From 083d01731ffebb348c749ad6ccdb0256571835c7 Mon Sep 17 00:00:00 2001
From: Rob Austein <sra@hactrn.net>
Date: Wed, 25 May 2016 21:40:18 -0400
Subject: Start cleaning up PIN code.

---
 utils/last_gasp_default_pin | 86 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100755 utils/last_gasp_default_pin

(limited to 'utils/last_gasp_default_pin')

diff --git a/utils/last_gasp_default_pin b/utils/last_gasp_default_pin
new file mode 100755
index 0000000..e0d9839
--- /dev/null
+++ b/utils/last_gasp_default_pin
@@ -0,0 +1,86 @@
+#!/usr/bin/env python
+
+"""
+Somewhere, the HSM has to have a last-gasp default PIN, even if it's
+only the null string, because there has to be **some** way to
+initialize the poor thing.  Absent a better plan (feel free to
+suggest one!), this last-gasp default is compiled in.
+
+The normal value of this last-gasp PIN is deliberately chosen to be
+annoying, so that people will change it, but since the derevation
+requires running PBKDF2 and you might want a different default if
+you're compiling this for yourself, we provide the script that
+generates the default.
+"""
+
+# Author: Rob Austein
+# Copyright (c) 2016, NORDUnet A/S
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+# - Redistributions of source code must retain the above copyright notice,
+#   this list of conditions and the following disclaimer.
+#
+# - Redistributions in binary form must reproduce the above copyright
+#   notice, this list of conditions and the following disclaimer in the
+#   documentation and/or other materials provided with the distribution.
+#
+# - Neither the name of the NORDUnet nor the names of its contributors may
+#   be used to endorse or promote products derived from this software
+#   without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+# TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from argparse                   import ArgumentParser, ArgumentDefaultsHelpFormatter
+from os                         import urandom
+from Crypto.Protocol.KDF        import PBKDF2
+from Crypto.Hash                import SHA256, HMAC
+
+parser = ArgumentParser(description = __doc__, formatter_class = ArgumentDefaultsHelpFormatter)
+parser.add_argument("-p", "--pin",
+                    default = "YouReallyNeedToChangeThisPINRightNowWeAreNotKidding",
+                    help    = "PIN plaintext before PBKDF2 processing")
+parser.add_argument("-i", "--iterations",
+                    type    = int,
+                    default = 100000,
+                    help    = "PBKDF2 iteration count")
+args = parser.parse_args()
+
+def HMAC_SHA256(pin, salt):
+    return HMAC.new(pin, salt, SHA256).digest()
+
+def hexify(value):
+    return ", ".join("0x%02x" % ord(v) for v in value)
+
+salt = urandom(16)
+
+pin  = PBKDF2(password = args.pin,
+              salt     = salt,
+              dkLen    = 32,
+              count    = args.iterations,
+              prf      = HMAC_SHA256)
+
+print '''\
+/*
+ * Automatically generated by a script, do not edit.
+ */
+
+static const hal_ks_pin_t hal_last_gasp_pin = {{
+  {iterations},
+  {{{pin}}},
+  {{{salt}}}
+}};'''.format(iterations = args.iterations,
+              pin        = hexify(pin),
+              salt       = hexify(salt))
-- 
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