path: root/tests/test_write.doctest

test_write.doctest - tests for writing PSKC files

Copyright (C) 2014-2024 Arthur de Jong

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA


>>> from pskc import PSKC

>>> import datetime
>>> import os
>>> import sys
>>> import tempfile
>>> from binascii import a2b_hex
>>> from dateutil.tz import tzutc


Build a PSKC structure.

>>> pskc = PSKC()


Add a key with all attributes set.

>>> key = pskc.add_key(id='456', manufacturer='Manufacturer')
>>> key.id = '123'
>>> key.serial = '987654321'
>>> key.model = 'Model'
>>> key.issue_no = 2
>>> key.start_date = datetime.datetime(2006, 5, 1, 0, 0, tzinfo=tzutc())
>>> key.expiry_date = datetime.datetime(2014, 5, 31, 0, 0, tzinfo=tzutc())
>>> key.device_userid = 'uid=arthur, dc=arthurdejong, dc=org'
>>> key.crypto_module = 'CyrptoId'
>>> key.algorithm = 'urn:ietf:params:xml:ns:keyprov:pskc:hotp'
>>> key.issuer = 'Issuer'
>>> key.key_profile = 'key profile id'
>>> key.key_reference = 'reference to some key'
>>> key.friendly_name = 'a friendly key'
>>> key.key_userid = 'cn=Arthur de Jong, dc=arthurdejong, dc=org'
>>> key.algorithm_suite = 'Clubs'
>>> key.challenge_encoding = 'DECIMAL'
>>> key.challenge_min_length = 6
>>> key.challenge_max_length = 8
>>> key.challenge_check = True
>>> key.response_encoding = 'DECIMAL'
>>> key.response_length = 8
>>> key.response_check = False
>>> key.counter = 0
>>> key.secret = a2b_hex('4e1790ba272406ba309c5a31')


Add policy information and a PIN.

>>> key.policy.key_usage.append('OTP')
>>> key.policy.key_usage.append(key.policy.KEY_USE_VERIFY)
>>> key.policy.start_date = datetime.datetime(2008, 5, 1, 0, 0, tzinfo=tzutc())
>>> key.policy.expiry_date = datetime.datetime(2012, 6, 13, 0, 0, tzinfo=tzutc())
>>> key.policy.number_of_transactions = 42
>>> key.policy.pin_key_id = 'pinID'
>>> key.policy.pin_usage = 'Local'
>>> key.policy.pin_max_failed_attempts = 3
>>> key.policy.pin_min_length = 4
>>> key.policy.pin_max_length = 4
>>> key.policy.pin_encoding = 'DECIMAL'
>>> pin_key = pskc.add_key(id='pinID', secret='1234',
...     algorithm='urn:ietf:params:xml:ns:keyprov:pskc:pin',
...     response_encoding='DECIMAL', response_length=4)


Add a second (TOTP) key:

>>> key = pskc.add_key()
>>> key.serial = key.id = '267469811'
>>> key.start_date = datetime.datetime(2006, 5, 1, 0, 0)
>>> key.expiry_date = datetime.datetime(2014, 5, 31, 0, 0)
>>> key.algorithm = 'urn:ietf:params:xml:ns:keyprov:pskc:totp'
>>> key.response_encoding = 'DECIMAL'
>>> key.response_length = 6
>>> key.time_offset = 0
>>> key.time_interval = 30
>>> key.time_drift = 6
>>> key.secret = a2b_hex('4e1790ba272406ba309c5a31')


Write the PSKC file (use temporary file to test passing file name as
argument).

>>> f = tempfile.NamedTemporaryFile()
>>> pskc.write(f.name)
>>> with open(f.name, 'r') as r:
...     x = sys.stdout.write(r.read())  #doctest: +REPORT_UDIFF
<?xml version="1.0" encoding="UTF-8"?>
<pskc:KeyContainer xmlns:pskc="urn:ietf:params:xml:ns:keyprov:pskc" Version="1.0">
 <pskc:KeyPackage>
  <pskc:DeviceInfo>
   <pskc:Manufacturer>Manufacturer</pskc:Manufacturer>
   <pskc:SerialNo>987654321</pskc:SerialNo>
   <pskc:Model>Model</pskc:Model>
   <pskc:IssueNo>2</pskc:IssueNo>
   <pskc:StartDate>2006-05-01T00:00:00Z</pskc:StartDate>
   <pskc:ExpiryDate>2014-05-31T00:00:00Z</pskc:ExpiryDate>
   <pskc:UserId>uid=arthur, dc=arthurdejong, dc=org</pskc:UserId>
  </pskc:DeviceInfo>
  <pskc:CryptoModuleInfo>
   <pskc:Id>CyrptoId</pskc:Id>
  </pskc:CryptoModuleInfo>
  <pskc:Key Algorithm="urn:ietf:params:xml:ns:keyprov:pskc:hotp" Id="123">
   <pskc:Issuer>Issuer</pskc:Issuer>
   <pskc:AlgorithmParameters>
    <pskc:Suite>Clubs</pskc:Suite>
    <pskc:ChallengeFormat CheckDigits="true" Encoding="DECIMAL" Max="8" Min="6"/>
    <pskc:ResponseFormat CheckDigits="false" Encoding="DECIMAL" Length="8"/>
   </pskc:AlgorithmParameters>
   <pskc:KeyProfileId>key profile id</pskc:KeyProfileId>
   <pskc:KeyReference>reference to some key</pskc:KeyReference>
   <pskc:FriendlyName>a friendly key</pskc:FriendlyName>
   <pskc:Data>
    <pskc:Secret>
     <pskc:PlainValue>TheQuickBrownFox</pskc:PlainValue>
    </pskc:Secret>
    <pskc:Counter>
     <pskc:PlainValue>0</pskc:PlainValue>
    </pskc:Counter>
   </pskc:Data>
   <pskc:UserId>cn=Arthur de Jong, dc=arthurdejong, dc=org</pskc:UserId>
   <pskc:Policy>
    <pskc:StartDate>2008-05-01T00:00:00Z</pskc:StartDate>
    <pskc:ExpiryDate>2012-06-13T00:00:00Z</pskc:ExpiryDate>
    <pskc:PINPolicy MaxFailedAttempts="3" MaxLength="4" MinLength="4" PINEncoding="DECIMAL" PINKeyId="pinID" PINUsageMode="Local"/>
    <pskc:KeyUsage>OTP</pskc:KeyUsage>
    <pskc:KeyUsage>Verify</pskc:KeyUsage>
    <pskc:NumberOfTransactions>42</pskc:NumberOfTransactions>
   </pskc:Policy>
  </pskc:Key>
 </pskc:KeyPackage>
 <pskc:KeyPackage>
  <pskc:Key Algorithm="urn:ietf:params:xml:ns:keyprov:pskc:pin" Id="pinID">
   <pskc:AlgorithmParameters>
    <pskc:ResponseFormat Encoding="DECIMAL" Length="4"/>
   </pskc:AlgorithmParameters>
   <pskc:Data>
    <pskc:Secret>
     <pskc:PlainValue>MTIzNA==</pskc:PlainValue>
    </pskc:Secret>
   </pskc:Data>
  </pskc:Key>
 </pskc:KeyPackage>
 <pskc:KeyPackage>
  <pskc:DeviceInfo>
   <pskc:SerialNo>267469811</pskc:SerialNo>
   <pskc:StartDate>2006-05-01T00:00:00</pskc:StartDate>
   <pskc:ExpiryDate>2014-05-31T00:00:00</pskc:ExpiryDate>
  </pskc:DeviceInfo>
  <pskc:Key Algorithm="urn:ietf:params:xml:ns:keyprov:pskc:totp" Id="267469811">
   <pskc:AlgorithmParameters>
    <pskc:ResponseFormat Encoding="DECIMAL" Length="6"/>
   </pskc:AlgorithmParameters>
   <pskc:Data>
    <pskc:Secret>
     <pskc:PlainValue>TheQuickBrownFox</pskc:PlainValue>
    </pskc:Secret>
    <pskc:Time>
     <pskc:PlainValue>0</pskc:PlainValue>
    </pskc:Time>
    <pskc:TimeInterval>
     <pskc:PlainValue>30</pskc:PlainValue>
    </pskc:TimeInterval>
    <pskc:TimeDrift>
     <pskc:PlainValue>6</pskc:PlainValue>
    </pskc:TimeDrift>
   </pskc:Data>
  </pskc:Key>
 </pskc:KeyPackage>
</pskc:KeyContainer>


Read an encrypted PSKC file and write it out as an unencrypted file.

>>> pskc = PSKC('tests/encryption/kw-aes128.pskcxml')
>>> pskc.encryption.key = a2b_hex('000102030405060708090a0b0c0d0e0f')
>>> pskc.encryption.remove_encryption()
>>> pskc.write(sys.stdout)  #doctest: +REPORT_UDIFF
<?xml version="1.0" encoding="UTF-8"?>
<pskc:KeyContainer xmlns:pskc="urn:ietf:params:xml:ns:keyprov:pskc" Version="1.0">
 <pskc:KeyPackage>
  <pskc:Key>
   <pskc:Data>
    <pskc:Secret>
     <pskc:PlainValue>ABEiM0RVZneImaq7zN3u/w==</pskc:PlainValue>
    </pskc:Secret>
   </pskc:Data>
  </pskc:Key>
 </pskc:KeyPackage>
</pskc:KeyContainer>


Read an encrypted PSKC file and write it out as-is. This does not require
providing the encryption key.

>>> pskc = PSKC('tests/rfc6030/figure6.pskcxml')
>>> pskc.write(sys.stdout)  #doctest: +ELLIPSIS +REPORT_UDIFF
<?xml version="1.0" encoding="UTF-8"?>
<pskc:KeyContainer ... Version="1.0">
 <pskc:EncryptionKey>
  <ds:KeyName>Pre-shared-key</ds:KeyName>
 </pskc:EncryptionKey>
 <pskc:MACMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1">
  <pskc:MACKey>
   <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"/>
   <xenc:CipherData>
    <xenc:CipherValue>ESIzRFVmd4iZABEiM0RVZgKn6WjLaTC1sbeBMSvIhRejN9vJa2BOlSaMrR7I5wSX</xenc:CipherValue>
   </xenc:CipherData>
  </pskc:MACKey>
 </pskc:MACMethod>
 <pskc:KeyPackage>
  <pskc:DeviceInfo>
   <pskc:Manufacturer>Manufacturer</pskc:Manufacturer>
   <pskc:SerialNo>987654321</pskc:SerialNo>
  </pskc:DeviceInfo>
  <pskc:CryptoModuleInfo>
   <pskc:Id>CM_ID_001</pskc:Id>
  </pskc:CryptoModuleInfo>
  <pskc:Key Algorithm="urn:ietf:params:xml:ns:keyprov:pskc:hotp" Id="12345678">
   <pskc:Issuer>Issuer</pskc:Issuer>
   <pskc:AlgorithmParameters>
    <pskc:ResponseFormat Encoding="DECIMAL" Length="8"/>
   </pskc:AlgorithmParameters>
   <pskc:Data>
    <pskc:Secret>
     <pskc:EncryptedValue>
      <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"/>
      <xenc:CipherData>
       <xenc:CipherValue>AAECAwQFBgcICQoLDA0OD+cIHItlB3Wra1DUpxVvOx2lef1VmNPCMl8jwZqIUqGv</xenc:CipherValue>
      </xenc:CipherData>
     </pskc:EncryptedValue>
     <pskc:ValueMAC>Su+NvtQfmvfJzF6bmQiJqoLRExc=</pskc:ValueMAC>
    </pskc:Secret>
    <pskc:Counter>
     <pskc:PlainValue>0</pskc:PlainValue>
    </pskc:Counter>
   </pskc:Data>
  </pskc:Key>
 </pskc:KeyPackage>
</pskc:KeyContainer>


Read a legacy encrypted PSKC file and write it out as-is. This should convert
the format to RFC 6030 format as best it can. Note that this does not include
a MAC key (but does include a MAC algorithm because the MAC key is not
specified and we assume to use the encryption key as MAC key).

>>> pskc = PSKC('tests/draft-hoyer-keyprov-portable-symmetric-key-container-01/password-encrypted.pskcxml')
>>> pskc.write(sys.stdout)  #doctest: +ELLIPSIS +REPORT_UDIFF
<?xml version="1.0" encoding="UTF-8"?>
<pskc:KeyContainer ... Version="1.0">
 <pskc:EncryptionKey>
  <xenc11:DerivedKey>
   <xenc11:KeyDerivationMethod Algorithm="http://www.rsasecurity.com/rsalabs/pkcs/schemas/pkcs-5v2-0#pbkdf2">
    <xenc11:PBKDF2-params>
     <Salt>
      <Specified>y6TzckeLRQw=</Specified>
     </Salt>
     <IterationCount>999</IterationCount>
     <KeyLength>16</KeyLength>
    </xenc11:PBKDF2-params>
   </xenc11:KeyDerivationMethod>
  </xenc11:DerivedKey>
 </pskc:EncryptionKey>
 <pskc:MACMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1"/>
 <pskc:KeyPackage>
  <pskc:DeviceInfo>
   <pskc:Manufacturer>Token Manufacturer</pskc:Manufacturer>
   <pskc:SerialNo>98765432187</pskc:SerialNo>
   <pskc:ExpiryDate>2008-01-01T00:00:00</pskc:ExpiryDate>
  </pskc:DeviceInfo>
  <pskc:Key Algorithm="HOTP" Id="77654321870">
   <pskc:Issuer>Credential Issuer</pskc:Issuer>
   <pskc:AlgorithmParameters>
    <pskc:ResponseFormat Encoding="DECIMAL" Length="6"/>
   </pskc:AlgorithmParameters>
   <pskc:FriendlyName>MySecondToken</pskc:FriendlyName>
   <pskc:Data>
    <pskc:Secret>
     <pskc:EncryptedValue>
      <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#tripledes-cbc"/>
      <xenc:CipherData>
       <xenc:CipherValue>F/CY93NYc/SvmxT3oB6PzG7p6zpG92/t</xenc:CipherValue>
      </xenc:CipherData>
     </pskc:EncryptedValue>
     <pskc:ValueMAC>hN793ZE7GM6yCM6gz9OKNRzibhg=</pskc:ValueMAC>
    </pskc:Secret>
    <pskc:Counter>
     <pskc:EncryptedValue>
      <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#tripledes-cbc"/>
      <xenc:CipherData>
       <xenc:CipherValue>VVBYqRF1QSpetvIB2vBAzw==</xenc:CipherValue>
      </xenc:CipherData>
     </pskc:EncryptedValue>
     <pskc:ValueMAC>6clqJvT9l0xIZtWSch2t6zr0IwU=</pskc:ValueMAC>
    </pskc:Counter>
   </pskc:Data>
  </pskc:Key>
 </pskc:KeyPackage>
</pskc:KeyContainer>

If we decrypt the file the MAC key will be included in encrypted form.

>>> pskc.encryption.derive_key(b'qwerty')
>>> pskc.write(sys.stdout)  #doctest: +ELLIPSIS +REPORT_UDIFF
<?xml version="1.0" encoding="UTF-8"?>
<pskc:KeyContainer ... Version="1.0">
 <pskc:EncryptionKey>
  <xenc11:DerivedKey>
   <xenc11:KeyDerivationMethod Algorithm="http://www.rsasecurity.com/rsalabs/pkcs/schemas/pkcs-5v2-0#pbkdf2">
    <xenc11:PBKDF2-params>
     <Salt>
      <Specified>y6TzckeLRQw=</Specified>
     </Salt>
     <IterationCount>999</IterationCount>
     <KeyLength>16</KeyLength>
    </xenc11:PBKDF2-params>
   </xenc11:KeyDerivationMethod>
  </xenc11:DerivedKey>
 </pskc:EncryptionKey>
 <pskc:MACMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1">
  <pskc:MACKey>
   <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#tripledes-cbc"/>
   <xenc:CipherData>
    <xenc:CipherValue>...</xenc:CipherValue>
   </xenc:CipherData>
  </pskc:MACKey>
 </pskc:MACMethod>
 <pskc:KeyPackage>
...
 </pskc:KeyPackage>
</pskc:KeyContainer>


Set up an encrypted PSKC file and generate a pre-shared key for it.

>>> pskc = PSKC()
>>> key = pskc.add_key(
...     id='1', serial='123456', secret=b'1234', counter=42)
>>> pskc.encryption.setup_preshared_key(
...     algorithm='aes128-cbc',
...     key=a2b_hex('12345678901234567890123456789012'),
...     key_name='Pre-shared KEY', fields = ['secret', 'counter'])
>>> f = tempfile.NamedTemporaryFile()
>>> pskc.write(f.name)
>>> with open(f.name, 'r') as r:
...     x = sys.stdout.write(r.read())  #doctest: +ELLIPSIS +REPORT_UDIFF
<?xml version="1.0" encoding="UTF-8"?>
<pskc:KeyContainer ... Version="1.0">
 <pskc:EncryptionKey>
  <ds:KeyName>Pre-shared KEY</ds:KeyName>
 </pskc:EncryptionKey>
 <pskc:MACMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1">
  <pskc:MACKey>
   <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"/>
   <xenc:CipherData>
    <xenc:CipherValue>...</xenc:CipherValue>
   </xenc:CipherData>
  </pskc:MACKey>
 </pskc:MACMethod>
 <pskc:KeyPackage>
  <pskc:DeviceInfo>
   <pskc:SerialNo>123456</pskc:SerialNo>
  </pskc:DeviceInfo>
  <pskc:Key Id="1">
   <pskc:Data>
    <pskc:Secret>
     <pskc:EncryptedValue>
      <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"/>
      <xenc:CipherData>
       <xenc:CipherValue>...</xenc:CipherValue>
      </xenc:CipherData>
     </pskc:EncryptedValue>
     <pskc:ValueMAC>...</pskc:ValueMAC>
    </pskc:Secret>
    <pskc:Counter>
     <pskc:EncryptedValue>
      <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"/>
      <xenc:CipherData>
       <xenc:CipherValue>...</xenc:CipherValue>
      </xenc:CipherData>
     </pskc:EncryptedValue>
     <pskc:ValueMAC>...</pskc:ValueMAC>
    </pskc:Counter>
   </pskc:Data>
  </pskc:Key>
 </pskc:KeyPackage>
</pskc:KeyContainer>


Read the generated file back in and verify that it matches the original data.

>>> newpskc = PSKC(f.name)
>>> newpskc.encryption.algorithm == pskc.encryption.algorithm
True
>>> newpskc.encryption.key = pskc.encryption.key
>>> all(newkey.check() for newkey in newpskc.keys)
True
>>> key = pskc.keys[0]
>>> newkey = newpskc.keys[0]
>>> newkey.secret == key.secret
True
>>> newkey.counter == key.counter
True


Use PBKDF2 to derive a key instead of using a pre-shared key.

>>> pskc = PSKC()
>>> key = pskc.add_key(
...     id='1', serial='123456', secret=b'1234', counter=42)
>>> pskc.encryption.setup_pbkdf2(
...     'passphrase', key_name='Passphrase')
>>> pskc.write(f.name)
>>> with open(f.name, 'r') as r:
...     x = sys.stdout.write(r.read())  #doctest: +ELLIPSIS +REPORT_UDIFF
<?xml version="1.0" encoding="UTF-8"?>
<pskc:KeyContainer ... Version="1.0">
 <pskc:EncryptionKey>
  <xenc11:DerivedKey>
   <xenc11:KeyDerivationMethod Algorithm="http://www.rsasecurity.com/rsalabs/pkcs/schemas/pkcs-5v2-0#pbkdf2">
    <xenc11:PBKDF2-params>
     <Salt>
      <Specified>...</Specified>
     </Salt>
     <IterationCount>...</IterationCount>
     <KeyLength>16</KeyLength>
    </xenc11:PBKDF2-params>
   </xenc11:KeyDerivationMethod>
   <xenc11:MasterKeyName>Passphrase</xenc11:MasterKeyName>
  </xenc11:DerivedKey>
 </pskc:EncryptionKey>
 <pskc:MACMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1">
  <pskc:MACKey>
   <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"/>
   <xenc:CipherData>
    <xenc:CipherValue>...</xenc:CipherValue>
   </xenc:CipherData>
  </pskc:MACKey>
 </pskc:MACMethod>
 <pskc:KeyPackage>
  <pskc:DeviceInfo>
   <pskc:SerialNo>123456</pskc:SerialNo>
  </pskc:DeviceInfo>
  <pskc:Key Id="1">
   <pskc:Data>
    <pskc:Secret>
     <pskc:EncryptedValue>
      <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"/>
      <xenc:CipherData>
       <xenc:CipherValue>...</xenc:CipherValue>
      </xenc:CipherData>
     </pskc:EncryptedValue>
     <pskc:ValueMAC>...</pskc:ValueMAC>
    </pskc:Secret>
    <pskc:Counter>
     <pskc:PlainValue>42</pskc:PlainValue>
    </pskc:Counter>
   </pskc:Data>
  </pskc:Key>
 </pskc:KeyPackage>
</pskc:KeyContainer>


Read the generated file back in and verify that it matches the original data.

>>> newpskc = PSKC(f.name)
>>> newpskc.encryption.algorithm == pskc.encryption.algorithm
True
>>> newpskc.encryption.derive_key('passphrase')
>>> all(newkey.check() for newkey in newpskc.keys)
True
>>> key = pskc.keys[0]
>>> newkey = newpskc.keys[0]
>>> newkey.secret == key.secret
True
>>> newkey.counter == key.counter
True


Test encryption and decryption of the generated file to test encryption/
decryption combinations.

>>> def test_algorithm(algorithm):
...     f = tempfile.NamedTemporaryFile()
...     pskc1 = PSKC()
...     pskc1.add_key(secret=os.urandom(16))
...     pskc1.encryption.setup_preshared_key(algorithm=algorithm)
...     pskc1.write(f.name)
...     pskc2 = PSKC(f.name)
...     pskc2.encryption.key = pskc1.encryption.key
...     assert pskc1.keys[0].secret == pskc2.keys[0].secret
...     return (pskc1, pskc2)
>>> pskc1, pskc2 = test_algorithm('aes192-cbc')
>>> len(pskc1.encryption.key)
24
>>> pskc1, pskc2 = test_algorithm('aes256-cbc')
>>> len(pskc1.encryption.key)
32
>>> pskc1, pskc2 = test_algorithm('tripledes-cbc')
>>> len(pskc1.encryption.key)
24
>>> pskc1, pskc2 = test_algorithm('kw-aes128')
>>> len(pskc1.encryption.key)
16
>>> pskc1, pskc2 = test_algorithm('kw-aes192')
>>> len(pskc1.encryption.key)
24
>>> pskc1, pskc2 = test_algorithm('kw-aes256')
>>> len(pskc1.encryption.key)
32
>>> pskc1, pskc2 = test_algorithm('kw-tripledes')
>>> len(pskc1.encryption.key)
24


Not having a key and trying encryption will fail.

>>> f = tempfile.NamedTemporaryFile()
>>> pskc = PSKC()
>>> key = pskc.add_key(secret='1234')
>>> pskc.encryption.setup_preshared_key()
>>> pskc.encryption.key = None
>>> pskc.write(f.name)
Traceback (most recent call last):
    ...
EncryptionError: No key available
>>> pskc = PSKC()
>>> key = pskc.add_key(secret='1234')
>>> pskc.encryption.setup_preshared_key()
>>> pskc.encryption.algorithm = None
>>> pskc.write(f.name)
Traceback (most recent call last):
    ...
EncryptionError: No algorithm specified
>>> pskc = PSKC()
>>> key = pskc.add_key(secret='1234')
>>> pskc.encryption.setup_preshared_key()
>>> pskc.encryption.algorithm = 'FOOBAR'
>>> pskc.write(f.name)
Traceback (most recent call last):
    ...
DecryptionError: Unsupported algorithm: 'FOOBAR'
>>> pskc = PSKC()
>>> key = pskc.add_key(secret='1234')
>>> pskc.encryption.setup_preshared_key()
>>> pskc.encryption.algorithm = 'aes256-cbc'
>>> pskc.write(f.name)
Traceback (most recent call last):
    ...
EncryptionError: Invalid key length


Setting up something else than PBKDF2 as derivation algorithm will just
result in an empty KeyDerivation element.

>>> pskc = PSKC()
>>> key = pskc.add_key(secret='1234')
>>> pskc.encryption.setup_pbkdf2('qwerty')
>>> pskc.encryption.derivation.algorithm = 'unknown'
>>> pskc.write(sys.stdout)  #doctest: +ELLIPSIS +REPORT_UDIFF
<?xml version="1.0" encoding="UTF-8"?>
<pskc:KeyContainer ... Version="1.0">
 <pskc:EncryptionKey>
  <xenc11:DerivedKey>
   <xenc11:KeyDerivationMethod Algorithm="unknown"/>
  </xenc11:DerivedKey>
 </pskc:EncryptionKey>
 <pskc:MACMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1">
  ...
 </pskc:MACMethod>
 <pskc:KeyPackage>
  ...
 </pskc:KeyPackage>
</pskc:KeyContainer>


We can make the PKKDF2 salt have to be transmitted out-of-bounds:

>>> pskc = PSKC()
>>> key = pskc.add_key(secret='1234')
>>> pskc.encryption.setup_pbkdf2('qwerty', salt=a2b_hex('1234567890'))
>>> pskc.encryption.derivation.pbkdf2_salt = None
>>> pskc.write(sys.stdout)  #doctest: +ELLIPSIS +REPORT_UDIFF
<?xml version="1.0" encoding="UTF-8"?>
<pskc:KeyContainer ... Version="1.0">
 <pskc:EncryptionKey>
  <xenc11:DerivedKey>
   <xenc11:KeyDerivationMethod Algorithm="http://www.rsasecurity.com/rsalabs/pkcs/schemas/pkcs-5v2-0#pbkdf2">
    <xenc11:PBKDF2-params>
     <IterationCount>...</IterationCount>
     <KeyLength>16</KeyLength>
    </xenc11:PBKDF2-params>
   </xenc11:KeyDerivationMethod>
  </xenc11:DerivedKey>
 </pskc:EncryptionKey>
 <pskc:MACMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1">
  ...
 </pskc:MACMethod>
 <pskc:KeyPackage>
  ...
 </pskc:KeyPackage>
</pskc:KeyContainer>


Write a PSKC file with two keys in onde KeyPackage section. Note that this
is not allowed in the RFC 6030 schema. Note that device properties that are
set on one key end up being applied to both keys.

>>> pskc = PSKC()
>>> device = pskc.add_device(manufacturer='TokenVendorAcme')
>>> key = device.add_key(id='1', serial='123456', secret='1234', counter=42)
>>> key = device.add_key(id='pin0', secret='5678')
>>> pskc.write(sys.stdout)  #doctest: +ELLIPSIS +REPORT_UDIFF
<?xml version="1.0" encoding="UTF-8"?>
<pskc:KeyContainer xmlns:pskc="urn:ietf:params:xml:ns:keyprov:pskc" Version="1.0">
 <pskc:KeyPackage>
  <pskc:DeviceInfo>
   <pskc:Manufacturer>TokenVendorAcme</pskc:Manufacturer>
   <pskc:SerialNo>123456</pskc:SerialNo>
  </pskc:DeviceInfo>
  <pskc:Key Id="1">
   <pskc:Data>
    <pskc:Secret>
     <pskc:PlainValue>MTIzNA==</pskc:PlainValue>
    </pskc:Secret>
    <pskc:Counter>
     <pskc:PlainValue>42</pskc:PlainValue>
    </pskc:Counter>
   </pskc:Data>
  </pskc:Key>
  <pskc:Key Id="pin0">
   <pskc:Data>
    <pskc:Secret>
     <pskc:PlainValue>NTY3OA==</pskc:PlainValue>
    </pskc:Secret>
   </pskc:Data>
  </pskc:Key>
 </pskc:KeyPackage>
</pskc:KeyContainer>


If we specify a global IV it will be used for all encrypted values but will
be not be written as a global IV in the PSKC file because RFC 6030 does not
specify this (and re-using an IV is a bad idea).

>>> pskc = PSKC()
>>> key = pskc.add_key(secret='1234')
>>> pskc.encryption.setup_preshared_key(key=a2b_hex('12345678901234567890123456789012'))
>>> pskc.encryption.iv = a2b_hex('000102030405060708090a0b0c0d0e0f')
>>> pskc.write(sys.stdout)  #doctest: +ELLIPSIS +REPORT_UDIFF
<?xml version="1.0" encoding="UTF-8"?>
<pskc:KeyContainer ... Version="1.0">
 <pskc:EncryptionKey/>
 <pskc:MACMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1">
  <pskc:MACKey>
   <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"/>
   <xenc:CipherData>
    <xenc:CipherValue>AAECAwQFBgcICQoLDA0OD...</xenc:CipherValue>
   </xenc:CipherData>
  </pskc:MACKey>
 </pskc:MACMethod>
 <pskc:KeyPackage>
  <pskc:Key>
   <pskc:Data>
    <pskc:Secret>
     <pskc:EncryptedValue>
      <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"/>
      <xenc:CipherData>
       <xenc:CipherValue>AAECAwQFBgcICQoLDA0OD...</xenc:CipherValue>
      </xenc:CipherData>
     </pskc:EncryptedValue>
     <pskc:ValueMAC>...</pskc:ValueMAC>
    </pskc:Secret>
   </pskc:Data>
  </pskc:Key>
 </pskc:KeyPackage>
</pskc:KeyContainer>


Check that we can add secrets as bytearray values

>>> pskc = PSKC()
>>> key = pskc.add_key(
...     id='1', serial='123456', secret=bytearray(b'1234'), counter=42)
>>> pskc.encryption.setup_preshared_key(
...     algorithm='aes128-cbc',
...     key=bytearray(a2b_hex('12345678901234567890123456789012')),
...     key_name='Pre-shared KEY', fields = ['secret', 'counter'])
>>> f = tempfile.NamedTemporaryFile()
>>> pskc.write(f.name)
>>> with open(f.name, 'r') as r:
...     x = sys.stdout.write(r.read())  #doctest: +ELLIPSIS +REPORT_UDIFF
<?xml version="1.0" encoding="UTF-8"?>
<pskc:KeyContainer ... Version="1.0">
 <pskc:EncryptionKey>
  <ds:KeyName>Pre-shared KEY</ds:KeyName>
 </pskc:EncryptionKey>
 <pskc:MACMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1">
  <pskc:MACKey>
   <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"/>
   <xenc:CipherData>
    <xenc:CipherValue>...</xenc:CipherValue>
   </xenc:CipherData>
  </pskc:MACKey>
 </pskc:MACMethod>
 <pskc:KeyPackage>
  <pskc:DeviceInfo>
   <pskc:SerialNo>123456</pskc:SerialNo>
  </pskc:DeviceInfo>
  <pskc:Key Id="1">
   <pskc:Data>
    <pskc:Secret>
     <pskc:EncryptedValue>
      <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"/>
      <xenc:CipherData>
       <xenc:CipherValue>...</xenc:CipherValue>
      </xenc:CipherData>
     </pskc:EncryptedValue>
     <pskc:ValueMAC>...</pskc:ValueMAC>
    </pskc:Secret>
    <pskc:Counter>
     <pskc:EncryptedValue>
      <xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes128-cbc"/>
      <xenc:CipherData>
       <xenc:CipherValue>...</xenc:CipherValue>
      </xenc:CipherData>
     </pskc:EncryptedValue>
     <pskc:ValueMAC>...</pskc:ValueMAC>
    </pskc:Counter>
   </pskc:Data>
  </pskc:Key>
 </pskc:KeyPackage>
</pskc:KeyContainer>