コード例 #1
0
class Account(object):
    """ ACME server class """

    def __init__(self, debug=None, srv_name=None, logger=None):
        self.server_name = srv_name
        self.logger = logger
        self.dbstore = DBstore(debug, self.logger)
        self.message = Message(debug, self.server_name, self.logger)
        self.path_dic = {'acct_path' : '/acme/acct/'}
        self.ecc_only = False
        self.contact_check_disable = False
        self.tos_check_disable = False
        self.inner_header_nonce_allow = False
        self.tos_url = None
        self.eab_check = False
        self.eab_handler = None

    def __enter__(self):
        """ Makes ACMEHandler a Context Manager """
        self._config_load()
        return self

    def __exit__(self, *args):
        """ cose the connection at the end of the context """

    def _add(self, content, payload, contact):
        """ prepare db insert and call DBstore helper """
        self.logger.debug('Account.account._add()')
        account_name = generate_random_string(self.logger, 12)

        # check request
        if 'alg' in content and 'jwk' in content:

            if not self.contact_check_disable and not contact:
                code = 400
                message = 'urn:ietf:params:acme:error:malformed'
                detail = 'incomplete protected payload'
            else:
                # ecc_only check
                if self.ecc_only and not content['alg'].startswith('ES'):
                    code = 403
                    message = 'urn:ietf:params:acme:error:badPublicKey'
                    detail = 'Only ECC keys are supported'
                else:
                    # check jwk
                    data_dic = {
                        'name': account_name,
                        'alg': content['alg'],
                        'jwk': json.dumps(content['jwk']),
                        'contact': json.dumps(contact),
                    }
                    # add eab_kid to data_dic if eab_check is enabled and kid is part of the request
                    if self.eab_check:
                        if payload and 'externalaccountbinding' in payload and payload['externalaccountbinding']:
                            if 'protected' in payload['externalaccountbinding']:
                                eab_kid = self._eab_kid_get(payload['externalaccountbinding']['protected'])
                                self.logger.info('add eab_kid: {0} to data_dic'.format(eab_kid))
                                if eab_kid:
                                    data_dic['eab_kid'] = eab_kid
                    try:
                        (db_name, new) = self.dbstore.account_add(data_dic)
                    except BaseException as err_:
                        self.logger.critical('Account.account._add(): Database error: {0}'.format(err_))
                        db_name = None
                        new = False
                    self.logger.debug('got account_name:{0} new:{1}'.format(db_name, new))
                    if new:
                        code = 201
                        message = account_name
                    else:
                        code = 200
                        message = db_name
                    detail = None
        else:
            code = 400
            message = 'urn:ietf:params:acme:error:malformed'
            detail = 'incomplete protected payload'

        self.logger.debug('Account.account._add() ended with:{0}'.format(code))
        return(code, message, detail)

    def _contact_check(self, content):
        """ check contact information from payload"""
        self.logger.debug('Account._contact_check()')
        code = 200
        message = None
        detail = None
        if 'contact' in content:
            contact_check = validate_email(self.logger, content['contact'])
            if not contact_check:
                # invalidcontact message
                code = 400
                message = 'urn:ietf:params:acme:error:invalidContact'
                detail = ', '.join(content['contact'])
        else:
            code = 400
            message = 'urn:ietf:params:acme:error:invalidContact'
            detail = 'no contacts specified'

        self.logger.debug('Account._contact_check() ended with:{0}'.format(code))
        return(code, message, detail)

    def _contacts_update(self, aname, payload):
        """ update account """
        self.logger.debug('Account.update()')
        (code, message, detail) = self._contact_check(payload)
        if code == 200:
            data_dic = {'name' : aname, 'contact' : json.dumps(payload['contact'])}
            try:
                result = self.dbstore.account_update(data_dic)
            except BaseException as err_:
                self.logger.critical('acme2certifier database error in Account._contacts_update(): {0}'.format(err_))
                result = None

            if result:
                code = 200
            else:
                code = 400
                message = 'urn:ietf:params:acme:error:accountDoesNotExist'
                detail = 'update failed'

        return(code, message, detail)

    def _delete(self, aname):
        """ delete account """
        self.logger.debug('Account._delete({0})'.format(aname))
        try:
            result = self.dbstore.account_delete(aname)
        except BaseException as err_:
            self.logger.critical('acme2certifier database error in Account._delete(): {0}'.format(err_))
            result = None

        if result:
            code = 200
            message = None
            detail = None
        else:
            code = 400
            message = 'urn:ietf:params:acme:error:accountDoesNotExist'
            detail = 'deletion failed'

        self.logger.debug('Account._delete() ended with:{0}'.format(code))
        return(code, message, detail)

    def _eab_jwk_compare(self, protected, payload):
        """ compare jwk from outer header with jwk in eab playload """
        self.logger.debug('_eab_jwk_compare()')
        result = False
        if 'jwk' in protected:
            # convert outer jwk into string for better comparison
            if isinstance(protected, dict):
                jwk_outer = json.dumps(protected['jwk'])
                # decode inner jwk
                jwk_inner = b64decode_pad(self.logger, payload)
                jwk_inner = json.dumps(json.loads(jwk_inner))
                if jwk_outer == jwk_inner:
                    result = True

        self.logger.debug('_eab_jwk_compare() ended with: {0}'.format(result))
        return result

    def _eab_kid_get(self, protected):
        """ get key identifier for eab validation """
        self.logger.debug('_eab_kid_get()')
        # load protected into json format
        protected_dic = json.loads(b64decode_pad(self.logger, protected))
        # extract kid
        if isinstance(protected_dic, dict):
            eab_key_id = protected_dic.get('kid', None)
        else:
            eab_key_id = None

        self.logger.debug('_eab_kid_get() ended with: {0}'.format(eab_key_id))
        return eab_key_id

    def _eab_check(self, protected, payload):
        """" check for external account binding """
        self.logger.debug('_eab_check()')

        if self.eab_handler and protected and payload and 'externalaccountbinding' in payload and payload['externalaccountbinding']:
            # compare JWK from protected (outer) header if jwk included in payload of external account binding
            jwk_compare = self._eab_jwk_compare(protected, payload['externalaccountbinding']['payload'])

            if jwk_compare and 'protected' in payload['externalaccountbinding']:
                # get key identifier
                eab_kid = self._eab_kid_get(payload['externalaccountbinding']['protected'])
                if eab_kid:
                    # get eab_mac_key
                    with self.eab_handler(self.logger) as eab_handler:
                        eab_mac_key = eab_handler.mac_key_get(eab_kid)
                else:
                    eab_mac_key = None

                if eab_mac_key:
                    (result, error) = self._eab_signature_verify(payload['externalaccountbinding'], eab_mac_key)
                    if result:
                        code = 200
                        message = None
                        detail = None
                    else:
                        code = 403
                        message = 'urn:ietf:params:acme:error:unauthorized'
                        detail = 'eab signature verification failed'
                        self.logger.error('Account._eab_check() returned error: {0}'.format(error))
                else:
                    code = 403
                    message = 'urn:ietf:params:acme:error:unauthorized'
                    detail = 'eab kid lookup failed'
            else:
                code = 403
                message = 'urn:ietf:params:acme:error:malformed'
                detail = 'Malformed request'
        else:
            # no external account binding key in payload - error
            code = 403
            message = 'urn:ietf:params:acme:error:externalAccountRequired'
            detail = 'external account binding required'

        self.logger.debug('Account._eab_check() ended with:{0}'.format(code))
        return (code, message, detail)

    def _eab_signature_verify(self, content, mac_key):
        """ verify inner signature """
        self.logger.debug('Account._eab_signature_verify()')

        if content and mac_key:
            signature = Signature(None, self.server_name, self.logger)
            jwk_ = json.dumps({'k': mac_key, 'kty': 'oct'})
            (sig_check, error) = signature.eab_check(json.dumps(content), jwk_)
        else:
            sig_check = False
            error = None
        self.logger.debug('Account._eab_signature_verify() ended with: {0}'.format(sig_check))
        return (sig_check, error)

    def _inner_jws_check(self, outer_protected, inner_protected):
        """ RFC8655 7.3.5 checs of inner JWS """
        self.logger.debug('Account._inner_jws_check()')

        # check for jwk header
        if 'jwk' in inner_protected:
            if 'url' in outer_protected and 'url' in inner_protected:
                # inner and outer JWS must have the same "url" header parameter
                if outer_protected['url'] == inner_protected['url']:
                    if self.inner_header_nonce_allow:
                        code = 200
                        message = None
                        detail = None
                    else:
                        # inner JWS must omit nonce header
                        if 'nonce' not in inner_protected:
                            code = 200
                            message = None
                            detail = None
                        else:
                            code = 400
                            message = 'urn:ietf:params:acme:error:malformed'
                            detail = 'inner jws must omit nonce header'
                else:
                    code = 400
                    message = 'urn:ietf:params:acme:error:malformed'
                    detail = 'url parameter differ in inner and outer jws'
            else:
                code = 400
                message = 'urn:ietf:params:acme:error:malformed'
                detail = 'inner or outer jws is missing url header parameter'
        else:
            code = 400
            message = 'urn:ietf:params:acme:error:malformed'
            detail = 'inner jws is missing jwk'

        self.logger.debug('Account._inner_jws_check() ended with: {0}:{1}'.format(code, detail))
        return(code, message, detail)

    def _inner_payload_check(self, aname, outer_protected, inner_payload):
        """ RFC8655 7.3.5 checs of inner payload """
        self.logger.debug('Account._inner_payload_check()')

        if 'kid' in outer_protected:
            if 'account' in inner_payload:
                if outer_protected['kid'] == inner_payload['account']:
                    if 'oldkey' in inner_payload:
                        # compare oldkey with database
                        (code, message, detail) = self._key_compare(aname, inner_payload['oldkey'])
                    else:
                        code = 400
                        message = 'urn:ietf:params:acme:error:malformed'
                        detail = 'old key is missing'
                else:
                    code = 400
                    message = 'urn:ietf:params:acme:error:malformed'
                    detail = 'kid and account objects do not match'
            else:
                code = 400
                message = 'urn:ietf:params:acme:error:malformed'
                detail = 'account object is missing on inner payload'
        else:
            code = 400
            message = 'urn:ietf:params:acme:error:malformed'
            detail = 'kid is missing in outer header'

        self.logger.debug('Account._inner_payload_check() ended with: {0}:{1}'.format(code, detail))
        return(code, message, detail)

    def _key_change_validate(self, aname, outer_protected, inner_protected, inner_payload):
        """ validate key_change before exectution """
        self.logger.debug('Account._key_change_validate({0})'.format(aname))
        if 'jwk' in inner_protected:
            # check if we already have the key stored in DB
            key_exists = self._lookup(json.dumps(inner_protected['jwk']), 'jwk')
            if not key_exists:
                (code, message, detail) = self._inner_jws_check(outer_protected, inner_protected)

                if code == 200:
                    (code, message, detail) = self._inner_payload_check(aname, outer_protected, inner_payload)
            else:
                code = 400
                message = 'urn:ietf:params:acme:error:badPublicKey'
                detail = 'public key does already exists'
        else:
            code = 400
            message = 'urn:ietf:params:acme:error:malformed'
            detail = 'inner jws is missing jwk'

        self.logger.debug('Account._key_change_validate() ended with: {0}:{1}'.format(code, detail))
        return(code, message, detail)

    def _key_change(self, aname, payload, protected):
        """ key change for a given account """
        self.logger.debug('Account._key_change({0})'.format(aname))

        if 'url' in protected:
            if 'key-change' in protected['url']:
                # check message
                (code, message, detail, inner_protected, inner_payload, _account_name) = self.message.check(json.dumps(payload), use_emb_key=True, skip_nonce_check=True)
                if code == 200:
                    (code, message, detail) = self._key_change_validate(aname, protected, inner_protected, inner_payload)
                    if code == 200:
                        data_dic = {'name' : aname, 'jwk' : json.dumps(inner_protected['jwk'])}
                        try:
                            result = self.dbstore.account_update(data_dic)
                        except BaseException as err_:
                            self.logger.critical('acme2certifier database error in Account._key_change(): {0}'.format(err_))
                            result = None
                        if result:
                            code = 200
                            message = None
                            detail = None
                        else:
                            code = 500
                            message = 'urn:ietf:params:acme:error:serverInternal'
                            detail = 'key rollover failed'
            else:
                code = 400
                message = 'urn:ietf:params:acme:error:malformed'
                detail = 'malformed request. not a key-change'
        else:
            code = 400
            message = 'urn:ietf:params:acme:error:malformed'
            detail = 'malformed request'

        return(code, message, detail)

    def _key_compare(self, aname, old_key):
        """ compare key with the one stored in database """
        self.logger.debug('Account._key_compare({0})'.format(aname))

        # load current public key from database
        try:
            pub_key = self.dbstore.jwk_load(aname)
        except BaseException as err_:
            self.logger.critical('acme2certifier database error in Account._key_compare(): {0}'.format(err_))
            pub_key = None

        if old_key and pub_key:
            # rewrite alg statement in pubkey statement
            if 'alg' in pub_key and 'alg' in old_key:
                if pub_key['alg'].startswith('ES') and old_key['alg'] == 'ECDSA':
                    pub_key['alg'] = 'ECDSA'

            if old_key == pub_key:
                code = 200
                message = None
                detail = None
            else:
                code = 401
                message = 'urn:ietf:params:acme:error:unauthorized'
                detail = 'wrong public key'
        else:
            code = 401
            message = 'urn:ietf:params:acme:error:unauthorized'
            detail = 'wrong public key'

        self.logger.debug('Account._key_compare() ended with: {0}'.format(code))
        return(code, message, detail)

    def _config_load(self):
        """" load config from file """
        self.logger.debug('Account._config_load()')
        config_dic = load_config()
        if 'Account' in config_dic:
            self.inner_header_nonce_allow = config_dic.getboolean('Account', 'inner_header_nonce_allow', fallback=False)
            self.ecc_only = config_dic.getboolean('Account', 'ecc_only', fallback=False)
            self.tos_check_disable = config_dic.getboolean('Account', 'tos_check_disable', fallback=False)
            self.contact_check_disable = config_dic.getboolean('Account', 'contact_check_disable', fallback=False)

        if 'EABhandler' in config_dic:
            self.logger.debug('Account._config.load(): loading eab_handler')
            if 'eab_handler_file' in config_dic['EABhandler']:
                # mandate eab check regardless if handler could get loaded or not
                self.eab_check = True
                try:
                    eab_handler_module = importlib.import_module(ca_handler_get(self.logger, config_dic['EABhandler']['eab_handler_file']))
                except BaseException as err_:
                    self.logger.critical('Account._config_load(): loading EABHandler configured in cfg failed with err: {0}'.format(err_))
                    try:
                        eab_handler_module = importlib.import_module('acme_srv.eab_handler')
                    except BaseException as err_:
                        eab_handler_module = None
                        self.logger.critical('Account._config_load(): loading default EABHandler failed with err: {0}'.format(err_))

                if eab_handler_module:
                    # store handler in variable
                    self.eab_handler = eab_handler_module.EABhandler
                else:
                    self.logger.critical('Account._config_load(): EABHandler configuration is missing in config file')

        if 'Directory' in config_dic:
            if 'tos_url' in config_dic['Directory']:
                self.tos_url = config_dic['Directory']['tos_url']
            if 'url_prefix' in config_dic['Directory']:
                self.path_dic = {k: config_dic['Directory']['url_prefix'] + v for k, v in self.path_dic.items()}
        self.logger.debug('Account._config_load() ended')


    def _lookup(self, value, field='name'):
        """ lookup account """
        self.logger.debug('Account._lookup({0}:{1})'.format(field, value))
        try:
            result = self.dbstore.account_lookup(field, value)
        except BaseException as err_:
            self.logger.critical('acme2certifier database error in Account._lookup(): {0}'.format(err_))
            result = None
        return result

    # pylint: disable=W0212
    def _name_get(self, content):
        """ get id for account depricated"""
        self.logger.debug('Account._name_get()')
        _deprecated = True
        return self.message._name_get(content)

    def _onlyreturnexisting(self, protected, payload):
        """ check onlyreturnexisting """
        self.logger.debug('Account._onlyreturnexisting(}')
        if 'onlyreturnexisting' in payload:
            if payload['onlyreturnexisting']:
                code = None
                message = None
                detail = None

                if 'jwk' in protected:
                    try:
                        result = self.dbstore.account_lookup('jwk', json.dumps(protected['jwk']))
                    except BaseException as err_:
                        self.logger.critical('acme2certifier database error in Account._onlyreturnexisting(): {0}'.format(err_))
                        result = None

                    if result:
                        code = 200
                        message = result['name']
                        detail = None
                    else:
                        code = 400
                        message = 'urn:ietf:params:acme:error:accountDoesNotExist'
                        detail = None
                else:
                    code = 400
                    message = 'urn:ietf:params:acme:error:malformed'
                    detail = 'jwk structure missing'

            else:
                code = 400
                message = 'urn:ietf:params:acme:error:userActionRequired'
                detail = 'onlyReturnExisting must be true'
        else:
            code = 500
            message = 'urn:ietf:params:acme:error:serverInternal'
            detail = 'onlyReturnExisting without payload'

        self.logger.debug('Account.onlyreturnexisting() ended with:{0}'.format(code))
        return(code, message, detail)

    def _tos_check(self, content):
        """ check terms of service """
        self.logger.debug('Account._tos_check()')
        if 'termsofserviceagreed' in content:
            self.logger.debug('tos:{0}'.format(content['termsofserviceagreed']))
            if content['termsofserviceagreed']:
                code = 200
                message = None
                detail = None
            else:
                code = 403
                message = 'urn:ietf:params:acme:error:userActionRequired'
                detail = 'tosfalse'
        else:
            self.logger.debug('no tos statement found.')
            code = 403
            message = 'urn:ietf:params:acme:error:userActionRequired'
            detail = 'tosfalse'

        self.logger.debug('Account._tos_check() ended with:{0}'.format(code))
        return(code, message, detail)

    def new(self, content):
        """ generate a new account """
        self.logger.debug('Account.account_new()')

        response_dic = {}
        # check message but skip signature check as this is a new account (True)
        (code, message, detail, protected, payload, _account_name) = self.message.check(content, True)
        if code == 200:
            # onlyReturnExisting check
            if 'onlyreturnexisting' in payload:
                (code, message, detail) = self._onlyreturnexisting(protected, payload)
            else:
                # tos check
                if self.tos_url and not self.tos_check_disable:
                    (code, message, detail) = self._tos_check(payload)

                # check for external account binding
                if code == 200 and self.eab_check:
                    (code, message, detail) = self._eab_check(protected, payload)

                # contact check
                if code == 200 and not self.contact_check_disable:
                    (code, message, detail) = self._contact_check(payload)

                # add account to database
                if code == 200:
                    if 'contact' in payload:
                        contact_list = payload['contact']
                    else:
                        contact_list = []
                    (code, message, detail) = self._add(protected, payload, contact_list)

        if code in (200, 201):
            response_dic['data'] = {}
            if code == 201:
                response_dic['data'] = {
                    'status': 'valid',
                    'orders': '{0}{1}{2}/orders'.format(self.server_name, self.path_dic['acct_path'], message),
                }
                if 'contact' in payload:
                    response_dic['data']['contact'] = payload['contact']

            response_dic['header'] = {}
            response_dic['header']['Location'] = '{0}{1}{2}'.format(self.server_name, self.path_dic['acct_path'], message)

            # add exernal account binding
            if self.eab_check and 'externalaccountbinding' in payload:
                response_dic['data']['externalaccountbinding'] = payload['externalaccountbinding']

        else:
            if detail == 'tosfalse':
                detail = 'Terms of service must be accepted'

        # prepare/enrich response
        status_dic = {'code': code, 'message' : message, 'detail' : detail}
        response_dic = self.message.prepare_response(response_dic, status_dic)

        self.logger.debug('Account.account_new() returns: {0}'.format(json.dumps(response_dic)))
        return response_dic

    def parse(self, content):
        """ parse message """
        self.logger.debug('Account.parse()')

        response_dic = {}
        # check message
        (code, message, detail, protected, payload, account_name) = self.message.check(content)
        if code == 200:
            if 'status' in payload:
                # account deactivation
                if payload['status'].lower() == 'deactivated':
                    # account_name = self.message.name_get(protected)
                    (code, message, detail) = self._delete(account_name)
                    if code == 200:
                        response_dic['data'] = payload
                else:
                    code = 400
                    message = 'urn:ietf:params:acme:error:malformed'
                    detail = 'status attribute without sense'
            elif 'contact' in payload:
                (code, message, detail) = self._contacts_update(account_name, payload)
                if code == 200:
                    account_obj = self._lookup(account_name)
                    response_dic['data'] = {}
                    response_dic['data']['status'] = 'valid'
                    response_dic['data']['key'] = json.loads(account_obj['jwk'])
                    response_dic['data']['contact'] = json.loads(account_obj['contact'])
                    response_dic['data']['createdAt'] = date_to_datestr(account_obj['created_at'])
                else:
                    code = 400
                    message = 'urn:ietf:params:acme:error:accountDoesNotExist'
                    detail = 'update failed'
            elif 'payload' in payload:
                # this could be a key-change
                (code, message, detail) = self._key_change(account_name, payload, protected)
                if code == 200:
                    response_dic['data'] = {}
            else:
                code = 400
                message = 'urn:ietf:params:acme:error:malformed'
                detail = 'dont know what to do with this request'
        # prepare/enrich response
        status_dic = {'code': code, 'message' : message, 'detail' : detail}
        response_dic = self.message.prepare_response(response_dic, status_dic)

        self.logger.debug('Account.account_parse() returns: {0}'.format(json.dumps(response_dic)))
        return response_dic
コード例 #2
0
class Message(object):
    """ Message  handler """
    def __init__(self, debug=None, srv_name=None, logger=None):
        self.debug = debug
        self.logger = logger
        self.nonce = Nonce(self.debug, self.logger)
        self.dbstore = DBstore(self.debug, self.logger)
        self.server_name = srv_name
        self.path_dic = {
            'acct_path': '/acme/acct/',
            'revocation_path': '/acme/revokecert'
        }
        self.disable_dic = {
            'signature_check_disable': False,
            'nonce_check_disable': False
        }
        self._config_load()

    def __enter__(self):
        """ Makes ACMEHandler a Context Manager """
        return self

    def __exit__(self, *args):
        """ cose the connection at the end of the context """

    def _config_load(self):
        """" load config from file """
        self.logger.debug('_config_load()')
        config_dic = load_config()
        if 'Nonce' in config_dic:
            self.disable_dic['nonce_check_disable'] = config_dic.getboolean(
                'Nonce', 'nonce_check_disable', fallback=False)
            self.disable_dic[
                'signature_check_disable'] = config_dic.getboolean(
                    'Nonce', 'signature_check_disable', fallback=False)

        if 'Directory' in config_dic:
            if 'url_prefix' in config_dic['Directory']:
                self.path_dic = {
                    k: config_dic['Directory']['url_prefix'] + v
                    for k, v in self.path_dic.items()
                }

    def _name_get(self, content):
        """ get name for account """
        self.logger.debug('Message._name_get()')

        if 'kid' in content:
            self.logger.debug('kid: {0}'.format(content['kid']))
            kid = content['kid'].replace(
                '{0}{1}'.format(self.server_name, self.path_dic['acct_path']),
                '')
            if '/' in kid:
                kid = None
        elif 'jwk' in content and 'url' in content:
            if content['url'] == '{0}{1}'.format(
                    self.server_name, self.path_dic['revocation_path']):
                # this is needed for cases where we get a revocation message signed with account key but account name is missing)
                try:
                    account_list = self.dbstore.account_lookup(
                        'jwk', json.dumps(content['jwk']))
                except BaseException as err_:
                    self.logger.critical(
                        'acme2certifier database error in Message._name_get(): {0}'
                        .format(err_))
                    account_list = []
                if account_list:
                    if 'name' in account_list:
                        kid = account_list['name']
                    else:
                        kid = None
                else:
                    kid = None
            else:
                kid = None
        else:
            kid = None
        self.logger.debug('Message._name_get() returns: {0}'.format(kid))
        return kid

    def check(self, content, use_emb_key=False, skip_nonce_check=False):
        """ validate message """
        self.logger.debug('Message.check()')
        # disable signature check if paramter has been set
        if self.disable_dic['signature_check_disable']:
            self.logger.error(
                '**** SIGNATURE_CHECK_DISABLE!!! Severe security issue ****')
            skip_signature_check = True
        else:
            skip_signature_check = False

        # decode message
        (result, error_detail, protected, payload,
         _signature) = decode_message(self.logger, content)
        account_name = None
        if result:
            # decoding successful - check nonce for anti replay protection
            if skip_nonce_check or self.disable_dic['nonce_check_disable']:
                # nonce check can be skipped by configuration and in case of key-rollover
                if self.disable_dic['nonce_check_disable']:
                    self.logger.error(
                        '**** NONCE CHECK DISABLED!!! Severe security issue ****'
                    )
                else:
                    self.logger.info(
                        'skip nonce check of inner payload during keyrollover')
                code = 200
                message = None
                detail = None
            else:
                (code, message, detail) = self.nonce.check(protected)

            if code == 200 and not skip_signature_check:
                # nonce check successful - check signature
                account_name = self._name_get(protected)
                signature = Signature(self.debug, self.server_name,
                                      self.logger)
                # we need the decoded protected header to grab a key to verify signature
                (sig_check, error,
                 error_detail) = signature.check(account_name, content,
                                                 use_emb_key, protected)
                if sig_check:
                    code = 200
                    message = None
                    detail = None
                else:
                    code = 403
                    message = error
                    detail = error_detail
        else:
            # message could not get decoded
            code = 400
            message = 'urn:ietf:params:acme:error:malformed'
            detail = error_detail

        self.logger.debug('Message.check() ended with:{0}'.format(code))
        return (code, message, detail, protected, payload, account_name)

    def prepare_response(self, response_dic, status_dic):
        """ prepare response_dic """
        self.logger.debug('Message.prepare_response()')
        if 'code' not in status_dic:
            status_dic['code'] = 400
            status_dic['message'] = 'urn:ietf:params:acme:error:serverInternal'
            status_dic['detail'] = 'http status code missing'

        if 'message' not in status_dic:
            status_dic['message'] = 'urn:ietf:params:acme:error:serverInternal'

        if 'detail' not in status_dic:
            status_dic['detail'] = None

        # create response
        response_dic['code'] = status_dic['code']

        # create header if not existing
        if 'header' not in response_dic:
            response_dic['header'] = {}

        if status_dic['code'] >= 400:
            if status_dic['detail']:
                # some error occured get details
                error_message = Error(self.debug, self.logger)
                status_dic['detail'] = error_message.enrich_error(
                    status_dic['message'], status_dic['detail'])
                response_dic['data'] = {
                    'status': status_dic['code'],
                    'message': status_dic['message'],
                    'detail': status_dic['detail']
                }
            else:
                response_dic['data'] = {
                    'status': status_dic['code'],
                    'message': status_dic['message']
                }
                # response_dic['data'] = {'status': status_dic['code'], 'message': status_dic['message'], 'detail': None}
        else:
            # add nonce to header
            response_dic['header'][
                'Replay-Nonce'] = self.nonce.generate_and_add()

        return response_dic