refactor(drm): resolve content keys in one licence path behind ServerKeySource

Drop null keys from every licence, server and export source, not only Widevine. dl now finds remote sessions and imports through ServerKeySource instead of private fields.

tests/remote/unit/test_server_cdm_vault_write.py

@@ -13,6 +13,7 @@ from uuid import UUID
 import pytest
 from rich.table import Table
 
+from tests.remote.key_source import remote_keys
 from unshackle.commands.dl import dl
 
 pytestmark = pytest.mark.unit
@@ -68,7 +69,7 @@ def make_cmd(vaults):
     cmd.vaults = vaults
     cmd.vault_cache_tally = None
     cmd.debug_logger = None
-    cmd._remote_service = SimpleNamespace(_server_cdm=True, _server_cdm_type="widevine")
+    cmd._remote_service = remote_keys()
     dl.LICENSE_KEY_CACHE.clear()
     dl.DRM_LOCKS.clear()
     return cmd
@@ -78,7 +79,7 @@ def prepare(cmd, drm, licence, track_kid, **kwargs):
     table = Table.grid()
     table.add_row("")
     cmd.prepare_drm(
-        track=SimpleNamespace(drm=[drm]),
+        track=SimpleNamespace(id="vid", drm=[drm]),
         title=None,
         drm=drm,
         licence=licence,
@@ -128,7 +129,7 @@ def test_batch_resolved_keys_are_cached_before_download():
     drm.content_keys = {NEW: "k_new"}
     title = SimpleNamespace(tracks=[SimpleNamespace(drm=[drm]), SimpleNamespace(drm=None)])
 
-    cmd.cache_resolved_keys(title)
+    cmd.cache_resolved_keys(remote_keys(), title)
     cmd.wait_vault_writes()
 
     assert vaults.added == {NEW: "k_new"}
@@ -168,7 +169,7 @@ def test_server_vault_keys_are_held_back_until_verified():
     drm2 = FakeWidevine([CACHED])
     drm2.content_keys = {CACHED: "k_cached"}
     dl.LICENSE_KEY_CACHE.clear()
-    cmd.cache_resolved_keys(SimpleNamespace(tracks=[SimpleNamespace(drm=[drm2])]))
+    cmd.cache_resolved_keys(remote, SimpleNamespace(tracks=[SimpleNamespace(drm=[drm2])]))
     cmd.wait_vault_writes()
     assert vaults.added == {NEW: "k_new"}
 
@@ -242,7 +243,7 @@ def test_no_cdm_and_no_server_cdm_names_the_missing_cdm(system):
     from unshackle.core.drm import PlayReady, Widevine
 
     cmd = make_cmd(FakeVaults())
-    cmd._remote_service = SimpleNamespace(_server_cdm=False)
+    cmd._remote_service = remote_keys(server_cdm=False)
     cmd.cdm = None
     cmd.cdm_for = lambda system, quality=None: None
     drm_class = PlayReady if system == "playready" else Widevine
@@ -250,3 +251,32 @@ def test_no_cdm_and_no_server_cdm_names_the_missing_cdm(system):
     drm.content_keys = {}
     with pytest.raises(click.ClickException, match="No CDM configured for TEST"):
         prepare(cmd, drm, lambda **kwargs: None, NEW)
+
+
+NULL = UUID("0b3e2d1c4a5f46e7b8c9d0e1f2a3b4c5")
+
+
+def test_a_null_key_from_the_server_licence_is_dropped():
+    vaults = FakeVaults()
+    drm = run_prepare(vaults, [NEW], {NEW: "k_new", NULL: "0" * 32}, track_kid=NEW)
+    assert drm.content_keys == {NEW: "k_new"}
+    assert vaults.added == {NEW: "k_new"}
+    assert NULL not in dl.LICENSE_KEY_CACHE
+
+
+def test_a_null_key_from_the_batch_licence_is_dropped(monkeypatch):
+    vaults = FakeVaults()
+    cmd = make_cmd(vaults)
+    drm = FakeWidevine([NEW])
+    title = SimpleNamespace(tracks=[SimpleNamespace(drm=[drm])])
+    source = cmd._remote_service
+    monkeypatch.setattr(
+        source, "resolve_server_keys", lambda t: drm.content_keys.update({NEW: "k_new", NULL: "0" * 32})
+    )
+
+    cmd.take_server_keys(source, title, cdm_only=False)
+    cmd.wait_vault_writes()
+
+    assert drm.content_keys == {NEW: "k_new"}
+    assert vaults.added == {NEW: "k_new"}
+    assert NULL not in dl.LICENSE_KEY_CACHE