-#----------------------------------------------------------------------\r
-# Copyright (c) 2008 Board of Trustees, Princeton University\r
-#\r
-# Permission is hereby granted, free of charge, to any person obtaining\r
-# a copy of this software and/or hardware specification (the "Work") to\r
-# deal in the Work without restriction, including without limitation the\r
-# rights to use, copy, modify, merge, publish, distribute, sublicense,\r
-# and/or sell copies of the Work, and to permit persons to whom the Work\r
-# is furnished to do so, subject to the following conditions:\r
-#\r
-# The above copyright notice and this permission notice shall be\r
-# included in all copies or substantial portions of the Work.\r
-#\r
-# THE WORK IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS \r
-# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF \r
-# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND \r
-# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT \r
-# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, \r
-# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, \r
-# OUT OF OR IN CONNECTION WITH THE WORK OR THE USE OR OTHER DEALINGS \r
-# IN THE WORK.\r
-#----------------------------------------------------------------------\r
-\r
-##\r
-# SFA uses two crypto libraries: pyOpenSSL and M2Crypto to implement\r
-# the necessary crypto functionality. Ideally just one of these libraries\r
-# would be used, but unfortunately each of these libraries is independently\r
-# lacking. The pyOpenSSL library is missing many necessary functions, and\r
-# the M2Crypto library has crashed inside of some of the functions. The\r
-# design decision is to use pyOpenSSL whenever possible as it seems more\r
-# stable, and only use M2Crypto for those functions that are not possible\r
-# in pyOpenSSL.\r
-#\r
-# This module exports two classes: Keypair and Certificate.\r
-##\r
-#\r
-\r
-import functools\r
-import os\r
-import tempfile\r
-import base64\r
-import traceback\r
-from tempfile import mkstemp\r
-\r
-from OpenSSL import crypto\r
-import M2Crypto\r
-from M2Crypto import X509\r
-\r
-from sfa.util.sfalogging import logger\r
-from sfa.util.xrn import urn_to_hrn\r
-from sfa.util.faults import *\r
-from sfa.util.sfalogging import logger\r
-\r
-glo_passphrase_callback = None\r
-\r
-##\r
-# A global callback msy be implemented for requesting passphrases from the\r
-# user. The function will be called with three arguments:\r
-#\r
-# keypair_obj: the keypair object that is calling the passphrase\r
-# string: the string containing the private key that's being loaded\r
-# x: unknown, appears to be 0, comes from pyOpenSSL and/or m2crypto\r
-#\r
-# The callback should return a string containing the passphrase.\r
-\r
-def set_passphrase_callback(callback_func):\r
- global glo_passphrase_callback\r
-\r
- glo_passphrase_callback = callback_func\r
-\r
-##\r
-# Sets a fixed passphrase.\r
-\r
-def set_passphrase(passphrase):\r
- set_passphrase_callback( lambda k,s,x: passphrase )\r
-\r
-##\r
-# Check to see if a passphrase works for a particular private key string.\r
-# Intended to be used by passphrase callbacks for input validation.\r
-\r
-def test_passphrase(string, passphrase):\r
- try:\r
- crypto.load_privatekey(crypto.FILETYPE_PEM, string, (lambda x: passphrase))\r
- return True\r
- except:\r
- return False\r
-\r
-def convert_public_key(key):\r
- keyconvert_path = "/usr/bin/keyconvert.py"\r
- if not os.path.isfile(keyconvert_path):\r
- raise IOError, "Could not find keyconvert in %s" % keyconvert_path\r
-\r
- # we can only convert rsa keys\r
- if "ssh-dss" in key:\r
- return None\r
-\r
- (ssh_f, ssh_fn) = tempfile.mkstemp()\r
- ssl_fn = tempfile.mktemp()\r
- os.write(ssh_f, key)\r
- os.close(ssh_f)\r
-\r
- cmd = keyconvert_path + " " + ssh_fn + " " + ssl_fn\r
- os.system(cmd)\r
-\r
- # this check leaves the temporary file containing the public key so\r
- # that it can be expected to see why it failed.\r
- # TODO: for production, cleanup the temporary files\r
- if not os.path.exists(ssl_fn):\r
- return None\r
-\r
- k = Keypair()\r
- try:\r
- k.load_pubkey_from_file(ssl_fn)\r
- except:\r
- logger.log_exc("convert_public_key caught exception")\r
- k = None\r
-\r
- # remove the temporary files\r
- os.remove(ssh_fn)\r
- os.remove(ssl_fn)\r
-\r
- return k\r
-\r
-##\r
-# Public-private key pairs are implemented by the Keypair class.\r
-# A Keypair object may represent both a public and private key pair, or it\r
-# may represent only a public key (this usage is consistent with OpenSSL).\r
-\r
-class Keypair:\r
- key = None # public/private keypair\r
- m2key = None # public key (m2crypto format)\r
-\r
- ##\r
- # Creates a Keypair object\r
- # @param create If create==True, creates a new public/private key and\r
- # stores it in the object\r
- # @param string If string!=None, load the keypair from the string (PEM)\r
- # @param filename If filename!=None, load the keypair from the file\r
-\r
- def __init__(self, create=False, string=None, filename=None):\r
- if create:\r
- self.create()\r
- if string:\r
- self.load_from_string(string)\r
- if filename:\r
- self.load_from_file(filename)\r
-\r
- ##\r
- # Create a RSA public/private key pair and store it inside the keypair object\r
-\r
- def create(self):\r
- self.key = crypto.PKey()\r
- self.key.generate_key(crypto.TYPE_RSA, 1024)\r
-\r
- ##\r
- # Save the private key to a file\r
- # @param filename name of file to store the keypair in\r
-\r
- def save_to_file(self, filename):\r
- open(filename, 'w').write(self.as_pem())\r
- self.filename=filename\r
-\r
- ##\r
- # Load the private key from a file. Implicity the private key includes the public key.\r
-\r
- def load_from_file(self, filename):\r
- self.filename=filename\r
- buffer = open(filename, 'r').read()\r
- self.load_from_string(buffer)\r
-\r
- ##\r
- # Load the private key from a string. Implicitly the private key includes the public key.\r
-\r
- def load_from_string(self, string):\r
- if glo_passphrase_callback:\r
- self.key = crypto.load_privatekey(crypto.FILETYPE_PEM, string, functools.partial(glo_passphrase_callback, self, string) )\r
- self.m2key = M2Crypto.EVP.load_key_string(string, functools.partial(glo_passphrase_callback, self, string) )\r
- else:\r
- self.key = crypto.load_privatekey(crypto.FILETYPE_PEM, string)\r
- self.m2key = M2Crypto.EVP.load_key_string(string)\r
-\r
- ##\r
- # Load the public key from a string. No private key is loaded.\r
-\r
- def load_pubkey_from_file(self, filename):\r
- # load the m2 public key\r
- m2rsakey = M2Crypto.RSA.load_pub_key(filename)\r
- self.m2key = M2Crypto.EVP.PKey()\r
- self.m2key.assign_rsa(m2rsakey)\r
-\r
- # create an m2 x509 cert\r
- m2name = M2Crypto.X509.X509_Name()\r
- m2name.add_entry_by_txt(field="CN", type=0x1001, entry="junk", len=-1, loc=-1, set=0)\r
- m2x509 = M2Crypto.X509.X509()\r
- m2x509.set_pubkey(self.m2key)\r
- m2x509.set_serial_number(0)\r
- m2x509.set_issuer_name(m2name)\r
- m2x509.set_subject_name(m2name)\r
- ASN1 = M2Crypto.ASN1.ASN1_UTCTIME()\r
- ASN1.set_time(500)\r
- m2x509.set_not_before(ASN1)\r
- m2x509.set_not_after(ASN1)\r
- # x509v3 so it can have extensions\r
- # prob not necc since this cert itself is junk but still...\r
- m2x509.set_version(2)\r
- junk_key = Keypair(create=True)\r
- m2x509.sign(pkey=junk_key.get_m2_pkey(), md="sha1")\r
-\r
- # convert the m2 x509 cert to a pyopenssl x509\r
- m2pem = m2x509.as_pem()\r
- pyx509 = crypto.load_certificate(crypto.FILETYPE_PEM, m2pem)\r
-\r
- # get the pyopenssl pkey from the pyopenssl x509\r
- self.key = pyx509.get_pubkey()\r
- self.filename=filename\r
-\r
- ##\r
- # Load the public key from a string. No private key is loaded.\r
-\r
- def load_pubkey_from_string(self, string):\r
- (f, fn) = tempfile.mkstemp()\r
- os.write(f, string)\r
- os.close(f)\r
- self.load_pubkey_from_file(fn)\r
- os.remove(fn)\r
-\r
- ##\r
- # Return the private key in PEM format.\r
-\r
- def as_pem(self):\r
- return crypto.dump_privatekey(crypto.FILETYPE_PEM, self.key)\r
-\r
- ##\r
- # Return an M2Crypto key object\r
-\r
- def get_m2_pkey(self):\r
- if not self.m2key:\r
- self.m2key = M2Crypto.EVP.load_key_string(self.as_pem())\r
- return self.m2key\r
-\r
- ##\r
- # Returns a string containing the public key represented by this object.\r
-\r
- def get_pubkey_string(self):\r
- m2pkey = self.get_m2_pkey()\r
- return base64.b64encode(m2pkey.as_der())\r
-\r
- ##\r
- # Return an OpenSSL pkey object\r
-\r
- def get_openssl_pkey(self):\r
- return self.key\r
-\r
- ##\r
- # Given another Keypair object, return TRUE if the two keys are the same.\r
-\r
- def is_same(self, pkey):\r
- return self.as_pem() == pkey.as_pem()\r
-\r
- def sign_string(self, data):\r
- k = self.get_m2_pkey()\r
- k.sign_init()\r
- k.sign_update(data)\r
- return base64.b64encode(k.sign_final())\r
-\r
- def verify_string(self, data, sig):\r
- k = self.get_m2_pkey()\r
- k.verify_init()\r
- k.verify_update(data)\r
- return M2Crypto.m2.verify_final(k.ctx, base64.b64decode(sig), k.pkey)\r
-\r
- def compute_hash(self, value):\r
- return self.sign_string(str(value))\r
-\r
- # only informative\r
- def get_filename(self):\r
- return getattr(self,'filename',None)\r
-\r
- def dump (self, *args, **kwargs):\r
- print self.dump_string(*args, **kwargs)\r
-\r
- def dump_string (self):\r
- result=""\r
- result += "KEYPAIR: pubkey=%40s..."%self.get_pubkey_string()\r
- filename=self.get_filename()\r
- if filename: result += "Filename %s\n"%filename\r
- return result\r
-\r
-##\r
-# The certificate class implements a general purpose X509 certificate, making\r
-# use of the appropriate pyOpenSSL or M2Crypto abstractions. It also adds\r
-# several addition features, such as the ability to maintain a chain of\r
-# parent certificates, and storage of application-specific data.\r
-#\r
-# Certificates include the ability to maintain a chain of parents. Each\r
-# certificate includes a pointer to it's parent certificate. When loaded\r
-# from a file or a string, the parent chain will be automatically loaded.\r
-# When saving a certificate to a file or a string, the caller can choose\r
-# whether to save the parent certificates as well.\r
-\r
-class Certificate:\r
- digest = "md5"\r
-\r
- cert = None\r
- issuerKey = None\r
- issuerSubject = None\r
- parent = None\r
- isCA = None # will be a boolean once set\r
-\r
- separator="-----parent-----"\r
-\r
- ##\r
- # Create a certificate object.\r
- #\r
- # @param lifeDays life of cert in days - default is 1825==5 years\r
- # @param create If create==True, then also create a blank X509 certificate.\r
- # @param subject If subject!=None, then create a blank certificate and set\r
- # it's subject name.\r
- # @param string If string!=None, load the certficate from the string.\r
- # @param filename If filename!=None, load the certficiate from the file.\r
- # @param isCA If !=None, set whether this cert is for a CA\r
-\r
- def __init__(self, lifeDays=1825, create=False, subject=None, string=None, filename=None, isCA=None):\r
- self.data = {}\r
- if create or subject:\r
- self.create(lifeDays)\r
- if subject:\r
- self.set_subject(subject)\r
- if string:\r
- self.load_from_string(string)\r
- if filename:\r
- self.load_from_file(filename)\r
-\r
- # Set the CA bit if a value was supplied\r
- if isCA != None:\r
- self.set_is_ca(isCA)\r
-\r
- # Create a blank X509 certificate and store it in this object.\r
-\r
- def create(self, lifeDays=1825):\r
- self.cert = crypto.X509()\r
- # FIXME: Use different serial #s\r
- self.cert.set_serial_number(3)\r
- self.cert.gmtime_adj_notBefore(0) # 0 means now\r
- self.cert.gmtime_adj_notAfter(lifeDays*60*60*24) # five years is default\r
- self.cert.set_version(2) # x509v3 so it can have extensions\r
-\r
-\r
- ##\r
- # Given a pyOpenSSL X509 object, store that object inside of this\r
- # certificate object.\r
-\r
- def load_from_pyopenssl_x509(self, x509):\r
- self.cert = x509\r
-\r
- ##\r
- # Load the certificate from a string\r
-\r
- def load_from_string(self, string):\r
- # if it is a chain of multiple certs, then split off the first one and\r
- # load it (support for the ---parent--- tag as well as normal chained certs)\r
-\r
- string = string.strip()\r
- \r
- # If it's not in proper PEM format, wrap it\r
- if string.count('-----BEGIN CERTIFICATE') == 0:\r
- string = '-----BEGIN CERTIFICATE-----\n%s\n-----END CERTIFICATE-----' % string\r
-\r
- # If there is a PEM cert in there, but there is some other text first\r
- # such as the text of the certificate, skip the text\r
- beg = string.find('-----BEGIN CERTIFICATE')\r
- if beg > 0:\r
- # skipping over non cert beginning \r
- string = string[beg:]\r
-\r
- parts = []\r
-\r
- if string.count('-----BEGIN CERTIFICATE-----') > 1 and \\r
- string.count(Certificate.separator) == 0:\r
- parts = string.split('-----END CERTIFICATE-----',1)\r
- parts[0] += '-----END CERTIFICATE-----'\r
- else:\r
- parts = string.split(Certificate.separator, 1)\r
-\r
- self.cert = crypto.load_certificate(crypto.FILETYPE_PEM, parts[0])\r
-\r
- # if there are more certs, then create a parent and let the parent load\r
- # itself from the remainder of the string\r
- if len(parts) > 1 and parts[1] != '':\r
- self.parent = self.__class__()\r
- self.parent.load_from_string(parts[1])\r
-\r
- ##\r
- # Load the certificate from a file\r
-\r
- def load_from_file(self, filename):\r
- file = open(filename)\r
- string = file.read()\r
- self.load_from_string(string)\r
- self.filename=filename\r
-\r
- ##\r
- # Save the certificate to a string.\r
- #\r
- # @param save_parents If save_parents==True, then also save the parent certificates.\r
-\r
- def save_to_string(self, save_parents=True):\r
- string = crypto.dump_certificate(crypto.FILETYPE_PEM, self.cert)\r
- if save_parents and self.parent:\r
- string = string + self.parent.save_to_string(save_parents)\r
- return string\r
-\r
- ##\r
- # Save the certificate to a file.\r
- # @param save_parents If save_parents==True, then also save the parent certificates.\r
-\r
- def save_to_file(self, filename, save_parents=True, filep=None):\r
- string = self.save_to_string(save_parents=save_parents)\r
- if filep:\r
- f = filep\r
- else:\r
- f = open(filename, 'w')\r
- f.write(string)\r
- f.close()\r
- self.filename=filename\r
-\r
- ##\r
- # Save the certificate to a random file in /tmp/\r
- # @param save_parents If save_parents==True, then also save the parent certificates.\r
- def save_to_random_tmp_file(self, save_parents=True):\r
- fp, filename = mkstemp(suffix='cert', text=True)\r
- fp = os.fdopen(fp, "w")\r
- self.save_to_file(filename, save_parents=True, filep=fp)\r
- return filename\r
-\r
- ##\r
- # Sets the issuer private key and name\r
- # @param key Keypair object containing the private key of the issuer\r
- # @param subject String containing the name of the issuer\r
- # @param cert (optional) Certificate object containing the name of the issuer\r
-\r
- def set_issuer(self, key, subject=None, cert=None):\r
- self.issuerKey = key\r
- if subject:\r
- # it's a mistake to use subject and cert params at the same time\r
- assert(not cert)\r
- if isinstance(subject, dict) or isinstance(subject, str):\r
- req = crypto.X509Req()\r
- reqSubject = req.get_subject()\r
- if (isinstance(subject, dict)):\r
- for key in reqSubject.keys():\r
- setattr(reqSubject, key, subject[key])\r
- else:\r
- setattr(reqSubject, "CN", subject)\r
- subject = reqSubject\r
- # subject is not valid once req is out of scope, so save req\r
- self.issuerReq = req\r
- if cert:\r
- # if a cert was supplied, then get the subject from the cert\r
- subject = cert.cert.get_subject()\r
- assert(subject)\r
- self.issuerSubject = subject\r
-\r
- ##\r
- # Get the issuer name\r
-\r
- def get_issuer(self, which="CN"):\r
- x = self.cert.get_issuer()\r
- return getattr(x, which)\r
-\r
- ##\r
- # Set the subject name of the certificate\r
-\r
- def set_subject(self, name):\r
- req = crypto.X509Req()\r
- subj = req.get_subject()\r
- if (isinstance(name, dict)):\r
- for key in name.keys():\r
- setattr(subj, key, name[key])\r
- else:\r
- setattr(subj, "CN", name)\r
- self.cert.set_subject(subj)\r
-\r
- ##\r
- # Get the subject name of the certificate\r
-\r
- def get_subject(self, which="CN"):\r
- x = self.cert.get_subject()\r
- return getattr(x, which)\r
-\r
- ##\r
- # Get a pretty-print subject name of the certificate\r
-\r
- def get_printable_subject(self):\r
- x = self.cert.get_subject()\r
- return "[ OU: %s, CN: %s, SubjectAltName: %s ]" % (getattr(x, "OU"), getattr(x, "CN"), self.get_data())\r
-\r
- ##\r
- # Get the public key of the certificate.\r
- #\r
- # @param key Keypair object containing the public key\r
-\r
- def set_pubkey(self, key):\r
- assert(isinstance(key, Keypair))\r
- self.cert.set_pubkey(key.get_openssl_pkey())\r
-\r
- ##\r
- # Get the public key of the certificate.\r
- # It is returned in the form of a Keypair object.\r
-\r
- def get_pubkey(self):\r
- m2x509 = X509.load_cert_string(self.save_to_string())\r
- pkey = Keypair()\r
- pkey.key = self.cert.get_pubkey()\r
- pkey.m2key = m2x509.get_pubkey()\r
- return pkey\r
-\r
- def set_intermediate_ca(self, val):\r
- return self.set_is_ca(val)\r
-\r
- # Set whether this cert is for a CA. All signers and only signers should be CAs.\r
- # The local member starts unset, letting us check that you only set it once\r
- # @param val Boolean indicating whether this cert is for a CA\r
- def set_is_ca(self, val):\r
- if val is None:\r
- return\r
-\r
- if self.isCA != None:\r
- # Can't double set properties\r
- raise "Cannot set basicConstraints CA:?? more than once. Was %s, trying to set as %s" % (self.isCA, val)\r
-\r
- self.isCA = val\r
- if val:\r
- self.add_extension('basicConstraints', 1, 'CA:TRUE')\r
- else:\r
- self.add_extension('basicConstraints', 1, 'CA:FALSE')\r
-\r
-\r
-\r
- ##\r
- # Add an X509 extension to the certificate. Add_extension can only be called\r
- # once for a particular extension name, due to limitations in the underlying\r
- # library.\r
- #\r
- # @param name string containing name of extension\r
- # @param value string containing value of the extension\r
-\r
- def add_extension(self, name, critical, value):\r
- oldExtVal = None\r
- try:\r
- oldExtVal = self.get_extension(name)\r
- except:\r
- # M2Crypto LookupError when the extension isn't there (yet)\r
- pass\r
-\r
- # This code limits you from adding the extension with the same value\r
- # The method comment says you shouldn't do this with the same name\r
- # But actually it (m2crypto) appears to allow you to do this.\r
- if oldExtVal and oldExtVal == value:\r
- # don't add this extension again\r
- # just do nothing as here\r
- return\r
- # FIXME: What if they are trying to set with a different value?\r
- # Is this ever OK? Or should we raise an exception?\r
-# elif oldExtVal:\r
-# raise "Cannot add extension %s which had val %s with new val %s" % (name, oldExtVal, value)\r
-\r
- ext = crypto.X509Extension (name, critical, value)\r
- self.cert.add_extensions([ext])\r
-\r
- ##\r
- # Get an X509 extension from the certificate\r
-\r
- def get_extension(self, name):\r
-\r
- # pyOpenSSL does not have a way to get extensions\r
- m2x509 = X509.load_cert_string(self.save_to_string())\r
- value = m2x509.get_ext(name).get_value()\r
-\r
- return value\r
-\r
- ##\r
- # Set_data is a wrapper around add_extension. It stores the parameter str in\r
- # the X509 subject_alt_name extension. Set_data can only be called once, due\r
- # to limitations in the underlying library.\r
-\r
- def set_data(self, str, field='subjectAltName'):\r
- # pyOpenSSL only allows us to add extensions, so if we try to set the\r
- # same extension more than once, it will not work\r
- if self.data.has_key(field):\r
- raise "Cannot set ", field, " more than once"\r
- self.data[field] = str\r
- self.add_extension(field, 0, str)\r
-\r
- ##\r
- # Return the data string that was previously set with set_data\r
-\r
- def get_data(self, field='subjectAltName'):\r
- if self.data.has_key(field):\r
- return self.data[field]\r
-\r
- try:\r
- uri = self.get_extension(field)\r
- self.data[field] = uri\r
- except LookupError:\r
- return None\r
-\r
- return self.data[field]\r
-\r
- ##\r
- # Sign the certificate using the issuer private key and issuer subject previous set with set_issuer().\r
-\r
- def sign(self):\r
- logger.debug('certificate.sign')\r
- assert self.cert != None\r
- assert self.issuerSubject != None\r
- assert self.issuerKey != None\r
- self.cert.set_issuer(self.issuerSubject)\r
- self.cert.sign(self.issuerKey.get_openssl_pkey(), self.digest)\r
-\r
- ##\r
- # Verify the authenticity of a certificate.\r
- # @param pkey is a Keypair object representing a public key. If Pkey\r
- # did not sign the certificate, then an exception will be thrown.\r
-\r
- def verify(self, pkey):\r
- # pyOpenSSL does not have a way to verify signatures\r
- m2x509 = X509.load_cert_string(self.save_to_string())\r
- m2pkey = pkey.get_m2_pkey()\r
- # verify it\r
- return m2x509.verify(m2pkey)\r
-\r
- # XXX alternatively, if openssl has been patched, do the much simpler:\r
- # try:\r
- # self.cert.verify(pkey.get_openssl_key())\r
- # return 1\r
- # except:\r
- # return 0\r
-\r
- ##\r
- # Return True if pkey is identical to the public key that is contained in the certificate.\r
- # @param pkey Keypair object\r
-\r
- def is_pubkey(self, pkey):\r
- return self.get_pubkey().is_same(pkey)\r
-\r
- ##\r
- # Given a certificate cert, verify that this certificate was signed by the\r
- # public key contained in cert. Throw an exception otherwise.\r
- #\r
- # @param cert certificate object\r
-\r
- def is_signed_by_cert(self, cert):\r
- k = cert.get_pubkey()\r
- result = self.verify(k)\r
- return result\r
-\r
- ##\r
- # Set the parent certficiate.\r
- #\r
- # @param p certificate object.\r
-\r
- def set_parent(self, p):\r
- self.parent = p\r
-\r
- ##\r
- # Return the certificate object of the parent of this certificate.\r
-\r
- def get_parent(self):\r
- return self.parent\r
-\r
- ##\r
- # Verification examines a chain of certificates to ensure that each parent\r
- # signs the child, and that some certificate in the chain is signed by a\r
- # trusted certificate.\r
- #\r
- # Verification is a basic recursion: <pre>\r
- # if this_certificate was signed by trusted_certs:\r
- # return\r
- # else\r
- # return verify_chain(parent, trusted_certs)\r
- # </pre>\r
- #\r
- # At each recursion, the parent is tested to ensure that it did sign the\r
- # child. If a parent did not sign a child, then an exception is thrown. If\r
- # the bottom of the recursion is reached and the certificate does not match\r
- # a trusted root, then an exception is thrown.\r
- # Also require that parents are CAs.\r
- #\r
- # @param Trusted_certs is a list of certificates that are trusted.\r
- #\r
-\r
- def verify_chain(self, trusted_certs = None):\r
- # Verify a chain of certificates. Each certificate must be signed by\r
- # the public key contained in it's parent. The chain is recursed\r
- # until a certificate is found that is signed by a trusted root.\r
-\r
- # verify expiration time\r
- if self.cert.has_expired():\r
- logger.debug("verify_chain: NO, Certificate %s has expired" % self.get_printable_subject())\r
- raise CertExpired(self.get_printable_subject(), "client cert")\r
-\r
- # if this cert is signed by a trusted_cert, then we are set\r
- for trusted_cert in trusted_certs:\r
- if self.is_signed_by_cert(trusted_cert):\r
- # verify expiration of trusted_cert ?\r
- if not trusted_cert.cert.has_expired():\r
- logger.debug("verify_chain: YES. Cert %s signed by trusted cert %s"%(\r
- self.get_printable_subject(), trusted_cert.get_printable_subject()))\r
- return trusted_cert\r
- else:\r
- logger.debug("verify_chain: NO. Cert %s is signed by trusted_cert %s, but that signer is expired..."%(\r
- self.get_printable_subject(),trusted_cert.get_printable_subject()))\r
- raise CertExpired(self.get_printable_subject()," signer trusted_cert %s"%trusted_cert.get_printable_subject())\r
-\r
- # if there is no parent, then no way to verify the chain\r
- if not self.parent:\r
- logger.debug("verify_chain: NO. %s has no parent and issuer %s is not in %d trusted roots"%(self.get_printable_subject(), self.get_issuer(), len(trusted_certs)))\r
- raise CertMissingParent(self.get_printable_subject() + ": Issuer %s not trusted by any of %d trusted roots, and cert has no parent." % (self.get_issuer(), len(trusted_certs)))\r
-\r
- # if it wasn't signed by the parent...\r
- if not self.is_signed_by_cert(self.parent):\r
- logger.debug("verify_chain: NO. %s is not signed by parent %s, but by %s"%self.get_printable_subject(), self.parent.get_printable_subject(), self.get_issuer())\r
- raise CertNotSignedByParent(self.get_printable_subject() + ": Parent %s, issuer %s" % (self.parent.get_printable_subject(), self.get_issuer()))\r
-\r
- # Confirm that the parent is a CA. Only CAs can be trusted as\r
- # signers.\r
- # Note that trusted roots are not parents, so don't need to be\r
- # CAs.\r
- # Ugly - cert objects aren't parsed so we need to read the\r
- # extension and hope there are no other basicConstraints\r
- if not self.parent.isCA and not (self.parent.get_extension('basicConstraints') == 'CA:TRUE'):\r
- logger.warn("verify_chain: cert %s's parent %s is not a CA" % (self.get_printable_subject(), self.parent.get_printable_subject()))\r
- raise CertNotSignedByParent(self.get_printable_subject() + ": Parent %s not a CA" % self.parent.get_printable_subject())\r
-\r
- # if the parent isn't verified...\r
- logger.debug("verify_chain: .. %s, -> verifying parent %s"%(self.get_printable_subject(),self.parent.get_printable_subject()))\r
- self.parent.verify_chain(trusted_certs)\r
-\r
- return\r
-\r
- ### more introspection\r
- def get_extensions(self):\r
- # pyOpenSSL does not have a way to get extensions\r
- triples=[]\r
- m2x509 = X509.load_cert_string(self.save_to_string())\r
- nb_extensions=m2x509.get_ext_count()\r
- logger.debug("X509 had %d extensions"%nb_extensions)\r
- for i in range(nb_extensions):\r
- ext=m2x509.get_ext_at(i)\r
- triples.append( (ext.get_name(), ext.get_value(), ext.get_critical(),) )\r
- return triples\r
-\r
- def get_data_names(self):\r
- return self.data.keys()\r
-\r
- def get_all_datas (self):\r
- triples=self.get_extensions()\r
- for name in self.get_data_names():\r
- triples.append( (name,self.get_data(name),'data',) )\r
- return triples\r
-\r
- # only informative\r
- def get_filename(self):\r
- return getattr(self,'filename',None)\r
-\r
- def dump (self, *args, **kwargs):\r
- print self.dump_string(*args, **kwargs)\r
-\r
- def dump_string (self,show_extensions=False):\r
- result = ""\r
- result += "CERTIFICATE for %s\n"%self.get_printable_subject()\r
- result += "Issued by %s\n"%self.get_issuer()\r
- filename=self.get_filename()\r
- if filename: result += "Filename %s\n"%filename\r
- if show_extensions:\r
- all_datas=self.get_all_datas()\r
- result += " has %d extensions/data attached"%len(all_datas)\r
- for (n,v,c) in all_datas:\r
- if c=='data':\r
- result += " data: %s=%s\n"%(n,v)\r
- else:\r
- result += " ext: %s (crit=%s)=<<<%s>>>\n"%(n,c,v)\r
- return result\r
+#----------------------------------------------------------------------
+# Copyright (c) 2008 Board of Trustees, Princeton University
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and/or hardware specification (the "Work") to
+# deal in the Work without restriction, including without limitation the
+# rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Work, and to permit persons to whom the Work
+# is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Work.
+#
+# THE WORK IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE WORK OR THE USE OR OTHER DEALINGS
+# IN THE WORK.
+#----------------------------------------------------------------------
+
+##
+# SFA uses two crypto libraries: pyOpenSSL and M2Crypto to implement
+# the necessary crypto functionality. Ideally just one of these libraries
+# would be used, but unfortunately each of these libraries is independently
+# lacking. The pyOpenSSL library is missing many necessary functions, and
+# the M2Crypto library has crashed inside of some of the functions. The
+# design decision is to use pyOpenSSL whenever possible as it seems more
+# stable, and only use M2Crypto for those functions that are not possible
+# in pyOpenSSL.
+#
+# This module exports two classes: Keypair and Certificate.
+##
+#
+
+import functools
+import os
+import tempfile
+import base64
+from tempfile import mkstemp
+
+from OpenSSL import crypto
+import M2Crypto
+from M2Crypto import X509
+
+from sfa.util.faults import CertExpired, CertMissingParent, CertNotSignedByParent
+from sfa.util.sfalogging import logger
+
+glo_passphrase_callback = None
+
+##
+# A global callback msy be implemented for requesting passphrases from the
+# user. The function will be called with three arguments:
+#
+# keypair_obj: the keypair object that is calling the passphrase
+# string: the string containing the private key that's being loaded
+# x: unknown, appears to be 0, comes from pyOpenSSL and/or m2crypto
+#
+# The callback should return a string containing the passphrase.
+
+def set_passphrase_callback(callback_func):
+ global glo_passphrase_callback
+
+ glo_passphrase_callback = callback_func
+
+##
+# Sets a fixed passphrase.
+
+def set_passphrase(passphrase):
+ set_passphrase_callback( lambda k,s,x: passphrase )
+
+##
+# Check to see if a passphrase works for a particular private key string.
+# Intended to be used by passphrase callbacks for input validation.
+
+def test_passphrase(string, passphrase):
+ try:
+ crypto.load_privatekey(crypto.FILETYPE_PEM, string, (lambda x: passphrase))
+ return True
+ except:
+ return False
+
+def convert_public_key(key):
+ keyconvert_path = "/usr/bin/keyconvert.py"
+ if not os.path.isfile(keyconvert_path):
+ raise IOError, "Could not find keyconvert in %s" % keyconvert_path
+
+ # we can only convert rsa keys
+ if "ssh-dss" in key:
+ return None
+
+ (ssh_f, ssh_fn) = tempfile.mkstemp()
+ ssl_fn = tempfile.mktemp()
+ os.write(ssh_f, key)
+ os.close(ssh_f)
+
+ cmd = keyconvert_path + " " + ssh_fn + " " + ssl_fn
+ os.system(cmd)
+
+ # this check leaves the temporary file containing the public key so
+ # that it can be expected to see why it failed.
+ # TODO: for production, cleanup the temporary files
+ if not os.path.exists(ssl_fn):
+ return None
+
+ k = Keypair()
+ try:
+ k.load_pubkey_from_file(ssl_fn)
+ except:
+ logger.log_exc("convert_public_key caught exception")
+ k = None
+
+ # remove the temporary files
+ os.remove(ssh_fn)
+ os.remove(ssl_fn)
+
+ return k
+
+##
+# Public-private key pairs are implemented by the Keypair class.
+# A Keypair object may represent both a public and private key pair, or it
+# may represent only a public key (this usage is consistent with OpenSSL).
+
+class Keypair:
+ key = None # public/private keypair
+ m2key = None # public key (m2crypto format)
+
+ ##
+ # Creates a Keypair object
+ # @param create If create==True, creates a new public/private key and
+ # stores it in the object
+ # @param string If string!=None, load the keypair from the string (PEM)
+ # @param filename If filename!=None, load the keypair from the file
+
+ def __init__(self, create=False, string=None, filename=None):
+ if create:
+ self.create()
+ if string:
+ self.load_from_string(string)
+ if filename:
+ self.load_from_file(filename)
+
+ ##
+ # Create a RSA public/private key pair and store it inside the keypair object
+
+ def create(self):
+ self.key = crypto.PKey()
+ self.key.generate_key(crypto.TYPE_RSA, 1024)
+
+ ##
+ # Save the private key to a file
+ # @param filename name of file to store the keypair in
+
+ def save_to_file(self, filename):
+ open(filename, 'w').write(self.as_pem())
+ self.filename=filename
+
+ ##
+ # Load the private key from a file. Implicity the private key includes the public key.
+
+ def load_from_file(self, filename):
+ self.filename=filename
+ buffer = open(filename, 'r').read()
+ self.load_from_string(buffer)
+
+ ##
+ # Load the private key from a string. Implicitly the private key includes the public key.
+
+ def load_from_string(self, string):
+ if glo_passphrase_callback:
+ self.key = crypto.load_privatekey(crypto.FILETYPE_PEM, string, functools.partial(glo_passphrase_callback, self, string) )
+ self.m2key = M2Crypto.EVP.load_key_string(string, functools.partial(glo_passphrase_callback, self, string) )
+ else:
+ self.key = crypto.load_privatekey(crypto.FILETYPE_PEM, string)
+ self.m2key = M2Crypto.EVP.load_key_string(string)
+
+ ##
+ # Load the public key from a string. No private key is loaded.
+
+ def load_pubkey_from_file(self, filename):
+ # load the m2 public key
+ m2rsakey = M2Crypto.RSA.load_pub_key(filename)
+ self.m2key = M2Crypto.EVP.PKey()
+ self.m2key.assign_rsa(m2rsakey)
+
+ # create an m2 x509 cert
+ m2name = M2Crypto.X509.X509_Name()
+ m2name.add_entry_by_txt(field="CN", type=0x1001, entry="junk", len=-1, loc=-1, set=0)
+ m2x509 = M2Crypto.X509.X509()
+ m2x509.set_pubkey(self.m2key)
+ m2x509.set_serial_number(0)
+ m2x509.set_issuer_name(m2name)
+ m2x509.set_subject_name(m2name)
+ ASN1 = M2Crypto.ASN1.ASN1_UTCTIME()
+ ASN1.set_time(500)
+ m2x509.set_not_before(ASN1)
+ m2x509.set_not_after(ASN1)
+ # x509v3 so it can have extensions
+ # prob not necc since this cert itself is junk but still...
+ m2x509.set_version(2)
+ junk_key = Keypair(create=True)
+ m2x509.sign(pkey=junk_key.get_m2_pkey(), md="sha1")
+
+ # convert the m2 x509 cert to a pyopenssl x509
+ m2pem = m2x509.as_pem()
+ pyx509 = crypto.load_certificate(crypto.FILETYPE_PEM, m2pem)
+
+ # get the pyopenssl pkey from the pyopenssl x509
+ self.key = pyx509.get_pubkey()
+ self.filename=filename
+
+ ##
+ # Load the public key from a string. No private key is loaded.
+
+ def load_pubkey_from_string(self, string):
+ (f, fn) = tempfile.mkstemp()
+ os.write(f, string)
+ os.close(f)
+ self.load_pubkey_from_file(fn)
+ os.remove(fn)
+
+ ##
+ # Return the private key in PEM format.
+
+ def as_pem(self):
+ return crypto.dump_privatekey(crypto.FILETYPE_PEM, self.key)
+
+ ##
+ # Return an M2Crypto key object
+
+ def get_m2_pkey(self):
+ if not self.m2key:
+ self.m2key = M2Crypto.EVP.load_key_string(self.as_pem())
+ return self.m2key
+
+ ##
+ # Returns a string containing the public key represented by this object.
+
+ def get_pubkey_string(self):
+ m2pkey = self.get_m2_pkey()
+ return base64.b64encode(m2pkey.as_der())
+
+ ##
+ # Return an OpenSSL pkey object
+
+ def get_openssl_pkey(self):
+ return self.key
+
+ ##
+ # Given another Keypair object, return TRUE if the two keys are the same.
+
+ def is_same(self, pkey):
+ return self.as_pem() == pkey.as_pem()
+
+ def sign_string(self, data):
+ k = self.get_m2_pkey()
+ k.sign_init()
+ k.sign_update(data)
+ return base64.b64encode(k.sign_final())
+
+ def verify_string(self, data, sig):
+ k = self.get_m2_pkey()
+ k.verify_init()
+ k.verify_update(data)
+ return M2Crypto.m2.verify_final(k.ctx, base64.b64decode(sig), k.pkey)
+
+ def compute_hash(self, value):
+ return self.sign_string(str(value))
+
+ # only informative
+ def get_filename(self):
+ return getattr(self,'filename',None)
+
+ def dump (self, *args, **kwargs):
+ print self.dump_string(*args, **kwargs)
+
+ def dump_string (self):
+ result=""
+ result += "KEYPAIR: pubkey=%40s..."%self.get_pubkey_string()
+ filename=self.get_filename()
+ if filename: result += "Filename %s\n"%filename
+ return result
+
+##
+# The certificate class implements a general purpose X509 certificate, making
+# use of the appropriate pyOpenSSL or M2Crypto abstractions. It also adds
+# several addition features, such as the ability to maintain a chain of
+# parent certificates, and storage of application-specific data.
+#
+# Certificates include the ability to maintain a chain of parents. Each
+# certificate includes a pointer to it's parent certificate. When loaded
+# from a file or a string, the parent chain will be automatically loaded.
+# When saving a certificate to a file or a string, the caller can choose
+# whether to save the parent certificates as well.
+
+class Certificate:
+ digest = "md5"
+
+ cert = None
+ issuerKey = None
+ issuerSubject = None
+ parent = None
+ isCA = None # will be a boolean once set
+
+ separator="-----parent-----"
+
+ ##
+ # Create a certificate object.
+ #
+ # @param lifeDays life of cert in days - default is 1825==5 years
+ # @param create If create==True, then also create a blank X509 certificate.
+ # @param subject If subject!=None, then create a blank certificate and set
+ # it's subject name.
+ # @param string If string!=None, load the certficate from the string.
+ # @param filename If filename!=None, load the certficiate from the file.
+ # @param isCA If !=None, set whether this cert is for a CA
+
+ def __init__(self, lifeDays=1825, create=False, subject=None, string=None, filename=None, isCA=None):
+ self.data = {}
+ if create or subject:
+ self.create(lifeDays)
+ if subject:
+ self.set_subject(subject)
+ if string:
+ self.load_from_string(string)
+ if filename:
+ self.load_from_file(filename)
+
+ # Set the CA bit if a value was supplied
+ if isCA != None:
+ self.set_is_ca(isCA)
+
+ # Create a blank X509 certificate and store it in this object.
+
+ def create(self, lifeDays=1825):
+ self.cert = crypto.X509()
+ # FIXME: Use different serial #s
+ self.cert.set_serial_number(3)
+ self.cert.gmtime_adj_notBefore(0) # 0 means now
+ self.cert.gmtime_adj_notAfter(lifeDays*60*60*24) # five years is default
+ self.cert.set_version(2) # x509v3 so it can have extensions
+
+
+ ##
+ # Given a pyOpenSSL X509 object, store that object inside of this
+ # certificate object.
+
+ def load_from_pyopenssl_x509(self, x509):
+ self.cert = x509
+
+ ##
+ # Load the certificate from a string
+
+ def load_from_string(self, string):
+ # if it is a chain of multiple certs, then split off the first one and
+ # load it (support for the ---parent--- tag as well as normal chained certs)
+
+ string = string.strip()
+
+ # If it's not in proper PEM format, wrap it
+ if string.count('-----BEGIN CERTIFICATE') == 0:
+ string = '-----BEGIN CERTIFICATE-----\n%s\n-----END CERTIFICATE-----' % string
+
+ # If there is a PEM cert in there, but there is some other text first
+ # such as the text of the certificate, skip the text
+ beg = string.find('-----BEGIN CERTIFICATE')
+ if beg > 0:
+ # skipping over non cert beginning
+ string = string[beg:]
+
+ parts = []
+
+ if string.count('-----BEGIN CERTIFICATE-----') > 1 and \
+ string.count(Certificate.separator) == 0:
+ parts = string.split('-----END CERTIFICATE-----',1)
+ parts[0] += '-----END CERTIFICATE-----'
+ else:
+ parts = string.split(Certificate.separator, 1)
+
+ self.cert = crypto.load_certificate(crypto.FILETYPE_PEM, parts[0])
+
+ # if there are more certs, then create a parent and let the parent load
+ # itself from the remainder of the string
+ if len(parts) > 1 and parts[1] != '':
+ self.parent = self.__class__()
+ self.parent.load_from_string(parts[1])
+
+ ##
+ # Load the certificate from a file
+
+ def load_from_file(self, filename):
+ file = open(filename)
+ string = file.read()
+ self.load_from_string(string)
+ self.filename=filename
+
+ ##
+ # Save the certificate to a string.
+ #
+ # @param save_parents If save_parents==True, then also save the parent certificates.
+
+ def save_to_string(self, save_parents=True):
+ string = crypto.dump_certificate(crypto.FILETYPE_PEM, self.cert)
+ if save_parents and self.parent:
+ string = string + self.parent.save_to_string(save_parents)
+ return string
+
+ ##
+ # Save the certificate to a file.
+ # @param save_parents If save_parents==True, then also save the parent certificates.
+
+ def save_to_file(self, filename, save_parents=True, filep=None):
+ string = self.save_to_string(save_parents=save_parents)
+ if filep:
+ f = filep
+ else:
+ f = open(filename, 'w')
+ f.write(string)
+ f.close()
+ self.filename=filename
+
+ ##
+ # Save the certificate to a random file in /tmp/
+ # @param save_parents If save_parents==True, then also save the parent certificates.
+ def save_to_random_tmp_file(self, save_parents=True):
+ fp, filename = mkstemp(suffix='cert', text=True)
+ fp = os.fdopen(fp, "w")
+ self.save_to_file(filename, save_parents=True, filep=fp)
+ return filename
+
+ ##
+ # Sets the issuer private key and name
+ # @param key Keypair object containing the private key of the issuer
+ # @param subject String containing the name of the issuer
+ # @param cert (optional) Certificate object containing the name of the issuer
+
+ def set_issuer(self, key, subject=None, cert=None):
+ self.issuerKey = key
+ if subject:
+ # it's a mistake to use subject and cert params at the same time
+ assert(not cert)
+ if isinstance(subject, dict) or isinstance(subject, str):
+ req = crypto.X509Req()
+ reqSubject = req.get_subject()
+ if (isinstance(subject, dict)):
+ for key in reqSubject.keys():
+ setattr(reqSubject, key, subject[key])
+ else:
+ setattr(reqSubject, "CN", subject)
+ subject = reqSubject
+ # subject is not valid once req is out of scope, so save req
+ self.issuerReq = req
+ if cert:
+ # if a cert was supplied, then get the subject from the cert
+ subject = cert.cert.get_subject()
+ assert(subject)
+ self.issuerSubject = subject
+
+ ##
+ # Get the issuer name
+
+ def get_issuer(self, which="CN"):
+ x = self.cert.get_issuer()
+ return getattr(x, which)
+
+ ##
+ # Set the subject name of the certificate
+
+ def set_subject(self, name):
+ req = crypto.X509Req()
+ subj = req.get_subject()
+ if (isinstance(name, dict)):
+ for key in name.keys():
+ setattr(subj, key, name[key])
+ else:
+ setattr(subj, "CN", name)
+ self.cert.set_subject(subj)
+
+ ##
+ # Get the subject name of the certificate
+
+ def get_subject(self, which="CN"):
+ x = self.cert.get_subject()
+ return getattr(x, which)
+
+ ##
+ # Get a pretty-print subject name of the certificate
+
+ def get_printable_subject(self):
+ x = self.cert.get_subject()
+ return "[ OU: %s, CN: %s, SubjectAltName: %s ]" % (getattr(x, "OU"), getattr(x, "CN"), self.get_data())
+
+ ##
+ # Get the public key of the certificate.
+ #
+ # @param key Keypair object containing the public key
+
+ def set_pubkey(self, key):
+ assert(isinstance(key, Keypair))
+ self.cert.set_pubkey(key.get_openssl_pkey())
+
+ ##
+ # Get the public key of the certificate.
+ # It is returned in the form of a Keypair object.
+
+ def get_pubkey(self):
+ m2x509 = X509.load_cert_string(self.save_to_string())
+ pkey = Keypair()
+ pkey.key = self.cert.get_pubkey()
+ pkey.m2key = m2x509.get_pubkey()
+ return pkey
+
+ def set_intermediate_ca(self, val):
+ return self.set_is_ca(val)
+
+ # Set whether this cert is for a CA. All signers and only signers should be CAs.
+ # The local member starts unset, letting us check that you only set it once
+ # @param val Boolean indicating whether this cert is for a CA
+ def set_is_ca(self, val):
+ if val is None:
+ return
+
+ if self.isCA != None:
+ # Can't double set properties
+ raise Exception, "Cannot set basicConstraints CA:?? more than once. Was %s, trying to set as %s" % (self.isCA, val)
+
+ self.isCA = val
+ if val:
+ self.add_extension('basicConstraints', 1, 'CA:TRUE')
+ else:
+ self.add_extension('basicConstraints', 1, 'CA:FALSE')
+
+
+
+ ##
+ # Add an X509 extension to the certificate. Add_extension can only be called
+ # once for a particular extension name, due to limitations in the underlying
+ # library.
+ #
+ # @param name string containing name of extension
+ # @param value string containing value of the extension
+
+ def add_extension(self, name, critical, value):
+ oldExtVal = None
+ try:
+ oldExtVal = self.get_extension(name)
+ except:
+ # M2Crypto LookupError when the extension isn't there (yet)
+ pass
+
+ # This code limits you from adding the extension with the same value
+ # The method comment says you shouldn't do this with the same name
+ # But actually it (m2crypto) appears to allow you to do this.
+ if oldExtVal and oldExtVal == value:
+ # don't add this extension again
+ # just do nothing as here
+ return
+ # FIXME: What if they are trying to set with a different value?
+ # Is this ever OK? Or should we raise an exception?
+# elif oldExtVal:
+# raise "Cannot add extension %s which had val %s with new val %s" % (name, oldExtVal, value)
+
+ ext = crypto.X509Extension (name, critical, value)
+ self.cert.add_extensions([ext])
+
+ ##
+ # Get an X509 extension from the certificate
+
+ def get_extension(self, name):
+
+ # pyOpenSSL does not have a way to get extensions
+ m2x509 = X509.load_cert_string(self.save_to_string())
+ value = m2x509.get_ext(name).get_value()
+
+ return value
+
+ ##
+ # Set_data is a wrapper around add_extension. It stores the parameter str in
+ # the X509 subject_alt_name extension. Set_data can only be called once, due
+ # to limitations in the underlying library.
+
+ def set_data(self, str, field='subjectAltName'):
+ # pyOpenSSL only allows us to add extensions, so if we try to set the
+ # same extension more than once, it will not work
+ if self.data.has_key(field):
+ raise "Cannot set ", field, " more than once"
+ self.data[field] = str
+ self.add_extension(field, 0, str)
+
+ ##
+ # Return the data string that was previously set with set_data
+
+ def get_data(self, field='subjectAltName'):
+ if self.data.has_key(field):
+ return self.data[field]
+
+ try:
+ uri = self.get_extension(field)
+ self.data[field] = uri
+ except LookupError:
+ return None
+
+ return self.data[field]
+
+ ##
+ # Sign the certificate using the issuer private key and issuer subject previous set with set_issuer().
+
+ def sign(self):
+ logger.debug('certificate.sign')
+ assert self.cert != None
+ assert self.issuerSubject != None
+ assert self.issuerKey != None
+ self.cert.set_issuer(self.issuerSubject)
+ self.cert.sign(self.issuerKey.get_openssl_pkey(), self.digest)
+
+ ##
+ # Verify the authenticity of a certificate.
+ # @param pkey is a Keypair object representing a public key. If Pkey
+ # did not sign the certificate, then an exception will be thrown.
+
+ def verify(self, pkey):
+ # pyOpenSSL does not have a way to verify signatures
+ m2x509 = X509.load_cert_string(self.save_to_string())
+ m2pkey = pkey.get_m2_pkey()
+ # verify it
+ return m2x509.verify(m2pkey)
+
+ # XXX alternatively, if openssl has been patched, do the much simpler:
+ # try:
+ # self.cert.verify(pkey.get_openssl_key())
+ # return 1
+ # except:
+ # return 0
+
+ ##
+ # Return True if pkey is identical to the public key that is contained in the certificate.
+ # @param pkey Keypair object
+
+ def is_pubkey(self, pkey):
+ return self.get_pubkey().is_same(pkey)
+
+ ##
+ # Given a certificate cert, verify that this certificate was signed by the
+ # public key contained in cert. Throw an exception otherwise.
+ #
+ # @param cert certificate object
+
+ def is_signed_by_cert(self, cert):
+ k = cert.get_pubkey()
+ result = self.verify(k)
+ return result
+
+ ##
+ # Set the parent certficiate.
+ #
+ # @param p certificate object.
+
+ def set_parent(self, p):
+ self.parent = p
+
+ ##
+ # Return the certificate object of the parent of this certificate.
+
+ def get_parent(self):
+ return self.parent
+
+ ##
+ # Verification examines a chain of certificates to ensure that each parent
+ # signs the child, and that some certificate in the chain is signed by a
+ # trusted certificate.
+ #
+ # Verification is a basic recursion: <pre>
+ # if this_certificate was signed by trusted_certs:
+ # return
+ # else
+ # return verify_chain(parent, trusted_certs)
+ # </pre>
+ #
+ # At each recursion, the parent is tested to ensure that it did sign the
+ # child. If a parent did not sign a child, then an exception is thrown. If
+ # the bottom of the recursion is reached and the certificate does not match
+ # a trusted root, then an exception is thrown.
+ # Also require that parents are CAs.
+ #
+ # @param Trusted_certs is a list of certificates that are trusted.
+ #
+
+ def verify_chain(self, trusted_certs = None):
+ # Verify a chain of certificates. Each certificate must be signed by
+ # the public key contained in it's parent. The chain is recursed
+ # until a certificate is found that is signed by a trusted root.
+
+ # verify expiration time
+ if self.cert.has_expired():
+ logger.debug("verify_chain: NO, Certificate %s has expired" % self.get_printable_subject())
+ raise CertExpired(self.get_printable_subject(), "client cert")
+
+ # if this cert is signed by a trusted_cert, then we are set
+ for trusted_cert in trusted_certs:
+ if self.is_signed_by_cert(trusted_cert):
+ # verify expiration of trusted_cert ?
+ if not trusted_cert.cert.has_expired():
+ logger.debug("verify_chain: YES. Cert %s signed by trusted cert %s"%(
+ self.get_printable_subject(), trusted_cert.get_printable_subject()))
+ return trusted_cert
+ else:
+ logger.debug("verify_chain: NO. Cert %s is signed by trusted_cert %s, but that signer is expired..."%(
+ self.get_printable_subject(),trusted_cert.get_printable_subject()))
+ raise CertExpired(self.get_printable_subject()," signer trusted_cert %s"%trusted_cert.get_printable_subject())
+
+ # if there is no parent, then no way to verify the chain
+ if not self.parent:
+ logger.debug("verify_chain: NO. %s has no parent and issuer %s is not in %d trusted roots"%(self.get_printable_subject(), self.get_issuer(), len(trusted_certs)))
+ raise CertMissingParent(self.get_printable_subject() + ": Issuer %s not trusted by any of %d trusted roots, and cert has no parent." % (self.get_issuer(), len(trusted_certs)))
+
+ # if it wasn't signed by the parent...
+ if not self.is_signed_by_cert(self.parent):
+ logger.debug("verify_chain: NO. %s is not signed by parent %s, but by %s"%\
+ (self.get_printable_subject(),
+ self.parent.get_printable_subject(),
+ self.get_issuer()))
+ raise CertNotSignedByParent("%s: Parent %s, issuer %s"\
+ % (self.get_printable_subject(),
+ self.parent.get_printable_subject(),
+ self.get_issuer()))
+
+ # Confirm that the parent is a CA. Only CAs can be trusted as
+ # signers.
+ # Note that trusted roots are not parents, so don't need to be
+ # CAs.
+ # Ugly - cert objects aren't parsed so we need to read the
+ # extension and hope there are no other basicConstraints
+ if not self.parent.isCA and not (self.parent.get_extension('basicConstraints') == 'CA:TRUE'):
+ logger.warn("verify_chain: cert %s's parent %s is not a CA" % \
+ (self.get_printable_subject(), self.parent.get_printable_subject()))
+ raise CertNotSignedByParent("%s: Parent %s not a CA" % (self.get_printable_subject(),
+ self.parent.get_printable_subject()))
+
+ # if the parent isn't verified...
+ logger.debug("verify_chain: .. %s, -> verifying parent %s"%\
+ (self.get_printable_subject(),self.parent.get_printable_subject()))
+ self.parent.verify_chain(trusted_certs)
+
+ return
+
+ ### more introspection
+ def get_extensions(self):
+ # pyOpenSSL does not have a way to get extensions
+ triples=[]
+ m2x509 = X509.load_cert_string(self.save_to_string())
+ nb_extensions=m2x509.get_ext_count()
+ logger.debug("X509 had %d extensions"%nb_extensions)
+ for i in range(nb_extensions):
+ ext=m2x509.get_ext_at(i)
+ triples.append( (ext.get_name(), ext.get_value(), ext.get_critical(),) )
+ return triples
+
+ def get_data_names(self):
+ return self.data.keys()
+
+ def get_all_datas (self):
+ triples=self.get_extensions()
+ for name in self.get_data_names():
+ triples.append( (name,self.get_data(name),'data',) )
+ return triples
+
+ # only informative
+ def get_filename(self):
+ return getattr(self,'filename',None)
+
+ def dump (self, *args, **kwargs):
+ print self.dump_string(*args, **kwargs)
+
+ def dump_string (self,show_extensions=False):
+ result = ""
+ result += "CERTIFICATE for %s\n"%self.get_printable_subject()
+ result += "Issued by %s\n"%self.get_issuer()
+ filename=self.get_filename()
+ if filename: result += "Filename %s\n"%filename
+ if show_extensions:
+ all_datas=self.get_all_datas()
+ result += " has %d extensions/data attached"%len(all_datas)
+ for (n,v,c) in all_datas:
+ if c=='data':
+ result += " data: %s=%s\n"%(n,v)
+ else:
+ result += " ext: %s (crit=%s)=<<<%s>>>\n"%(n,c,v)
+ return result
git://git.onelab.eu / sfa.git / blobdiff