Use ReadFull in blockcipher

utils/read_full.go

@@ -0,0 +1,20 @@
+package utils
+
+import "io"
+
+const readFullBufferSize = 1024 + 1 // +1 because telegram opreates with blocks mod 4
+
+func ReadFull(src io.Reader) (rv []byte, err error) {
+	buf := make([]byte, readFullBufferSize)
+	n := readFullBufferSize
+
+	for n == len(buf) {
+		n, err = src.Read(buf)
+		if err != nil {
+			return nil, err
+		}
+		rv = append(rv, buf[:n]...)
+	}
+
+	return rv, nil
+}