Add scripts to generate simple test data for certificate verification.

net/data/verify_certificate_chain_unittest/generate-target-signed-by-512bit-rsa.py

Index: net/data/verify_certificate_chain_unittest/generate-target-signed-by-512bit-rsa.py
diff --git a/net/data/verify_certificate_chain_unittest/generate-target-signed-by-512bit-rsa.py b/net/data/verify_certificate_chain_unittest/generate-target-signed-by-512bit-rsa.py
new file mode 100755
index 0000000000000000000000000000000000000000..75144a0d8eaed88b80757b7b92a7e02d1b477ec1
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+++ b/net/data/verify_certificate_chain_unittest/generate-target-signed-by-512bit-rsa.py
@@ -0,0 +1,27 @@
+#!/usr/bin/python
+# Copyright (c) 2015 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Certificate chain with 1 intermediary and a trusted root. The target
+certificate is signed using a weak RSA key (512-bit modulus), and so
+verification is expected to fail."""
+
+import common
+
+# Self-signed root certificate (part of trust store).
+root = common.create_self_signed_root_certificate('Root')
+
+# Intermediary with a very weak key size (512-bit RSA).
+intermediary = common.create_intermediary_certificate('Intermediary', root)
+intermediary.generate_rsa_key(512)
+
+# Target certificate.
+target = common.create_end_entity_certificate('Target', intermediary)
+
+chain = [target, intermediary]
+trusted = [root]
+time = common.DEFAULT_TIME
+verify_result = False
+
+common.write_test_file(__doc__, chain, trusted, time, verify_result)