✨ Validate Election Manifest (#126)

* ✨ Validate Election Manifest

- Add `election/validate/description` to validate election manifests and descriptions
- Add postman tests
- ♻️ Update to use lru cache

* 🆙 Upgrade electionguard

Author: keithrfung

app/api/v1/mediator/election.py

@@ -1,15 +1,22 @@
 from os.path import realpath, join
-from typing import Any
+from typing import Any, Optional
 from electionguard.election import (
     ElectionDescription,
     ElectionConstants,
     make_ciphertext_election_context,
 )
 from electionguard.group import ElementModP
+from electionguard.schema import validate_json_schema
 from electionguard.serializable import read_json_object, write_json_object
-from fastapi import APIRouter, Body
 
-from ..models import ElectionContextRequest
+from fastapi import APIRouter, Body, Depends
+
+from app.core.schema import get_description_schema
+from ..models import (
+    ElectionContextRequest,
+    ValidationResponse,
+    ValidateElectionDescriptionRequest,
+)
 from ..tags import CONFIGURE_ELECTION
 
 router = APIRouter()
@@ -47,3 +54,43 @@ def build_election_context(request: ElectionContextRequest = Body(...)) -> Any:
     )
 
     return write_json_object(context)
+
+
+@router.post("/validate/description", tags=[CONFIGURE_ELECTION])
+def validate_election_description(
+    request: ValidateElectionDescriptionRequest = Body(...),
+    schema: Any = Depends(get_description_schema),
+) -> Any:
+    """
+    Validate an Election description or manifest for a given election
+    """
+
+    success = True
+    message = "Election description successfully validated"
+    details = ""
+
+    # Check schema
+    schema = request.schema_override if request.schema_override else schema
+    (schema_success, error_details) = validate_json_schema(request.description, schema)
+    if not schema_success:
+        success = schema_success
+        message = "Election description did not match schema"
+        details = error_details
+
+    # Check object parse
+    description: Optional[ElectionDescription] = None
+    if success:
+        try:
+            description = ElectionDescription.from_json_object(request.description)
+        except Exception:  # pylint: disable=broad-except
+            success = False
+            message = "Election description could not be read from JSON"
+
+    if success:
+        if description:
+            valid_success = description.is_valid()
+            if not valid_success:
+                message = "Election description was not valid well formed data"
+
+    # Check
+    return ValidationResponse(success=success, message=message, details=details)

app/api/v1/models/__init__.py

@@ -5,3 +5,4 @@
 from .key import *
 from .tally import *
 from .tracker import *
+from .validation import *

app/api/v1/models/election.py

@@ -1,7 +1,15 @@
 from typing import Any
+
 from .base import Base
+from .validation import BaseValidationRequest
+
 
-__all__ = ["CiphertextElectionContext", "ElectionContextRequest", "ElectionDescription"]
+__all__ = [
+    "CiphertextElectionContext",
+    "ElectionContextRequest",
+    "ElectionDescription",
+    "ValidateElectionDescriptionRequest",
+]
 
 ElectionDescription = Any
 
@@ -17,3 +25,11 @@ class ElectionContextRequest(Base):
     elgamal_public_key: str
     number_of_guardians: int
     quorum: int
+
+
+class ValidateElectionDescriptionRequest(BaseValidationRequest):
+    """
+    A request to validate an Election Description
+    """
+
+    description: ElectionDescription

app/api/v1/models/validation.py

@@ -0,0 +1,20 @@
+from typing import Any, Optional
+from .base import Base
+
+__all__ = ["BaseValidationRequest", "ValidationResponse", "Schema"]
+
+Schema = Any
+
+
+class BaseValidationRequest(Base):
+    """Base validation request"""
+
+    schema_override: Optional[Schema] = None
+
+
+class ValidationResponse(Base):
+    """Response for validating models"""
+
+    success: bool
+    message: str
+    details: str = ""

app/core/schema.py

@@ -0,0 +1,10 @@
+from functools import lru_cache
+from typing import Any
+from electionguard.schema import get_election_description_schema
+
+__all__ = ["get_description_schema"]
+
+
+@lru_cache
+def get_description_schema() -> Any:
+    return get_election_description_schema()