feat(hash-uri-map): #56: add generate hash uri map function

c2pie/signing.py

@@ -170,6 +170,22 @@ def _load_certificates_and_key(
     return key, certificates
 
 
+def _generate_hashed_uri_map(
+    url: str,
+    hash_value: bytes,
+    hash_algorithm: str | None = None,
+) -> dict[str, str | bytes]:
+    result: dict[str, str | bytes] = {
+        "url": url,
+        "hash": hash_value,
+    }
+
+    if hash_algorithm:
+        result["alg"] = hash_algorithm
+
+    return result
+
+
 def sign_file(
     input_path: Path | str,
     output_path: Path | str | None = None,

tests/c2pa/signing_test.py

@@ -0,0 +1,21 @@
+from c2pie.signing import _generate_hashed_uri_map
+
+
+def test_generate_hashed_uri_map_required_fields():
+    result = _generate_hashed_uri_map(url="self#jumbf=c2pa.assertions/c2pa.ingredient.v3", hash_value=b"\x01\x02\x03")
+    assert result["url"] == "self#jumbf=c2pa.assertions/c2pa.ingredient.v3"
+    assert result["hash"] == b"\x01\x02\x03"
+
+
+def test_generate_hashed_uri_map_no_alg_by_default():
+    result = _generate_hashed_uri_map(url="self#jumbf=c2pa.assertions/c2pa.ingredient.v3", hash_value=b"\x01\x02\x03")
+    assert "alg" not in result
+
+
+def test_generate_hashed_uri_map_with_alg():
+    result = _generate_hashed_uri_map(
+        url="self#jumbf=c2pa.assertions/c2pa.ingredient.v3",
+        hash_value=b"\x01\x02\x03",
+        hash_algorithm="sha256",
+    )
+    assert result["alg"] == "sha256"