Add foundational components for EAR generation (JWT creation and signing) and CI setup

.flake8

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+[flake8]
+max-line-length = 88

.github/workflows/tox.yml

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+name: Run Tox on PR
+
+on:
+  pull_request:
+    branches:
+      - main
+      - '**'  # Run on all branches for PRs
+
+jobs:
+  tox-tests:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        python-version: [3.9, 3.11]  # Test against multiple Python versions
+
+    steps:
+      # Checkout the code
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      # Setup Python
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v4
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      # Install tox
+      - name: Install tox
+        run: pip install tox
+
+      # Run tox
+      - name: Run tox
+        run: tox

.pylintrc

@@ -1,8 +1,9 @@
 [MESSAGES CONTROL]
-disable = C0114, C0115, C0116  ; Disable missing module/class/function docstring warnings
+disable = C0114, C0115, C0116, redefined-outer-name, duplicate-code
 
 [FORMAT]
 max-line-length = 88  ; Match Black's default line length
+max-attributes=10
 
 [MASTER]
 ignore = venv  ; Ignore virtual environment folder

README.md

@@ -1,26 +1,68 @@
-# python-ear
+# **python-ear**
 
-A python implementation of [draft-fv-rats-ear](https://datatracker.ietf.org/doc/draft-fv-rats-ear/).
+A Python library that implements the EAT Attestation Result (EAR) data format, as specified in [draft-fv-rats-ear](https://datatracker.ietf.org/doc/draft-fv-rats-ear/). This library provides implementations for both CBOR-based and JSON-based serialisations.
 
-# Proposal
+---
 
-Following are the tools that will be used in the development of this library
+## **Overview**
 
-## CWT and JWT creation
+The goal of this project is to standardize attestation results by defining a shared information and data model, enabling seamless integration with other components of the RATS architecture. This focuses specifically on harmonizing attestation results to facilitate interoperability between various verifiers and relying parties.
 
-1. [python-cwt](https://python-cwt.readthedocs.io/en/stable/)
-2. [python-jwt](https://pypi.org/project/python-jose/)
+This implementation was initiated as part of the **Veraison Mentorship** under the Linux Foundation Mentorship Program (**LFX Mentorship**), focusing on the following capabilities:
 
-## Code formatting and styling
+- **Populating EAR Claims-Sets:** Define and populate claims that represent evidence and attestation results.
+- **Signing EAR Claims-Sets:** Support signing using private keys, ensuring data integrity and authenticity.
+- **Encoding and Decoding:**  
+  - Encode signed EAR claims as **CWT** (Concise Binary Object Representation Web Tokens) or **JWT** (JSON Web Tokens).  
+  - Decode signed EARs from CWT or JWT formats, enabling interoperability between different systems.
+- **Signature Verification:** Verify signatures using public keys to ensure the authenticity of claims.
+- **Accessing Claims:** Provide interfaces to access and manage EAR claims efficiently.
 
-1. [black](https://pypi.org/project/black/)
-2. [isort](https://pypi.org/project/isort/)
+This library is developed in Python and makes use of existing packages for CWT and JWT management, static code analysis, and testing.
 
-## Linting and static analysis
+---
 
-1. [flake8](https://pypi.org/project/flake8/)
-2. [mypy](https://pypi.org/project/mypy/)
+## **Key Features**
 
-## Testing
+1. **Standards Compliance:**  
+   Implements draft-fv-rats-ear as per IETF specifications to ensure compatibility with the RATS architecture.
 
-1. [pytest](https://pypi.org/project/pytest/)
+2. **Token Management:**  
+   - **CWT Support:** Utilizes [python-cwt](https://python-cwt.readthedocs.io/en/stable/) for handling CBOR Web Tokens.  
+   - **JWT Support:** Uses [python-jose](https://pypi.org/project/python-jose/) for JSON Web Tokens management.
+
+3. **Security:**  
+   - Supports signing of EAR claims with private keys and verification with public keys.  
+   - Adopts secure cryptographic practices for token creation and verification.
+
+4. **Static Analysis and Code Quality:**  
+   - Ensures code quality using linters and static analysis tools.  
+   - Maintains type safety and code consistency.
+
+5. **Testing:**  
+   - Comprehensive unit tests using `pytest` to validate all functionalities.
+
+---
+
+## **Technical Stack**
+
+### **Token Creation and Management**
+
+- **CWT:** [python-cwt](https://python-cwt.readthedocs.io/en/stable/)  
+- **JWT:** [python-jose](https://pypi.org/project/python-jose/)
+
+### **Code Formatting and Styling**
+
+- **black:** Ensures consistent code formatting.  
+- **isort:** Manages import statements.  
+
+### **Linting and Static Analysis**
+
+- **flake8:** For PEP 8 compliance and linting.  
+- **mypy:** Static type checking.  
+- **pyright:** Advanced type checking for Python.  
+- **pylint:** Code analysis for error detection and enforcing coding standards.  
+
+### **Testing**
+
+- **pytest:** Framework for writing and executing tests.

src/base.py

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+import json
+from abc import ABC
+from collections import namedtuple
+from typing import Any, ClassVar, Dict, Tuple, Type, TypeVar, Union, get_args
+
+T = TypeVar("T", bound="BaseJCSerializable")
+
+KeyMapping = namedtuple("KeyMapping", ["int_key", "str_key"])
+
+
+def to_data(value: Any, keys_as_int=False) -> Any:
+    if hasattr(value, "to_data"):
+        return value.to_data(keys_as_int)
+    if hasattr(value, "items"):  # dict-like
+        return {
+            to_data(k, keys_as_int): to_data(v, keys_as_int) for k, v in value.items()
+        }
+    if hasattr(value, "__iter__") and not isinstance(value, str):  # list-like
+        return [to_data(v, keys_as_int) for v in value]
+
+    if hasattr(
+        value, "value"
+    ):  # custom classes that have value attr but don't have 'to_data'
+        return value.value  # type: ignore[attr-defined]
+    # scalar and no to_data(), so assume serializable as-is
+    return value
+
+
+class BaseJCSerializable(ABC):
+    jc_map: ClassVar[Dict[str, Tuple[int, str]]]
+
+    def to_data(self, keys_as_int=False) -> Dict[Union[str, int], Any]:
+        return {
+            (int_key if keys_as_int else str_key): to_data(
+                getattr(self, attr), keys_as_int
+            )
+            for attr, (int_key, str_key) in self.jc_map.items()
+        }
+
+    @classmethod
+    def from_data(cls: Type[T], data: dict, keys_as_int=False) -> T:
+        key_attr = "int_key" if keys_as_int else "str_key"
+        init_kwargs = {}
+        reverse_map = {
+            getattr(mapping, key_attr): attr for attr, mapping in cls.jc_map.items()
+        }
+
+        for key, value in data.items():
+            if key not in reverse_map:
+                continue
+
+            attr = reverse_map[key]
+            field_type = getattr(cls, "__annotations__", {}).get(attr)
+            if field_type is None:
+                continue
+
+            args = get_args(field_type)
+
+            if hasattr(field_type, "from_data"):
+                # Direct object
+                init_kwargs[attr] = field_type.from_data(value, keys_as_int=keys_as_int)
+
+            elif hasattr(field_type, "items") and hasattr(args[1], "from_data"):
+                # Dict[str | int, CustomClass]
+                init_kwargs[attr] = {
+                    k: args[1].from_data(v, keys_as_int=keys_as_int)
+                    for k, v in value.items()
+                }
+
+            elif args:
+                # custom classes that dont have 'from_data'
+                init_kwargs[attr] = args[0](value)
+
+            else:
+                init_kwargs[attr] = field_type(value)
+
+        return cls(**init_kwargs)
+
+    def to_dict(self) -> Dict[str, Any]:
+        # default str_keys
+        return self.to_data()  # type: ignore[return-value] # pyright: ignore[reportGeneralTypeIssues] # noqa: E501 # pylint: disable=line-too-long
+
+    def to_int_keys(self) -> Dict[Union[str, int], Any]:
+        return self.to_data(keys_as_int=True)
+
+    @classmethod
+    def from_dict(cls: Type[T], data: Dict[str, Any]) -> T:
+        return cls.from_data(data)
+
+    @classmethod
+    def from_int_keys(cls: Type[T], data: Dict[int, Any]) -> T:
+        return cls.from_data(data, keys_as_int=True)
+
+    @classmethod
+    def from_json(cls, json_str: str):
+        return cls.from_dict(json.loads(json_str))
+
+    def to_json(self):
+        return json.dumps(self.to_data())

src/claims.py

@@ -1,35 +1,76 @@
-import json
 from dataclasses import dataclass, field
-from typing import Any, Dict
+from datetime import datetime, timedelta
+from typing import Dict
 
+from jose import jwt  # type: ignore # pylint: disable=import-error
 
+from src.base import BaseJCSerializable, KeyMapping
+from src.errors import EARValidationError
+from src.jwt_config import DEFAULT_ALGORITHM, DEFAULT_EXPIRATION_MINUTES
+from src.submod import Submod
+from src.verifier_id import VerifierID
+
+
+# https://datatracker.ietf.org/doc/draft-fv-rats-ear/
 @dataclass
-class EARClaims:
+class AttestationResult(BaseJCSerializable):
     profile: str
     issued_at: int
-    verifier_id: Dict[str, str] = field(default_factory=dict)
-    submods: Dict[str, Any] = field(default_factory=dict)
+    verifier_id: VerifierID
+    submods: Dict[str, Submod] = field(default_factory=dict)
 
-    def to_dict(self) -> Dict[str, Any]:
-        return {
-            "eat_profile": self.profile,
-            "iat": self.issued_at,
-            "ear.verifier-id": self.verifier_id,
-            "submods": self.submods,
-        }
+    # https://www.ietf.org/archive/id/draft-ietf-rats-eat-31.html#section-7.2.4
+    jc_map = {
+        "profile": KeyMapping(265, "eat_profile"),
+        "issued_at": KeyMapping(6, "iat"),
+        "verifier_id": KeyMapping(1004, "ear.verifier-id"),
+        "submods": KeyMapping(266, "submods"),
+    }
 
-    @classmethod
-    def from_dict(cls, data: Dict[str, Any]):
-        return cls(
-            profile=data.get("eat_profile", ""),
-            issued_at=data.get("iat", 0),
-            verifier_id=data.get("ear.verifier-id", {}),
-            submods=data.get("submods", {}),
-        )
+    def validate(self):
+        # Validates an AttestationResult object
+        if not isinstance(self.profile, str) or not self.profile:
+            raise EARValidationError(
+                "AttestationResult profile must be a non-empty string"
+            )
+        if not isinstance(self.issued_at, int) or self.issued_at <= 0:
+            raise EARValidationError(
+                "AttestationResult issued_at must be a positive integer"
+            )
 
-    def to_json(self) -> str:
-        return json.dumps(self.to_dict())
+        self.verifier_id.validate()
+
+        for submod, details in self.submods.items():
+            if not isinstance(details, Submod):
+                raise EARValidationError(
+                    f"Submodule {submod} must contain a valid trust_vector and status"
+                )
+
+            trust_vector = details.trust_vector
+            trust_vector.validate()
+
+    def encode_jwt(
+        self,
+        secret_key: str,
+        algorithm: str = DEFAULT_ALGORITHM,
+        expiration_minutes: int = DEFAULT_EXPIRATION_MINUTES,
+    ) -> str:
+        # Signs an AttestationResult object and returns a JWT
+        payload = self.to_dict()
+        payload["exp"] = int(
+            datetime.timestamp(datetime.now() + timedelta(minutes=expiration_minutes))
+        )
+        return jwt.encode(
+            payload, secret_key, algorithm=algorithm
+        )  # pyright: ignore[reportGeneralTypeIssues]
 
     @classmethod
-    def from_json(cls, json_str: str):
-        return cls.from_dict(json.loads(json_str))
+    def decode_jwt(
+        cls, token: str, secret_key: str, algorithm: str = DEFAULT_ALGORITHM
+    ):
+        # Verifies a JWT and returns the decoded AttestationResult object.
+        try:
+            payload = jwt.decode(token, secret_key, algorithms=[algorithm])
+            return cls.from_dict(payload)
+        except Exception as exc:
+            raise ValueError(f"JWT decoding failed: {exc}") from exc

src/errors.py

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+class EARValidationError(Exception):
+    # Custom exception for validation errors in AttestationResult
+    pass

src/example/jwt_example.py

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+from datetime import datetime
+
+from src.claims import AttestationResult
+from src.jwt_config import generate_secret_key
+from src.submod import Submod
+from src.trust_claims import TRUSTWORTHY_INSTANCE_CLAIM, UNRECOGNIZED_INSTANCE_CLAIM
+from src.trust_tier import TRUST_TIER_AFFIRMING, TRUST_TIER_CONTRAINDICATED
+from src.trust_vector import TrustVector
+from src.verifier_id import VerifierID
+
+# import json
+
+# Generate a secret key for signing
+secret_key = generate_secret_key()
+
+# Create an AttestationResult object
+attestation_result = AttestationResult(
+    profile="test_profile",
+    issued_at=int(datetime.timestamp(datetime.now())),
+    verifier_id=VerifierID(developer="Acme Inc.", build="v1"),
+    submods={
+        "submod1": Submod(
+            trust_vector=TrustVector(instance_identity=UNRECOGNIZED_INSTANCE_CLAIM),
+            status=TRUST_TIER_AFFIRMING,
+        ),
+        "submod2": Submod(
+            trust_vector=TrustVector(instance_identity=TRUSTWORTHY_INSTANCE_CLAIM),
+            status=TRUST_TIER_CONTRAINDICATED,
+        ),
+    },
+)
+
+# payload = attestation_result.encode_jwt(secret_key=secret_key)
+# print(payload)
+
+# decoded = AttestationResult.decode_jwt(token=payload, secret_key=secret_key)
+# output_data = decoded.to_dict()
+
+# with open("jwt_output.json", "w", encoding="utf-8") as f:
+#     json.dump(output_data, f, indent=4)
+
+# print("Output successfully written to output.json")