diff options
Diffstat (limited to 'paramiko/auth_handler.py')
| -rw-r--r-- | paramiko/auth_handler.py | 207 |
1 files changed, 202 insertions, 5 deletions
diff --git a/paramiko/auth_handler.py b/paramiko/auth_handler.py index 57babef..b5fea65 100644 --- a/paramiko/auth_handler.py +++ b/paramiko/auth_handler.py @@ -28,20 +28,27 @@ from paramiko.common import cMSG_SERVICE_REQUEST, cMSG_DISCONNECT, \ cMSG_USERAUTH_INFO_REQUEST, WARNING, AUTH_FAILED, cMSG_USERAUTH_PK_OK, \ cMSG_USERAUTH_INFO_RESPONSE, MSG_SERVICE_REQUEST, MSG_SERVICE_ACCEPT, \ MSG_USERAUTH_REQUEST, MSG_USERAUTH_SUCCESS, MSG_USERAUTH_FAILURE, \ - MSG_USERAUTH_BANNER, MSG_USERAUTH_INFO_REQUEST, MSG_USERAUTH_INFO_RESPONSE + MSG_USERAUTH_BANNER, MSG_USERAUTH_INFO_REQUEST, MSG_USERAUTH_INFO_RESPONSE, \ + cMSG_USERAUTH_GSSAPI_RESPONSE, cMSG_USERAUTH_GSSAPI_TOKEN, \ + cMSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, cMSG_USERAUTH_GSSAPI_ERROR, \ + cMSG_USERAUTH_GSSAPI_ERRTOK, cMSG_USERAUTH_GSSAPI_MIC,\ + MSG_USERAUTH_GSSAPI_RESPONSE, MSG_USERAUTH_GSSAPI_TOKEN, \ + MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, MSG_USERAUTH_GSSAPI_ERROR, \ + MSG_USERAUTH_GSSAPI_ERRTOK, MSG_USERAUTH_GSSAPI_MIC from paramiko.message import Message from paramiko.py3compat import bytestring from paramiko.ssh_exception import SSHException, AuthenticationException, \ BadAuthenticationType, PartialAuthentication from paramiko.server import InteractiveQuery +from paramiko.ssh_gss import GSSAuth class AuthHandler (object): """ Internal class to handle the mechanics of authentication. """ - + def __init__(self, transport): self.transport = weakref.proxy(transport) self.username = None @@ -56,7 +63,10 @@ class AuthHandler (object): # for server mode: self.auth_username = None self.auth_fail_count = 0 - + # for GSSAPI + self.gss_host = None + self.gss_deleg_creds = True + def is_authenticated(self): return self.authenticated @@ -97,7 +107,7 @@ class AuthHandler (object): self._request_auth() finally: self.transport.lock.release() - + def auth_interactive(self, username, handler, event, submethods=''): """ response_list = handler(title, instructions, prompt_list) @@ -112,7 +122,29 @@ class AuthHandler (object): self._request_auth() finally: self.transport.lock.release() - + + def auth_gssapi_with_mic(self, username, gss_host, gss_deleg_creds, event): + self.transport.lock.acquire() + try: + self.auth_event = event + self.auth_method = 'gssapi-with-mic' + self.username = username + self.gss_host = gss_host + self.gss_deleg_creds = gss_deleg_creds + self._request_auth() + finally: + self.transport.lock.release() + + def auth_gssapi_keyex(self, username, event): + self.transport.lock.acquire() + try: + self.auth_event = event + self.auth_method = 'gssapi-keyex' + self.username = username + self._request_auth() + finally: + self.transport.lock.release() + def abort(self): if self.auth_event is not None: self.auth_event.set() @@ -211,6 +243,77 @@ class AuthHandler (object): elif self.auth_method == 'keyboard-interactive': m.add_string('') m.add_string(self.submethods) + elif self.auth_method == "gssapi-with-mic": + sshgss = GSSAuth(self.auth_method, self.gss_deleg_creds) + m.add_bytes(sshgss.ssh_gss_oids()) + # send the supported GSSAPI OIDs to the server + self.transport._send_message(m) + ptype, m = self.transport.packetizer.read_message() + if ptype == MSG_USERAUTH_BANNER: + self._parse_userauth_banner(m) + ptype, m = self.transport.packetizer.read_message() + if ptype == MSG_USERAUTH_GSSAPI_RESPONSE: + # Read the mechanism selected by the server. We send just + # the Kerberos V5 OID, so the server can only respond with + # this OID. + mech = m.get_string() + m = Message() + m.add_byte(cMSG_USERAUTH_GSSAPI_TOKEN) + m.add_string(sshgss.ssh_init_sec_context(self.gss_host, + mech, + self.username,)) + self.transport._send_message(m) + while True: + ptype, m = self.transport.packetizer.read_message() + if ptype == MSG_USERAUTH_GSSAPI_TOKEN: + srv_token = m.get_string() + next_token = sshgss.ssh_init_sec_context(self.gss_host, + mech, + self.username, + srv_token) + # After this step the GSSAPI should not return any + # token. If it does, we keep sending the token to + # the server until no more token is returned. + if next_token is None: + break + else: + m = Message() + m.add_byte(cMSG_USERAUTH_GSSAPI_TOKEN) + m.add_string(next_token) + self.transport.send_message(m) + else: + raise SSHException("Received Package: %s" % MSG_NAMES[ptype]) + m = Message() + m.add_byte(cMSG_USERAUTH_GSSAPI_MIC) + # send the MIC to the server + m.add_string(sshgss.ssh_get_mic(self.transport.session_id)) + elif ptype == MSG_USERAUTH_GSSAPI_ERRTOK: + # RFC 4462 says we are not required to implement GSS-API + # error messages. + # See RFC 4462 Section 3.8 in + # http://www.ietf.org/rfc/rfc4462.txt + raise SSHException("Server returned an error token") + elif ptype == MSG_USERAUTH_GSSAPI_ERROR: + maj_status = m.get_int() + min_status = m.get_int() + err_msg = m.get_string() + lang_tag = m.get_string() # we don't care! + raise SSHException("GSS-API Error:\nMajor Status: %s\n\ + Minor Status: %s\ \nError Message:\ + %s\n") % (str(maj_status), + str(min_status), + err_msg) + elif ptype == MSG_USERAUTH_FAILURE: + self._parse_userauth_failure(m) + return + else: + raise SSHException("Received Package: %s" % MSG_NAMES[ptype]) + elif self.auth_method == 'gssapi-keyex' and\ + self.transport.gss_kex_used: + kexgss = self.transport.kexgss_ctxt + kexgss.set_username(self.username) + mic_token = kexgss.ssh_get_mic(self.transport.session_id) + m.add_string(mic_token) elif self.auth_method == 'none': pass else: @@ -278,6 +381,8 @@ class AuthHandler (object): self._disconnect_no_more_auth() return self.auth_username = username + # check if GSS-API authentication is enabled + gss_auth = self.transport.server_object.enable_auth_gssapi() if method == 'none': result = self.transport.server_object.check_auth_none(username) @@ -343,6 +448,98 @@ class AuthHandler (object): # make interactive query instead of response self._interactive_query(result) return + elif method == "gssapi-with-mic" and gss_auth: + sshgss = GSSAuth(method) + # Read the number of OID mechanisms supported by the client. + # OpenSSH sends just one OID. It's the Kerveros V5 OID and that's + # the only OID we support. + mechs = m.get_int() + # We can't accept more than one OID, so if the SSH client sends + # more than one, disconnect. + if mechs > 1: + self.transport._log(INFO, + 'Disconnect: Received more than one GSS-API OID mechanism') + self._disconnect_no_more_auth() + desired_mech = m.get_string() + mech_ok = sshgss.ssh_check_mech(desired_mech) + # if we don't support the mechanism, disconnect. + if not mech_ok: + self.transport._log(INFO, + 'Disconnect: Received an invalid GSS-API OID mechanism') + self._disconnect_no_more_auth() + # send the Kerberos V5 GSSAPI OID to the client + supported_mech = sshgss.ssh_gss_oids("server") + # RFC 4462 says we are not required to implement GSS-API error + # messages. See section 3.8 in http://www.ietf.org/rfc/rfc4462.txt + while True: + m = Message() + m.add_byte(cMSG_USERAUTH_GSSAPI_RESPONSE) + m.add_bytes(supported_mech) + self.transport._send_message(m) + ptype, m = self.transport.packetizer.read_message() + if ptype == MSG_USERAUTH_GSSAPI_TOKEN: + client_token = m.get_string() + # use the client token as input to establish a secure + # context. + try: + token = sshgss.ssh_accept_sec_context(self.gss_host, + client_token, + username) + except Exception: + result = AUTH_FAILED + self._send_auth_result(username, method, result) + raise + if token is not None: + m = Message() + m.add_byte(cMSG_USERAUTH_GSSAPI_TOKEN) + m.add_string(token) + self.transport._send_message(m) + else: + raise SSHException("Client asked to handle paket %s" + %MSG_NAMES[ptype]) + # check MIC + ptype, m = self.transport.packetizer.read_message() + if ptype == MSG_USERAUTH_GSSAPI_MIC: + break + mic_token = m.get_string() + try: + sshgss.ssh_check_mic(mic_token, + self.transport.session_id, + username) + except Exception: + result = AUTH_FAILED + self._send_auth_result(username, method, result) + raise + if retval == 0: + # TODO: Implement client credential saving. + # The OpenSSH server is able to create a TGT with the delegated + # client credentials, but this is not supported by GSS-API. + result = AUTH_SUCCESSFUL + self.transport.server_object.check_auth_gssapi_with_mic( + username, result) + else: + result = AUTH_FAILED + elif method == "gssapi-keyex" and gss_auth: + mic_token = m.get_string() + sshgss = self.transport.kexgss_ctxt + if sshgss is None: + # If there is no valid context, we reject the authentication + result = AUTH_FAILED + self._send_auth_result(username, method, result) + try: + sshgss.ssh_check_mic(mic_token, + self.transport.session_id, + self.auth_username) + except Exception: + result = AUTH_FAILED + self._send_auth_result(username, method, result) + raise + if retval == 0: + result = AUTH_SUCCESSFUL + self.transport.server_object.check_auth_gssapi_keyex(username, + result) + else: + result = AUTH_FAILED else: result = self.transport.server_object.check_auth_none(username) # okay, send result |