Add external CA signing and abstract out the RA backend

External CA signing is a 2-step process. You first have to run the IPA
installer which will generate a CSR. You pass this CSR to your external
CA and get back a cert. You then pass this cert and the CA cert and
re-run the installer. The CSR is always written to /root/ipa.csr.

A run would look like:

 # ipa-server-install --ca --external-ca -p password -a password -r EXAMPLE.COM -u dirsrv -n example.com --hostname=ipa.example.com -U
[ sign cert request ]
 # ipa-server-install --ca --external-ca -p password -a password --external_cert_file=/tmp/rob.crt --external_ca_file=/tmp/cacert.crt  -U -p password -a password -r EXAMPLE.COM -u dirsrv -n example.com --hostname=ipa.example.com

This also abstracts out the RA backend plugin so the self-signed CA we
create can be used in a running server. This means that the cert plugin
can request certs (and nothing else). This should let us do online replica
creation.

To handle the self-signed CA the simple ca_serialno file now contains
additional data so we don't have overlapping serial numbers in replicas.
This isn't used yet. Currently the cert plugin will not work on self-signed
replicas.

One very important change for self-signed CAs is that the CA is no longer
held in the DS database. It is now in the Apache database.

Lots of general fixes were also made in ipaserver.install.certs including:
 - better handling when multiple CA certificates are in a single file
 - A temporary directory for request certs is not always created when the
   class is instantiated (you have to call setup_cert_request())

1 files changed, 15 insertions, 6 deletions

diff --git a/ipalib/plugins/service.py b/ipalib/plugins/service.py
index 8e9554282..70812579d 100644
--- a/ipalib/plugins/service.py
+++ b/ipalib/plugins/service.py
@@ -33,6 +33,17 @@ from ipalib import uuid
 _container_dn = api.env.container_service
 _default_attributes = ['krbprincipalname', 'usercertificate']
 
+def get_serial(certificate):
+    """
+    Given a certificate, return the serial number in that cert
+    """
+    try:
+        x509 = crypto.load_certificate(crypto.FILETYPE_ASN1, certificate)
+        serial = str(x509.get_serial_number())
+    except crypto.Error:
+        raise errors.GenericError(format='Unable to decode certificate in entry')
+
+    return serial
 
 def split_principal(principal):
     service = hostname = realm = None
@@ -194,10 +205,8 @@ class service_del(crud.Delete):
             'krbprincipalname', principal, 'ipaservice'
         )
 
-        if 'usercerfificate' in entry_attrs:
-            cert = entry_attrs['usercertificate']
-            x509 = crypto.load_certificate(crypto.FILETYPE_ASN1, cert)
-            serial = str(x509.get_serial_number())
+        if 'usercertificate' in entry_attrs:
+            serial = get_serial(entry_attrs['usercertificate'])
             api.Command['cert_revoke'](unicode(serial), revocation_reason=5)
 
         ldap.delete_entry(dn)
@@ -226,9 +235,9 @@ class service_mod(crud.Update):
         dn = ldap.make_dn_from_attr('krbprincipalname', principal, _container_dn)
 
         (dn, old_entry_attrs) = ldap.get_entry(dn)
-        if 'usercertificate' in old_entry_attrs and 'usercerficate' in options:
+        if 'usercertificate' in old_entry_attrs and 'usercertificate' in options:
             # FIXME, what to do here? Do we revoke the old cert?
-            raise errors.GenericError(format='entry already has a certificate')
+            raise errors.GenericError(format='entry already has a certificate, serial number %s' % get_serial(old_entry_attrs['usercertificate']))
 
         try:
             ldap.update_entry(dn, entry_attrs)