refactor: cleanup

- lazy load backend
- proper config evaluation
- object-orientation of configuration

src/httpaste/__init__.py

@@ -137,21 +137,23 @@ NOTES
     SUCH DAMAGES.
 
 """
-from typing import NamedTuple, Tuple, Any
+from typing import NamedTuple
-from string import ascii_uppercase, digits, ascii_letters, punctuation
-from inspect import isclass
 from configparser import ConfigParser
-from ast import literal_eval
-from io import StringIO
-from os import environ
 from importlib.resources import path as resource_path
+from pathlib import Path
 
 from connexion import FlaskApp
 from connexion.resolver import RestyResolver
 
-from httpaste.model import Backend
+from httpaste.server import get_server_config
-from httpaste.backend import get_backend_map
+from httpaste.server import Config as ServerConfig
-from httpaste.helper.common import generate_random_string
+from httpaste.context import get_context_config
+from httpaste.context import Config as ContextConfig
+from httpaste.model import get_model_config
+from httpaste.model import Config as ModelConfig
+from httpaste.backend import get_backend_config
+from httpaste.backend import Config as BackendConfig
+from httpaste.helper.config import get_configparser, CONFIGPATH_ENVIRON
 from httpaste.helper.http import (
     BadRequestError,
     ForbiddenError,
@@ -160,147 +162,48 @@ from httpaste.helper.http import (
     UnauthorizedError)
 
 
-CONFIGPATH_ENVIRON = 'HTTPASTE_CONFIGPATH'
+class Config(NamedTuple):
-
-
-def get_sanitized_config_charset(charset: str):
-
-    for x in ["$", "%"]:
-
-        charset = charset.replace(x, f'{x}{x}')
-
-    return charset
-
-
-class ConfigError(Exception):
-    """Config Exception
     """
-
-
-class Config:
-    """httpaste global config
     """
-    salt: bytes = get_sanitized_config_charset(generate_random_string(
+    context: ContextConfig
-        32, ascii_letters + digits + punctuation)).encode('utf-8')
+    server: ServerConfig
-    paste_id_size: int = 8
+    model: ModelConfig
-    paste_id_charset: str = ascii_letters + digits
+    backend: BackendConfig
-    paste_key_size: int = 32
-    paste_key_charset: str = get_sanitized_config_charset(
-        ascii_letters + digits + punctuation)
-    paste_lifetime: int = 5
-    backend: Backend = None
-    hmac_iterations: int = 20000
-    paste_default_encoding: str = 'utf-8'
 
 
-class ServerConfig:
+def get_config(configIni: ConfigParser, path: Path):
-    """connexion config
-    """
-    swagger_ui: bool = True
-    bind_address = None
-
-
-def get_config_path(var_name: str = CONFIGPATH_ENVIRON):
     """
     """
 
-    try:
+    from httpaste.model import Config as ModelConfig
 
-        return environ[var_name]
+    context_config = get_context_config(configIni)
-    except KeyError as e:
+    server_config = get_server_config(configIni)
+    model_config = get_model_config(configIni, path)
+    backend_config = get_backend_config(configIni, path)
 
-        raise ConfigError(
+    return Config(
-            f'environment variable \'{var_name}\' not set.') from e
+        context=context_config,
+        server=server_config,
+        model=model_config,
+        backend=backend_config
+    )
 
 
-def load_config(path: str) -> Tuple[Config, ServerConfig]:
+def load_config(path: str = None, var_name: str = CONFIGPATH_ENVIRON):
-    """get config objects from file
-    """
-
-    _config = ConfigParser()
-    _config.read(path)
-
-    backends = get_backend_map()
-    bconf = dict(_config.items('backend'))
-    btype = bconf.pop('type')
-
-    try:
-        bcl, bparamcl = backends[btype]
-    except KeyError as e:
-        bids = ', '.join(backends.keys())
-        raise ConfigError(' '.join((
-            f'invalid backend \'{btype}\' in \'{path}\'. ',
-            f'must be any of [{bids}]'
-        ))) from e
-
-    config = dict(_config.items('general'))
-    server_config = dict(_config.items('server'))
-
-    c = Config()
-    sc = ServerConfig()
-
-    # typecast model_backend section items
-    bconf = {k: literal_eval(v) for k, v in bconf.items()}
-    # initialize model backend
-    c.backend = bcl(bparamcl(**bconf))
-
-    # typecast general section items
-    for k, v in config.items():
-        setattr(c, k, literal_eval(v))
-    # typecast server section items
-    for k, v in server_config.items():
-        setattr(sc, k, literal_eval(v))
-
-    c.salt = c.salt.encode('utf-8')
-
-    return c, sc
-
-
-def default_config() -> str:
     """
     """
 
-    config = ConfigParser()
+    configIni, _ = get_configparser(path, var_name)
 
-    config['general'] = {
+    return get_config(configIni, Path(path).resolve().parent)
-        'salt': Config.salt.decode('utf-8'),
-        'paste_key_charset': Config.paste_key_charset,
-        'paste_id_charset': Config.paste_id_charset
-    }
-
-    for literal in [
-        'paste_id_size',
-        'paste_key_size',
-        'paste_lifetime'
-    ]:
-        config['general'][literal] = str(getattr(Config, literal))
-
-    config['backend'] = {
-        'type': 'sqlite',
-        'path': 'file::memory:?cache=shared'
-    }
-
-    config['server'] = {}
-    for literal in [
-        'swagger_ui',
-        'bind_address'
-    ]:
-        config['server'][literal] = str(getattr(ServerConfig, literal))
-
-    stream = StringIO()
-    config.write(stream)
-    stream.seek(0)
-
-    return stream.read()
 
 
-def get_flask_app(
+def get_flask_app(config: Config) -> FlaskApp:
-        config: Config,
-        server_config: ServerConfig = ServerConfig) -> FlaskApp:
     """get a flask app object
     """
 
-    options = {"swagger_ui": server_config.swagger_ui}
+    options = {"swagger_ui": config.server.swagger_ui}
 
     #context manager returns a pathlib.Path object
     with resource_path('httpaste.schema', 'httpaste.openapi.json') as path:
@@ -340,8 +243,6 @@ def get_flask_app(
 
 __all__ = [
     Config,
-    ServerConfig,
     load_config,
-    default_config,
     get_flask_app
 ]

src/httpaste/__main__.py

@@ -40,9 +40,9 @@ def command_standalone(**kwargs):
             'Please install it by running \'python3 -m pip install gevent\'.'
         ))) from e
 
-    config, server_config = load_config(kwargs.get('config_path'))
+    config = load_config(kwargs.get('config_path'))
 
-    application = get_flask_app(config, server_config)
+    application = get_flask_app(config)
 
     http_server = WSGIServer(('', kwargs.get('port')), application)
     http_server.serve_forever()
@@ -122,7 +122,7 @@ def parser():
 
     p_standalone = sp.add_parser('standalone', help=command_standalone.__doc__)
     p_standalone.add_argument('--config-path', '-c', required=True)
-    p_standalone.add_argument('--port', '-p', default=8080)
+    p_standalone.add_argument('--port', '-p', default=8082)
 
     p_wsgi = sp.add_parser('wsgi', help=command_wsgi.__doc__)
     p_wsgi.add_argument('--echo', '-e', action='store_true')

src/httpaste/backend/__init__.py

@@ -2,83 +2,114 @@
 
 implements backend of model
 """
-import sys
+from abc import ABC, abstractmethod
-from inspect import isclass
+from importlib import import_module
-from typing import Dict, Tuple
+from configparser import ConfigParser
+from typing import NamedTuple
+from pathlib import Path
 
-from httpaste.model import Backend, UserDataSchema, PasteDataSchema, User, Paste
+from httpaste.schema import User, Paste, UserDataSchema, PasteDataSchema
-from .sqlite import Parameters as SqliteParameters
+from httpaste.helper.config import get_config, ConfigError
-from .sqlite import User as SqliteUser
-from .sqlite import Paste as SqlitePaste
-from .sqlite import get_connection as get_sqlite_connection
-from .mysql import get_connection as get_mysql_connection
-from .file import Parameters as FileParameters
-from .file import User as FileUser
-from .file import Paste as FilePaste
-from .mysql import Parameters as MySQLParameters
-from .mysql import User as MySQLUser
-from .mysql import Paste as MySQLPaste
 
 
-class SQLite(Backend):
+class BackendError(Exception):
-    """SQLite backend interface
+    """
     """
 
-    parameter_class = SqliteParameters
-    user: SqliteUser
-    paste: SqlitePaste
 
-    def __init__(self, parameters: SqliteParameters):
+class ObjectBackend(ABC):
-
+    """
-        parameters = SqliteParameters(parameters.path, get_sqlite_connection(parameters))
-
-        self.user = SqliteUser(parameters, User)
-        self.paste = SqlitePaste(parameters, Paste)
-
-
-class File(Backend):
-    """File backend interface
     """
 
-    parameter_class = FileParameters
+    @abstractmethod
-    user: FileUser
+    def load(self, proto: object) -> object:
-    paste: FilePaste
+        pass
 
-    def __init__(self, parameters: FileParameters):
+    @abstractmethod
+    def dump(self, model: object) -> None:
+        pass
 
-        self.user = FileUser(parameters, User, UserDataSchema)
+    @abstractmethod
-        self.paste = FilePaste(parameters, Paste, PasteDataSchema)
+    def delete(self, proto: object) -> None:
+        pass
+
+    @abstractmethod
+    def init(self) -> object:
+        pass
+
+    @abstractmethod
+    def sanitize(self) -> None:
+        pass
 
 
-class MySQL(Backend):
+class BackendInterface(ABC):
-    """MySQL backend interface
+    """
     """
 
-    parameter_class = MySQLParameters
+    @abstractmethod
-    user: MySQLUser
+    def __init__(self, params: object,
-    paste: MySQLPaste
+                 user_model_class: type,
+                 paste_model_class: type,
+                 user_schema: type,
+                 paste_schema: type) -> None:
+        pass
 
-    def __init__(self, parameters: MySQLParameters):
+    @property
+    @abstractmethod
+    def user(self) -> ObjectBackend:
+        pass
 
-        #parameters = MySQLParameters(*parameters[1:], get_mysql_connection(parameters))
+    @property
-
+    @abstractmethod
-        self.user = MySQLUser(parameters, User)
+    def paste(self) -> ObjectBackend:
-        self.paste = MySQLPaste(parameters, Paste)
+        pass
 
 
-def get_backend_map() -> Dict[str, Tuple[type, type]]:
+class Config(NamedTuple):
-    """get a map of backend ids and their classes
+    """Backend Configuration
+    """
+    interface: type
+    config: dict
+
+
+def load_backend(config: Config) -> BackendInterface:
+    """load a backend
     """
 
-    mod = sys.modules[__name__]
+    backend = config.interface(config.config, Paste, User, PasteDataSchema,
-    out = {}
+                               UserDataSchema)
 
-    for i in dir(mod):
+    return backend
 
-        obj = getattr(mod, i)
 
-        if isclass(obj) and obj.__module__ == __name__:
+def get_backend_config(configIni: ConfigParser, path:Path) -> Config:
+    """retrieve a cascaded backend configuration from an INI config object
+    """
 
-            out[i.lower()] = (obj, obj.parameter_class)
+    if 'backend' not in configIni:
 
-    return out
+        raise ConfigError('missing [backend] section.')
+
+    if 'type' not in configIni['backend']:
+
+        raise ConfigError('missing [backend] \'type\'.')
+
+    mod_name = configIni['backend']['type']
+
+    section = f'backend.{mod_name}'
+
+    try:
+        mod = import_module(f'.{mod_name}', 'httpaste.backend')
+    except ImportError as e:
+        raise BackendError(f'backend \'{mod_name}\' does not exist: {e}') from e
+    else:
+        interface = mod.Backend
+        config = get_config(configIni, section, mod.Config, path)
+
+    return Config(interface=interface,config=config)
+
+
+__all__ = [
+    load_backend,
+    get_backend_config
+]

src/httpaste/backend/file/__init__.py

@@ -3,110 +3,117 @@
 from os import path
 from pathlib import Path
 from typing import NamedTuple, Optional
-
+from httpaste.backend import BackendInterface as BackendAbc
-from . import user
+from httpaste.backend import ObjectBackend as ObjectBackendAbc
-from . import paste
 
 
-class Parameters(NamedTuple):
+class Config(NamedTuple):
-    """Filesystem backend parameters
+    """Filesystem backend config
     """
 
     #: path of base directory
-    base_dirname: str
+    base_dirname: Path
     #: basename of users table directory
-    user_dirname: Optional[str] = 'users'
+    user_dirname: str = 'users'
     #: basename of pastes table directory
-    paste_dirname: Optional[str] = 'pastes'
+    paste_dirname: str = 'pastes'
 
 
-class User(object):
+class ObjectBackendBc(ObjectBackendAbc):
-    """Filesystem user model backend
-    """
 
     dirname: Path
     path: Path
 
     def __init__(
             self,
-            parameters: Parameters,
+            interface: object,
+            basename_attr: str,
+            config: Config,
             model_class: type,
             model_schema: type):
 
+        self.interface = interface
         self.model_class = model_class
-
         self.model_schema = model_schema
-
+        self.dirname = path.join(config.base_dirname,
-        self.dirname = path.join(parameters.base_dirname,
+                                 getattr(config, basename_attr))
-                                 parameters.user_dirname)
-
         self.path = Path(self.dirname)
 
     def load(self, proto: object):
 
-        return user.load(proto, self.path, self.model_class, self.model_schema)
+        return self.interface.load(proto, self.path, self.model_class, self.model_schema)
 
     def dump(self, model: object):
 
-        return user.dump(model, self.path, self.model_schema)
+        return self.interface.dump(model, self.path, self.model_schema)
 
     def delete(self, proto: object):
 
-        return user.delete(proto, self.path)
+        return self.interface.delete(proto, self.path)
 
     def init(self):
 
-        return user.init(self.path)
+        return self.interface.init(self.path)
 
     def sanitize(self):
 
         if self.path.exists():
-            return user.sanitize(self.path, self.model_class, self.model_schema)
+            return self.interface.sanitize(self.path, self.model_class, self.model_schema)
 
         return None
 
 
-class Paste(object):
+class UserBackend(ObjectBackendBc):
+    """Filesystem user model backend
+    """
+
+    def __init__(self, *args):
+
+        from . import user
+
+        super().__init__(user, 'user_dirname', *args)
+
+
+class PasteBackend(ObjectBackendBc):
     """Filesystem paste model backend
     """
 
-    dirname: str
+    def __init__(self, *args):
-    path: Path
 
-    def __init__(
+        from . import paste
-            self,
-            parameters: Parameters,
-            model_class: type,
-            model_schema: type):
 
-        self.model_class = model_class
+        super().__init__(paste, 'paste_dirname', *args)
 
-        self.model_schema = model_schema
 
-        self.dirname = path.join(parameters.base_dirname,
+class Backend(BackendAbc):
-                                 parameters.paste_dirname)
+    """File backend interface
+    """
 
-        self.path = Path(self.dirname)
+    _user: UserBackend
+    _paste: PasteBackend
 
-    def load(self, proto: object):
+    def __init__(self,
+                 config: Config,
+                 paste_model_class: type,
+                 user_model_class: type,
+                 paste_schema: type,
+                 user_schema: type):
 
-        return paste.load(proto, self.path, self.model_class, self.model_schema)
+        self._user = UserBackend(config, user_model_class, user_schema)
+        self._paste = PasteBackend(config, paste_model_class, paste_schema)
 
-    def dump(self, model: object):
+    @property
+    def user(self) -> UserBackend:
 
-        return paste.dump(model, self.path, self.model_schema)
+        return self._user
 
-    def delete(self, proto: object):
+    @property
+    def paste(self) -> PasteBackend:
 
-        return paste.delete(proto, self.path)
+        return self._paste
 
-    def init(self):
 
-        return paste.init(self.path)
+__all__ = [
-
+    Config,
-    def sanitize(self):
+    Backend
-
+]
-        if self.path.exists():
-            return paste.sanitize(self.path, self.model_class, self.model_schema)
-
-        return None

src/httpaste/backend/mysql/__init__.py

@@ -1,10 +1,12 @@
 """MySQL backend
 """
-from typing import NamedTuple, Optional, Callable
+from typing import NamedTuple, Optional
+from httpaste.backend import BackendInterface as BackendAbc
+from httpaste.backend import ObjectBackend as ObjectBackendAbc
 
 
-class Parameters(NamedTuple):
+class Config(NamedTuple):
-    """MySQL parameters
+    """MySQL config
     """
 
     #: user name
@@ -16,26 +18,18 @@ class Parameters(NamedTuple):
     #: database identifier
     database: str
     #: a mysql.connection.MySQLConnection object (does not apply to config)
-    connection: Optional[object] = None
+    connection: object = None
 
 
-class User(object):
+class ObjectBackendBc(ObjectBackendAbc):
-    """MySQL user model backend
-    """
 
     connection: object
 
-    def __init__(self, parameters: Parameters, model_class: type) -> None:
+    def __init__(self, interface: object, config: Config, model_class: type) -> None:
-
-        from . import user
-
-        connect = get_mysql_connect_callee()
-
-        self.interface = user
 
+        self.interface = interface
         self.model_class = model_class
-
+        self.connection = get_connection(config)
-        self.connection = get_connection(parameters, connect)
 
     def load(self, proto: object) -> object:
 
@@ -58,50 +52,54 @@ class User(object):
         return self.interface.sanitize(self.connection, self.model_class)
 
 
-class Paste(object):
+class UserBackend(ObjectBackendBc):
+    """MySQL user model backend
+    """
+
+    def __init__(self, *args) -> None:
+
+        from . import user
+
+        super().__init__(paste, *args)
+
+
+class PasteBackend(ObjectBackendBc):
     """MySQL paste model backend
     """
 
     connection: object
 
-    def __init__(self, parameters: Parameters, model_class: type) -> None:
+    def __init__(self, *args) -> None:
 
         from . import paste
 
-        connect = get_mysql_connect_callee()
+        super().__init__(paste, *args)
-
-        self.interface = paste
-
-        self.model_class = model_class
-
-        self.connection = get_connection(parameters, connect)
-
-    def load(self, proto: object) -> object:
-
-        return self.interface.load(proto, self.connection, self.model_class)
-
-    def dump(self, model: object) -> None:
-
-        return self.interface.dump(model, self.connection)
-
-    def delete(self, proto: object) -> None:
-
-        return self.interface.delete(proto, self.connection)
-
-    def init(self) -> None:
-
-        return paste.init(self.connection)
-
-    def sanitize(self) -> None:
-
-        return self.interface.sanitize(self.connection, self.model_class)
 
 
-def get_mysql_connect_callee() -> object:
+class Backend(BackendAbc):
+    """MySQL backend interface
+    """
+
+    user: UserBackend
+    paste: PasteBackend
+
+    def __init__(self,
+                 config: Config,
+                 paste_model_class: type,
+                 user_model_class: type,
+                 paste_schema: type,
+                 user_schema: type):
+
+        self.user = UserBackend(config, user_model_class, user_schema)
+        self.paste = PasteBackend(config, paste_model_class, paste_schema)
+
+
+def get_connection(config: Config) -> object:
+    """get a mysql.connection.MySQLConnection object
+    """
 
     try:
         from mysql.connector import connect
-        from mysql.connector.connection import MySQLConnection
     except ImportError as e:
         raise ImportError(' '.join((
             '\'mysql-connector-python\' is not installed.',
@@ -109,26 +107,18 @@ def get_mysql_connect_callee() -> object:
             '\'python3 -m pip install mysql-connector-python\'.'
         ))) from e
 
-    return connect
+    if config.connection is not None:
 
+        return config.connection
 
-def get_connection(parameters: Parameters, connect: Callable) -> object:
+    connection = connect(user=config.user, password=config.password,
-    """get a mysql.connection.MySQLConnection object
+                         host=config.host,
-    """
+                         database=config.database)
-
-    if parameters.connection is not None:
-
-        return parameters.connection
-
-    connection = connect(user=parameters.user, password=parameters.password,
-                         host=parameters.host,
-                         database=parameters.database)
 
     return connection
 
 
 __all__ = [
-    Parameters,
+    Config,
-    User,
+    Backend
-    Paste
 ]

src/httpaste/backend/mysql/paste.py

@@ -1,16 +1,6 @@
 from os import path
 from time import time
-from importlib.resources import open_text
-
-
-try:
 from mysql.connector.connection import MySQLConnection
-except ImportError as e:
-    raise ImportError(' '.join((
-        '\'mysql-connector-python\' is not installed.',
-        'Install it by running',
-        '\'python3 -m pip install mysql-connector-python\'.'
-    ))) from e
 
 
 def load(proto:object, connection: MySQLConnection, model_class: type):
@@ -94,9 +84,17 @@ def init(connection: MySQLConnection):
 
     cursor = connection.cursor()
 
-    with open_text('httpaste.backend.mysql', 'paste.sql') as fh:
+    statement = '''CREATE TABLE `httpaste_pastes` (
+                       `pid` blob NOT NULL,
+                       `data` longblob NOT NULL,
+                       `data_hash` blob NOT NULL,
+                       `sub` blob DEFAULT NULL,
+                       `expiration` int(16) NOT NULL,
+                       `encoding` tinytext DEFAULT NULL,
+                       PRIMARY KEY (`pid`(128))
+                   ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;'''
 
-        cursor.execute(fh.read())
+    cursor.execute(statement)
 
     connection.commit()
 

src/httpaste/backend/mysql/paste.sql

@@ -1,9 +0,0 @@
-CREATE TABLE `httpaste_pastes` (
-  `pid` blob NOT NULL,
-  `data` longblob NOT NULL,
-  `data_hash` blob NOT NULL,
-  `sub` blob DEFAULT NULL,
-  `expiration` int(16) NOT NULL,
-  `encoding` tinytext DEFAULT NULL,
-  PRIMARY KEY (`pid`(128))
-) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

src/httpaste/backend/mysql/user.py

@@ -1,13 +1,5 @@
 from os import path
-from importlib.resources import open_text
-try:
 from mysql.connector.connection import MySQLConnection
-except ImportError as e:
-    raise ImportError(' '.join((
-        '\'mysql-connector-python\' is not installed.',
-        'Install it by running',
-        '\'python3 -m pip install mysql-connector-python\'.'
-    ))) from e
 
 
 def load(proto:object, connection: MySQLConnection, model_class: type):
@@ -84,9 +76,14 @@ def init(connection: MySQLConnection):
 
     cursor = connection.cursor()
 
-    with open_text('httpaste.backend.mysql', 'user.sql') as fh:
+    statement = '''CREATE TABLE `httpaste_users` (
+                       `sub` blob NOT NULL,
+                       `key_hash` blob NOT NULL,
+                       `paste_index` blob NOT NULL,
+                       PRIMARY KEY (`sub`(128))
+                   ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;'''
 
-        cursor.execute(fh.read())
+    cursor.execute(statement)
 
     connection.commit()
 

src/httpaste/backend/mysql/user.sql

@@ -1,6 +0,0 @@
-CREATE TABLE `httpaste_users` (
-  `sub` blob NOT NULL,
-  `key_hash` blob NOT NULL,
-  `paste_index` blob NOT NULL,
-  PRIMARY KEY (`sub`(128))
-) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

src/httpaste/backend/sqlite/__init__.py

@@ -2,96 +2,113 @@
 """
 from sqlite3 import Connection, Row, connect
 from typing import NamedTuple, Optional
+from pathlib import Path
 
-from . import user
+from httpaste.backend import BackendInterface as BackendAbc
-from . import paste
+from httpaste.backend import ObjectBackend as ObjectBackendAbc
 
 
-class Parameters(NamedTuple):
+class Config(NamedTuple):
-    """SQLite backend parameters
+    """SQLite backend config
     """
 
     #: local path or URI
-    path: str
+    uri: Path
+    user_table_name: str = 'httpaste_users'
+    paste_table_name: str = 'httpaste_pastes'
     #: a sqlite3.Connection object (does not apply to config)
-    connection: Optional[object] = None
+    connection: Connection = None
 
 
-class User(object):
+class ObjectBackendBc(ObjectBackendAbc):
-    """SQLite user model backend
+
+    connection: object
+
+    def __init__(self, interface: object, table_name_attr: str, config: Config, model_class: type, schema: type) -> None:
+
+        self.interface = interface
+        self.model_class = model_class
+        self.connection = get_connection(config)
+        self.table = getattr(config, table_name_attr)
+
+    def load(self, proto: object) -> object:
+
+        return self.interface.load(proto, self.connection, self.table, self.model_class)
+
+    def dump(self, model: object) -> None:
+
+        return self.interface.dump(model, self.connection, self.table)
+
+    def delete(self, proto: object) -> None:
+
+        return self.interface.delete(proto, self.connection, self.table)
+
+    def init(self) -> None:
+
+        return self.interface.init(self.connection, self.table)
+
+    def sanitize(self) -> None:
+
+        return self.interface.sanitize(self.connection, self.table, self.model_class)
+
+
+class UserBackend(ObjectBackendBc):
+    """sqlite user model backend
     """
 
-    connection: Connection
+    def __init__(self, *args) -> None:
 
-    def __init__(self, parameters: Parameters, model_class: type):
+        from . import user
 
-        self.model_class = model_class
+        super().__init__(paste, 'user_table_name', *args)
-
-        self.connection = get_connection(parameters)
-
-    def load(self, proto: object):
-
-        return user.load(proto, self.connection, self.model_class)
-
-    def dump(self, model: object):
-
-        return user.dump(model, self.connection)
-
-    def delete(self, proto: object):
-
-        return user.delete(proto, self.connection)
-
-    def init(self):
-
-        return user.init(self.connection)
-
-    def sanitize(self):
-
-        return user.sanitize(self.connection, self.model_class)
 
 
-class Paste(object):
+class PasteBackend(ObjectBackendBc):
-    """SQLite paste model backend
+    """sqlite paste model backend
     """
 
-    connection: Connection
+    connection: object
 
-    def __init__(self, parameters: Parameters, model_class: type):
+    def __init__(self, *args) -> None:
 
-        self.model_class = model_class
+        from . import paste
 
-        self.connection = get_connection(parameters)
+        super().__init__(paste, 'paste_table_name', *args)
-
-    def load(self, proto: object):
-
-        return paste.load(proto, self.connection, self.model_class)
-
-    def dump(self, model: object):
-
-        return paste.dump(model, self.connection)
-
-    def delete(self, proto: object):
-
-        return paste.delete(proto, self.connection)
-
-    def init(self):
-
-        return paste.init(self.connection)
-
-    def sanitize(self):
-
-        return paste.sanitize(self.connection, self.model_class)
 
 
-def get_connection(parameters: Parameters):
+class Backend(BackendAbc):
+    """sqlite backend interface
+    """
+
+    user: UserBackend
+    paste: PasteBackend
+
+    def __init__(self,
+                 config: Config,
+                 paste_model_class: type,
+                 user_model_class: type,
+                 paste_schema: type,
+                 user_schema: type):
+
+        self.user = UserBackend(config, user_model_class, user_schema)
+        self.paste = PasteBackend(config, paste_model_class, paste_schema)
+
+
+def get_connection(config: Config):
     """get an sqlite connection object
     """
 
-    if parameters.connection:
+    if config.connection:
 
-        return parameters.connection
+        return config.connection
 
-    connection = connect(parameters.path, check_same_thread=False)
+    connection = connect(config.uri, check_same_thread=False)
     connection.row_factory = Row
 
     return connection
+
+
+__all__ = [
+    Config,
+    Backend
+]

src/httpaste/backend/sqlite/paste.py

@@ -6,14 +6,14 @@ from time import time
 from importlib.resources import open_text
 
 
-def load(proto: object, connection: Connection, model_class: type):
+def load(proto: object, connection: Connection, table: str, model_class: type):
     """load a paste
     """
 
     cursor = connection.cursor()
 
-    statement = '''SELECT pid, data, data_hash, sub, expiration, encoding 
+    statement = f'''SELECT pid, data, data_hash, sub, expiration, encoding 
-                   FROM pastes
+                   FROM {table}
                    WHERE pid=?'''
 
     cursor.execute(statement, (proto.pid,))
@@ -33,13 +33,13 @@ def load(proto: object, connection: Connection, model_class: type):
     return None
 
 
-def dump(model: object, connection: Connection) -> None:
+def dump(model: object, connection: Connection, table: str) -> None:
     """dump a paste
     """
 
     cursor = connection.cursor()
 
-    statement = '''INSERT INTO pastes 
+    statement = f'''INSERT INTO "{table}"
                    (pid, data, data_hash, sub, expiration, encoding)
                    VALUES (?,?,?,?,?,?)'''
 
@@ -57,35 +57,41 @@ def dump(model: object, connection: Connection) -> None:
     return None
 
 
-def delete(proto: object, connection: Connection) -> None:
+def delete(proto: object, connection: Connection, table: str) -> None:
 
     cursor = connection.cursor()
 
-    cursor.execute('''DELETE FROM pastes WHERE pid=?''', (proto.pid,))
+    cursor.execute(f'''DELETE FROM {table} WHERE pid=?''', (proto.pid,))
 
     connection.commit()
 
     return None
 
 
-def init(connection: Connection):
+def init(connection: Connection, table: str):
 
     cursor = connection.cursor()
 
-    with open_text('httpaste.backend.sqlite', 'paste.sql') as fh:
+    statement = f'''CREATE TABLE IF NOT EXISTS "{table}" (
-
+                       "pid"	BLOB NOT NULL UNIQUE,
-        statement = fh.read()
+                       "data"	BLOB NOT NULL,
+                       "data_hash"	BLOB NOT NULL,
+                       "sub"	BLOB UNIQUE,
+                       "expiration"	INTEGER NOT NULL,
+                       "encoding" TEXT,
+                       PRIMARY KEY("pid")
+                   );'''
 
     cursor.execute(statement)
 
     connection.commit()
 
 
-def sanitize(connection: Connection, model_class: type) -> int:
+def sanitize(connection: Connection, table: str, model_class: type) -> int:
 
     cursor = connection.cursor()
 
-    statement = '''SELECT pid FROM pastes 
+    statement = f'''SELECT pid FROM {table}
                    WHERE expiration < ? AND expiration > 0'''
 
     cursor.execute(statement, (int(time()),))

src/httpaste/backend/sqlite/paste.sql

@@ -1,9 +0,0 @@
-CREATE TABLE IF NOT EXISTS "pastes" (
-	"pid"	BLOB NOT NULL UNIQUE,
-	"data"	BLOB NOT NULL,
-	"data_hash"	BLOB NOT NULL,
-	"sub"	BLOB UNIQUE,
-	"expiration"	INTEGER NOT NULL,
-	"encoding" TEXT,
-	PRIMARY KEY("pid")
-);

src/httpaste/backend/sqlite/user.py

@@ -6,14 +6,14 @@ from httpaste.model import User
 from importlib.resources import open_text
 
 
-def load(proto: object, connection: Connection, model_class: type):
+def load(proto: object, connection: Connection, table: str, model_class: type):
     """load a user
     """
 
     cursor = connection.cursor()
 
-    statement = '''SELECT sub, key_hash, paste_index 
+    statement = f'''SELECT sub, key_hash, paste_index 
-                   FROM users
+                   FROM {table}
                    WHERE sub=?'''
 
     cursor.execute(statement, (proto.sub,))
@@ -27,13 +27,13 @@ def load(proto: object, connection: Connection, model_class: type):
     return None
 
 
-def dump(model: object, connection: Connection) -> None:
+def dump(model: object, connection: Connection, table: str) -> None:
     """dump a user
     """
 
     cursor = connection.cursor()
 
-    statement = '''INSERT OR REPLACE INTO users
+    statement = f'''INSERT OR REPLACE INTO {table}
                    (sub, key_hash, paste_index)
                    VALUES (?,?,?)'''
 
@@ -44,24 +44,27 @@ def dump(model: object, connection: Connection) -> None:
     return None
 
 
-def delete(proto: object, connection: Connection) -> None:
+def delete(proto: object, connection: Connection, table: str) -> None:
 
     cursor = connection.cursor()
 
-    cursor.execute('''DELETE FROM users WHERE sub=?''', (proto.sub,))
+    cursor.execute(f'''DELETE FROM {table} WHERE sub=?''', (proto.sub,))
 
     connection.commit()
 
     return None
 
 
-def init(connection: Connection) -> None:
+def init(connection: Connection, table: str) -> None:
 
     cursor = connection.cursor()
 
-    with open_text('httpaste.backend.sqlite', 'user.sql') as fh:
+    statement = f'''CREATE TABLE IF NOT EXISTS "{table}" (
-
+                       "sub"	BLOB NOT NULL UNIQUE,
-        statement = fh.read()
+                       "key_hash"	BLOB NOT NULL,
+                       "paste_index"	BLOB,
+                       PRIMARY KEY("sub")
+                   );'''
 
     cursor.execute(statement)
 
@@ -70,6 +73,6 @@ def init(connection: Connection) -> None:
     return None
 
 
-def sanitize(connection: Connection, model_class) -> int:
+def sanitize(connection: Connection, table: str, model_class) -> int:
 
     return 0

src/httpaste/backend/sqlite/user.sql

@@ -1,6 +0,0 @@
-CREATE TABLE IF NOT EXISTS "users" (
-	"sub"	BLOB NOT NULL UNIQUE,
-	"key_hash"	BLOB NOT NULL,
-	"paste_index"	BLOB,
-	PRIMARY KEY("sub")
-);

src/httpaste/context.py

@@ -0,0 +1,18 @@
+from typing import NamedTuple
+from string import ascii_uppercase, digits, ascii_letters, punctuation
+from configparser import ConfigParser
+
+from httpaste.helper.common import generate_random_string
+from httpaste.helper.config import get_sanitized_config_charset, get_config
+
+class Config(NamedTuple):
+    """httpaste global config
+    """
+    salt: bytes = get_sanitized_config_charset(generate_random_string(
+        32, ascii_letters + digits + punctuation)).encode('utf-8')
+    hmac_iter: int = 20000
+
+
+def get_context_config(configIni: ConfigParser) -> Config:
+
+    return get_config(configIni, 'context', Config)

src/httpaste/controller/__init__.py

@@ -5,12 +5,14 @@ import httpaste
 def get(**kwargs):
 
     config = current_app.httpaste
+    context = config.context
+    model = config.model
 
 
     return httpaste.__doc__.format(
         url=connexion.request.url,
-        hmac_iterations=config.hmac_iterations,
+        hmac_iterations=context.hmac_iter,
-        paste_lifetime=config.paste_lifetime,
+        paste_lifetime=model.paste.default_lifetime,
-        paste_max_lifetime=str(round(config.paste_max_lifetime / 60)),
+        paste_max_lifetime=str(round(model.paste.default_max_lifetime / 60)),
-        paste_default_encoding=config.paste_default_encoding
+        paste_default_encoding=model.paste.default_encoding
     ), 200

src/httpaste/controller/paste/__init__.py

@@ -5,8 +5,10 @@ from flask import current_app
 from httpaste.helper.common import decode, DecodeError, join_url
 import httpaste.model.paste as paste_model
 import httpaste.model.user as user_model
+from httpaste.backend import load_backend
 from httpaste.helper.http import BadRequestError, GoneError, NotFoundError
-from httpaste.model import (
+from httpaste.helper.syntax import highlight
+from httpaste.schema import (
     PasteKey,
     PasteData,
     PasteLifetime,
@@ -15,6 +17,13 @@ from httpaste.model import (
     Sub)
 
 
+class Config:
+    default_mime_type: str = 'text/plain'
+    default_linenos: bool = False
+    default_syntax: bool = False
+    default_formatter: str = 'terminal256'
+
+
 def delete(**kwargs):
     """
     """
@@ -45,12 +54,15 @@ def get(**kwargs):
     """
 
     config = current_app.httpaste
+    backend = load_backend(config.backend)
+    context = config.context
+
+    syntax = kwargs.get('syntax')
+    formatter = kwargs.get('format', Config.default_formatter)
+    linenos = kwargs.get('linenos', Config.default_linenos)
+    mime = kwargs.get('mime', Config.default_mime_type)
 
     pid = PasteKey(kwargs['id'].encode('utf-8'))
-    syntax = kwargs.get('syntax')
-    formatter = kwargs.get('format', 'terminal256')
-    linenos = kwargs.get('linenos', False)
-    mime = kwargs.get('mime', 'text/plain')
 
     if kwargs.get('user') is not None:
         # authenticated
@@ -58,26 +70,23 @@ def get(**kwargs):
         key = MasterKey(kwargs['token_info'].get('master_key'))
         sub = Sub(kwargs['token_info'].get('sub'))
 
-        pkey = user_model.load_paste_key(pid, sub, key, config.backend.user,
+        pkey = user_model.load_paste_key(pid, sub, key, backend.user, context)
-                                         config.salt, config.hmac_iterations)
 
         def call(): return paste_model.get_safe(pid, pkey, sub,
-                                                config.backend.paste,
+                                                config.model.paste,
-                                                config.salt, config.hmac_iterations)
+                                                backend.paste, context)
     else:
         # unauthenticated
 
-        def call(): return paste_model.get(pid, config.backend.paste,
+        def call(): return paste_model.get(pid, backend.paste, context)
-                                           config.salt, config.hmac_iterations)
 
     try:
         data, expiration, encoding = call()
     except paste_model.LifetimeError as e:
         if kwargs.get('user') is not None:
-            paste_model.remove_safe(pid, sub, pkey, config.backend.paste, 
+            paste_model.remove_safe(pid, sub, pkey, backend.paste, context)
-                                    config.salt, config.hmac_iterations)
         else:
-            paste_model.remove(pid, config.backend.paste)
+            paste_model.remove(pid, backend.paste)
         raise GoneError(str(e)) from e
     except paste_model.NotFoundError as e:
         raise NotFoundError(str(e))
@@ -87,10 +96,9 @@ def get(**kwargs):
     # burn after read
     if expiration < 0:
         if kwargs.get('user') is not None:
-            paste_model.remove_safe(pid, sub, pkey, config.backend.paste, 
+            paste_model.remove_safe(pid, sub, pkey, backend.paste, context)
-                                    config.salt, config.hmac_iterations)
         else:
-            paste_model.remove(pid, config.backend.paste)
+            paste_model.remove(pid, backend.paste)
 
     if syntax is not None:
         data = highlight(data, str(syntax), formatter, linenos)
@@ -110,12 +118,14 @@ def post(**kwargs):
     """
 
     config = current_app.httpaste
+    backend = load_backend(config.backend)
+    context = config.context
 
     if kwargs['body'].get('data') is None:
         raise BadRequestError('form field \'data\' missing.')
 
     encoding = PasteEncoding(kwargs.get('encoding', 'utf-8'))
-    lifetime = PasteLifetime(kwargs.get('lifetime', config.paste_lifetime))
+    lifetime = PasteLifetime(kwargs.get('lifetime', config.model.paste.default_lifetime))
 
     if encoding not in ['utf-8', 'utf-16', 'ascii']:
         try:
@@ -135,15 +145,15 @@ def post(**kwargs):
         sub = Sub(kwargs['token_info'].get('sub'))
 
         pid, pkey = paste_model.create_safe(pdata, lifetime, sub, encoding,
-                                            config.backend.paste, config.salt, config.hmac_iterations)
+                                            config.model.paste, backend.paste,
+                                            context)
 
-        user_model.dump_paste_key(pid, pkey, sub, key, config.backend.user,
+        user_model.dump_paste_key(pid, pkey, sub, key, backend.user, context)
-                                  config.salt, config.hmac_iterations)
     else:
         # unauthenticated
 
-        pid = paste_model.create(pdata, lifetime, encoding, config.backend.paste,
+        pid = paste_model.create(pdata, lifetime, encoding, config.model.paste,
-                                 config.salt, config.hmac_iterations)
+                                 backend.paste, context)
 
 
     base_url = join_url(request.root_url, request.path)

src/httpaste/controller/paste/private.py

@@ -5,8 +5,6 @@ def search(**kwargs):
     """
     """
 
-    print(args)
-
     return 'Hallo', 200
 
 

src/httpaste/controller/user/session.py

@@ -4,20 +4,22 @@ from flask import current_app
 
 from httpaste.helper.http import ForbiddenError
 from httpaste.model.user import authenticate, AuthenticationError
-
+from httpaste.backend import load_backend
 
 def post(*args, **kwargs):
     """
     """
 
     config = current_app.httpaste
+    backend = load_backend(config.backend)
+    context = config.context
 
     user_id = args[0].encode('utf-8')
     password = args[1].encode('utf-8')
 
     try:
 
-        return authenticate(user_id, password, config.backend.user, config.salt, config.hmac_iterations)
+        return authenticate(user_id, password, backend.user, context)
     except AuthenticationError as e:
 
         raise ForbiddenError('You shall not pass!') from e

src/httpaste/helper/config.py

@@ -0,0 +1,111 @@
+import os
+from pathlib import Path
+from configparser import ConfigParser, NoSectionError
+from typing import Optional, NamedTuple
+from os import environ
+
+
+CONFIGPATH_ENVIRON = 'HTTPASTE_CONFIGPATH'
+
+
+class ConfigError(Exception):
+    """
+    """
+
+
+def get_sanitized_config_charset(charset: str):
+
+    for x in ["$", "%"]:
+
+        charset = charset.replace(x, f'{x}{x}')
+
+    return charset
+
+
+def typecast(obj: dict, aclass: type, dirname:Optional[Path] = None) -> dict:
+    """typecast a dictionary according to class annotations
+
+        :param obj: dictionary to typecast
+        :param aclass: class containing typehint annotations
+        :param basepath: basepath for filesystem path typecasting
+
+        :returns: typecasted dictionary
+    """
+
+    casted = {}
+
+    for k,v in obj.items():
+
+        v = v.strip('\'"')
+
+        try:
+            bclass = aclass.__annotations__[k]
+        except KeyError as e:
+            raise KeyError(f'{k}: not allowed') from e
+
+        if issubclass(bclass, Path) and not str(v[0]).startswith(os.path.sep):
+            if not isinstance(dirname, Path):
+                raise TypeError('no dirname for Path type specified.')
+
+            casted[k] = casted_val = dirname / v
+        elif issubclass(bclass, bytes):
+            
+            casted[k] = bclass(v.encode('utf-8'))
+        else:
+            try:
+                casted_val = bclass(v)
+            except ValueError as e:
+                raise ValueError(f'{k}: {e}') from e
+            else:
+                casted[k] = casted_val
+
+    return casted
+
+
+def get_config(configIni: ConfigParser, section: str, bclass: type, dirname: Path = None) -> object:
+    """get an object-oriented configuration from an INI file
+
+        :param configIni: configparser.Configparser object with initialized stream
+        :param section: name of section to get configuration for
+        :param bclass: configuration base class 
+        :param dirname: directory name of INI file stream
+
+        :returns: initialized configuration instance
+    """
+
+    try:
+        raw_config = dict(configIni.items(section))
+    except NoSectionError as e:
+        raw_config = {}
+
+    try:
+        casted_config = typecast(raw_config, bclass, dirname)
+    except KeyError as e:
+        raise ConfigError(f'[{section}] {e}') from e
+    except ValueError as e:
+        raise ConfigError(f'[{section}] {e}') from e
+
+    try:
+        config = bclass(**casted_config)
+    except TypeError as e:
+        raise ConfigError(f'[{section}] {e}') from e
+
+    return config
+
+
+
+def get_configparser(path: Path = None, var_name: str = CONFIGPATH_ENVIRON):
+    """
+    """
+
+    if path is None:
+        try:
+            path = environ[var_name]
+        except KeyError as e:
+            raise ConfigError(
+                f'environment variable \'{var_name}\' not set.') from e
+
+    configIni = ConfigParser()
+    configIni.read(path)
+
+    return configIni, path

src/httpaste/helper/crypto.py

@@ -8,7 +8,7 @@ from cryptography.hazmat.primitives import hashes
 from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
 from cryptography.fernet import Fernet, InvalidToken
 
-from httpaste import Config
+from httpaste.context import Config
 
 
 DEFAULT_HMAC_ITERATIONS = 20000
@@ -38,7 +38,7 @@ def dhash(data: bytes):
     return hashlib.sha512(data).digest()
 
 
-def derive_key(main_key: str, salt: bytes = Config.salt, iterations:int=DEFAULT_HMAC_ITERATIONS) -> bytes:
+def derive_key(main_key: str, salt: bytes, iterations:int=DEFAULT_HMAC_ITERATIONS) -> bytes:
     """derive a key from a main key
 
         :param main_key: main key to derive from

src/httpaste/model/__init__.py

@@ -1,144 +1,19 @@
 """Model
 """
-from typing import NamedTuple, Optional, Dict, Union, Any, TypedDict
+from typing import NamedTuple
+from configparser import ConfigParser
+from pathlib import Path
+
+from httpaste.model.paste import Config as PasteConfig
+from httpaste.model.paste import get_paste_model_config
+
+class Config(NamedTuple):
+    """Model Configuration"""
+    paste: PasteConfig
 
 
-class PasteDataSchema:
+def get_model_config(configIni: ConfigParser, path:Path) -> Config:
-    """Paste Interface schema between Model and Backend
-    """
-    pid = bytes
-    data = bytes
-    data_hash = bytes
-    sub = bytes
-    timestamp = int
-    lifetime = int
-    expiration = int
-    encoding = str
 
+    paste_config = get_paste_model_config(configIni)
 
-class UserDataSchema:
+    return Config(paste=paste_config)
-    """User Interface Schema between Model and Backend
-    """
-    sub = bytes
-    key_hash = bytes
-    index = bytes
-
-
-class Backend(object):
-    """Backend
-    """
-    parameter_class: str
-
-
-class Salt(bytes):
-    """Salt
-    """
-
-
-class PasteData(PasteDataSchema.data):
-    """Paste Data
-    """
-
-
-class PasteHash(PasteDataSchema.data_hash):
-    """Paste Data Hash
-    """
-
-
-class PasteTimestamp(PasteDataSchema.timestamp):
-    """Paste Timestamp
-    """
-
-
-class PasteEncoding(PasteDataSchema.encoding):
-    """
-    """
-
-
-class PasteExpiration(PasteDataSchema.expiration):
-    """Paste Expiration
-
-        < 0: after first acccess
-        0: never
-    """
-
-
-class PasteLifetime(PasteDataSchema.lifetime):
-    """Paste Lifetime
-    """
-
-
-class PasteSub(PasteDataSchema.sub):
-    """Hashed user id
-    """
-
-
-class KeyHash(UserDataSchema.key_hash):
-    """User Master Key Hash
-    """
-
-
-class PasteKey(bytes):
-    """Paste encryption key
-    """
-
-
-class PasteId(PasteDataSchema.pid):
-    """Paste unique identifier
-    """
-
-
-class MasterKey(bytes):
-    """User's master encryption key
-    """
-
-
-class Sub(UserDataSchema.sub):
-    """User id
-    """
-
-
-class Index(TypedDict):
-    """User Paste Index
-    """
-    auth_expires: int
-    pastes: Dict[str, Dict[str, Any]]
-
-
-class SerializedIndex(UserDataSchema.index):
-    """User Paste Index (serialized)
-    """
-
-
-class User(NamedTuple):
-    """Global User Model (and Prototype)
-
-        non-optional values are prototype values
-    """
-
-    #: user id
-    sub: Sub
-    #: user's master key hash
-    key_hash: Optional[KeyHash] = None
-    #: user's paste index
-    index: Optional[Union[Index, SerializedIndex]] = None
-
-
-class Paste(NamedTuple):
-    """Global Paste Model (and Prototype)
-
-        non-optional values are prototype values
-    """
-
-    #: paste id
-    pid: PasteId
-    #: paste owner
-    sub: Optional[PasteSub] = None
-    #: paste data
-    data: Optional[PasteData] = None
-    #: paste data hash
-    data_hash: Optional[PasteHash] = None
-    #: paste timestamp
-    expiration: Optional[PasteExpiration] = None
-    #: paste encoding
-    encoding: Optional[PasteEncoding] = None

src/httpaste/model/paste.py

@@ -2,17 +2,32 @@
 """paste model interface
 """
 import json
-from typing import Optional, Tuple
+from typing import Optional, Tuple, NamedTuple
 import time
+from configparser import ConfigParser
+from string import ascii_uppercase, digits, ascii_letters, punctuation
 
-from httpaste import Config
+
+from httpaste.context import Config as ContextConfig
 from httpaste.helper.crypto import dhash, shash, encrypt, decrypt
+from httpaste.helper.config import get_sanitized_config_charset, get_config
 from httpaste.helper.common import generate_random_string
-from httpaste.model import (Paste, PasteId, Sub, MasterKey, PasteKey, Salt,
+from httpaste.schema import (Paste, PasteId, Sub, MasterKey, PasteKey, Salt,
                              PasteData, PasteHash, PasteTimestamp, PasteSub,
                              PasteLifetime, PasteEncoding, PasteExpiration)
 
 
+class Config(NamedTuple):
+    id_size: int = 8
+    id_charset: str = ascii_letters + digits
+    key_size: int = 32
+    key_charset: str = get_sanitized_config_charset(ascii_letters + digits + punctuation)
+    default_lifetime: int = 5
+    default_max_lifetime: int = 1440
+    default_min_lifetime: int = 1
+    default_encoding: str = 'utf-8'
+
+
 class NotFoundError(Exception):
     """Paste Exception
     """
@@ -38,9 +53,7 @@ class BackendError(Exception):
     """
 
 
-def generate_paste_id(
+def generate_paste_id(length: int, charset: str) -> bytes:
-        length: int = Config.paste_id_size,
-        charset: str = Config.paste_id_charset) -> bytes:
     """generate a paste id
 
         :param length: length of id
@@ -50,9 +63,7 @@ def generate_paste_id(
     return generate_random_string(length, charset).encode('utf-8')
 
 
-def generate_paste_key(
+def generate_paste_key(length: int, charset: str) -> bytes:
-        length: int = Config.paste_key_size,
-        charset: str = Config.paste_key_charset) -> bytes:
     """generate a paste encryption key
 
         :param length: length of key
@@ -98,8 +109,7 @@ def load_safe(
         proto: Paste,
         key: PasteKey,
         backend: object,
-        salt: Salt = Config.salt,
+        context: ContextConfig):
-        hmac_iter: int = Config.hmac_iterations):
     """load an encrypted paste model
 
         :param proto: paste model prototype
@@ -109,7 +119,7 @@ def load_safe(
 
     model = load(proto, backend)
 
-    data = decrypt(model.data, key, salt, hmac_iter)
+    data = decrypt(model.data, key, context.salt, context.hmac_iter)
 
     if model.data_hash and dhash(data) != model.data_hash:
 
@@ -131,10 +141,7 @@ def dump(model: Paste, backend: object) -> None:
         :param backend: model backend object
     """
 
-    try:
     backend.dump(model)
-    except Exception as e:
-        raise BackendError(str(e)) from e
 
 
 def delete(proto: Paste, backend: object) -> None:
@@ -158,13 +165,12 @@ def delete_safe(
         proto: Paste,
         key: PasteKey,
         backend: object,
-        salt: Salt = Config.salt,
+        context: ContextConfig) -> None:
-        hmac_iter: int = Config.hmac_iterations) -> None:
     """
     """
 
     try:
-        model = load_safe(proto, key, backend, salt, hmac_iter)
+        model = load_safe(proto, key, backend, context)
     except LifetimeError:
         pass
 
@@ -177,9 +183,9 @@ def create(
         data: PasteData,
         lifetime: PasteLifetime,
         encoding: PasteEncoding,
+        config: Config,
         backend: object,
-        salt: Salt = Config.salt,
+        context: ContextConfig) -> PasteId:
-        hmac_iter: int = Config.hmac_iterations) -> PasteId:
     """create an unencrypted paste
 
         :param data: paste data
@@ -187,18 +193,20 @@ def create(
         :param backend: model backend object
     """
 
-    pid = PasteId(generate_paste_id())
+    pid = PasteId(generate_paste_id(config.id_size, config.id_charset))
     safe_pid = PasteId(dhash(pid))
     data_hash = PasteHash(dhash(data))
     sub = None
     timestamp = PasteTimestamp(int(time.time()))
 
-    if lifetime < 0:
+    if lifetime is None:
+        lifetime = config.default_lifetime
+    elif lifetime < 0:
         expiration = -1
     else:
         expiration = PasteExpiration(timestamp + (lifetime * 60))
 
-    safe_data = PasteData(encrypt(data, pid, salt, hmac_iter))
+    safe_data = PasteData(encrypt(data, pid, context.salt, context.hmac_iter))
 
     model = Paste(
         safe_pid,
@@ -217,9 +225,9 @@ def create_safe(data: PasteData,
                 lifetime: PasteLifetime,
                 sub: Sub,
                 encoding: PasteEncoding,
+                config: Config,
                 backend: object,
-                salt: Salt = Config.salt,
+                context: ContextConfig) -> Tuple[PasteId,PasteKey]:
-                hmac_iter: int = Config.hmac_iterations) -> Tuple[PasteId,PasteKey]:
     """create an encrypted paste
 
         :param data: paste data
@@ -229,19 +237,21 @@ def create_safe(data: PasteData,
         :param salt: randomization salt
     """
 
-    pid = PasteId(generate_paste_id())
+    pid = PasteId(generate_paste_id(config.id_size, config.id_charset))
     safe_pid = PasteId(dhash(pid))
-    pkey = PasteKey(generate_paste_key())
+    pkey = PasteKey(generate_paste_key(config.key_size, config.key_charset))
     data_hash = PasteHash(dhash(data))
     safe_sub = PasteSub(shash(sub, data_hash, pid))
     timestamp = PasteTimestamp(int(time.time()))
 
-    if lifetime < 0:
+    if lifetime is None:
+        lifetime = config.default_lifetime
+    elif lifetime < 0:
         expiration = -1
     else:
         expiration = PasteExpiration(timestamp + (lifetime * 60))
 
-    safe_data = PasteData(encrypt(data, pkey, salt, hmac_iter))
+    safe_data = PasteData(encrypt(data, pkey, context.salt, context.hmac_iter))
 
     dump(Paste(
         safe_pid,
@@ -269,21 +279,20 @@ def remove_safe(
         sub: Sub,
         key: PasteKey,
         backend: object,
-        salt: Salt = Config.salt,
+        context: ContextConfig):
-        hmac_iter: int = Config.hmac_iterations):
 
     proto = Paste(pid, sub)
 
-    delete_safe(proto, key, backend, salt, hmac_iter)
+    delete_safe(proto, key, backend, context)
 
 
-def get(pid: PasteId, backend: object, salt: Salt = Config.salt, hmac_iter: int = Config.hmac_iterations) -> PasteData:
+def get(pid: PasteId, backend: object, context: ContextConfig) -> PasteData:
     """conveniently load an unencrypted paste
     """
 
     model = load(Paste(pid), backend)
 
-    data = decrypt(model.data, pid, salt, hmac_iter)
+    data = decrypt(model.data, pid, context.salt, context.hmac_iter)
 
     return PasteData(data), model.expiration, model.encoding
 
@@ -292,12 +301,22 @@ def get_safe(
         pid: PasteId,
         pkey: PasteKey,
         sub: Sub,
+        config: Config,
         backend: object,
-        salt: Salt = Config.salt,
+        context: ContextConfig) -> PasteData:
-        hmac_iter: int = Config.hmac_iterations) -> PasteData:
     """conveniently load an encrypted paste
     """
 
-    model = load_safe(Paste(pid, sub), pkey, backend, salt, hmac_iter)
+    model = load_safe(Paste(pid, sub), pkey, backend, context)
 
     return PasteData(model.data), model.expiration, model.encoding
+
+
+def get_paste_model_config(configIni: ConfigParser) -> Config:
+
+    return get_config(configIni, 'model.paste', Config)
+
+
+__all__ = [
+    get_paste_model_config
+]

src/httpaste/model/user.py

@@ -5,7 +5,7 @@ import json
 from time import time
 from typing import Optional
 
-from httpaste import Config
+from httpaste.context import Config as ContextConfig
 from httpaste.helper.crypto import (
     dhash,
     shash,
@@ -13,7 +13,7 @@ from httpaste.helper.crypto import (
     decrypt,
     derive_key,
     DecryptionError)
-from httpaste.model import (
+from httpaste.schema import (
     User,
     KeyHash,
     Index,
@@ -39,8 +39,7 @@ def _load(
         proto: User,
         master_key: str,
         backend: object,
-        salt: Salt = Config.salt,
+        context: ContextConfig) -> Optional[User]:
-        hmac_iter: int = Config.hmac_iterations) -> Optional[User]:
     """load user model
 
         :param model: user model prototype
@@ -55,7 +54,7 @@ def _load(
         return None
 
     try:
-        serialized_data = decrypt(model.index, master_key, salt, hmac_iter)
+        serialized_data = decrypt(model.index, master_key, context.salt, context.hmac_iter)
     except DecryptionError as e:
         raise IndexError('unable to decrypt user index') from e
     else:
@@ -71,8 +70,7 @@ def _dump(
         model: User,
         key: MasterKey,
         backend: object,
-        salt: Salt = Config.salt,
+        context: ContextConfig) -> None:
-        hmac_iter: int = Config.hmac_iterations) -> None:
     """dump a user model
 
         :param model: user model
@@ -87,7 +85,7 @@ def _dump(
 
     serialized_index = json.dumps(model.index).encode('utf-8')
 
-    safe_index = SerializedIndex(encrypt(serialized_index, key, salt, hmac_iter))
+    safe_index = SerializedIndex(encrypt(serialized_index, key, context.salt, context.hmac_iter))
 
     backend.dump(User(*model[:-1], safe_index))
 
@@ -96,7 +94,8 @@ def load_paste_key(
         pid: PasteId,
         sub: Sub,
         key: MasterKey,
-        backend: object, salt: Salt = Config.salt, hmac_iter: int = Config.hmac_iterations) -> Optional[PasteKey]:
+        backend: object,
+        context: ContextConfig) -> Optional[PasteKey]:
     """load a user paste key
 
         :param pid: paste id
@@ -106,7 +105,7 @@ def load_paste_key(
         :param salt: randomization salt
     """
 
-    model = _load(User(sub), key, backend, salt, hmac_iter)
+    model = _load(User(sub), key, backend, context)
 
     for k, v in model.index.get('pastes').items():
 
@@ -123,8 +122,7 @@ def dump_paste_key(
         sub: Sub,
         key: MasterKey,
         backend: object,
-        salt: str = Config.salt,
+        context: ContextConfig) -> None:
-        hmac_iter: int = Config.hmac_iterations) -> None:
     """dump a user paste key
 
         :param pid: paste id
@@ -134,21 +132,20 @@ def dump_paste_key(
         :param backend: user model backend
     """
 
-    model = _load(User(sub), key, backend, salt, hmac_iter)
+    model = _load(User(sub), key, backend, context)
 
     model.index.setdefault('pastes', {})[pid.hex()] = {
         'key': pkey.hex()
     }
 
-    _dump(model, key, backend, salt, hmac_iter)
+    _dump(model, key, backend, context)
 
 
 def authenticate(
         user_id: bytes,
         password: bytes,
         backend: object,
-        salt: Salt = Config.salt,
+        context: ContextConfig):
-        hmac_iter: int = Config.hmac_iterations):
     """authenticate a user
 
         :param user_id: human-readable user id
@@ -156,7 +153,7 @@ def authenticate(
     """
 
     sub = Sub(dhash(user_id))
-    key = MasterKey(derive_key(password, salt, hmac_iter))
+    key = MasterKey(derive_key(password, context.salt, context.hmac_iter))
     key_hash = KeyHash(dhash(key))
 
     proto = User(sub)
@@ -164,7 +161,7 @@ def authenticate(
     bogus_decline_msg = 'unable to authenticate'
 
     try:
-        model = _load(proto, key, backend, salt, hmac_iter)
+        model = _load(proto, key, backend, context)
     except IndexError as e:
         raise AuthenticationError(bogus_decline_msg) from e
 
@@ -175,7 +172,7 @@ def authenticate(
         }
 
         model = User(sub, key_hash, Index(data))
-        _dump(model, key, backend, salt, hmac_iter)
+        _dump(model, key, backend, context)
     else:
 
         if model.key_hash != key_hash:

src/httpaste/schema/__init__.py

@@ -0,0 +1,137 @@
+from typing import NamedTuple, Optional, Dict, Union, Any, TypedDict
+
+
+class PasteDataSchema:
+    """Paste Interface schema between Model and Backend
+    """
+    pid = bytes
+    data = bytes
+    data_hash = bytes
+    sub = bytes
+    timestamp = int
+    lifetime = int
+    expiration = int
+    encoding = str
+
+
+class UserDataSchema:
+    """User Interface Schema between Model and Backend
+    """
+    sub = bytes
+    key_hash = bytes
+    index = bytes
+
+
+
+class Salt(bytes):
+    """Salt
+    """
+
+
+class PasteData(PasteDataSchema.data):
+    """Paste Data
+    """
+
+
+class PasteHash(PasteDataSchema.data_hash):
+    """Paste Data Hash
+    """
+
+
+class PasteTimestamp(PasteDataSchema.timestamp):
+    """Paste Timestamp
+    """
+
+
+class PasteEncoding(PasteDataSchema.encoding):
+    """
+    """
+
+
+class PasteExpiration(PasteDataSchema.expiration):
+    """Paste Expiration
+
+        < 0: after first acccess
+        0: never
+    """
+
+
+class PasteLifetime(PasteDataSchema.lifetime):
+    """Paste Lifetime
+    """
+
+
+class PasteSub(PasteDataSchema.sub):
+    """Hashed user id
+    """
+
+
+class KeyHash(UserDataSchema.key_hash):
+    """User Master Key Hash
+    """
+
+
+class PasteKey(bytes):
+    """Paste encryption key
+    """
+
+
+class PasteId(PasteDataSchema.pid):
+    """Paste unique identifier
+    """
+
+
+class MasterKey(bytes):
+    """User's master encryption key
+    """
+
+
+class Sub(UserDataSchema.sub):
+    """User id
+    """
+
+
+class Index(TypedDict):
+    """User Paste Index
+    """
+    auth_expires: int
+    pastes: Dict[str, Dict[str, Any]]
+
+
+class SerializedIndex(UserDataSchema.index):
+    """User Paste Index (serialized)
+    """
+
+
+class User(NamedTuple):
+    """Global User Model (and Prototype)
+
+        non-optional values are prototype values
+    """
+
+    #: user id
+    sub: Sub
+    #: user's master key hash
+    key_hash: Optional[KeyHash] = None
+    #: user's paste index
+    index: Optional[Union[Index, SerializedIndex]] = None
+
+
+class Paste(NamedTuple):
+    """Global Paste Model (and Prototype)
+
+        non-optional values are prototype values
+    """
+
+    #: paste id
+    pid: PasteId
+    #: paste owner
+    sub: Optional[PasteSub] = None
+    #: paste data
+    data: Optional[PasteData] = None
+    #: paste data hash
+    data_hash: Optional[PasteHash] = None
+    #: paste timestamp
+    expiration: Optional[PasteExpiration] = None
+    #: paste encoding
+    encoding: Optional[PasteEncoding] = None

src/httpaste/server.py

@@ -0,0 +1,17 @@
+from typing import NamedTuple
+from configparser import ConfigParser
+
+
+from httpaste.helper.config import get_config
+
+
+class Config(NamedTuple):
+    """connexion config
+    """
+    swagger_ui: bool = True
+    bind_address: str = None
+
+
+def get_server_config(configIni: ConfigParser) -> Config:
+
+    return get_config(configIni, 'server', Config)