blob: 268f4567d19209af982274cba66edc6a39fdd770 [file] [log] [blame]
#!/usr/bin/env python
# Copyright (c) 2016 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Utility for generating experimental API tokens
usage: [-h] [--key-file KEY_FILE]
[--expire-days EXPIRE_DAYS |
--expire-timestamp EXPIRE_TIMESTAMP]
origin trial_name
Run " -h" for more help on usage.
import argparse
import base64
from datetime import datetime
import json
import re
import os
import struct
import sys
import time
import urlparse
script_dir = os.path.dirname(os.path.realpath(__file__))
sys.path.insert(0, os.path.join(script_dir, 'third_party', 'ed25519'))
import ed25519
# Matches a valid DNS name label (alphanumeric plus hyphens, except at the ends,
# no longer than 63 ASCII characters)
DNS_LABEL_REGEX = re.compile(r"^(?!-)[a-z\d-]{1,63}(?<!-)$", re.IGNORECASE)
# This script generates Version 2 tokens.
VERSION = "\x02"
# Default key file, relative to script_dir.
DEFAULT_KEY_FILE = 'eftest.key'
def HostnameFromArg(arg):
"""Determines whether a string represents a valid hostname.
Returns the canonical hostname if its argument is valid, or None otherwise.
if not arg or len(arg) > 255:
return None
if arg[-1] == ".":
arg = arg[:-1]
if "." not in arg and arg != "localhost":
return None
if all(DNS_LABEL_REGEX.match(label) for label in arg.split(".")):
return arg.lower()
def OriginFromArg(arg):
"""Constructs the origin for the token from a command line argument.
Returns None if this is not possible (neither a valid hostname nor a
valid origin URL was provided.)
# Does it look like a hostname?
hostname = HostnameFromArg(arg)
if hostname:
return "https://" + hostname + ":443"
# If not, try to construct an origin URL from the argument
origin = urlparse.urlparse(arg)
if not origin or not origin.scheme or not origin.netloc:
raise argparse.ArgumentTypeError("%s is not a hostname or a URL" % arg)
# HTTPS or HTTP only
if origin.scheme not in ('https','http'):
raise argparse.ArgumentTypeError("%s does not use a recognized URL scheme" %
# Add default port if it is not specified
port = origin.port
except ValueError:
raise argparse.ArgumentTypeError("%s is not a hostname or a URL" % arg)
if not port:
port = {"https": 443, "http": 80}[origin.scheme]
# Strip any extra components and return the origin URL:
return "{0}://{1}:{2}".format(origin.scheme, origin.hostname, port)
def ExpiryFromArgs(args):
if args.expire_timestamp:
return int(args.expire_timestamp)
return (int(time.time()) + (int(args.expire_days) * 86400))
def GenerateTokenData(origin, api_name, expiry):
return json.dumps({"origin": origin,
"feature": api_name,
"expiry": expiry}).encode('utf-8')
def GenerateDataToSign(version, data):
return version + struct.pack(">I",len(data)) + data
def Sign(private_key, data):
return ed25519.signature(data, private_key[:32], private_key[32:])
def FormatToken(version, signature, data):
return base64.b64encode(version + signature +
struct.pack(">I",len(data)) + data)
def main():
default_key_file_absolute = os.path.join(script_dir, DEFAULT_KEY_FILE)
parser = argparse.ArgumentParser(
description="Generate tokens for enabling experimental APIs")
help="Origin for which to enable the API. This can be "
"either a hostname (default scheme HTTPS, default "
"port 443) or a URL.",
help="Feature to enable. The current list of "
"experimental feature trials can be found in "
help="Ed25519 private key file to sign the token with",
expiry_group = parser.add_mutually_exclusive_group()
help="Days from now when the token should exipire",
help="Exact time (seconds since 1970-01-01 "
"00:00:00 UTC) when the token should exipire",
args = parser.parse_args()
expiry = ExpiryFromArgs(args)
key_file = open(os.path.expanduser(args.key_file), mode="rb")
private_key =
# Validate that the key file read was a proper Ed25519 key -- running the
# publickey method on the first half of the key should return the second
# half.
if (len(private_key) < 64 or
ed25519.publickey(private_key[:32]) != private_key[32:]):
print("Unable to use the specified private key file.")
token_data = GenerateTokenData(args.origin, args.trial_name, expiry)
data_to_sign = GenerateDataToSign(VERSION, token_data)
signature = Sign(private_key, data_to_sign)
# Verify that that the signature is correct before printing it.
ed25519.checkvalid(signature, data_to_sign, private_key[32:])
except Exception, exc:
print "There was an error generating the signature."
print "(The original error was: %s)" % exc
# Output the token details
print "Token details:"
print " Origin: %s" % args.origin
print " Feature: %s" % args.trial_name
print " Expiry: %d (%s UTC)" % (expiry, datetime.utcfromtimestamp(expiry))
# Output the properly-formatted token.
print FormatToken(VERSION, signature, token_data)
if __name__ == "__main__":