Google OAuth demo

google_oauth.py

#!/usr/bin/python
'demo Google OAuth'
import sys, os, urllib, urllib2, time, httplib
import hmac, hashlib, random, re, base64
PARAMETERS = {
    'oauth_consumer_key': os.getenv('OAUTH_CONSUMER_KEY') or 'anonymous',
    'oauth_signature_method': 'HMAC-SHA1',
    'oauth_signature': '',
    'oauth_timestamp': os.getenv('OAUTH_TIMESTAMP') or '%d' % time.time(),
    'oauth_nonce': os.getenv('OAUTH_NONCE') or '%x' % random.getrandbits(64),
    'oauth_version': '1.0',
    'oauth_callback': os.getenv('OAUTH_CALLBACK') or 'callback',
}
SCOPE = {'scope': 'https://www.google.com/calendar/feeds/'}
SECRET = os.getenv('OAUTH_CONSUMER_SECRET') or 'anonymous'
def google_oauth():
    'OAuthGetRequestToken, OAuthAuthorizeToken, OAuthGetAccessToken'
    request_token = get_request_token()
    return request_token
def get_request_token():
    'ask Google for a request token'
    url = 'https://www.google.com/accounts/OAuthGetRequestToken'
    token_secret = ''  # we don't have a token secret yet
    PARAMETERS['oauth_signature'] = sign('&'.join((SECRET, token_secret)),
                                         '&'.join(map(urlencode, ('GET', url, parameters('signing')))))
    body = urllib.urlencode(SCOPE)
    request = urllib2.Request(url + '?' + body)
    request.add_header('Authorization', 'OAuth ' + parameters('header'))
    opener = urllib2.build_opener(urllib2.HTTPSHandler(debuglevel = 1))
    request = opener.open(request)
    reply = request.read()
    request.close()
    return reply
def byte_encode(match):
    'for use with re.sub'
    return '%%%02X' % ord(match.group())
def urlencode(string):
    "unreserved = ALPHA, DIGIT, '-', '.', '_', '~'"
    return re.sub(re.compile('[^0-9A-Za-z._~-]'),
                  byte_encode, string.encode('utf8'))
def sign(secret, text):
    print >>sys.stderr, 'signature base string: "%s", secret: %s' % (
        repr(text), repr(secret))
    digest = hmac.new(secret, text, hashlib.sha1).digest()
    return urlencode(base64.encodestring(digest).rstrip())
def base64string(hexstring):
    recoded = urlencode(base64.encodestring(hexstring.decode('hex')).rstrip())
    print >>sys.stderr, 'recoded:', recoded
    return recoded
def parameters(format):
    if format == 'header':
        formatted = ', '.join(['%s="%s"' % (key, value)
                               for key, value in PARAMETERS.items()])
        return formatted
    elif format == 'signing':
        formatted = '&'.join(sorted(['%s=%s' % (key,
                                                urlencode(value.encode('utf8'))) for
                                     key, value in (PARAMETERS.items() + SCOPE.items()) if
                                     key not in ['oauth_signature']]))
        #print >>sys.stderr, format, formatted
        return formatted
def hmac_sha1_test():
    'from tools.ietf.org/html/rfc2202'
    assert sign('\x0b' * 20, 'Hi There') == base64string(
        'b617318655057264e28bc0b6fb378c8ef146be00')
    assert sign('Jefe', 'what do ya want for nothing?') == base64string(
        'effcdf6ae5eb2fa2d27416d5f184df9c259a7c79')
    assert sign('\xaa' * 20, '\xdd' * 50) == base64string(
        '125d7342b9ac11cd91a39af48aa17b4f63f175d3')
    # last test from http://oauth.net/core/1.0/#rfc.section.9.1.1, app. A.5.2
    assert sign('kd94hf93k423kf44&pfkkdhi9sl3r4s00',
                'GET&http%3A%2F%2Fphotos.example.net%2Fphotos&file%3Dvacation.jpg%26' + \
                'oauth_consumer_key%3Ddpf43f3p2l4k3l03%26oauth_nonce%3D' + \
                'kllo9940pd9333jh%26oauth_signature_method%3DHMAC-SHA1%26' + \
                'oauth_timestamp%3D1191242096%26oauth_token%3Dnnch734d00sl2jdk%26' + \
                'oauth_version%3D1.0%26size%3Doriginal') == urlencode(
                    'tR3+Ty81lMeYAr/Fid0kMTYa/WM=')
    return True
if __name__ == '__main__':
    command = os.path.splitext(os.path.basename(sys.argv[0]))[0]
    print eval(command)(*sys.argv[1:])