Changeset 5c0d244

Timestamp:

Sep 13, 2010 9:51:13 AM (14 years ago)

Author:

Ted Faber <faber@…>

Branches:

axis_example, compt_changes, info-ops, master

Children:

9cce15a

Parents:

49e66b4

Message:

Beginnings of an ABAC authorizer

File:

• fedd/federation/authorizer.py (modified) (6 diffs)

fedd/federation/authorizer.py

@@ -1 +1 @@
 #/usr/local/bin/python
 
+from tempfile import mkstemp
+from subprocess import call
 from fedid import fedid
 from remote_service import service_caller
@@ -6 +8 @@
 from service_error import service_error
 
+import ABAC
+import pickle
+
 import sys
+import os
 
 class authorizer_base:
@@ -17 +23 @@
     # general error exception for badly formed names.  
     class bad_name(RuntimeError): pass
+    # difficulty creating an attribute
+    class attribute_error(RuntimeError): pass
 
     @staticmethod
@@ -146 +154 @@
         return rv
 
+    def clone(self):
+        rv = authorizer()
+        rv.attrs = self.attrs.copy()
+        rv.globals = self.globals.copy()
+        return rv
+
+    def save(self, fn):
+        f = open(fn, "w")
+        pickle.dump(self, f)
+        f.close()
+
+    def load(self, fn):
+        f = open(fn, "r")
+        a = pickle.load(f)
+        f.close()
+        self.attrs = a.attrs
+        self.globals = a.globals
+        
+
 class abac_authorizer(authorizer_base):
     """
@@ -151 +178 @@
     """
 
-    def __init__(self, url=None, cert_file=None, cert_pwd=None,
-            trusted_certs=None, me=None):
-        self.call_CreateContext = abac_service_caller('CreateContext')
-        self.call_CredentialUpdate = abac_service_caller('CredentialUpdate')
-        self.call_Access = abac_service_caller('Access')
+    def __init__(self, certs=None, me=None, key=None, from_dir=None):
+        self.bad_name = authorizer_base.bad_name
+        self.attribute_error = authorizer_base.attribute_error
         self.globals = set()
-
-        self.url = url
-        self.cert_file = cert_file
-        self.cert_pwd = cert_pwd
-        self.trusted_certs = trusted_certs
+        self.creddy = '/usr/local/bin/creddy'
         self.me = me
-        req = { 'context': { 'self': me.get_hexstr()} }
-        # May throw a service error
-        resp = self.call_CreateContext(self.url, req, self.cert_file,
-                self.cert_pwd, self.trusted_certs, tracefile=sys.stderr)
-
-        if resp.has_key('CreateContextResponseBody'):
-            resp =  resp['CreateContextResponseBody']
-            if resp.has_key('contextID'):
-                self.contextID = resp['contextID']
+        self.my_key = key
+        self.context = ABAC.Context()
+        for dir in certs or []:
+            self.context.load_directory(dir)
+
+    def set_attribute(self, name=None, attr=None, cert=None):
+        if name and attr:
+            if isinstance(name, tuple):
+                raise self.bad_name("ABAC doesn't understand three-names")
+            if self.me and self.key:
+                # Create a credential and insert it into context
+                # This will simplify when we have libcreddy
+                try:
+                    # create temp file
+                    f, fn = mkstemp()
+                    f.close()
+                except EnvironmentError, e:
+                    raise self.attribute_error(
+                            "Cannot create temp file: %s" %e)
+
+                # Create the attribute certificate with creddy
+                rv = call([creddy, '--attribute', '--issuer=%s' % self.me, 
+                    '--key=%s' % self.key, '--role=%s' % attr, 
+                    '--subject-id=%s' % name, '--out=%s' % fn])
+                if rv == 0:
+                    # load it to context and remove the file
+                    self.context.load_attribute(fn)
+                    os.unlink(fn)
+                else:
+                    os.unlink(fn)
+                    raise self.attribute_error("creddy returned %s" % rv)
             else:
-                raise service_error(service_error.internal, 
-                        "No context ID for the new authorization context")
-        else:
-            raise service_error(service_error.internal, 
-                    "Bad response to creating service context")
-
-    def set_attribute(self, name, attr):
-        self.valid_name(name)
+                raise self.attribute_error(
+                        "Identity and key not specified on creation")
+        elif cert:
+            # Insert this credential into the context
+            self.context.load_attribute_chunk(cert)
+        else:
+            raise self.attribute_error("Neither name/attr nor cert is set")
+
+    def check_attribute(self, name, attr):
+        # XXX proof soon
         if isinstance(name, tuple):
-            if not isinstance(name[0], fedid):
-                raise service_error(service_error.internal, 
-                        "Triple not anchored in testbed")
-            if not name[1] and not name[2]:
-                raise service_error(service_error.internal,
-                        "Anonymous access not yet permitted")
-
-            preconditions = "^".join(
-                    [ "%s.%s" % (name[0], self.auth_name(n)) \
-                            for n in name[1:3] if n ])
-
-            req = { 
-                    'credential': [ '%s.%s<--%s' % \
-                            ( self.me, attr, preconditions) ],
-                    'context': { 'contextID': self.contextID  }
-                }
-        else:
-            req = { 
-                    'credential': [ '%s.%s<--%s' % \
-                            ( self.me, attr, self.auth_name(name)) ],
-                    'context': { 'contextID': self.contextID }
-                }
-        print req
-        self.call_CredentialUpdate(self.url, req, self.cert_file, 
-                self.cert_pwd, self.trusted_certs, tracefile=sys.stderr)
-
-    def check_attribute(self, name, attr):
-        self.valid_name(name)
-        if attr in self.globals: return True
-
-        if isinstance(name, tuple):
-            raise service_error(service_error.internal, 
-                    "Only fedids permitted here")
-        req = {
-                'goal': '%s:%s<<---%s' % (self.me, attr, name),
-                'context': { 'contextID': self.contextID }
-            }
-        resp = self.call_Access(self.url, req, self.cert_file, self.cert_pwd, 
-                self.trusted_certs)
-        if resp.has_key('AccessResponseBody'):
-            resp = resp['AccessResponseBody']
-
-        result = resp.get('result', None)
-        return (result and result.lower() == 'true')
+            raise self.bad_name("ABAC doesn't understand three-names")
+        else:
+            proof, rv = self.context.query(attr, name)
+            # XXX delete soon
+            if not rv and attr in self.globals: return True
+            else: return rv
 
     def set_global_attribute(self, attr):
@@ -241 +248 @@
         self.globals.discard(attr)
 
+    def clone(self):
+        rv = abac_authorizer(me=self.me, key=self.key)
+        rv.globals = self.globals.copy()
+        rv.context = ABAC.Context(self.context)
+        return rv
+
+    def save(self, dir):
+        os.mkdir(dir)
+
+        f = open("%s/globals" % dir, "w")
+        pickle.dump(self.globals, f)
+        f.close()
+
+        if self.me and self.key:
+            f = open("%s/me" % dir, "w")
+            pickle.dump(self.me, f)
+            f.close()
+            f = open("%s/key" % dir, "w")
+            pickle.dump(self.key, f)
+            f.close()
+        os.mkdir("%s/certs" % dir)
+        seenit = set()
+        ii = 0
+        ai = 0
+        for c in self.context.credentials():
+            id = c.issuer_cert()
+            attr = c.attribute_cert()
+            if id not in seenit:
+                f = open("%s/certs/%03d_ID.der" % (dir, ii), "w")
+                print >>f, id
+                f.close()
+                ii += 1
+                seenit.add(id)
+            if attr:
+                f = open("%s/certs/%03d_attr.der" % (dir, ai), "w")
+                print >>f, attr
+                f.close()
+                ai += 1
+
+    def load(self, dir):
+        if os.access("%s/me" % dir, os.R_OK):
+            f = open("%s/me" % dir, "r")
+            self.me = pickle.load(f)
+            f.close()
+        else:
+            self.me = None
+        if os.access("%s/key" % dir, os.R_OK):
+            f = open("%s/key" % dir, "r")
+            self.key = pickle.load(f)
+            f.close()
+        else:
+            self.key = None
+        f = open("%s/globals" % dir, "r")
+        self.globals = pickle.load(f)
+        f.close()
+        self.context = ABAC.context()
+        self.context.load_directory("%s/certs" % dir)
+