root / lib / serializer.py @ cc6484c4
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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 | fe267188 | Iustin Pop | # pylint: disable-msg=C0103
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28 | fe267188 | Iustin Pop | |
29 | fe267188 | Iustin Pop | # C0103: Invalid name, since pylint doesn't see that Dump points to a
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30 | fe267188 | Iustin Pop | # function and not a constant
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31 | 8d14b30d | Iustin Pop | |
32 | 8d14b30d | Iustin Pop | import simplejson |
33 | 8d14b30d | Iustin Pop | import re |
34 | f4a2f532 | Guido Trotter | import hmac |
35 | f4a2f532 | Guido Trotter | |
36 | f4a2f532 | Guido Trotter | from ganeti import errors |
37 | 8d14b30d | Iustin Pop | |
38 | 541822e0 | Guido Trotter | try:
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39 | 541822e0 | Guido Trotter | from hashlib import sha1 |
40 | 541822e0 | Guido Trotter | except ImportError: |
41 | 541822e0 | Guido Trotter | import sha as sha1 |
42 | 071448fb | Michael Hanselmann | |
43 | d357f531 | Michael Hanselmann | |
44 | 8d14b30d | Iustin Pop | _JSON_INDENT = 2
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45 | 8d14b30d | Iustin Pop | |
46 | e91ffe49 | Michael Hanselmann | _RE_EOLSP = re.compile('[ \t]+$', re.MULTILINE)
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47 | 8d14b30d | Iustin Pop | |
48 | 8d14b30d | Iustin Pop | |
49 | 02141fb1 | Michael Hanselmann | def _GetJsonDumpers(_encoder_class=simplejson.JSONEncoder): |
50 | d357f531 | Michael Hanselmann | """Returns two JSON functions to serialize data.
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51 | d357f531 | Michael Hanselmann |
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52 | d357f531 | Michael Hanselmann | @rtype: (callable, callable)
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53 | d357f531 | Michael Hanselmann | @return: The function to generate a compact form of JSON and another one to
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54 | d357f531 | Michael Hanselmann | generate a more readable, indented form of JSON (if supported)
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55 | d357f531 | Michael Hanselmann |
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56 | d357f531 | Michael Hanselmann | """
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57 | 02141fb1 | Michael Hanselmann | plain_encoder = _encoder_class(sort_keys=True)
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58 | d357f531 | Michael Hanselmann | |
59 | d357f531 | Michael Hanselmann | # Check whether the simplejson module supports indentation
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60 | d357f531 | Michael Hanselmann | try:
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61 | 02141fb1 | Michael Hanselmann | indent_encoder = _encoder_class(indent=_JSON_INDENT, sort_keys=True)
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62 | d357f531 | Michael Hanselmann | except TypeError: |
63 | d357f531 | Michael Hanselmann | # Indentation not supported
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64 | 02141fb1 | Michael Hanselmann | indent_encoder = plain_encoder |
65 | d357f531 | Michael Hanselmann | |
66 | 02141fb1 | Michael Hanselmann | return (plain_encoder.encode, indent_encoder.encode)
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67 | d357f531 | Michael Hanselmann | |
68 | d357f531 | Michael Hanselmann | |
69 | d357f531 | Michael Hanselmann | (_DumpJson, _DumpJsonIndent) = _GetJsonDumpers() |
70 | d357f531 | Michael Hanselmann | |
71 | d357f531 | Michael Hanselmann | |
72 | 071448fb | Michael Hanselmann | def DumpJson(data, indent=True): |
73 | 8d14b30d | Iustin Pop | """Serialize a given object.
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74 | 8d14b30d | Iustin Pop |
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75 | c41eea6e | Iustin Pop | @param data: the data to serialize
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76 | c41eea6e | Iustin Pop | @param indent: whether to indent output (depends on simplejson version)
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77 | c41eea6e | Iustin Pop |
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78 | c41eea6e | Iustin Pop | @return: the string representation of data
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79 | 071448fb | Michael Hanselmann |
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80 | 8d14b30d | Iustin Pop | """
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81 | d357f531 | Michael Hanselmann | if indent:
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82 | d357f531 | Michael Hanselmann | fn = _DumpJsonIndent |
83 | 8d14b30d | Iustin Pop | else:
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84 | d357f531 | Michael Hanselmann | fn = _DumpJson |
85 | 071448fb | Michael Hanselmann | |
86 | d357f531 | Michael Hanselmann | txt = _RE_EOLSP.sub("", fn(data))
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87 | 8d14b30d | Iustin Pop | if not txt.endswith('\n'): |
88 | 8d14b30d | Iustin Pop | txt += '\n'
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89 | d357f531 | Michael Hanselmann | |
90 | 8d14b30d | Iustin Pop | return txt
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91 | 8d14b30d | Iustin Pop | |
92 | 8d14b30d | Iustin Pop | |
93 | 228538cf | Michael Hanselmann | def LoadJson(txt): |
94 | 8d14b30d | Iustin Pop | """Unserialize data from a string.
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95 | 8d14b30d | Iustin Pop |
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96 | c41eea6e | Iustin Pop | @param txt: the json-encoded form
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97 | c41eea6e | Iustin Pop |
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98 | c41eea6e | Iustin Pop | @return: the original data
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99 | c41eea6e | Iustin Pop |
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100 | 8d14b30d | Iustin Pop | """
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101 | 8d14b30d | Iustin Pop | return simplejson.loads(txt)
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102 | 228538cf | Michael Hanselmann | |
103 | 228538cf | Michael Hanselmann | |
104 | 72ca1dcb | Balazs Lecz | def DumpSignedJson(data, key, salt=None, key_selector=None): |
105 | f4a2f532 | Guido Trotter | """Serialize a given object and authenticate it.
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106 | f4a2f532 | Guido Trotter |
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107 | f4a2f532 | Guido Trotter | @param data: the data to serialize
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108 | f4a2f532 | Guido Trotter | @param key: shared hmac key
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109 | 72ca1dcb | Balazs Lecz | @param key_selector: name/id that identifies the key (in case there are
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110 | 72ca1dcb | Balazs Lecz | multiple keys in use, e.g. in a multi-cluster environment)
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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 | f4a2f532 | Guido Trotter | } |
121 | 72ca1dcb | Balazs Lecz | if key_selector:
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122 | 72ca1dcb | Balazs Lecz | signed_dict["key_selector"] = key_selector
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123 | 72ca1dcb | Balazs Lecz | message = salt + key_selector + txt |
124 | 72ca1dcb | Balazs Lecz | else:
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125 | 72ca1dcb | Balazs Lecz | message = salt + txt |
126 | 72ca1dcb | Balazs Lecz | signed_dict["hmac"] = hmac.new(key, message,
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127 | 72ca1dcb | Balazs Lecz | sha1).hexdigest() |
128 | 72ca1dcb | Balazs Lecz | |
129 | 40765aa0 | Guido Trotter | return DumpJson(signed_dict, indent=False) |
130 | f4a2f532 | Guido Trotter | |
131 | f4a2f532 | Guido Trotter | |
132 | 4e9dac14 | Guido Trotter | def LoadSignedJson(txt, key): |
133 | f4a2f532 | Guido Trotter | """Verify that a given message was signed with the given key, and load it.
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134 | f4a2f532 | Guido Trotter |
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135 | f4a2f532 | Guido Trotter | @param txt: json-encoded hmac-signed message
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136 | 72ca1dcb | Balazs Lecz | @param key: the shared hmac key or a callable taking one argument (the key
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137 | 72ca1dcb | Balazs Lecz | selector), which returns the hmac key belonging to the key selector.
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138 | 72ca1dcb | Balazs Lecz | Typical usage is to pass a reference to the get method of a dict.
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139 | f4a2f532 | Guido Trotter | @rtype: tuple of original data, string
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140 | 4e9dac14 | Guido Trotter | @return: original data, salt
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141 | f4a2f532 | Guido Trotter | @raises errors.SignatureError: if the message signature doesn't verify
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142 | f4a2f532 | Guido Trotter |
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143 | f4a2f532 | Guido Trotter | """
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144 | f4a2f532 | Guido Trotter | signed_dict = LoadJson(txt) |
145 | f4a2f532 | Guido Trotter | if not isinstance(signed_dict, dict): |
146 | f4a2f532 | Guido Trotter | raise errors.SignatureError('Invalid external message') |
147 | f4a2f532 | Guido Trotter | try:
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148 | f4a2f532 | Guido Trotter | msg = signed_dict['msg']
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149 | f4a2f532 | Guido Trotter | salt = signed_dict['salt']
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150 | f4a2f532 | Guido Trotter | hmac_sign = signed_dict['hmac']
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151 | f4a2f532 | Guido Trotter | except KeyError: |
152 | f4a2f532 | Guido Trotter | raise errors.SignatureError('Invalid external message') |
153 | f4a2f532 | Guido Trotter | |
154 | 72ca1dcb | Balazs Lecz | if callable(key): |
155 | 72ca1dcb | Balazs Lecz | key_selector = signed_dict.get("key_selector", None) |
156 | 72ca1dcb | Balazs Lecz | hmac_key = key(key_selector) |
157 | 72ca1dcb | Balazs Lecz | if not hmac_key: |
158 | 72ca1dcb | Balazs Lecz | raise errors.SignatureError("No key with key selector '%s' found" % |
159 | 72ca1dcb | Balazs Lecz | key_selector) |
160 | 72ca1dcb | Balazs Lecz | else:
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161 | 72ca1dcb | Balazs Lecz | key_selector = ""
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162 | 72ca1dcb | Balazs Lecz | hmac_key = key |
163 | 72ca1dcb | Balazs Lecz | |
164 | 72ca1dcb | Balazs Lecz | if hmac.new(hmac_key, salt + key_selector + msg,
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165 | 72ca1dcb | Balazs Lecz | sha1).hexdigest() != hmac_sign: |
166 | f4a2f532 | Guido Trotter | raise errors.SignatureError('Invalid Signature') |
167 | f4a2f532 | Guido Trotter | |
168 | 4e9dac14 | Guido Trotter | return LoadJson(msg), salt
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169 | f4a2f532 | Guido Trotter | |
170 | f4a2f532 | Guido Trotter | |
171 | 228538cf | Michael Hanselmann | Dump = DumpJson |
172 | 228538cf | Michael Hanselmann | Load = LoadJson |
173 | f4a2f532 | Guido Trotter | DumpSigned = DumpSignedJson |
174 | f4a2f532 | Guido Trotter | LoadSigned = LoadSignedJson |