Enforce text type of NameAttribute.value

2 files changed, 12 insertions, 0 deletions

diff --git a/src/cryptography/x509.py b/src/cryptography/x509.py
index 87028be1..2e2e8512 100644
--- a/src/cryptography/x509.py
+++ b/src/cryptography/x509.py
@@ -148,6 +148,11 @@ class NameAttribute(object):
                 "oid argument must be an ObjectIdentifier instance."
             )
 
+        if not isinstance(value, six.text_type):
+            raise TypeError(
+                "value argument must be a text type."
+            )
+
         self._oid = oid
         self._value = value
 
diff --git a/tests/test_x509.py b/tests/test_x509.py
index a3bed85f..d9aa22db 100644
--- a/tests/test_x509.py
+++ b/tests/test_x509.py
@@ -794,6 +794,13 @@ class TestNameAttribute(object):
         with pytest.raises(TypeError):
             x509.NameAttribute(None, 'value')
 
+    def test_init_bad_value(self):
+        with pytest.raises(TypeError):
+            x509.NameAttribute(
+                x509.ObjectIdentifier('oid'),
+                b'bytes'
+            )
+
     def test_eq(self):
         assert x509.NameAttribute(
             x509.ObjectIdentifier('oid'), 'value'