siv_aead: Overhead is always 16

Add a test for that.

Also test operations using a 64-byte key.

1 files changed, 1 insertions, 5 deletions

diff --git a/internal/siv_aead/siv_aead.go b/internal/siv_aead/siv_aead.go
index 21106a5..a0ed882 100644
--- a/internal/siv_aead/siv_aead.go
+++ b/internal/siv_aead/siv_aead.go
@@ -22,11 +22,7 @@ func (s *sivAead) NonceSize() int {
 }
 
 func (s *sivAead) Overhead() int {
-	// RFC5297:
-	// [...] the key length used by AES in CTR and S2V is len(K)/2 and will
-	// each be either 128 bits, 192 bits, or 256 bits.
-	return len(s.key) / 2
-
+	return 16
 }
 
 // Seal - encrypt "in" using "nonce" and "authData" and append the result to "dst"