[3f6bc5f] | 1 | #/usr/local/bin/python |
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| 2 | |
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[5c0d244] | 3 | from tempfile import mkstemp |
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| 4 | from subprocess import call |
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[3f6bc5f] | 5 | from fedid import fedid |
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[a31b94d] | 6 | from remote_service import service_caller |
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| 7 | from abac_remote_service import abac_service_caller |
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| 8 | from service_error import service_error |
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[3f6bc5f] | 9 | |
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[5c0d244] | 10 | import ABAC |
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| 11 | import pickle |
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| 12 | |
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[a31b94d] | 13 | import sys |
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[5c0d244] | 14 | import os |
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[a31b94d] | 15 | |
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| 16 | class authorizer_base: |
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[3f6bc5f] | 17 | """ |
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[a31b94d] | 18 | Classes based on this one keep track of authorization attributes for the |
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| 19 | various modules running. This base class holds some utility functions that |
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| 20 | they all potentially use. |
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[3f6bc5f] | 21 | """ |
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[a31b94d] | 22 | |
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[3f6bc5f] | 23 | # general error exception for badly formed names. |
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| 24 | class bad_name(RuntimeError): pass |
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[5c0d244] | 25 | # difficulty creating an attribute |
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| 26 | class attribute_error(RuntimeError): pass |
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[3f6bc5f] | 27 | |
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| 28 | @staticmethod |
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| 29 | def auth_name(name): |
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| 30 | """ |
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| 31 | Helper to convert a non-unicode local name to a unicode string. Mixed |
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| 32 | representations can needlessly confuse the authorizer. |
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| 33 | """ |
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| 34 | if isinstance(name, basestring): |
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| 35 | if not isinstance(name, unicode): return unicode(name) |
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| 36 | else: return name |
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| 37 | else: return name |
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| 38 | |
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[a31b94d] | 39 | @staticmethod |
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| 40 | def valid_name(name): |
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[3f6bc5f] | 41 | """ |
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| 42 | Ensure that the given name is valid. A valid name can either be a |
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| 43 | triple of strings and fedids representing one of our generalized Emulab |
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| 44 | names or a single fedid. Compound names can include wildcards (None) |
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| 45 | and must anchor to a fedid at their highest level (unless they're all |
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| 46 | None) |
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| 47 | |
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| 48 | This either returns True or throws an exception. More an assertion |
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| 49 | than a function. |
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| 50 | """ |
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| 51 | if isinstance(name, tuple) and len(name) == 3: |
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| 52 | for n in name: |
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| 53 | if n: |
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| 54 | if not (isinstance(n, basestring) or isinstance(n, fedid)): |
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[a31b94d] | 55 | raise authorizer_base.bad_name( |
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| 56 | "names must be either a triple or a fedid") |
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[3f6bc5f] | 57 | for n in name: |
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| 58 | if n: |
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| 59 | if isinstance(n, fedid): |
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| 60 | return True |
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| 61 | else: |
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[a31b94d] | 62 | raise authorizer_base.bad_name( |
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| 63 | "Compound names must be " + \ |
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[3f6bc5f] | 64 | "rooted in fedids: %s" % str(name)) |
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| 65 | |
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| 66 | return True |
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| 67 | elif isinstance(name, fedid): |
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| 68 | return True |
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| 69 | else: |
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[a31b94d] | 70 | raise authorizer_base.bad_name( |
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| 71 | "Names must be a triple or a fedid (%s)" % name) |
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| 72 | |
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| 73 | |
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| 74 | class authorizer(authorizer_base): |
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| 75 | """ |
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| 76 | This class keeps track of authorization attributes for the various modules |
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| 77 | running. When it gets smarter it will be the basis for a real |
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| 78 | attribute-based authentication system. |
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| 79 | """ |
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| 80 | def __init__(self, def_attr="testbed"): |
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| 81 | self.attrs = { } |
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| 82 | self.globals=set() |
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[3f6bc5f] | 83 | |
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| 84 | def set_attribute(self, name, attr): |
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| 85 | """ |
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| 86 | Attach attr to name. Multiple attrs can be attached. |
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| 87 | """ |
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| 88 | self.valid_name(name) |
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| 89 | if isinstance(name, tuple): |
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| 90 | aname = tuple([ self.auth_name(n) for n in name]) |
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| 91 | else: |
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| 92 | aname = self.auth_name(name) |
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| 93 | |
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| 94 | if not self.attrs.has_key(aname): |
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| 95 | self.attrs[aname] = set() |
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| 96 | self.attrs[aname].add(attr) |
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| 97 | |
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| 98 | def unset_attribute(self, name, attr): |
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| 99 | """ |
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| 100 | Remove an attribute from name |
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| 101 | """ |
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| 102 | self.valid_name(name) |
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| 103 | if isinstance(name, tuple): |
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| 104 | aname = tuple([ self.auth_name(n) for n in name]) |
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| 105 | else: |
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| 106 | aname = self.auth_name(name) |
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| 107 | |
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| 108 | attrs = self.attrs.get(aname, None) |
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| 109 | if attrs: attrs.discard(attr) |
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| 110 | |
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| 111 | def check_attribute(self, name, attr): |
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| 112 | """ |
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[05191a6] | 113 | Return True if name has attr (or if attr is global). Tuple names match |
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| 114 | any tuple name that matches all names present and has None entries in |
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| 115 | other fileds. For tuple names True implies that there is a matching |
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| 116 | tuple name with the attribute. |
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[3f6bc5f] | 117 | """ |
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| 118 | def tup(tup, i, p): |
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| 119 | mask = 1 << i |
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| 120 | if p & mask : return authorizer.auth_name(tup[i]) |
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| 121 | else: return None |
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| 122 | |
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| 123 | self.valid_name(name) |
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[05191a6] | 124 | if attr in self.globals: |
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| 125 | return True |
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[3f6bc5f] | 126 | |
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| 127 | if isinstance(name, tuple): |
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| 128 | for p in range(0,8): |
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| 129 | lookup = ( tup(name, 0, p), tup(name,1, p), tup(name,2,p)) |
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| 130 | if self.attrs.has_key(lookup): |
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| 131 | if attr in self.attrs[lookup]: |
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| 132 | return True |
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| 133 | else: |
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| 134 | return attr in self.attrs.get(self.auth_name(name), set()) |
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| 135 | |
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[05191a6] | 136 | def set_global_attribute(self, attr): |
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| 137 | """ |
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| 138 | Set a global attribute. All names, even those otherwise unknown to the |
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| 139 | authorizer have this attribute. |
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| 140 | """ |
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| 141 | self.globals.add(attr) |
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| 142 | |
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| 143 | def unset_global_attribute(self, attr): |
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| 144 | """ |
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| 145 | Remove a global attribute |
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| 146 | """ |
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| 147 | |
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| 148 | self.globals.discard(attr) |
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[3f6bc5f] | 149 | |
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[358e0b8] | 150 | def __str__(self): |
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| 151 | rv = "" |
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| 152 | rv += "attrs %s\n" % self.attrs |
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| 153 | rv += "globals %s" % self.globals |
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| 154 | return rv |
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| 155 | |
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[5c0d244] | 156 | def clone(self): |
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| 157 | rv = authorizer() |
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| 158 | rv.attrs = self.attrs.copy() |
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| 159 | rv.globals = self.globals.copy() |
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| 160 | return rv |
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| 161 | |
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| 162 | def save(self, fn): |
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| 163 | f = open(fn, "w") |
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| 164 | pickle.dump(self, f) |
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| 165 | f.close() |
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| 166 | |
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| 167 | def load(self, fn): |
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| 168 | f = open(fn, "r") |
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| 169 | a = pickle.load(f) |
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| 170 | f.close() |
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| 171 | self.attrs = a.attrs |
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| 172 | self.globals = a.globals |
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| 173 | |
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| 174 | |
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[a31b94d] | 175 | class abac_authorizer(authorizer_base): |
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| 176 | """ |
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| 177 | Use the ABAC authorization system to make attribute decisions. |
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| 178 | """ |
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| 179 | |
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[5c0d244] | 180 | def __init__(self, certs=None, me=None, key=None, from_dir=None): |
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| 181 | self.bad_name = authorizer_base.bad_name |
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| 182 | self.attribute_error = authorizer_base.attribute_error |
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[a31b94d] | 183 | self.globals = set() |
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[5c0d244] | 184 | self.creddy = '/usr/local/bin/creddy' |
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[a31b94d] | 185 | self.me = me |
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[5c0d244] | 186 | self.my_key = key |
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| 187 | self.context = ABAC.Context() |
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| 188 | for dir in certs or []: |
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| 189 | self.context.load_directory(dir) |
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| 190 | |
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| 191 | def set_attribute(self, name=None, attr=None, cert=None): |
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| 192 | if name and attr: |
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| 193 | if isinstance(name, tuple): |
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| 194 | raise self.bad_name("ABAC doesn't understand three-names") |
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| 195 | if self.me and self.key: |
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| 196 | # Create a credential and insert it into context |
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| 197 | # This will simplify when we have libcreddy |
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| 198 | try: |
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| 199 | # create temp file |
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| 200 | f, fn = mkstemp() |
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| 201 | f.close() |
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| 202 | except EnvironmentError, e: |
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| 203 | raise self.attribute_error( |
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| 204 | "Cannot create temp file: %s" %e) |
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| 205 | |
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| 206 | # Create the attribute certificate with creddy |
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| 207 | rv = call([creddy, '--attribute', '--issuer=%s' % self.me, |
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| 208 | '--key=%s' % self.key, '--role=%s' % attr, |
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| 209 | '--subject-id=%s' % name, '--out=%s' % fn]) |
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| 210 | if rv == 0: |
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| 211 | # load it to context and remove the file |
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| 212 | self.context.load_attribute(fn) |
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| 213 | os.unlink(fn) |
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| 214 | else: |
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| 215 | os.unlink(fn) |
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| 216 | raise self.attribute_error("creddy returned %s" % rv) |
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[a31b94d] | 217 | else: |
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[5c0d244] | 218 | raise self.attribute_error( |
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| 219 | "Identity and key not specified on creation") |
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| 220 | elif cert: |
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| 221 | # Insert this credential into the context |
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| 222 | self.context.load_attribute_chunk(cert) |
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[a31b94d] | 223 | else: |
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[5c0d244] | 224 | raise self.attribute_error("Neither name/attr nor cert is set") |
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[a31b94d] | 225 | |
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| 226 | def check_attribute(self, name, attr): |
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[5c0d244] | 227 | # XXX proof soon |
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[a31b94d] | 228 | if isinstance(name, tuple): |
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[5c0d244] | 229 | raise self.bad_name("ABAC doesn't understand three-names") |
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| 230 | else: |
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| 231 | proof, rv = self.context.query(attr, name) |
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| 232 | # XXX delete soon |
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| 233 | if not rv and attr in self.globals: return True |
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| 234 | else: return rv |
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[a31b94d] | 235 | |
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| 236 | def set_global_attribute(self, attr): |
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| 237 | """ |
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| 238 | Set a global attribute. All names, even those otherwise unknown to the |
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| 239 | authorizer have this attribute. |
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| 240 | """ |
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| 241 | self.globals.add(attr) |
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| 242 | |
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| 243 | def unset_global_attribute(self, attr): |
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| 244 | """ |
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| 245 | Remove a global attribute |
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| 246 | """ |
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| 247 | |
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| 248 | self.globals.discard(attr) |
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| 249 | |
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[5c0d244] | 250 | def clone(self): |
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| 251 | rv = abac_authorizer(me=self.me, key=self.key) |
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| 252 | rv.globals = self.globals.copy() |
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| 253 | rv.context = ABAC.Context(self.context) |
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| 254 | return rv |
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| 255 | |
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| 256 | def save(self, dir): |
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| 257 | os.mkdir(dir) |
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| 258 | |
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| 259 | f = open("%s/globals" % dir, "w") |
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| 260 | pickle.dump(self.globals, f) |
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| 261 | f.close() |
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| 262 | |
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| 263 | if self.me and self.key: |
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| 264 | f = open("%s/me" % dir, "w") |
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| 265 | pickle.dump(self.me, f) |
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| 266 | f.close() |
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| 267 | f = open("%s/key" % dir, "w") |
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| 268 | pickle.dump(self.key, f) |
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| 269 | f.close() |
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| 270 | os.mkdir("%s/certs" % dir) |
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| 271 | seenit = set() |
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| 272 | ii = 0 |
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| 273 | ai = 0 |
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| 274 | for c in self.context.credentials(): |
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| 275 | id = c.issuer_cert() |
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| 276 | attr = c.attribute_cert() |
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| 277 | if id not in seenit: |
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| 278 | f = open("%s/certs/%03d_ID.der" % (dir, ii), "w") |
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| 279 | print >>f, id |
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| 280 | f.close() |
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| 281 | ii += 1 |
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| 282 | seenit.add(id) |
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| 283 | if attr: |
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| 284 | f = open("%s/certs/%03d_attr.der" % (dir, ai), "w") |
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| 285 | print >>f, attr |
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| 286 | f.close() |
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| 287 | ai += 1 |
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| 288 | |
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| 289 | def load(self, dir): |
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| 290 | if os.access("%s/me" % dir, os.R_OK): |
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| 291 | f = open("%s/me" % dir, "r") |
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| 292 | self.me = pickle.load(f) |
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| 293 | f.close() |
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| 294 | else: |
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| 295 | self.me = None |
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| 296 | if os.access("%s/key" % dir, os.R_OK): |
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| 297 | f = open("%s/key" % dir, "r") |
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| 298 | self.key = pickle.load(f) |
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| 299 | f.close() |
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| 300 | else: |
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| 301 | self.key = None |
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| 302 | f = open("%s/globals" % dir, "r") |
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| 303 | self.globals = pickle.load(f) |
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| 304 | f.close() |
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| 305 | self.context = ABAC.context() |
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| 306 | self.context.load_directory("%s/certs" % dir) |
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| 307 | |
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