) % (order - 1)) + 1
assert 1 <= number < order, (1, number, order)
return number
def lsb_of_ones(numbits):
return (1 << numbits) - 1
def bits_and_bytes(order):
bits = int(math.log(order - 1, 2) + 1)
bytes = bits // 8
extrabits = bits % 8
return bits, bytes, extrabits
# the following randrange_from_seed__METHOD() functions take an
# arbitrarily-sized secret seed and turn it into a number that obeys the same
# range limits as randrange() above. They are meant for deriving consistent
# signing keys from a secret rather than generating them randomly, for
# example a protocol in which three signing keys are derived from a master
# secret. You should use a uniformly-distributed unguessable seed with about
# curve.baselen bytes of entropy. To use one, do this:
# seed = os.urandom(curve.baselen) # or other starting point
# secexp = ecdsa.util.randrange_from_seed__trytryagain(sed, curve.order)
# sk = SigningKey.from_secret_exponent(secexp, curve)
def randrange_from_seed__truncate_bytes(seed, order, hashmod=sha256):
# hash the seed, then turn the digest into a number in [1,order), but
# don't worry about trying to uniformly fill the range. This will lose,
# on average, four bits of entropy.
bits, _bytes, extrabits = bits_and_bytes(order)
if extrabits:
_bytes += 1
base = hashmod(seed).digest()[:_bytes]
base = "\x00" * (_bytes - len(base)) + base
number = 1 + int(binascii.hexlify(base), 16)
assert 1 <= number < order
return number
def randrange_from_seed__truncate_bits(seed, order, hashmod=sha256):
# like string_to_randrange_truncate_bytes, but only lose an average of
# half a bit
bits = int(math.log(order - 1, 2) + 1)
maxbytes = (bits + 7) // 8
base = hashmod(seed).digest()[:maxbytes]
base = "\x00" * (maxbytes - len(base)) + base
topbits = 8 * maxbytes - bits
if topbits:
base = int.to_bytes(ord(base[0]) & lsb_of_ones(topbits), 1, 'big') + base[1:]
number = 1 + int(binascii.hexlify(base), 16)
assert 1 <= number < order
return number
def randrange_from_seed__trytryagain(seed, order):
# figure out exactly how many bits we need (rounded up to the nearest
# bit), so we can reduce the chance of looping to less than 0.5 . This is
# specified to feed from a byte-oriented PRNG, and discards the
# high-order bits of the first byte as necessary to get the right number
# of bits. The average number of loops will range from 1.0 (when
# order=2**k-1) to 2.0 (when order=2**k+1).
assert order > 1
bits, bytes, extrabits = bits_and_bytes(order)
generate = PRNG(seed)
while True:
extrabyte = b''
if extrabits:
extrabyte = int.to_bytes(ord(generate(1)) & lsb_of_ones(extrabits), 1, 'big')
guess = string_to_number(extrabyte + generate(bytes)) + 1
if 1 <= guess < order:
return guess
def number_to_string(num, order):
l = orderlen(order)
fmt_str = "%0" + str(2 * l) + "x"
string = binascii.unhexlify((fmt_str % num).encode())
assert len(string) == l, (len(string), l)
return string
def number_to_string_crop(num, order):
l = orderlen(order)
fmt_str = "%0" + str(2 * l) + "x"
string = binascii.unhexlify((fmt_str % num).encode())
return string[:l]
def string_to_number(string):
return int(binascii.hexlify(string), 16)
def string_to_number_fixedlen(string, order):
l = orderlen(order)
assert len(string) == l, (len(string), l)
return int(binascii.hexlify(string), 16)
# these methods are useful for the sigencode= argument to SK.sign() and the
# sigdecode= argument to VK.verify(), and control how the signature is packed
# or unpacked.
def sigencode_strings(r, s, order, v=None):
r_str = number_to_string(r, order)
s_str = number_to_string(s, order)
return r_str, s_str, v
def sigencode_string(r, s, order, v=None):
# for any given curve, the size of the signature numbers is
# fixed, so just use simple concatenation
r_str, s_str, v = sigencode_strings(r, s, order)
return r_str + s_str
def sigencode_der(r, s, order, v=None):
return der.encode_sequence(der.encode_integer(r), der.encode_integer(s))
# canonical versions of sigencode methods
# these enforce low S values, by negating the value (modulo the order) if above order/2
# see CECKey::Sign() https://github.com/bitcoin/bitcoin/blob/master/src/key.cpp#L214
def sigencode_strings_canonize(r, s, order, v=None):
if s > order / 2:
s = order - s
if v is not None:
v ^= 1
return sigencode_strings(r, s, order, v)
def sigencode_string_canonize(r, s, order, v=None):
if s > order / 2:
s = order - s
if v is not None:
v ^= 1
return sigencode_string(r, s, order, v)
def sigencode_der_canonize(r, s, order, v=None):
if s > order / 2:
s = order - s
if v is not None:
v ^= 1
return sigencode_der(r, s, order, v)
def sigdecode_string(signature, order):
l = orderlen(order)
assert len(signature) == 2 * l, (len(signature), 2 * l)
r = string_to_number_fixedlen(signature[:l], order)
s = string_to_number_fixedlen(signature[l:], order)
return r, s
def sigdecode_strings(rs_strings, order):
(r_str, s_str) = rs_strings
l = orderlen(order)
assert len(r_str) == l, (len(r_str), l)
assert len(s_str) == l, (len(s_str), l)
r = string_to_number_fixedlen(r_str, order)
s = string_to_number_fixedlen(s_str, order)
return r, s
def sigdecode_der(sig_der, order):
# return der.encode_sequence(der.encode_integer(r), der.encode_integer(s))
rs_strings, empty = der.remove_sequence(sig_der)
if empty != b'':
raise der.UnexpectedDER("trailing junk after DER sig: %s" %
binascii.hexlify(empty))
r, rest = der.remove_integer(rs_strings)
s, empty = der.remove_integer(rest)
if empty != b'':
raise der.UnexpectedDER("trailing junk after DER numbers: %s" %
binascii.hexlify(empty))
return r, s