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import binascii
import weakref
import ldap3
from typing import Optional
from typing import MutableMapping # noqa
from typing import Tuple
import passlib.apache
import mitmproxy.net.http
from mitmproxy import connections # noqa
from mitmproxy import exceptions
from mitmproxy import http
from mitmproxy import ctx
from mitmproxy.net.http import status_codes
REALM = "mitmproxy"
def mkauth(username: str, password: str, scheme: str = "basic") -> str:
"""
Craft a basic auth string
"""
v = binascii.b2a_base64(
(username + ":" + password).encode("utf8")
).decode("ascii")
return scheme + " " + v
def parse_http_basic_auth(s: str) -> Tuple[str, str, str]:
"""
Parse a basic auth header.
Raises a ValueError if the input is invalid.
"""
scheme, authinfo = s.split()
if scheme.lower() != "basic":
raise ValueError("Unknown scheme")
try:
user, password = binascii.a2b_base64(authinfo.encode()).decode("utf8", "replace").split(":")
except binascii.Error as e:
raise ValueError(str(e))
return scheme, user, password
class ProxyAuth:
def __init__(self):
self.nonanonymous = False
self.htpasswd = None
self.singleuser = None
self.ldapconn = None
self.ldapserver = None
self.authenticated: MutableMapping[connections.ClientConnection, Tuple[str, str]] = weakref.WeakKeyDictionary()
"""Contains all connections that are permanently authenticated after an HTTP CONNECT"""
def load(self, loader):
loader.add_option(
"proxyauth", Optional[str], None,
"""
Require proxy authentication. Format:
"username:pass",
"any" to accept any user/pass combination,
"@path" to use an Apache htpasswd file,
or "ldap[s]:url_server_ldap:dn_auth:password:dn_subtree" for LDAP authentication.
"""
)
def enabled(self) -> bool:
return any([self.nonanonymous, self.htpasswd, self.singleuser, self.ldapconn, self.ldapserver])
def is_proxy_auth(self) -> bool:
"""
Returns:
- True, if authentication is done as if mitmproxy is a proxy
- False, if authentication is done as if mitmproxy is a HTTP server
"""
return ctx.options.mode == "regular" or ctx.options.mode.startswith("upstream:")
def which_auth_header(self) -> str:
if self.is_proxy_auth():
return 'Proxy-Authorization'
else:
return 'Authorization'
def auth_required_response(self) -> http.HTTPResponse:
if self.is_proxy_auth():
return http.make_error_response(
status_codes.PROXY_AUTH_REQUIRED,
headers=mitmproxy.net.http.Headers(Proxy_Authenticate='Basic realm="{}"'.format(REALM)),
)
else:
return http.make_error_response(
status_codes.UNAUTHORIZED,
headers=mitmproxy.net.http.Headers(WWW_Authenticate='Basic realm="{}"'.format(REALM)),
)
def check(self, f: http.HTTPFlow) -> Optional[Tuple[str, str]]:
"""
Check if a request is correctly authenticated.
Returns:
- a (username, password) tuple if successful,
- None, otherwise.
"""
auth_value = f.request.headers.get(self.which_auth_header(), "")
try:
scheme, username, password = parse_http_basic_auth(auth_value)
except ValueError:
return None
if self.nonanonymous:
return username, password
elif self.singleuser:
if self.singleuser == [username, password]:
return username, password
elif self.htpasswd:
if self.htpasswd.check_password(username, password):
return username, password
elif self.ldapconn:
if not username or not password:
return None
self.ldapconn.search(ctx.options.proxyauth.split(':')[4], '(cn=' + username + ')')
if self.ldapconn.response:
conn = ldap3.Connection(
self.ldapserver,
self.ldapconn.response[0]['dn'],
password,
auto_bind=True)
if conn:
return username, password
return None
def authenticate(self, f: http.HTTPFlow) -> bool:
valid_credentials = self.check(f)
if valid_credentials:
f.metadata["proxyauth"] = valid_credentials
del f.request.headers[self.which_auth_header()]
return True
else:
f.response = self.auth_required_response()
return False
# Handlers
def configure(self, updated):
if "proxyauth" in updated:
self.nonanonymous = False
self.singleuser = None
self.htpasswd = None
self.ldapserver = None
if ctx.options.proxyauth:
if ctx.options.proxyauth == "any":
self.nonanonymous = True
elif ctx.options.proxyauth.startswith("@"):
p = ctx.options.proxyauth[1:]
try:
self.htpasswd = passlib.apache.HtpasswdFile(p)
except (ValueError, OSError):
raise exceptions.OptionsError(
"Could not open htpasswd file: %s" % p
)
elif ctx.options.proxyauth.startswith("ldap"):
parts = ctx.options.proxyauth.split(':')
if len(parts) != 5:
raise exceptions.OptionsError(
"Invalid ldap specification"
)
security = parts[0]
ldap_server = parts[1]
dn_baseauth = parts[2]
password_baseauth = parts[3]
if security == "ldaps":
server = ldap3.Server(ldap_server, use_ssl=True)
elif security == "ldap":
server = ldap3.Server(ldap_server)
else:
raise exceptions.OptionsError(
"Invalid ldap specification on the first part"
)
conn = ldap3.Connection(
server,
dn_baseauth,
password_baseauth,
auto_bind=True)
self.ldapconn = conn
self.ldapserver = server
else:
parts = ctx.options.proxyauth.split(':')
if len(parts) != 2:
raise exceptions.OptionsError(
"Invalid single-user auth specification."
)
self.singleuser = parts
if self.enabled():
if ctx.options.mode == "transparent":
raise exceptions.OptionsError(
"Proxy Authentication not supported in transparent mode."
)
if ctx.options.mode == "socks5":
raise exceptions.OptionsError(
"Proxy Authentication not supported in SOCKS mode. "
"https://github.com/mitmproxy/mitmproxy/issues/738"
)
# TODO: check for multiple auth options
def http_connect(self, f: http.HTTPFlow) -> None:
if self.enabled():
if self.authenticate(f):
self.authenticated[f.client_conn] = f.metadata["proxyauth"]
def requestheaders(self, f: http.HTTPFlow) -> None:
if self.enabled():
# Is this connection authenticated by a previous HTTP CONNECT?
if f.client_conn in self.authenticated:
f.metadata["proxyauth"] = self.authenticated[f.client_conn]
return
self.authenticate(f)
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