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, 49 insertions, 4 deletions

diff --git a/ipalib/plugins/cert.py b/ipalib/plugins/cert.py
index e38ec1812..1681a22f6 100644
--- a/ipalib/plugins/cert.py
+++ b/ipalib/plugins/cert.py
@@ -30,6 +30,24 @@ from ipalib import Command, Str, Int, Bytes, Flag
 from ipalib import errors
 from ipalib.plugins.virtual import *
 import base64
+from OpenSSL import crypto
+
+def get_serial(certificate):
+    """
+    Given a certificate, return the serial number in that cert
+
+    In theory there should be only one cert per object so even if we get
+    passed in a list/tuple only return the first one.
+    """
+    if type(certificate) in (list, tuple):
+        certificate = certificate[0]
+    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 validate_csr(ugettext, csr):
     """
@@ -76,14 +94,14 @@ class cert_request(VirtualCommand):
         # See if the service exists and punt if it doesn't and we aren't
         # going to add it
         try:
-            service = api.Command['service_show'](principal, **skw)
-            if service.get('usercertificate'):
+            (dn, service) = api.Command['service_show'](principal, **skw)
+            if 'usercertificate' in service:
                 # 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(service['usercertificate']))
 
         except errors.NotFound, e:
             if not add:
-                raise e
+                raise errors.NotFound(reason="The service principal for this request doesn't exist.")
 
         # Request the certificate
         result = self.Backend.ra.request_certificate(csr, **kw)
@@ -104,6 +122,33 @@ class cert_request(VirtualCommand):
         else:
             textui.print_plain('Failed to submit a certificate request.')
 
+    def run(self, *args, **options):
+        """
+        Dispatch to forward() and execute() to do work locally and on the
+        server.
+        """
+        if self.env.in_server:
+            return self.execute(*args, **options)
+
+        # Client-side code
+        csr = args[0]
+        if csr[:7] == "file://":
+            file = csr[7:]
+            try:
+                f = open(file, "r")
+                csr = f.readlines()
+                f.close()
+            except IOError, err:
+                raise errors.ValidationError(name='csr', error=err[1])
+            csr = "".join(csr)
+            # We just want the CSR bits, make sure there is nothing else
+            s = csr.find("-----BEGIN NEW CERTIFICATE REQUEST-----")
+            e = csr.find("-----END NEW CERTIFICATE REQUEST-----")
+            if s >= 0:
+                csr = csr[s+40:e]
+        csr = csr.decode('UTF-8')
+        return self.forward(csr, **options)
+
 api.register(cert_request)