1 files changed, 3 insertions, 3 deletions
diff --git a/internal/cryptoutil/oae2.go b/internal/cryptoutil/oae2.go
index 4e667b7..8eb18fb 100644
--- a/internal/cryptoutil/oae2.go
+++ b/internal/cryptoutil/oae2.go
@@ -35,7 +35,7 @@ type oae2 struct {
 	additionalData []byte
 
 	aead        cipher.AEAD
-	i           uint64
+	i           int64
 	noncePrefix [noncePrefixSize]byte
 }
 
@@ -56,10 +56,10 @@ func (o *oae2) initialize(header []byte) error {
 
 func (o *oae2) nonce(nonce []byte, lastBlock bool) error {
 	copy(nonce, o.noncePrefix[:])
-	if o.i == 0 {
+	if o.i < 0 {
 		return errors.New("counter overflowed (64 bits??)")
 	}
-	binary.BigEndian.PutUint64(nonce[noncePrefixSize:], o.i)
+	binary.BigEndian.PutUint64(nonce[noncePrefixSize:], uint64(o.i))
 	if lastBlock {
 		nonce[gcmNonceSize-1] = 1
 	}