1 files changed, 46 insertions, 0 deletions
diff --git a/packages/meshbay-common/tests/test_webcrypto.py b/packages/meshbay-common/tests/test_webcrypto.py
new file mode 100644
index 0000000..25bcd5c
--- /dev/null
+++ b/packages/meshbay-common/tests/test_webcrypto.py
@@ -0,0 +1,46 @@
+"""Tests for AES-256-GCM webcrypto variant."""
+
+import os
+import pytest
+import blake3
+from meshbay_common.crypto import generate_gek
+from meshbay_common.webcrypto import chunk_key_aes, encrypt_chunk_aes, decrypt_chunk_aes
+
+
+def test_aes_roundtrip():
+    gek  = generate_gek()
+    data = os.urandom(1024 * 1024)   # 1 MB
+    fh   = blake3.blake3(data).digest()
+    key  = chunk_key_aes(gek, fh, 0)
+    nonce, ct = encrypt_chunk_aes(key, data)
+    assert decrypt_chunk_aes(key, nonce, ct) == data
+
+
+def test_aes_key_distinct_from_chacha_key():
+    """AES and ChaCha20 keys for the same chunk must differ."""
+    from meshbay_common.crypto import chunk_key as chacha_key
+    gek  = generate_gek()
+    data = os.urandom(100)
+    fh   = blake3.blake3(data).digest()
+    aes_k    = chunk_key_aes(gek, fh, 0)
+    chacha_k = chacha_key(gek, fh, 0)
+    assert aes_k != chacha_k
+
+
+def test_aes_wrong_key_rejected():
+    gek  = generate_gek()
+    data = b"private content"
+    fh   = blake3.blake3(data).digest()
+    key  = chunk_key_aes(gek, fh, 0)
+    nonce, ct = encrypt_chunk_aes(key, data)
+    wrong_key = chunk_key_aes(generate_gek(), fh, 0)
+    with pytest.raises(Exception):
+        decrypt_chunk_aes(wrong_key, nonce, ct)
+
+
+def test_aes_chunk_keys_unique_per_chunk():
+    gek  = generate_gek()
+    data = os.urandom(32)
+    fh   = blake3.blake3(data).digest()
+    keys = {chunk_key_aes(gek, fh, i) for i in range(5)}
+    assert len(keys) == 5   # all distinct