Correctly handle errors in the reader

1 files changed, 4 insertions, 3 deletions

diff --git a/internal/cryptoutil/oae2.go b/internal/cryptoutil/oae2.go
index be4f1a9..a230c06 100644
--- a/internal/cryptoutil/oae2.go
+++ b/internal/cryptoutil/oae2.go
@@ -306,7 +306,7 @@ func (k EncryptionKey) NewReader(r io.Reader, options ...Option) *DecryptingRead
 		o(&opts)
 	}
 	return &DecryptingReader{
-		r: bufio.NewReaderSize(r, 1),
+		r: bufio.NewReaderSize(r, headerSize),
 		oae2: oae2{
 			key:            k,
 			additionalData: opts.additionalData,
@@ -316,13 +316,14 @@ func (k EncryptionKey) NewReader(r io.Reader, options ...Option) *DecryptingRead
 }
 
 func (r *DecryptingReader) initialize() error {
-	header := make([]byte, headerSize)
-	if _, err := io.ReadFull(r.r, header); err != nil {
+	header, err := r.r.Peek(headerSize)
+	if err != nil {
 		return err
 	}
 	if err := r.oae2.initialize(header); err != nil {
 		return err
 	}
+	r.r.Discard(len(header))
 	r.buf = *bytes.NewBuffer(make([]byte, 0, r.segmentSize+aeadOverhead))
 	r.initialized = true
 	return nil