# Thierry Parmentelat -- INRIA
-#
-# a minimal library for writing "lightweight" SFA clients
-#
+"""
+a minimal library for writing "lightweight" SFA clients
+"""
+
+from __future__ import print_function
+# xxx todo
+# this library should probably check for the expiration date of the various
+# certificates and automatically retrieve fresh ones when expired
+
+import sys
import os,os.path
+import subprocess
+from datetime import datetime
+from sfa.util.xrn import Xrn
import sfa.util.sfalogging
+# importing sfa.utils.faults does pull a lot of stuff
+# OTOH it's imported from Certificate anyways, so..
+from sfa.util.faults import RecordNotFound
from sfa.client.sfaserverproxy import SfaServerProxy
# see optimizing dependencies below
from sfa.trust.certificate import Keypair, Certificate
-
+from sfa.trust.credential import Credential
+from sfa.trust.gid import GID
##########
-# a helper class to implement the bootstrapping of crypto. material
+# a helper class to implement the bootstrapping of cryptoa. material
# assuming we are starting from scratch on the client side
# what's needed to complete a full slice creation cycle
# (**) prerequisites:
# obtained at the registry using Resolve
# using the step2 credential as credential
# default filename is <hrn>.user.gid
-##########
-# from that point on, the GID can/should be used as the SSL cert for anything
-# a new (slice) credential would be needed for slice operations and can be
-# obtained at the registry through GetCredential
+#
+# From that point on, the GID is used as the SSL certificate
+# and the following can be done
+#
+# (**) retrieve a slice (or authority) credential
+# obtained at the registry with GetCredential
+# using the (step2) user-credential as credential
+# default filename is <hrn>.<type>.cred
+# (**) retrieve a slice (or authority) GID
+# obtained at the registry with Resolve
+# using the (step2) user-credential as credential
+# default filename is <hrn>.<type>.cred
+#
+# (**) additionnally, it might make sense to upgrade a GID file
+# into a pkcs12 certificate usable in a browser
+# this bundled format allows for embedding the private key
+#
+
+########## Implementation notes
+#
+# (*) decorators
+#
+# this implementation is designed as a guideline for
+# porting to other languages
+#
+# the decision to go for decorators aims at focusing
+# on the core of what needs to be done when everything
+# works fine, and to take caching and error management
+# out of the way
+#
+# for non-pythonic developers, it should be enough to
+# implement the bulk of this code, namely the _produce methods
+# and to add caching and error management by whichever means
+# is available, including inline
+#
+# (*) self-signed certificates
+#
+# still with other languages in mind, we've tried to keep the
+# dependencies to the rest of the code as low as possible
+#
+# however this still relies on the sfa.trust.certificate module
+# for the initial generation of a self-signed-certificate that
+# is associated to the user's ssh-key
+# (for user-friendliness, and for smooth operations with planetlab,
+# the usage model is to reuse an existing keypair)
+#
+# there might be a more portable, i.e. less language-dependant way, to
+# implement this step by exec'ing the openssl command.
+# a known successful attempt at this approach that worked
+# for Java is documented below
+# http://nam.ece.upatras.gr/fstoolkit/trac/wiki/JavaSFAClient
+#
+# (*) pkcs12
+#
+# the implementation of the pkcs12 wrapping, which is a late addition,
+# is done through direct calls to openssl
+#
+####################
+
+class SfaClientException (Exception): pass
-# xxx todo should protect against write file permissions
-# xxx todo review exceptions
class SfaClientBootstrap:
- # xxx todo should account for verbose and timeout that the proxy offers
- def __init__ (self, user_hrn, registry_url, dir=None, logger=None):
+ # dir is mandatory but defaults to '.'
+ def __init__ (self, user_hrn, registry_url, dir=None,
+ verbose=False, timeout=None, logger=None):
self.hrn=user_hrn
self.registry_url=registry_url
if dir is None: dir="."
self.dir=dir
+ self.verbose=verbose
+ self.timeout=timeout
+ # default for the logger is to use the global sfa logger
if logger is None:
- print 'special case for logger'
logger = sfa.util.sfalogging.logger
self.logger=logger
+ ######################################## *_produce methods
+ ### step1
+ # unconditionnally create a self-signed certificate
+ def self_signed_cert_produce (self, output):
+ self.assert_private_key()
+ private_key_filename = self.private_key_filename()
+ keypair=Keypair(filename=private_key_filename)
+ self_signed = Certificate (subject = self.hrn)
+ self_signed.set_pubkey (keypair)
+ self_signed.set_issuer (keypair, self.hrn)
+ self_signed.sign ()
+ self_signed.save_to_file (output)
+ self.logger.debug("SfaClientBootstrap: Created self-signed certificate for %s in %s"%\
+ (self.hrn, output))
+ return output
+
+ ### step2
+ # unconditionnally retrieve my credential (GetSelfCredential)
+ # we always use the self-signed-cert as the SSL cert
+ def my_credential_produce (self, output):
+ self.assert_self_signed_cert()
+ certificate_filename = self.self_signed_cert_filename()
+ certificate_string = self.plain_read (certificate_filename)
+ self.assert_private_key()
+ registry_proxy = SfaServerProxy (self.registry_url,
+ self.private_key_filename(),
+ certificate_filename)
+ try:
+ credential_string=registry_proxy.GetSelfCredential (certificate_string, self.hrn, "user")
+ except:
+ # some urns hrns may replace non hierarchy delimiters '.' with an '_' instead of escaping the '.'
+ hrn = Xrn(self.hrn).get_hrn().replace('\.', '_')
+ credential_string=registry_proxy.GetSelfCredential (certificate_string, hrn, "user")
+ self.plain_write (output, credential_string)
+ self.logger.debug("SfaClientBootstrap: Wrote result of GetSelfCredential in %s"%output)
+ return output
+
+ ### step3
+ # unconditionnally retrieve my GID - use the general form
+ def my_gid_produce (self,output):
+ return self.gid_produce (output, self.hrn, "user")
+
+ ### retrieve any credential (GetCredential) unconditionnal form
+ # we always use the GID as the SSL cert
+ def credential_produce (self, output, hrn, type):
+ self.assert_my_gid()
+ certificate_filename = self.my_gid_filename()
+ self.assert_private_key()
+ registry_proxy = SfaServerProxy (self.registry_url, self.private_key_filename(),
+ certificate_filename)
+ self.assert_my_credential()
+ my_credential_string = self.my_credential_string()
+ credential_string=registry_proxy.GetCredential (my_credential_string, hrn, type)
+ self.plain_write (output, credential_string)
+ self.logger.debug("SfaClientBootstrap: Wrote result of GetCredential in %s"%output)
+ return output
+
+ def slice_credential_produce (self, output, hrn):
+ return self.credential_produce (output, hrn, "slice")
+
+ def authority_credential_produce (self, output, hrn):
+ return self.credential_produce (output, hrn, "authority")
+
+ ### retrieve any gid (Resolve) - unconditionnal form
+ # use my GID when available as the SSL cert, otherwise the self-signed
+ def gid_produce (self, output, hrn, type ):
+ try:
+ self.assert_my_gid()
+ certificate_filename = self.my_gid_filename()
+ except:
+ self.assert_self_signed_cert()
+ certificate_filename = self.self_signed_cert_filename()
+
+ self.assert_private_key()
+ registry_proxy = SfaServerProxy (self.registry_url, self.private_key_filename(),
+ certificate_filename)
+ credential_string=self.plain_read (self.my_credential())
+ records = registry_proxy.Resolve (hrn, credential_string)
+ records=[record for record in records if record['type']==type]
+ if not records:
+ raise RecordNotFound("hrn %s (%s) unknown to registry %s"%(hrn,type,self.registry_url))
+ record=records[0]
+ self.plain_write (output, record['gid'])
+ self.logger.debug("SfaClientBootstrap: Wrote GID for %s (%s) in %s"% (hrn,type,output))
+ return output
+
+
+# http://trac.myslice.info/wiki/MySlice/Developer/SFALogin
+### produce a pkcs12 bundled certificate from GID and private key
+# xxx for now we put a hard-wired password that's just, well, 'password'
+# when leaving this empty on the mac, result can't seem to be loaded in keychain..
+ def my_pkcs12_produce (self, filename):
+ password=raw_input("Enter password for p12 certificate: ")
+ openssl_command=['openssl', 'pkcs12', "-export"]
+ openssl_command += [ "-password", "pass:%s"%password ]
+ openssl_command += [ "-inkey", self.private_key_filename()]
+ openssl_command += [ "-in", self.my_gid_filename()]
+ openssl_command += [ "-out", filename ]
+ if subprocess.call(openssl_command) ==0:
+ print("Successfully created %s"%filename)
+ else:
+ print("Failed to create %s"%filename)
+
+ # Returns True if credential file is valid. Otherwise return false.
+ def validate_credential(self, filename):
+ valid = True
+ cred = Credential(filename=filename)
+ # check if credential is expires
+ if cred.get_expiration() < datetime.utcnow():
+ valid = False
+ return valid
+
+
#################### public interface
+
+ # return my_gid, run all missing steps in the bootstrap sequence
+ def bootstrap_my_gid (self):
+ self.self_signed_cert()
+ self.my_credential()
+ return self.my_gid()
+
+ # once we've bootstrapped we can use this object to issue any other SFA call
+ # always use my gid
+ def server_proxy (self, url):
+ self.assert_my_gid()
+ return SfaServerProxy (url, self.private_key_filename(), self.my_gid_filename(),
+ verbose=self.verbose, timeout=self.timeout)
+
+ # now in some cases the self-signed is enough
+ def server_proxy_simple (self, url):
+ self.assert_self_signed_cert()
+ return SfaServerProxy (url, self.private_key_filename(), self.self_signed_cert_filename(),
+ verbose=self.verbose, timeout=self.timeout)
- # xxx should that be called in the constructor ?
- # typically user_private_key is ~/.ssh/id_rsa
+ # this method can optionnally be invoked to ensure proper
+ # installation of the private key that belongs to this user
+ # installs private_key in working dir with expected name -- preserve mode
+ # typically user_private_key would be ~/.ssh/id_rsa
+ # xxx should probably check the 2 files are identical
def init_private_key_if_missing (self, user_private_key):
private_key_filename=self.private_key_filename()
if not os.path.isfile (private_key_filename):
self.logger.debug("SfaClientBootstrap: Copied private key from %s into %s"%\
(user_private_key,private_key_filename))
- # make sure we have the GID at hand
- def bootstrap_gid (self):
- if self.any_certificate_filename() is None:
- self.get_self_signed_cert()
- self.get_credential()
- self.get_gid()
-
- def server_proxy (self, url):
- return SfaServerProxy (url, self.private_key_filename(), self.gid_filename())
-
- def get_credential_string (self):
- return self.plain_read (self.get_credential())
-
- # more to come to get credentials about other objects (authority/slice)
-
#################### private details
# stupid stuff
def fullpath (self, file): return os.path.join (self.dir,file)
- # %s -> self.hrn
- def fullpath_format(self,format): return self.fullpath (format%self.hrn)
+ # the expected filenames for the various pieces
def private_key_filename (self):
- return self.fullpath_format ("%s.pkey")
+ return self.fullpath ("%s.pkey" % Xrn.unescape(self.hrn))
def self_signed_cert_filename (self):
- return self.fullpath_format ("%s.sscert")
- def credential_filename (self):
- return self.fullpath_format ("%s.user.cred")
- def gid_filename (self):
- return self.fullpath_format ("%s.user.gid")
+ return self.fullpath ("%s.sscert"%self.hrn)
+ def my_credential_filename (self):
+ return self.credential_filename (self.hrn, "user")
+ # the tests use sfi -u <pi-user>; meaning that the slice credential filename
+ # needs to keep track of the user too
+ def credential_filename (self, hrn, type):
+ if type in ['user']:
+ basename="%s.%s.cred"%(hrn,type)
+ else:
+ basename="%s-%s.%s.cred"%(self.hrn,hrn,type)
+ return self.fullpath (basename)
+ def slice_credential_filename (self, hrn):
+ return self.credential_filename(hrn,'slice')
+ def authority_credential_filename (self, hrn):
+ return self.credential_filename(hrn,'authority')
+ def my_gid_filename (self):
+ return self.gid_filename (self.hrn, "user")
+ def gid_filename (self, hrn, type):
+ return self.fullpath ("%s.%s.gid"%(hrn,type))
+ def my_pkcs12_filename (self):
+ return self.fullpath ("%s.p12"%self.hrn)
# optimizing dependencies
# originally we used classes GID or Credential or Certificate
# like e.g.
-# return Credential(filename=self.get_credential()).save_to_string()
+# return Credential(filename=self.my_credential()).save_to_string()
# but in order to make it simpler to other implementations/languages..
def plain_read (self, filename):
infile=file(filename,"r")
result=outfile.write(contents)
outfile.close()
- # the private key
- def check_private_key (self):
- if not os.path.isfile (self.private_key_filename()):
- raise Exception,"No such file %s"%self.private_key_filename()
+ def assert_filename (self, filename, kind):
+ if not os.path.isfile (filename):
+ raise IOError("Missing %s file %s"%(kind,filename))
return True
+
+ def assert_private_key (self):
+ return self.assert_filename (self.private_key_filename(),"private key")
+ def assert_self_signed_cert (self):
+ return self.assert_filename (self.self_signed_cert_filename(),"self-signed certificate")
+ def assert_my_credential (self):
+ return self.assert_filename (self.my_credential_filename(),"user's credential")
+ def assert_my_gid (self):
+ return self.assert_filename (self.my_gid_filename(),"user's GID")
- # get any certificate
- # rationale for this method, once we have the gid, it's actually safe
- # to remove the .sscert
- def any_certificate_filename (self):
- attempts=[ self.gid_filename(), self.self_signed_cert_filename() ]
- for attempt in attempts:
- if os.path.isfile (attempt): return attempt
- return None
- ### step1
- # unconditionnally
- def create_self_signed_certificate (self,output):
- self.check_private_key()
- private_key_filename = self.private_key_filename()
- keypair=Keypair(filename=private_key_filename)
- self_signed = Certificate (subject = self.hrn)
- self_signed.set_pubkey (keypair)
- self_signed.set_issuer (keypair, self.hrn)
- self_signed.sign ()
- self_signed.save_to_file (output)
- self.logger.debug("SfaClientBootstrap: Created self-signed certificate for %s in %s"%\
- (self.hrn,output))
- return output
+ # decorator to make up the other methods
+ def get_or_produce (filename_method, produce_method, validate_method=None):
+ # default validator returns true
+ def wrap (f):
+ def wrapped (self, *args, **kw):
+ filename=filename_method (self, *args, **kw)
+ if os.path.isfile ( filename ):
+ if not validate_method:
+ return filename
+ elif validate_method(self, filename):
+ return filename
+ else:
+ # remove invalid file
+ self.logger.warning ("Removing %s - has expired"%filename)
+ os.unlink(filename)
+ try:
+ produce_method (self, filename, *args, **kw)
+ return filename
+ except IOError:
+ raise
+ except :
+ error = sys.exc_info()[:2]
+ message="Could not produce/retrieve %s (%s -- %s)"%\
+ (filename,error[0],error[1])
+ self.logger.log_exc(message)
+ raise Exception(message)
+ return wrapped
+ return wrap
- def get_self_signed_cert (self):
- self_signed_cert_filename = self.self_signed_cert_filename()
- if os.path.isfile (self_signed_cert_filename):
- return self_signed_cert_filename
- return self.create_self_signed_certificate(self_signed_cert_filename)
-
- ### step2
- # unconditionnally
- def retrieve_credential (self, output):
- self.check_private_key()
- certificate_filename = self.any_certificate_filename()
- certificate_string = self.plain_read (certificate_filename)
- registry_proxy = SfaServerProxy (self.registry_url, self.private_key_filename(),
- certificate_filename)
- credential_string=registry_proxy.GetSelfCredential (certificate_string, self.hrn, "user")
- self.plain_write (output, credential_string)
- self.logger.debug("SfaClientBootstrap: Wrote result of GetSelfCredential in %s"%output)
- return output
+ @get_or_produce (self_signed_cert_filename, self_signed_cert_produce)
+ def self_signed_cert (self): pass
- def get_credential (self):
- credential_filename = self.credential_filename ()
- if os.path.isfile(credential_filename):
- return credential_filename
- return self.retrieve_credential (credential_filename)
+ @get_or_produce (my_credential_filename, my_credential_produce, validate_credential)
+ def my_credential (self): pass
- ### step3
- # unconditionnally
- def retrieve_gid (self, hrn, type, output):
- self.check_private_key()
- certificate_filename = self.any_certificate_filename()
- registry_proxy = SfaServerProxy (self.registry_url, self.private_key_filename(),
- certificate_filename)
- credential_string=self.plain_read (self.get_credential())
- records = registry_proxy.Resolve (hrn, credential_string)
- records=[record for record in records if record['type']==type]
- if not records:
- # RecordNotFound
- raise Exception, "hrn %s (%s) unknown to registry %s"%(hrn,type,self.registry_url)
- record=records[0]
- self.plain_write (output, record['gid'])
- self.logger.debug("SfaClientBootstrap: Wrote GID for %s (%s) in %s"% (hrn,type,output))
- return output
-
- def get_gid (self):
- gid_filename=self.gid_filename()
- if os.path.isfile(gid_filename):
- return gid_filename
- return self.retrieve_gid(self.hrn, "user", gid_filename)
+ @get_or_produce (my_gid_filename, my_gid_produce)
+ def my_gid (self): pass
+
+ @get_or_produce (my_pkcs12_filename, my_pkcs12_produce)
+ def my_pkcs12 (self): pass
+
+ @get_or_produce (credential_filename, credential_produce, validate_credential)
+ def credential (self, hrn, type): pass
+
+ @get_or_produce (slice_credential_filename, slice_credential_produce, validate_credential)
+ def slice_credential (self, hrn): pass
+
+ @get_or_produce (authority_credential_filename, authority_credential_produce, validate_credential)
+ def authority_credential (self, hrn): pass
+
+ @get_or_produce (gid_filename, gid_produce)
+ def gid (self, hrn, type ): pass
+
+
+ # get the credentials as strings, for inserting as API arguments
+ def my_credential_string (self):
+ self.my_credential()
+ return self.plain_read(self.my_credential_filename())
+ def slice_credential_string (self, hrn):
+ self.slice_credential(hrn)
+ return self.plain_read(self.slice_credential_filename(hrn))
+ def authority_credential_string (self, hrn):
+ self.authority_credential(hrn)
+ return self.plain_read(self.authority_credential_filename(hrn))
+
+ # for consistency
+ def private_key (self):
+ self.assert_private_key()
+ return self.private_key_filename()
+
+ def delegate_credential_string (self, original_credential, to_hrn, to_type='authority'):
+ """
+ sign a delegation credential to someone else
+
+ original_credential : typically one's user- or slice- credential to be delegated to s/b else
+ to_hrn : the hrn of the person that will be allowed to do stuff on our behalf
+ to_type : goes with to_hrn, usually 'user' or 'authority'
+
+ returns a string with the delegated credential
+
+ this internally uses self.my_gid()
+ it also retrieves the gid for to_hrn/to_type
+ and uses Credential.delegate()"""
+
+ # the gid and hrn of the object we are delegating
+ if isinstance (original_credential, str):
+ original_credential = Credential (string=original_credential)
+ original_gid = original_credential.get_gid_object()
+ original_hrn = original_gid.get_hrn()
+
+ if not original_credential.get_privileges().get_all_delegate():
+ self.logger.error("delegate_credential_string: original credential %s does not have delegate bit set"%original_hrn)
+ return
+
+ # the delegating user's gid
+ my_gid = self.my_gid()
+ # retrieve the GID for the entity that we're delegating to
+ to_gidfile = self.gid (to_hrn,to_type)
+# to_gid = GID ( to_gidfile )
+# to_hrn = delegee_gid.get_hrn()
+# print 'to_hrn',to_hrn
+ delegated_credential = original_credential.delegate(to_gidfile, self.private_key(), my_gid)
+ return delegated_credential.save_to_string(save_parents=True)
git://git.onelab.eu / sfa.git / blobdiff