Restore random seed function for byte endpoints

os.urandom() ignores random.seed(), so I'm restoring the use of
random.randint in a python3 compatible way.

httpbin/core.py

@@ -458,7 +458,9 @@ def random_bytes(n):
         random.seed(int(params['seed']))
 
     response = make_response()
-    response.data = os.urandom(n)
+
+    # Note: can't just use os.urandom here because it ignores the seed
+    response.data = bytearray(random.randint(0, 255) for i in range(n))
     response.content_type = 'application/octet-stream'
     return response
 
@@ -478,16 +480,16 @@ def stream_random_bytes(n):
         chunk_size = 10 * 1024
 
     def generate_bytes():
-        chunks = []
+        chunks = bytearray()
 
         for i in xrange(n):
-            chunks.append(os.urandom(1))
+            chunks.append(random.randint(0, 255))
             if len(chunks) == chunk_size:
-                yield(bytes().join(chunks))
-                chunks = []
+                yield(bytes(chunks))
+                chunks = bytearray()
 
         if chunks:
-            yield(bytes().join(chunks))
+            yield(bytes(chunks))
 
     headers = {'Transfer-Encoding': 'chunked',
                'Content-Type': 'application/octet-stream'}

test_httpbin.py

@@ -2,6 +2,7 @@
 # -*- coding: utf-8 -*-
 import base64
 import unittest
+import six
 from werkzeug.http import parse_dict_header
 from hashlib import md5
 from six import BytesIO
@@ -134,11 +135,31 @@ class HttpbinTestCase(unittest.TestCase):
         self.assertEqual(len(response.get_data()), 1024)
         self.assertEqual(response.status_code, 200)
 
+    def test_bytes_with_seed(self):
+        response = self.app.get('/bytes/10?seed=0')
+        # The RNG changed in python3, so even though we are
+        # setting the seed, we can't expect the value to be the
+        # same across both interpreters.
+        if six.PY3:
+            self.assertEqual(response.data, b'\xc5\xd7\x14\x84\xf8\xcf\x9b\xf4\xb7o')
+        else:
+            self.assertEqual(response.data, b'\xd8\xc2kB\x82g\xc8Mz\x95')
+
     def test_stream_bytes(self):
         response = self.app.get('/stream-bytes/1024')
         self.assertEqual(len(response.get_data()), 1024)
         self.assertEqual(response.status_code, 200)
 
+    def test_stream_bytes_with_seed(self):
+        response = self.app.get('/stream-bytes/10?seed=0')
+        # The RNG changed in python3, so even though we are
+        # setting the seed, we can't expect the value to be the
+        # same across both interpreters.
+        if six.PY3:
+            self.assertEqual(response.data, b'\xc5\xd7\x14\x84\xf8\xcf\x9b\xf4\xb7o')
+        else:
+            self.assertEqual(response.data, b'\xd8\xc2kB\x82g\xc8Mz\x95')
+
 
 if __name__ == '__main__':
     unittest.main()