# -*- coding: utf-8 -*-
"""
requests.auth
~~~~~~~~~~~~~
This module contains the authentication handlers for Requests.
"""
import os
import re
import time
import hashlib
from base64 import b64encode
from .compat import urlparse, str
from .cookies import extract_cookies_to_jar
from .utils import parse_dict_header, to_native_string
from .status_codes import codes
CONTENT_TYPE_FORM_URLENCODED = 'application/x-www-form-urlencoded'
CONTENT_TYPE_MULTI_PART = 'multipart/form-data'
def _basic_auth_str(username, password):
"""Returns a Basic Auth string."""
authstr = 'Basic ' + to_native_string(
b64encode(('%s:%s' % (username, password)).encode('latin1')).strip()
)
return authstr
class AuthBase(object):
"""Base class that all auth implementations derive from"""
def __call__(self, r):
raise NotImplementedError('Auth hooks must be callable.')
class HTTPBasicAuth(AuthBase):
"""Attaches HTTP Basic Authentication to the given Request object."""
def __init__(self, username, password):
self.username = username
self.password = password
def __call__(self, r):
r.headers['Authorization'] = _basic_auth_str(self.username, self.password)
return r
class HTTPProxyAuth(HTTPBasicAuth):
"""Attaches HTTP Proxy Authentication to a given Request object."""
def __call__(self, r):
r.headers['Proxy-Authorization'] = _basic_auth_str(self.username, self.password)
return r
class HTTPDigestAuth(AuthBase):
"""Attaches HTTP Digest Authentication to the given Request object."""
def __init__(self, username, password):
self.username = username
self.password = password
self.last_nonce = ''
self.nonce_count = 0
self.chal = {}
self.pos = None
self.num_401_calls = 1
def build_digest_header(self, method, url):
realm = self.chal['realm']
nonce = self.chal['nonce']
qop = self.chal.get('qop')
algorithm = self.chal.get('algorithm')
opaque = self.chal.get('opaque')
if algorithm is None:
_algorithm = 'MD5'
else:
_algorithm = algorithm.upper()
# lambdas assume digest modules are imported at the top level
if _algorithm == 'MD5' or _algorithm == 'MD5-SESS':
def md5_utf8(x):
if isinstance(x, str):
x = x.encode('utf-8')
return hashlib.md5(x).hexdigest()
hash_utf8 = md5_utf8
elif _algorithm == 'SHA':
def sha_utf8(x):
if isinstance(x, str):
x = x.encode('utf-8')
return hashlib.sha1(x).hexdigest()
hash_utf8 = sha_utf8
KD = lambda s, d: hash_utf8("%s:%s" % (s, d))
if hash_utf8 is None:
return None
# XXX not implemented yet
entdig = None
p_parsed = urlparse(url)
path = p_parsed.path
if p_parsed.query:
path += '?' + p_parsed.query
A1 = '%s:%s:%s' % (self.username, realm, self.password)
A2 = '%s:%s' % (method, path)
HA1 = hash_utf8(A1)
HA2 = hash_utf8(A2)
if nonce == self.last_nonce:
self.nonce_count += 1
else:
self.nonce_count = 1
ncvalue = '%08x' % self.nonce_count
s = str(self.nonce_count).encode('utf-8')
s += nonce.encode('utf-8')
s += time.ctime().encode('utf-8')
s += os.urandom(8)
cnonce = (hashlib.sha1(s).hexdigest()[:16])
if _algorithm == 'MD5-SESS':
HA1 = hash_utf8('%s:%s:%s' % (HA1, nonce, cnonce))
if qop is None:
respdig = KD(HA1, "%s:%s" % (nonce, HA2))
elif qop == 'auth' or 'auth' in qop.split(','):
noncebit = "%s:%s:%s:%s:%s" % (
nonce, ncvalue, cnonce, 'auth', HA2
)
respdig = KD(HA1, noncebit)
else:
# XXX handle auth-int.
return None
self.last_nonce = nonce
# XXX should the partial digests be encoded too?
base = 'username="%s", realm="%s", nonce="%s", uri="%s", ' \
'response="%s"' % (self.username, realm, nonce, path, respdig)
if opaque:
base += ', opaque="%s"' % opaque
if algorithm:
base += ', algorithm="%s"' % algorithm
if entdig:
base += ', digest="%s"' % entdig
if qop:
base += ', qop="auth", nc=%s, cnonce="%s"' % (ncvalue, cnonce)
return 'Digest %s' % (base)
def handle_redirect(self, r, **kwargs):
"""Reset num_401_calls counter on redirects."""
if r.is_redirect:
self.num_401_calls = 1
def handle_401(self, r, **kwargs):
"""Takes the given response and tries digest-auth, if needed."""
if self.pos is not None:
# Rewind the file position indicator of the body to where
# it was to resend the request.
r.request.body.seek(self.pos)
num_401_calls = getattr(self, 'num_401_calls', 1)
s_auth = r.headers.get('www-authenticate', '')
if 'digest' in s_auth.lower() and num_401_calls < 2:
self.num_401_calls += 1
pat = re.compile(r'digest ', flags=re.IGNORECASE)
self.chal = parse_dict_header(pat.sub('', s_auth, count=1))
# Consume content and release the original connection
# to allow our new request to reuse the same one.
r.content
r.raw.release_conn()
prep = r.request.copy()
extract_cookies_to_jar(prep._cookies, r.request, r.raw)
prep.prepare_cookies(prep._cookies)
prep.headers['Authorization'] = self.build_digest_header(
prep.method, prep.url)
_r = r.connection.send(prep, **kwargs)
_r.history.append(r)
_r.request = prep
return _r
self.num_401_calls = 1
return r
def __call__(self, r):
# If we have a saved nonce, skip the 401
if self.last_nonce:
r.headers['Authorization'] = self.build_digest_header(r.method, r.url)
try:
self.pos = r.body.tell()
except AttributeError:
# In the case of HTTPDigestAuth being reused and the body of
# the previous request was a file-like object, pos has the
# file position of the previous body. Ensure it's set to
# None.
self.pos = None
r.register_hook('response', self.handle_401)
r.register_hook('response', self.handle_redirect)
return r