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1# Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5import tempfile
6
7from autotest_lib.client.bin import utils
8from autotest_lib.client.common_lib import error
9from autotest_lib.client.cros import cryptohome
10
11class TPMStore(object):
12    """Context enclosing the use of the TPM."""
13
14    CHAPS_CLIENT_COMMAND = 'chaps_client'
15    CONVERT_TYPE_RSA = 'rsa'
16    CONVERT_TYPE_X509 = 'x509'
17    CRYPTOHOME_ACTION_TAKE_OWNERSHIP = 'tpm_take_ownership'
18    CRYPTOHOME_ACTION_WAIT_OWNERSHIP = 'tpm_wait_ownership'
19    CRYPTOHOME_COMMAND = '/usr/sbin/cryptohome'
20    OPENSSL_COMMAND = 'openssl'
21    OUTPUT_TYPE_CERTIFICATE = 'cert'
22    OUTPUT_TYPE_PRIVATE_KEY = 'privkey'
23    PIN = '11111'
24    # TPM maintain two slots for certificates, slot 0 for system specific
25    # certificates, slot 1 for user specific certificates. Currently, all
26    # certificates are programmed in slot 1. So hardcode this slot ID for now.
27    SLOT_ID = '1'
28    PKCS11_REPLAY_COMMAND = 'p11_replay --slot=%s' % SLOT_ID
29    TPM_GROUP = 'chronos-access'
30    TPM_USER = 'chaps'
31
32
33    def __enter__(self):
34        self.setup()
35        return self
36
37    def __exit__(self, exception, value, traceback):
38        self.reset()
39
40
41    def _cryptohome_action(self, action):
42        """Set the TPM up for operation in tests."""
43        utils.system('%s --action=%s' % (self.CRYPTOHOME_COMMAND, action),
44                     ignore_status=True)
45
46
47    def _install_object(self, pem, identifier, conversion_type, output_type):
48        """Convert a PEM object to DER and store it in the TPM.
49
50        @param pem string PEM encoded object to be stored.
51        @param identifier string associated with the new object.
52        @param conversion_type the object type to use in PEM to DER conversion.
53        @param output_type the object type to use in inserting into the TPM.
54
55        """
56        if cryptohome.is_tpm_lockout_in_effect():
57            raise error.TestError('The TPM is in dictonary defend mode. '
58                                  'The TPMStore may behave in unexpected '
59                                  'ways, exiting.')
60        pem_file = tempfile.NamedTemporaryFile()
61        pem_file.file.write(pem)
62        pem_file.file.flush()
63        der_file = tempfile.NamedTemporaryFile()
64        utils.system('%s %s -in %s -out %s -inform PEM -outform DER' %
65                     (self.OPENSSL_COMMAND, conversion_type, pem_file.name,
66                      der_file.name))
67        utils.system('%s --import --type=%s --path=%s --id="%s"' %
68                     (self.PKCS11_REPLAY_COMMAND, output_type, der_file.name,
69                      identifier))
70
71
72    def setup(self):
73        """Set the TPM up for operation in tests."""
74        self.reset()
75        self._directory = tempfile.mkdtemp()
76        utils.system('chown %s:%s %s' %
77                     (self.TPM_USER, self.TPM_GROUP, self._directory))
78        utils.system('%s --load --path=%s --auth="%s"' %
79                     (self.CHAPS_CLIENT_COMMAND, self._directory, self.PIN))
80
81
82    def reset(self):
83        """Reset the crypto store and take ownership of the device."""
84        utils.system('initctl restart chapsd')
85        self._cryptohome_action(self.CRYPTOHOME_ACTION_TAKE_OWNERSHIP)
86        self._cryptohome_action(self.CRYPTOHOME_ACTION_WAIT_OWNERSHIP)
87
88
89    def install_certificate(self, certificate, identifier):
90        """Install a certificate into the TPM, returning the certificate ID.
91
92        @param certificate string PEM x509 contents of the certificate.
93        @param identifier string associated with this certificate in the TPM.
94
95        """
96        return self._install_object(certificate,
97                                    identifier,
98                                    self.CONVERT_TYPE_X509,
99                                    self.OUTPUT_TYPE_CERTIFICATE)
100
101
102    def install_private_key(self, key, identifier):
103        """Install a private key into the TPM, returning the certificate ID.
104
105        @param key string PEM RSA private key contents.
106        @param identifier string associated with this private key in the TPM.
107
108        """
109        return self._install_object(key,
110                                    identifier,
111                                    self.CONVERT_TYPE_RSA,
112                                    self.OUTPUT_TYPE_PRIVATE_KEY)
113