def decode(self):
if not self.xml:
return
doc = parseString(self.xml)
sigs = []
signed_cred = doc.getElementsByTagName("signed-credential")
# Is this a signed-cred or just a cred?
if len(signed_cred) > 0:
creds = signed_cred[0].getElementsByTagName("credential")
signatures = signed_cred[0].getElementsByTagName("signatures")
if len(signatures) > 0:
sigs = signatures[0].getElementsByTagName("Signature")
else:
creds = doc.getElementsByTagName("credential")
if creds is None or len(creds) == 0:
# malformed cred file
raise CredentialNotVerifiable("Malformed XML: No credential tag found")
# Just take the first cred if there are more than one
cred = creds[0]
self.set_refid(cred.getAttribute("xml:id"))
self.set_expiration(utcparse(getTextNode(cred, "expires")))
# import traceback
# stack = traceback.extract_stack()
og = getTextNode(cred, "owner_gid")
# ABAC creds will have this be None and use this method
# if og is None:
# found = False
# for frame in stack:
# if 'super(ABACCredential, self).decode()' in frame:
# found = True
# break
# if not found:
# raise CredentialNotVerifiable("Malformed XML: No owner_gid found")
self.gidCaller = GID(string=og)
tg = getTextNode(cred, "target_gid")
# if tg is None:
# found = False
# for frame in stack:
# if 'super(ABACCredential, self).decode()' in frame:
# found = True
# break
# if not found:
# raise CredentialNotVerifiable("Malformed XML: No target_gid found")
self.gidObject = GID(string=tg)
# Process privileges
rlist = Rights()
priv_nodes = cred.getElementsByTagName("privileges")
if len(priv_nodes) > 0:
privs = priv_nodes[0]
for priv in privs.getElementsByTagName("privilege"):
kind = getTextNode(priv, "name")
deleg = str2bool(getTextNode(priv, "can_delegate"))
if kind == '*':
# Convert * into the default privileges for the credential's type
# Each inherits the delegatability from the * above
_ , type = urn_to_hrn(self.gidObject.get_urn())
rl = determine_rights(type, self.gidObject.get_urn())
for r in rl.rights:
r.delegate = deleg
rlist.add(r)
else:
rlist.add(Right(kind.strip(), deleg))
self.set_privileges(rlist)
# Is there a parent?
parent = cred.getElementsByTagName("parent")
if len(parent) > 0:
parent_doc = parent[0].getElementsByTagName("credential")[0]
parent_xml = parent_doc.toxml("utf-8")
if parent_xml is None or parent_xml.strip() == "":
raise CredentialNotVerifiable("Malformed XML: Had parent tag but it is empty")
self.parent = Credential(string=parent_xml)
self.updateRefID()
# Assign the signatures to the credentials
for sig in sigs:
Sig = Signature(string=sig.toxml("utf-8"))
for cur_cred in self.get_credential_list():
if cur_cred.get_refid() == Sig.get_refid():
cur_cred.set_signature(Sig)
def create_credential(caller_gid, object_gid, expiration, typename, issuer_keyfile, issuer_certfile, trusted_roots, delegatable=False):
'''Create and Return a Credential object issued by given key/cert for the given caller
and object GID objects, given life in seconds, and given type.
Privileges are determined by type per sfa/trust/rights.py
Privileges are delegatable if requested.'''
# FIXME: Validate args: my gids, >0 life,
# type of cred one I can issue
# and readable key and cert files
if caller_gid is None:
raise ValueError("Missing Caller GID")
if object_gid is None:
raise ValueError("Missing Object GID")
if expiration is None:
raise ValueError("Missing expiration")
naive_expiration = naiveUTC(expiration)
duration = naive_expiration - datetime.datetime.utcnow()
life_secs = duration.seconds + duration.days * 24 * 3600
if life_secs < 1:
raise ValueError("Credential expiration is in the past")
if trusted_roots is None:
raise ValueError("Missing list of trusted roots")
if typename is None or typename.strip() == '':
raise ValueError("Missing credential type")
typename = typename.strip().lower()
if typename not in ("user", "sa", "ma", "authority", "slice", "component"):
raise ValueError("Unknown credential type %s" % typename)
if not os.path.isfile(issuer_keyfile):
raise ValueError("Cant read issuer key file %s" % issuer_keyfile)
if not os.path.isfile(issuer_certfile):
raise ValueError("Cant read issuer cert file %s" % issuer_certfile)
issuer_gid = gid.GID(filename=issuer_certfile)
if not (object_gid.get_urn() == issuer_gid.get_urn() or
(issuer_gid.get_type().find('authority') == 0 and
hrn_authfor_hrn(issuer_gid.get_hrn(), object_gid.get_hrn()))):
raise ValueError("Issuer not authorized to issue credential: Issuer=%s Target=%s" % (issuer_gid.get_urn(), object_gid.get_urn()))
ucred = cred.Credential()
# FIXME: Validate the caller_gid and object_gid
# are my user and slice
# Do get_issuer and compare to the issuer cert?
# Or do gid.is_signed_by_cert(issuer_certfile)?
ucred.set_gid_caller(caller_gid)
ucred.set_gid_object(object_gid)
ucred.set_expiration(expiration)
# Use sfa/trust/rights.py to figure out what privileges
# the credential should have.
# user means refresh, resolve, info
# per the privilege_table that lets users do
# remove, update, resolve, list, getcredential,
# listslices, listnodes, getpolicy
# Note that it does not allow manipulating slivers
# And every right is delegatable if any are delegatable (default False)
privileges = rights.determine_rights(typename, None)
privileges.delegate_all_privileges(delegatable)
ucred.set_privileges(privileges)
ucred.encode()
ucred.set_issuer_keys(issuer_keyfile, issuer_certfile)
ucred.sign()
try:
ucred.verify(trusted_roots)
except Exception, exc:
raise Exception("Create Credential failed to verify new credential from trusted roots: %s" % exc)
