add entropy message test

tests/test_entropy.py

@@ -0,0 +1,35 @@
+import unittest
+import common
+import math
+
+from trezorlib import messages_pb2 as messages
+
+def entropy(data):
+    e = 0
+    for i in range(256):
+        p = 0
+        for c in data:
+            if ord(c) == i:
+                p += 1
+        if p == 0:
+            continue
+        p = 1.0 * p / len(data)
+        e -= p * math.log(p, 256)
+    return e
+
+class TestEntropy(common.TrezorTest):
+
+    def test_entropy(self):
+        self.client.load_device_by_mnemonic(mnemonic=self.mnemonic1,
+                                            pin='',
+                                            passphrase_protection=False,
+                                            label='test',
+                                            language='english')
+
+        for l in [0, 1, 2, 3, 4, 5, 8, 9, 16, 17, 32, 33, 64, 65, 128, 129, 256, 257, 512, 513, 1024]:
+            ent = self.client.get_entropy(l)
+            self.assertTrue(len(ent) >= l)
+            print 'entropy = ', entropy(ent)
+
+if __name__ == '__main__':
+    unittest.main()