Vendor aws-sdk-go (dep ensure) (#178)

vendor/github.com/aws/aws-sdk-go/service/s3/s3crypto/cipher.go

@@ -0,0 +1,43 @@
+package s3crypto
+
+import (
+	"io"
+)
+
+// Cipher interface allows for either encryption and decryption of an object
+type Cipher interface {
+	Encrypter
+	Decrypter
+}
+
+// Encrypter interface with only the encrypt method
+type Encrypter interface {
+	Encrypt(io.Reader) io.Reader
+}
+
+// Decrypter interface with only the decrypt method
+type Decrypter interface {
+	Decrypt(io.Reader) io.Reader
+}
+
+// CryptoReadCloser handles closing of the body and allowing reads from the decrypted
+// content.
+type CryptoReadCloser struct {
+	Body      io.ReadCloser
+	Decrypter io.Reader
+	isClosed  bool
+}
+
+// Close lets the CryptoReadCloser satisfy io.ReadCloser interface
+func (rc *CryptoReadCloser) Close() error {
+	rc.isClosed = true
+	return rc.Body.Close()
+}
+
+// Read lets the CryptoReadCloser satisfy io.ReadCloser interface
+func (rc *CryptoReadCloser) Read(b []byte) (int, error) {
+	if rc.isClosed {
+		return 0, io.EOF
+	}
+	return rc.Decrypter.Read(b)
+}