Index: tests/sys/opencrypto/cryptodev.py
===================================================================
--- tests/sys/opencrypto/cryptodev.py
+++ tests/sys/opencrypto/cryptodev.py
@@ -287,7 +287,7 @@
 
         ioctl(_cryptodev, CIOCCRYPTAEAD, bytes(caead))
 
-        if src is not None:
+        if src is not None and len(src) != 0:
             s = array_tobytes(s)
         else:
             s = empty_bytes()
@@ -372,24 +372,25 @@
 
     def __next__(self):
         while True:
-            didread = False
-            if self._pending is not None:
-                i = self._pending
-                self._pending = None
-            else:
-                i = self.fp.readline()
-                didread = True
-
-            if didread and not i:
-                return
+            while True:
+                didread = False
+                if self._pending is not None:
+                    i = self._pending
+                    self._pending = None
+                else:
+                    i = self.fp.readline()
+                    didread = True
+
+                if didread and not i:
+                    return
 
-            if not i.startswith('#') and i.strip():
-                break
+                if not i.startswith('#') and i.strip():
+                    break
 
-        if i[0] == '[':
-            yield i[1:].split(']', 1)[0], self.fielditer()
-        else:
-            raise ValueError('unknown line: %r' % repr(i))
+            if i[0] == '[':
+                yield i[1:].split(']', 1)[0], self.fielditer()
+            else:
+                raise ValueError('unknown line: %r' % repr(i))
 
     def eatblanks(self):
         while True: