fix incorrect unit test description

The process() method signals the caller that the maximum data length
has been reached by returning a ciphertext that is shorter than
the plaintext. The caller must then continue by finalizing the
current object and starting a new one.

The behavior in this case was changed in cb7a3911f8 to not
propagate the exception from Cryptography, but the unit test
retained the erroneous description.

diff --git a/testing/test_crypto.py b/testing/test_crypto.py
index f4d9254..7efb195 100644 (file)
--- a/testing/test_crypto.py
+++ b/testing/test_crypto.py
@@ -432,8 +432,10 @@ class AESGCMTest (CryptoLayerTest):
     def test_crypto_aes_gcm_enc_length_cap (self):
         """
         Artificially lower the maximum allowable data length and attempt to
-        encrypt a larger object. Verify that the crypto handler aborts with and
-        exception.
+        encrypt a larger object. Verify that the crypto handler only encrypts
+        data up to the size limit. A downstream user detects that condition by
+        testing whether the encryption step yielded less bytes than the
+        plaintext.
 
         The sibling to this test is test_restore_backup_max_file_length()
         in test_delatar.py. Deltatar will transparently create a splitted object
@@ -468,7 +470,10 @@ class AESGCMTest (CryptoLayerTest):
             assert (len (rest) == 0)
 
             if len (pt) > new_max:
-                assert n < len (pt)
+                # If the plaintext was longer than the artificially lowered
+                # maximum, then the number of ciphertext bytes must be clamped
+                # to the maximum.
+                assert n == new_max
             else:
                 assert n == len (pt) == len (ct)