python-ipalib 4.3.1-0ubuntu1 / usr / lib / python2.7 / dist-packages / ipalib / pkcs10.py

# Authors:
#   Rob Crittenden <rcritten@redhat.com>
#
# Copyright (C) 2010  Red Hat
# see file 'COPYING' for use and warranty information
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from __future__ import print_function

import os
import sys
import base64
import nss.nss as nss
from pyasn1.type import univ, char, namedtype, tag
from pyasn1.codec.der import decoder
import six

from ipapython import ipautil
from ipalib import api

if six.PY3:
    unicode = str

PEM = 0
DER = 1

SAN_DNSNAME = 'DNS name'
SAN_RFC822NAME = 'RFC822 Name'
SAN_OTHERNAME_UPN = 'Other Name (OID.1.3.6.1.4.1.311.20.2.3)'
SAN_OTHERNAME_KRB5PRINCIPALNAME = 'Other Name (OID.1.3.6.1.5.2.2)'

def get_subject(csr, datatype=PEM):
    """
    Given a CSR return the subject value.

    This returns an nss.DN object.
    """
    request = load_certificate_request(csr, datatype)
    try:
        return request.subject
    finally:
        del request

def get_extensions(csr, datatype=PEM):
    """
    Given a CSR return OIDs of certificate extensions.

    The return value is a tuple of strings
    """
    request = load_certificate_request(csr, datatype)

    # Work around a bug in python-nss where nss.oid_dotted_decimal
    # errors on unrecognised OIDs
    #
    # https://bugzilla.redhat.com/show_bug.cgi?id=1246729
    #
    def get_prefixed_oid_str(ext):
        """Returns a string like 'OID.1.2...'."""
        if ext.oid_tag == 0:
            return repr(ext)
        else:
            return nss.oid_dotted_decimal(ext.oid)

    return tuple(get_prefixed_oid_str(ext)[4:]
                 for ext in request.extensions)

class _PrincipalName(univ.Sequence):
    componentType = namedtype.NamedTypes(
        namedtype.NamedType('name-type', univ.Integer().subtype(
            explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0))
        ),
        namedtype.NamedType('name-string', univ.SequenceOf(char.GeneralString()).subtype(
            explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 1))
        ),
    )

class _KRB5PrincipalName(univ.Sequence):
    componentType = namedtype.NamedTypes(
        namedtype.NamedType('realm', char.GeneralString().subtype(
            explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0))
        ),
        namedtype.NamedType('principalName', _PrincipalName().subtype(
            explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 1))
        ),
    )

def _decode_krb5principalname(data):
    principal = decoder.decode(data, asn1Spec=_KRB5PrincipalName())[0]
    realm = (str(principal['realm']).replace('\\', '\\\\')
                                    .replace('@', '\\@'))
    name = principal['principalName']['name-string']
    name = '/'.join(str(n).replace('\\', '\\\\')
                          .replace('/', '\\/')
                          .replace('@', '\\@') for n in name)
    name = '%s@%s' % (name, realm)
    return name

class _AnotherName(univ.Sequence):
    componentType = namedtype.NamedTypes(
        namedtype.NamedType('type-id', univ.ObjectIdentifier()),
        namedtype.NamedType('value', univ.Any().subtype(
            explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0))
        ),
    )

class _GeneralName(univ.Choice):
    componentType = namedtype.NamedTypes(
        namedtype.NamedType('otherName', _AnotherName().subtype(
            implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0))
        ),
        namedtype.NamedType('rfc822Name', char.IA5String().subtype(
            implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 1))
        ),
        namedtype.NamedType('dNSName', char.IA5String().subtype(
            implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 2))
        ),
        namedtype.NamedType('x400Address', univ.Sequence().subtype(
            implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 3))
        ),
        namedtype.NamedType('directoryName', univ.Choice().subtype(
            implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 4))
        ),
        namedtype.NamedType('ediPartyName', univ.Sequence().subtype(
            implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 5))
        ),
        namedtype.NamedType('uniformResourceIdentifier', char.IA5String().subtype(
            implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 6))
        ),
        namedtype.NamedType('iPAddress', univ.OctetString().subtype(
            implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 7))
        ),
        namedtype.NamedType('registeredID', univ.ObjectIdentifier().subtype(
            implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 8))
        ),
    )

class _SubjectAltName(univ.SequenceOf):
    componentType = _GeneralName()

def get_subjectaltname(csr, datatype=PEM):
    """
    Given a CSR return the subjectaltname value, if any.

    The return value is a tuple of strings or None
    """
    request = load_certificate_request(csr, datatype)
    for extension in request.extensions:
        if extension.oid_tag == nss.SEC_OID_X509_SUBJECT_ALT_NAME:
            break
    else:
        return None
    del request

    nss_names = nss.x509_alt_name(extension.value, nss.AsObject)
    asn1_names = decoder.decode(extension.value.data,
                                asn1Spec=_SubjectAltName())[0]
    names = []
    for nss_name, asn1_name in zip(nss_names, asn1_names):
        name_type = nss_name.type_string
        if name_type == SAN_OTHERNAME_KRB5PRINCIPALNAME:
            name = _decode_krb5principalname(asn1_name['otherName']['value'])
        else:
            name = nss_name.name
        names.append((name_type, name))

    return tuple(names)

# Unfortunately, NSS can only parse the extension request attribute, so
# we have to parse friendly name ourselves (see RFC 2986)
class _Attribute(univ.Sequence):
    componentType = namedtype.NamedTypes(
        namedtype.NamedType('type', univ.ObjectIdentifier()),
        namedtype.NamedType('values', univ.Set()),
        )

class _Attributes(univ.SetOf):
    componentType = _Attribute()

class _CertificationRequestInfo(univ.Sequence):
    componentType = namedtype.NamedTypes(
        namedtype.NamedType('version', univ.Integer()),
        namedtype.NamedType('subject', univ.Sequence()),
        namedtype.NamedType('subjectPublicKeyInfo', univ.Sequence()),
        namedtype.OptionalNamedType('attributes', _Attributes().subtype(
            implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0)))
        )

class _CertificationRequest(univ.Sequence):
    componentType = namedtype.NamedTypes(
        namedtype.NamedType('certificationRequestInfo',
                            _CertificationRequestInfo()),
        namedtype.NamedType('signatureAlgorithm', univ.Sequence()),
        namedtype.NamedType('signatureValue', univ.BitString()),
        )

_FRIENDLYNAME = univ.ObjectIdentifier('1.2.840.113549.1.9.20')

def get_friendlyname(csr, datatype=PEM):
    """
    Given a CSR return the value of the friendlyname attribute, if any.

    The return value is a string.
    """
    if datatype == PEM:
        csr = strip_header(csr)
        csr = base64.b64decode(csr)

    csr = decoder.decode(csr, asn1Spec=_CertificationRequest())[0]
    for attribute in csr['certificationRequestInfo']['attributes']:
        if attribute['type'] == _FRIENDLYNAME:
            return unicode(attribute['values'][0])

    return None

def strip_header(csr):
    """
    Remove the header and footer from a CSR.
    """
    headerlen = 40
    s = csr.find("-----BEGIN NEW CERTIFICATE REQUEST-----")
    if s == -1:
        headerlen = 36
        s = csr.find("-----BEGIN CERTIFICATE REQUEST-----")
    if s >= 0:
        e = csr.find("-----END")
        csr = csr[s+headerlen:e]

    return csr

def load_certificate_request(csr, datatype=PEM):
    """
    Given a base64-encoded certificate request, with or without the
    header/footer, return a request object.
    """
    if datatype == PEM:
        csr = strip_header(csr)
        csr = base64.b64decode(csr)

    # A fail-safe so we can always read a CSR. python-nss/NSS will segfault
    # otherwise
    if not nss.nss_is_initialized():
        nss.nss_init_nodb()

    return nss.CertificateRequest(csr)

if __name__ == '__main__':
    nss.nss_init_nodb()

    # Read PEM request from stdin and print out its components

    csrlines = sys.stdin.readlines()
    csr = ''.join(csrlines)

    print(load_certificate_request(csr))
    print(get_subject(csr))
    print(get_subjectaltname(csr))
    print(get_friendlyname(csr))