create key server data interface

endpoints/keyserver/__init__.py

@@ -0,0 +1,196 @@
+import logging
+from datetime import datetime, timedelta
+
+from flask import Blueprint, jsonify, abort, request, make_response
+from jwt import get_unverified_header
+
+from app import app
+from data.interfaces.key_server import PreOCIModel as model, ServiceKeyDoesNotExist
+from data.model.log import log_action
+from util.security import jwtutil
+
+
+logger = logging.getLogger(__name__)
+key_server = Blueprint('key_server', __name__)
+
+JWT_HEADER_NAME = 'Authorization'
+JWT_AUDIENCE = app.config['PREFERRED_URL_SCHEME'] + '://' + app.config['SERVER_HOSTNAME']
+
+
+def _validate_jwk(jwk):
+  if 'kty' not in jwk:
+    abort(400)
+
+  if jwk['kty'] == 'EC':
+    if 'x' not in jwk or 'y' not in jwk:
+      abort(400)
+  elif jwk['kty'] == 'RSA':
+    if 'e' not in jwk or 'n' not in jwk:
+      abort(400)
+  else:
+    abort(400)
+
+
+def _validate_jwt(encoded_jwt, jwk, service):
+  public_key = jwtutil.jwk_dict_to_public_key(jwk)
+
+  try:
+    jwtutil.decode(encoded_jwt, public_key, algorithms=['RS256'],
+                   audience=JWT_AUDIENCE, issuer=service)
+  except jwtutil.InvalidTokenError:
+    logger.exception('JWT validation failure')
+    abort(400)
+
+
+def _signer_kid(encoded_jwt, allow_none=False):
+  headers = get_unverified_header(encoded_jwt)
+  kid = headers.get('kid', None)
+  if not kid and not allow_none:
+    abort(400)
+
+  return kid
+
+
+def _lookup_service_key(service, signer_kid, approved_only=True):
+  try:
+    return model.get_service_key(signer_kid, service=service, approved_only=approved_only)
+  except ServiceKeyDoesNotExist:
+    abort(403)
+
+
+@key_server.route('/services/<service>/keys', methods=['GET'])
+def list_service_keys(service):
+  keys = model.list_service_keys(service)
+  return jsonify({'keys': [key.jwk for key in keys]})
+
+
+@key_server.route('/services/<service>/keys/<kid>', methods=['GET'])
+def get_service_key(service, kid):
+  try:
+    key = model.get_service_key(kid, alive_only=False, approved_only=False)
+  except ServiceKeyDoesNotExist:
+    abort(404)
+
+  if key.approval is None:
+    abort(409)
+
+  if key.expiration_date is not None and key.expiration_date <= datetime.utcnow():
+    abort(403)
+
+  resp = jsonify(key.jwk)
+  lifetime = min(timedelta(days=1), ((key.expiration_date or datetime.max) - datetime.utcnow()))
+  resp.cache_control.max_age = max(0, lifetime.total_seconds())
+  return resp
+
+
+@key_server.route('/services/<service>/keys/<kid>', methods=['PUT'])
+def put_service_key(service, kid):
+  metadata = {'ip': request.remote_addr}
+
+  rotation_duration = request.args.get('rotation', None)
+  expiration_date = request.args.get('expiration', None)
+  if expiration_date is not None:
+    try:
+      expiration_date = datetime.utcfromtimestamp(float(expiration_date))
+    except ValueError:
+      logger.exception('Error parsing expiration date on key')
+      abort(400)
+
+  try:
+    jwk = request.get_json()
+  except ValueError:
+    logger.exception('Error parsing JWK')
+    abort(400)
+
+  jwt_header = request.headers.get(JWT_HEADER_NAME, '')
+  match = jwtutil.TOKEN_REGEX.match(jwt_header)
+  if match is None:
+    logger.error('Could not find matching bearer token')
+    abort(400)
+
+  encoded_jwt = match.group(1)
+
+  _validate_jwk(jwk)
+
+  signer_kid = _signer_kid(encoded_jwt, allow_none=True)
+  if kid == signer_kid or signer_kid is None:
+    # The key is self-signed. Create a new instance and await approval.
+    _validate_jwt(encoded_jwt, jwk, service)
+    model.create_service_key('', kid, service, jwk, metadata, expiration_date,
+                             rotation_duration=rotation_duration)
+
+    key_log_metadata = {
+      'kid': kid,
+      'preshared': False,
+      'service': service,
+      'name': '',
+      'expiration_date': expiration_date,
+      'user_agent': request.headers.get('User-Agent'),
+      'ip': request.remote_addr,
+    }
+
+    log_action('service_key_create', None, metadata=key_log_metadata, ip=request.remote_addr)
+    return make_response('', 202)
+
+  # Key is going to be rotated.
+  metadata.update({'created_by': 'Key Rotation'})
+  signer_key = _lookup_service_key(service, signer_kid)
+  signer_jwk = signer_key.jwk
+
+  _validate_jwt(encoded_jwt, signer_jwk, service)
+
+  try:
+    model.replace_service_key(signer_key.kid, kid, jwk, metadata, expiration_date)
+  except ServiceKeyDoesNotExist:
+    abort(404)
+
+  key_log_metadata = {
+    'kid': kid,
+    'signer_kid': signer_key.kid,
+    'service': service,
+    'name': signer_key.name,
+    'expiration_date': expiration_date,
+    'user_agent': request.headers.get('User-Agent'),
+    'ip': request.remote_addr,
+  }
+
+  log_action('service_key_rotate', None, metadata=key_log_metadata, ip=request.remote_addr)
+  return make_response('', 200)
+
+
+@key_server.route('/services/<service>/keys/<kid>', methods=['DELETE'])
+def delete_service_key(service, kid):
+  jwt_header = request.headers.get(JWT_HEADER_NAME, '')
+  match = jwtutil.TOKEN_REGEX.match(jwt_header)
+  if match is None:
+    abort(400)
+
+  encoded_jwt = match.group(1)
+
+  signer_kid = _signer_kid(encoded_jwt)
+  signer_key = _lookup_service_key(service, signer_kid, approved_only=False)
+
+  self_signed = kid == signer_kid
+  approved_key_for_service = signer_key.approval is not None
+
+  if self_signed or approved_key_for_service:
+    _validate_jwt(encoded_jwt, signer_key.jwk, service)
+
+    try:
+      model.delete_service_key(kid)
+    except ServiceKeyDoesNotExist:
+      abort(404)
+
+    key_log_metadata = {
+      'kid': kid,
+      'signer_kid': signer_key.kid,
+      'service': service,
+      'name': signer_key.name,
+      'user_agent': request.headers.get('User-Agent'),
+      'ip': request.remote_addr,
+    }
+
+    log_action('service_key_delete', None, metadata=key_log_metadata, ip=request.remote_addr)
+    return make_response('', 204)
+
+  abort(403)