Use certmonger D-Bus API instead of messing with its files.

FreeIPA certmonger module changed to use D-Bus to communicate with certmonger.
Using the D-Bus API should be more stable and supported way of using cermonger than
tampering with its files.

>=certmonger-0.75.13 is needed for this to work.

https://fedorahosted.org/freeipa/ticket/4280

Reviewed-By: Jan Cholasta <jcholast@redhat.com>

1 files changed, 270 insertions, 263 deletions

diff --git a/ipapython/certmonger.py b/ipapython/certmonger.py
index 673707384..f58b6dafb 100644
--- a/ipapython/certmonger.py
+++ b/ipapython/certmonger.py
@@ -1,4 +1,5 @@
 # Authors: Rob Crittenden <rcritten@redhat.com>
+#          David Kupka <dkupka@redhat.com>
 #
 # Copyright (C) 2010  Red Hat
 # see file 'COPYING' for use and warranty information
@@ -23,137 +24,202 @@
 
 import os
 import sys
-import re
 import time
+import dbus
 from ipapython import ipautil
 from ipapython import dogtag
 from ipapython.ipa_log_manager import *
 from ipaplatform.paths import paths
+from ipaplatform import services
+
+REQUEST_DIR = paths.CERTMONGER_REQUESTS_DIR
+CA_DIR = paths.CERTMONGER_CAS_DIR
+
+DBUS_CM_PATH = '/org/fedorahosted/certmonger'
+DBUS_CM_IF = 'org.fedorahosted.certmonger'
+DBUS_CM_REQUEST_IF = 'org.fedorahosted.certmonger.request'
+DBUS_CM_CA_IF = 'org.fedorahosted.certmonger.ca'
+DBUS_PROPERTY_IF = 'org.freedesktop.DBus.Properties'
+
+
+class _cm_dbus_object(object):
+    """
+    Auxiliary class for convenient DBus object handling.
+    """
+    def __init__(self, bus, object_path, object_dbus_interface,
+                 parent_dbus_interface=None, property_interface=False):
+        """
+        bus - DBus bus object, result of dbus.SystemBus() or dbus.SessionBus()
+              Object is accesible over this DBus bus instance.
+        object_path - path to requested object on DBus bus
+        object_dbus_interface
+        parent_dbus_interface
+        property_interface - create DBus property interface? True or False
+        """
+        if bus is None or object_path is None or object_dbus_interface is None:
+            raise RuntimeError(
+                "bus, object_path and dbus_interface must not be None.")
+        if parent_dbus_interface is None:
+            parent_dbus_interface = object_dbus_interface
+        self.bus = bus
+        self.path = object_path
+        self.obj_dbus_if = object_dbus_interface
+        self.parent_dbus_if = parent_dbus_interface
+        self.obj = bus.get_object(parent_dbus_interface, object_path)
+        self.obj_if = dbus.Interface(self.obj, object_dbus_interface)
+        if property_interface:
+            self.prop_if = dbus.Interface(self.obj, DBUS_PROPERTY_IF)
+
+
+def _start_certmonger():
+    """
+    Start certmonger daemon. If it's already running systemctl just ignores
+    the command.
+    """
+    if not services.knownservices.certmonger.is_running():
+        try:
+            services.knownservices.certmonger.start()
+        except Exception, e:
+            root_logger.error('Failed to start certmonger: %s' % e)
+            raise
+
+
+def _connect_to_certmonger():
+    """
+    Start certmonger daemon and connect to it via DBus.
+    """
+    try:
+        _start_certmonger()
+    except (KeyboardInterrupt, OSError), e:
+        root_logger.error('Failed to start certmonger: %s' % e)
+        raise
+
+    try:
+        bus = dbus.SystemBus()
+        cm = _cm_dbus_object(bus, DBUS_CM_PATH, DBUS_CM_IF)
+    except dbus.DBusException, e:
+        root_logger.error("Failed to access certmonger over DBus: %s", e)
+        raise
+    return cm
 
-REQUEST_DIR=paths.CERTMONGER_REQUESTS_DIR
-CA_DIR=paths.CERTMONGER_CAS_DIR
-
-# Normalizer types for critera in get_request_id()
-NPATH = 1
-
-def find_request_value(filename, directive):
-    """
-    Return a value from a certmonger request file for the requested directive
-
-    It tries to do this a number of times because sometimes there is a delay
-    when ipa-getcert returns and the file is fully updated, particularly
-    when doing a request. Generating a CSR is fast but not instantaneous.
-    """
-    tries = 1
-    value = None
-    found = False
-    while value is None and tries <= 5:
-        tries=tries + 1
-        time.sleep(1)
-        fp = open(filename, 'r')
-        lines = fp.readlines()
-        fp.close()
-
-        for line in lines:
-            if found:
-                # A value can span multiple lines. If it does then it has a
-                # leading space.
-                if not line.startswith(' '):
-                    # We hit the next directive, return now
-                    return value
-                else:
-                    value = value + line[1:]
+
+def _get_requests(criteria=dict()):
+    """
+    Get all requests that matches the provided criteria.
+    """
+    if not isinstance(criteria, dict):
+        raise TypeError('"criteria" must be dict.')
+
+    cm = _connect_to_certmonger()
+    requests = []
+    requests_paths = []
+    if 'nickname' in criteria:
+        request_path = cm.obj_if.find_request_by_nickname(criteria['nickname'])
+        if request_path:
+            requests_paths = [request_path]
+    else:
+        requests_paths = cm.obj_if.get_requests()
+
+    for request_path in requests_paths:
+        request = _cm_dbus_object(cm.bus, request_path, DBUS_CM_REQUEST_IF,
+                                  DBUS_CM_IF, True)
+        for criterion in criteria:
+            if criterion == 'ca-name':
+                ca_path = request.obj_if.get_ca()
+                ca = _cm_dbus_object(cm.bus, ca_path, DBUS_CM_CA_IF,
+                                     DBUS_CM_IF)
+                value = ca.obj_if.get_nickname()
             else:
-                if line.startswith(directive + '='):
-                    found = True
-                    value = line[len(directive)+1:]
+                value = request.prop_if.Get(DBUS_CM_REQUEST_IF, criterion)
+            if value != criteria[criterion]:
+                break
+        else:
+            requests.append(request)
+    return requests
+
+
+def _get_request(criteria):
+    """
+    Find request that matches criteria.
+    If 'nickname' is specified other criteria are ignored because 'nickname'
+    uniquely identify single request.
+    When multiple or none request matches specified criteria RuntimeError is
+    raised.
+    """
+    requests = _get_requests(criteria)
+    if len(requests) == 0:
+        return None
+    elif len(requests) == 1:
+        return requests[0]
+    else:
+        raise RuntimeError("Criteria expected to be met by 1 request, got %s."
+                           % len(requests))
 
-    return value
 
 def get_request_value(request_id, directive):
     """
-    There is no guarantee that the request_id will match the filename
-    in the certmonger requests directory, so open each one to find the
-    request_id.
+    Get property of request.
     """
-    fileList=os.listdir(REQUEST_DIR)
-    for file in fileList:
-        value = find_request_value('%s/%s' % (REQUEST_DIR, file), 'id')
-        if value is not None and value.rstrip() == request_id:
-            return find_request_value('%s/%s' % (REQUEST_DIR, file), directive)
+    try:
+        request = _get_request(dict(nickname=request_id))
+    except RuntimeError, e:
+        root_logger.error('Failed to get request: %s' % e)
+        raise
+    if request:
+        return request.prop_if.Get(DBUS_CM_REQUEST_IF, directive)
+    else:
+        return None
 
-    return None
 
 def get_request_id(criteria):
     """
     If you don't know the certmonger request_id then try to find it by looking
-    through all the request files. An alternative would be to parse the
-    ipa-getcert list output but this seems cleaner.
+    through all the requests.
 
-    criteria is a tuple of key/value/type to search for. The more specific
+    criteria is a tuple of key/value to search for. The more specific
     the better. An error is raised if multiple request_ids are returned for
     the same criteria.
 
     None is returned if none of the criteria match.
     """
-    assert type(criteria) is tuple
-
-    reqid=None
-    fileList=os.listdir(REQUEST_DIR)
-    for file in fileList:
-        match = True
-        for (key, value, valtype) in criteria:
-            rv = find_request_value('%s/%s' % (REQUEST_DIR, file), key)
-            if rv and valtype == NPATH:
-                rv = os.path.abspath(rv)
-            if rv is None or rv.rstrip() != value:
-                match = False
-                break
-        if match and reqid is not None:
-            raise RuntimeError('multiple certmonger requests match the criteria')
-        if match:
-            reqid = find_request_value('%s/%s' % (REQUEST_DIR, file), 'id').rstrip()
+    try:
+        request = _get_request(criteria)
+    except RuntimeError, e:
+        root_logger.error('Failed to get request: %s' % e)
+        raise
+    if request:
+        return request.prop_if.Get(DBUS_CM_REQUEST_IF, 'nickname')
+    else:
+        return None
 
-    return reqid
 
 def get_requests_for_dir(dir):
     """
     Return a list containing the request ids for a given NSS database
     directory.
     """
-    reqid=[]
-    fileList=os.listdir(REQUEST_DIR)
-    for file in fileList:
-        rv = find_request_value(os.path.join(REQUEST_DIR, file),
-                                'cert_storage_location')
-        if rv is None:
-            continue
-        rv = os.path.abspath(rv).rstrip()
-        if rv != dir:
-            continue
-        id = find_request_value(os.path.join(REQUEST_DIR, file), 'id')
-        if id is not None:
-            reqid.append(id.rstrip())
+    reqid = []
+    criteria = {'cert-storage': 'NSSDB', 'key-storage': 'NSSDB',
+                'cert-database': dir, 'key-database': dir, }
+    requests = _get_requests(criteria)
+    for request in requests:
+        reqid.append(request.prop_if.Get(DBUS_CM_REQUEST_IF, 'nickname'))
 
     return reqid
 
+
 def add_request_value(request_id, directive, value):
     """
     Add a new directive to a certmonger request file.
-
-    The certmonger service MUST be stopped in order for this to work.
     """
-    fileList=os.listdir(REQUEST_DIR)
-    for file in fileList:
-        id = find_request_value('%s/%s' % (REQUEST_DIR, file), 'id')
-        if id is not None and id.rstrip() == request_id:
-            current_value = find_request_value('%s/%s' % (REQUEST_DIR, file), directive)
-            if not current_value:
-                fp = open('%s/%s' % (REQUEST_DIR, file), 'a')
-                fp.write('%s=%s\n' % (directive, value))
-                fp.close()
+    try:
+        request = _get_request({'nickname': request_id})
+    except RuntimeError, e:
+        root_logger.error('Failed to get request: %s' % e)
+        raise
+    if request:
+        request.obj_if.modify({directive: value})
 
-    return
 
 def add_principal(request_id, principal):
     """
@@ -162,7 +228,8 @@ def add_principal(request_id, principal):
     When an existing certificate is added via start-tracking it won't have
     a principal.
     """
-    return add_request_value(request_id, 'template_principal', principal)
+    add_request_value(request_id, 'template-principal', [principal])
+
 
 def add_subject(request_id, subject):
     """
@@ -172,47 +239,29 @@ def add_subject(request_id, subject):
     When an existing certificate is added via start-tracking it won't have
     a subject_template set.
     """
-    return add_request_value(request_id, 'template_subject', subject)
+    add_request_value(request_id, 'template-subject', subject)
+
 
 def request_cert(nssdb, nickname, subject, principal, passwd_fname=None):
     """
-    Execute certmonger to request a server certificate
+    Execute certmonger to request a server certificate.
     """
-    args = [paths.IPA_GETCERT,
-            'request',
-            '-d', nssdb,
-            '-n', nickname,
-            '-N', subject,
-            '-K', principal,
-    ]
+    cm = _connect_to_certmonger()
+    request_parameters = dict(KEY_STORAGE='NSSDB', CERT_STORAGE='NSSDB',
+                              CERT_LOCATION=nssdb, CERT_NICKNAME=nickname,
+                              SUBJECT=subject, PRINCIPAL=principal,)
     if passwd_fname:
-        args.append('-p')
-        args.append(os.path.abspath(passwd_fname))
-    (stdout, stderr, returncode) = ipautil.run(args)
-    # FIXME: should be some error handling around this
-    m = re.match('New signing request "(\d+)" added', stdout)
-    request_id = m.group(1)
-    return request_id
-
-def cert_exists(nickname, secdir):
-    """
-    See if a nickname exists in an NSS database.
-
-    Returns True/False
-
-    This isn't very sophisticated in that it doesn't differentiate between
-    a database that doesn't exist and a nickname that doesn't exist within
-    the database.
-    """
-    args = [paths.CERTUTIL, "-L",
-           "-d", os.path.abspath(secdir),
-           "-n", nickname
-          ]
-    (stdout, stderr, rc) = ipautil.run(args, raiseonerr=False)
-    if rc == 0:
-        return True
-    else:
-        return False
+        request_parameters['KEY_PIN_FILE'] = passwd_fname
+    result = cm.obj_if.add_request(request_parameters)
+    try:
+        if result[0]:
+            request = _cm_dbus_object(cm.bus, result[1], DBUS_CM_REQUEST_IF,
+                                      DBUS_CM_IF, True)
+    except TypeError:
+        root_logger.error('Failed to get create new request.')
+        raise
+    return request.obj_if.get_nickname()
+
 
 def start_tracking(nickname, secdir, password_file=None, command=None):
     """
@@ -223,75 +272,69 @@ def start_tracking(nickname, secdir, password_file=None, command=None):
     certmonger to run when it renews a certificate. This command must
     reside in /usr/lib/ipa/certmonger to work with SELinux.
 
-    Returns the stdout, stderr and returncode from running ipa-getcert
-
-    This assumes that certmonger is already running.
+    Returns True or False
     """
-    if not cert_exists(nickname, os.path.abspath(secdir)):
-        raise RuntimeError('Nickname "%s" doesn\'t exist in NSS database "%s"' % (nickname, secdir))
-    args = [paths.IPA_GETCERT, "start-tracking",
-            "-d", os.path.abspath(secdir),
-            "-n", nickname]
-    if password_file:
-        args.append("-p")
-        args.append(os.path.abspath(password_file))
+    cm = _connect_to_certmonger()
+    params = {'TRACK': True}
+    params['cert-nickname'] = nickname
+    params['cert-database'] = os.path.abspath(secdir)
+    params['cert-storage'] = 'NSSDB'
+    params['key-nickname'] = nickname
+    params['key-database'] = os.path.abspath(secdir)
+    params['key-storage'] = 'NSSDB'
     if command:
-        args.append("-C")
-        args.append(command)
-
-    (stdout, stderr, returncode) = ipautil.run(args)
+        params['cert-postsave-command'] = command
+    if password_file:
+        params['KEY_PIN_FILE'] = os.path.abspath(password_file)
+    result = cm.obj_if.add_request(params)
+    try:
+        if result[0]:
+            request = _cm_dbus_object(cm.bus, result[1], DBUS_CM_REQUEST_IF,
+                                      DBUS_CM_IF, True)
+    except TypeError, e:
+        root_logger.error('Failed to add new request.')
+        raise
+    return request.prop_if.Get(DBUS_CM_REQUEST_IF, 'nickname')
 
-    return (stdout, stderr, returncode)
 
 def stop_tracking(secdir, request_id=None, nickname=None):
     """
     Stop tracking the current request using either the request_id or nickname.
 
-    This assumes that the certmonger service is running.
+    Returns True or False
     """
     if request_id is None and nickname is None:
         raise RuntimeError('Both request_id and nickname are missing.')
-    if nickname:
-        # Using the nickname find the certmonger request_id
-        criteria = (('cert_storage_location', os.path.abspath(secdir), NPATH),('cert_nickname', nickname, None))
-        try:
-            request_id = get_request_id(criteria)
-            if request_id is None:
-                return ('', '', 0)
-        except RuntimeError:
-            # This means that multiple requests matched, skip it for now
-            # Fall back to trying to stop tracking using nickname
-            pass
-
-    args = [paths.GETCERT,
-            'stop-tracking',
-    ]
-    if request_id:
-        args.append('-i')
-        args.append(request_id)
-    else:
-        args.append('-n')
-        args.append(nickname)
-        args.append('-d')
-        args.append(os.path.abspath(secdir))
 
-    (stdout, stderr, returncode) = ipautil.run(args)
+    criteria = {'cert-database': secdir}
+    if request_id:
+        criteria['nickname'] = request_id
+    if nickname:
+        criteria['cert-nickname'] = nickname
+    try:
+        request = _get_request(criteria)
+    except RuntimeError, e:
+        root_logger.error('Failed to get request: %s' % e)
+        raise
+    if request:
+        cm = _connect_to_certmonger()
+        cm.obj_if.remove_request(request.path)
 
-    return (stdout, stderr, returncode)
 
 def modify(request_id, profile=None):
-    args = [paths.GETCERT, 'start-tracking',
-            '-i', request_id]
     if profile:
-        args += ['-T', profile]
-    return ipautil.run(args)
+        request = _get_request({'nickname': request_id})
+        if request:
+            request.obj_if.modify({'template-profile': profile})
+
 
 def resubmit_request(request_id, profile=None):
-    args = [paths.IPA_GETCERT, 'resubmit',
-            '-i', request_id]
-    if profile:
-        args += ['-T', profile]
-    return ipautil.run(args)
+    request = _get_request({'nickname': request_id})
+    if request:
+        if profile:
+            request.obj_if.modify({'template-profile': profile})
+        request.obj_if.resubmit()
+
 
 def _find_IPA_ca():
     """
@@ -301,13 +344,10 @@ def _find_IPA_ca():
     We can use find_request_value because the ca files have the
     same file format.
     """
-    fileList=os.listdir(CA_DIR)
-    for file in fileList:
-        value = find_request_value('%s/%s' % (CA_DIR, file), 'id')
-        if value is not None and value.strip() == 'IPA':
-            return '%s/%s' % (CA_DIR, file)
+    cm = _connect_to_certmonger()
+    ca_path = cm.obj_if.find_ca_by_nickname('IPA')
+    return _cm_dbus_object(cm.bus, ca_path, DBUS_CM_CA_IF, DBUS_CM_IF, True)
 
-    return None
 
 def add_principal_to_cas(principal):
     """
@@ -317,58 +357,27 @@ def add_principal_to_cas(principal):
     /usr/libexec/certmonger/ipa-submit.
 
     We also need to restore this on uninstall.
-
-    The certmonger service MUST be stopped in order for this to work.
     """
-    cafile = _find_IPA_ca()
-    if cafile is None:
-        return
-
-    update = False
-    fp = open(cafile, 'r')
-    lines = fp.readlines()
-    fp.close()
-
-    for i in xrange(len(lines)):
-        if lines[i].startswith('ca_external_helper') and \
-            lines[i].find('-k') == -1:
-            lines[i] = '%s -k %s\n' % (lines[i].strip(), principal)
-            update = True
+    ca = _find_IPA_ca()
+    if ca:
+        ext_helper = ca.prop_if.Get(DBUS_CM_CA_IF, 'external-helper')
+        if ext_helper and ext_helper.find('-k') == -1:
+            ext_helper = '%s -k %s' % (ext_helper.strip(), principal)
+            ca.prop_if.Set(DBUS_CM_CA_IF, 'external-helper', ext_helper)
 
-    if update:
-        fp = open(cafile, 'w')
-        for line in lines:
-            fp.write(line)
-        fp.close()
 
 def remove_principal_from_cas():
     """
     Remove any -k principal options from the ipa_submit helper.
-
-    The certmonger service MUST be stopped in order for this to work.
     """
-    cafile = _find_IPA_ca()
-    if cafile is None:
-        return
-
-    update = False
-    fp = open(cafile, 'r')
-    lines = fp.readlines()
-    fp.close()
+    ca = _find_IPA_ca()
+    if ca:
+        ext_helper = ca.prop_if.Get(DBUS_CM_CA_IF, 'external-helper')
+        if ext_helper and ext_helper.find('-k'):
+            ext_helper = ext_helper.strip()[0]
+            ca.prop_if.Set(DBUS_CM_CA_IF, 'external-helper', ext_helper)
 
-    for i in xrange(len(lines)):
-        if lines[i].startswith('ca_external_helper') and \
-            lines[i].find('-k') > 0:
-            lines[i] = lines[i].strip().split(' ')[0] + '\n'
-            update = True
 
-    if update:
-        fp = open(cafile, 'w')
-        for line in lines:
-            fp.write(line)
-        fp.close()
-
-# Routines specific to renewing dogtag CA certificates
 def get_pin(token, dogtag_constants=None):
     """
     Dogtag stores its NSS pin in a file formatted as token:PIN.
@@ -384,6 +393,7 @@ def get_pin(token, dogtag_constants=None):
                 return pin.strip()
     return None
 
+
 def dogtag_start_tracking(ca, nickname, pin, pinfile, secdir, pre_command,
                           post_command, profile=None):
     """
@@ -398,52 +408,46 @@ def dogtag_start_tracking(ca, nickname, pin, pinfile, secdir, pre_command,
     post_command is the script to execute after a renewal is done.
 
     Both commands can be None.
-
-    Returns the stdout, stderr and returncode from running ipa-getcert
-
-    This assumes that certmonger is already running.
     """
-    if not cert_exists(nickname, os.path.abspath(secdir)):
-        raise RuntimeError('Nickname "%s" doesn\'t exist in NSS database "%s"' % (nickname, secdir))
 
-    args = [paths.GETCERT, "start-tracking",
-            "-d", os.path.abspath(secdir),
-            "-n", nickname,
-            "-c", ca,
-           ]
-
-    if pre_command is not None:
+    cm = _connect_to_certmonger()
+    certmonger_cmd_template = paths.CERTMONGER_COMMAND_TEMPLATE
+
+    params = {'TRACK': True}
+    params['cert-nickname'] = nickname
+    params['cert-database'] = os.path.abspath(secdir)
+    params['cert-storage'] = 'NSSDB'
+    params['key-nickname'] = nickname
+    params['key-database'] = os.path.abspath(secdir)
+    params['key-storage'] = 'NSSDB'
+    ca_path = cm.obj_if.find_ca_by_nickname(ca)
+    if ca_path:
+        params['ca'] = ca_path
+    if pin:
+        params['KEY_PIN'] = pin
+    if pinfile:
+        params['KEY_PIN_FILE'] = os.path.abspath(pinfile)
+    if pre_command:
         if not os.path.isabs(pre_command):
             if sys.maxsize > 2**32L:
                 libpath = 'lib64'
             else:
                 libpath = 'lib'
-            pre_command = paths.CERTMONGER_COMMAND_TEMPLATE % (libpath, pre_command)
-        args.append("-B")
-        args.append(pre_command)
-
-    if post_command is not None:
+            pre_command = certmonger_cmd_template % (libpath, pre_command)
+        params['cert-presave-command'] = pre_command
+    if post_command:
         if not os.path.isabs(post_command):
             if sys.maxsize > 2**32L:
                 libpath = 'lib64'
             else:
                 libpath = 'lib'
-            post_command = paths.CERTMONGER_COMMAND_TEMPLATE % (libpath, post_command)
-        args.append("-C")
-        args.append(post_command)
-
-    if pinfile:
-        args.append("-p")
-        args.append(pinfile)
-    else:
-        args.append("-P")
-        args.append(pin)
-
+            post_command = certmonger_cmd_template % (libpath, post_command)
+        params['cert-postsave-command'] = post_command
     if profile:
-        args.append("-T")
-        args.append(profile)
+        params['ca-profile'] = profile
+
+    cm.obj_if.add_request(params)
 
-    (stdout, stderr, returncode) = ipautil.run(args, nolog=[pin])
 
 def check_state(dirs):
     """
@@ -461,6 +465,7 @@ def check_state(dirs):
 
     return reqids
 
+
 def wait_for_request(request_id, timeout=120):
     for i in range(0, timeout, 5):
         state = get_request_value(request_id, 'state').strip()
@@ -475,7 +480,9 @@ def wait_for_request(request_id, timeout=120):
     return state
 
 if __name__ == '__main__':
-    request_id = request_cert(paths.HTTPD_ALIAS_DIR, "Test", "cn=tiger.example.com,O=IPA", "HTTP/tiger.example.com@EXAMPLE.COM")
+    request_id = request_cert(paths.HTTPD_ALIAS_DIR, "Test",
+                              "cn=tiger.example.com,O=IPA",
+                              "HTTP/tiger.example.com@EXAMPLE.COM")
     csr = get_request_value(request_id, 'csr')
     print csr
     stop_tracking(request_id)