root / lib / serializer.py @ 9b94905f
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1 | 8d14b30d | Iustin Pop | #
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2 | 8d14b30d | Iustin Pop | #
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3 | 8d14b30d | Iustin Pop | |
4 | 8d14b30d | Iustin Pop | # Copyright (C) 2007, 2008 Google Inc.
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5 | 8d14b30d | Iustin Pop | #
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6 | 8d14b30d | Iustin Pop | # This program is free software; you can redistribute it and/or modify
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7 | 8d14b30d | Iustin Pop | # it under the terms of the GNU General Public License as published by
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8 | 8d14b30d | Iustin Pop | # the Free Software Foundation; either version 2 of the License, or
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9 | 8d14b30d | Iustin Pop | # (at your option) any later version.
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10 | 8d14b30d | Iustin Pop | #
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11 | 8d14b30d | Iustin Pop | # This program is distributed in the hope that it will be useful, but
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12 | 8d14b30d | Iustin Pop | # WITHOUT ANY WARRANTY; without even the implied warranty of
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13 | 8d14b30d | Iustin Pop | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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14 | 8d14b30d | Iustin Pop | # General Public License for more details.
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15 | 8d14b30d | Iustin Pop | #
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16 | 8d14b30d | Iustin Pop | # You should have received a copy of the GNU General Public License
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17 | 8d14b30d | Iustin Pop | # along with this program; if not, write to the Free Software
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18 | 8d14b30d | Iustin Pop | # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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19 | 8d14b30d | Iustin Pop | # 02110-1301, USA.
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20 | 8d14b30d | Iustin Pop | |
21 | 8d14b30d | Iustin Pop | """Serializer abstraction module
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22 | 8d14b30d | Iustin Pop |
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23 | 8d14b30d | Iustin Pop | This module introduces a simple abstraction over the serialization
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24 | 8d14b30d | Iustin Pop | backend (currently json).
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25 | 8d14b30d | Iustin Pop |
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26 | 8d14b30d | Iustin Pop | """
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27 | 8d14b30d | Iustin Pop | |
28 | 8d14b30d | Iustin Pop | import simplejson |
29 | 8d14b30d | Iustin Pop | import re |
30 | f4a2f532 | Guido Trotter | import hmac |
31 | f4a2f532 | Guido Trotter | |
32 | f4a2f532 | Guido Trotter | from ganeti import errors |
33 | 8d14b30d | Iustin Pop | |
34 | 541822e0 | Guido Trotter | try:
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35 | 541822e0 | Guido Trotter | from hashlib import sha1 |
36 | 541822e0 | Guido Trotter | except ImportError: |
37 | 541822e0 | Guido Trotter | import sha as sha1 |
38 | 071448fb | Michael Hanselmann | |
39 | d357f531 | Michael Hanselmann | |
40 | 8d14b30d | Iustin Pop | _JSON_INDENT = 2
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41 | 8d14b30d | Iustin Pop | |
42 | e91ffe49 | Michael Hanselmann | _RE_EOLSP = re.compile('[ \t]+$', re.MULTILINE)
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43 | 8d14b30d | Iustin Pop | |
44 | 8d14b30d | Iustin Pop | |
45 | d357f531 | Michael Hanselmann | def _GetJsonDumpers(): |
46 | d357f531 | Michael Hanselmann | """Returns two JSON functions to serialize data.
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47 | d357f531 | Michael Hanselmann |
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48 | d357f531 | Michael Hanselmann | @rtype: (callable, callable)
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49 | d357f531 | Michael Hanselmann | @return: The function to generate a compact form of JSON and another one to
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50 | d357f531 | Michael Hanselmann | generate a more readable, indented form of JSON (if supported)
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51 | d357f531 | Michael Hanselmann |
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52 | d357f531 | Michael Hanselmann | """
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53 | d357f531 | Michael Hanselmann | plain_dump = simplejson.dumps |
54 | d357f531 | Michael Hanselmann | |
55 | d357f531 | Michael Hanselmann | # Check whether the simplejson module supports indentation
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56 | d357f531 | Michael Hanselmann | try:
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57 | d357f531 | Michael Hanselmann | simplejson.dumps(1, indent=_JSON_INDENT)
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58 | d357f531 | Michael Hanselmann | except TypeError: |
59 | d357f531 | Michael Hanselmann | # Indentation not supported
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60 | d357f531 | Michael Hanselmann | indent_dump = plain_dump |
61 | d357f531 | Michael Hanselmann | else:
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62 | d357f531 | Michael Hanselmann | # Indentation supported
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63 | d357f531 | Michael Hanselmann | indent_dump = lambda data: simplejson.dumps(data, indent=_JSON_INDENT)
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64 | d357f531 | Michael Hanselmann | |
65 | d357f531 | Michael Hanselmann | assert callable(plain_dump) |
66 | d357f531 | Michael Hanselmann | assert callable(indent_dump) |
67 | d357f531 | Michael Hanselmann | |
68 | d357f531 | Michael Hanselmann | return (plain_dump, indent_dump)
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69 | d357f531 | Michael Hanselmann | |
70 | d357f531 | Michael Hanselmann | |
71 | d357f531 | Michael Hanselmann | (_DumpJson, _DumpJsonIndent) = _GetJsonDumpers() |
72 | d357f531 | Michael Hanselmann | |
73 | d357f531 | Michael Hanselmann | |
74 | 071448fb | Michael Hanselmann | def DumpJson(data, indent=True): |
75 | 8d14b30d | Iustin Pop | """Serialize a given object.
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76 | 8d14b30d | Iustin Pop |
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77 | c41eea6e | Iustin Pop | @param data: the data to serialize
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78 | c41eea6e | Iustin Pop | @param indent: whether to indent output (depends on simplejson version)
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79 | c41eea6e | Iustin Pop |
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80 | c41eea6e | Iustin Pop | @return: the string representation of data
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81 | 071448fb | Michael Hanselmann |
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82 | 8d14b30d | Iustin Pop | """
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83 | d357f531 | Michael Hanselmann | if indent:
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84 | d357f531 | Michael Hanselmann | fn = _DumpJsonIndent |
85 | 8d14b30d | Iustin Pop | else:
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86 | d357f531 | Michael Hanselmann | fn = _DumpJson |
87 | 071448fb | Michael Hanselmann | |
88 | d357f531 | Michael Hanselmann | txt = _RE_EOLSP.sub("", fn(data))
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89 | 8d14b30d | Iustin Pop | if not txt.endswith('\n'): |
90 | 8d14b30d | Iustin Pop | txt += '\n'
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91 | d357f531 | Michael Hanselmann | |
92 | 8d14b30d | Iustin Pop | return txt
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93 | 8d14b30d | Iustin Pop | |
94 | 8d14b30d | Iustin Pop | |
95 | 228538cf | Michael Hanselmann | def LoadJson(txt): |
96 | 8d14b30d | Iustin Pop | """Unserialize data from a string.
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97 | 8d14b30d | Iustin Pop |
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98 | c41eea6e | Iustin Pop | @param txt: the json-encoded form
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99 | c41eea6e | Iustin Pop |
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100 | c41eea6e | Iustin Pop | @return: the original data
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101 | c41eea6e | Iustin Pop |
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102 | 8d14b30d | Iustin Pop | """
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103 | 8d14b30d | Iustin Pop | return simplejson.loads(txt)
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104 | 228538cf | Michael Hanselmann | |
105 | 228538cf | Michael Hanselmann | |
106 | f4a2f532 | Guido Trotter | def DumpSignedJson(data, key, salt=None): |
107 | f4a2f532 | Guido Trotter | """Serialize a given object and authenticate it.
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108 | f4a2f532 | Guido Trotter |
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109 | f4a2f532 | Guido Trotter | @param data: the data to serialize
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110 | f4a2f532 | Guido Trotter | @param key: shared hmac key
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111 | f4a2f532 | Guido Trotter | @return: the string representation of data signed by the hmac key
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112 | f4a2f532 | Guido Trotter |
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113 | f4a2f532 | Guido Trotter | """
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114 | f4a2f532 | Guido Trotter | txt = DumpJson(data, indent=False)
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115 | f4a2f532 | Guido Trotter | if salt is None: |
116 | f4a2f532 | Guido Trotter | salt = ''
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117 | f4a2f532 | Guido Trotter | signed_dict = { |
118 | f4a2f532 | Guido Trotter | 'msg': txt,
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119 | f4a2f532 | Guido Trotter | 'salt': salt,
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120 | 541822e0 | Guido Trotter | 'hmac': hmac.new(key, salt + txt, sha1).hexdigest(),
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121 | f4a2f532 | Guido Trotter | } |
122 | 40765aa0 | Guido Trotter | return DumpJson(signed_dict, indent=False) |
123 | f4a2f532 | Guido Trotter | |
124 | f4a2f532 | Guido Trotter | |
125 | 4e9dac14 | Guido Trotter | def LoadSignedJson(txt, key): |
126 | f4a2f532 | Guido Trotter | """Verify that a given message was signed with the given key, and load it.
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127 | f4a2f532 | Guido Trotter |
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128 | f4a2f532 | Guido Trotter | @param txt: json-encoded hmac-signed message
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129 | f4a2f532 | Guido Trotter | @param key: shared hmac key
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130 | f4a2f532 | Guido Trotter | @rtype: tuple of original data, string
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131 | 4e9dac14 | Guido Trotter | @return: original data, salt
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132 | f4a2f532 | Guido Trotter | @raises errors.SignatureError: if the message signature doesn't verify
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133 | f4a2f532 | Guido Trotter |
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134 | f4a2f532 | Guido Trotter | """
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135 | f4a2f532 | Guido Trotter | signed_dict = LoadJson(txt) |
136 | f4a2f532 | Guido Trotter | if not isinstance(signed_dict, dict): |
137 | f4a2f532 | Guido Trotter | raise errors.SignatureError('Invalid external message') |
138 | f4a2f532 | Guido Trotter | try:
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139 | f4a2f532 | Guido Trotter | msg = signed_dict['msg']
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140 | f4a2f532 | Guido Trotter | salt = signed_dict['salt']
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141 | f4a2f532 | Guido Trotter | hmac_sign = signed_dict['hmac']
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142 | f4a2f532 | Guido Trotter | except KeyError: |
143 | f4a2f532 | Guido Trotter | raise errors.SignatureError('Invalid external message') |
144 | f4a2f532 | Guido Trotter | |
145 | 541822e0 | Guido Trotter | if hmac.new(key, salt + msg, sha1).hexdigest() != hmac_sign:
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146 | f4a2f532 | Guido Trotter | raise errors.SignatureError('Invalid Signature') |
147 | f4a2f532 | Guido Trotter | |
148 | 4e9dac14 | Guido Trotter | return LoadJson(msg), salt
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149 | f4a2f532 | Guido Trotter | |
150 | f4a2f532 | Guido Trotter | |
151 | 228538cf | Michael Hanselmann | Dump = DumpJson |
152 | 228538cf | Michael Hanselmann | Load = LoadJson |
153 | f4a2f532 | Guido Trotter | DumpSigned = DumpSignedJson |
154 | f4a2f532 | Guido Trotter | LoadSigned = LoadSignedJson |