Add --out option to service, host and cert-show to save the cert to a file.

Override forward() to grab the result and if a certificate is in the entry
and the file is writable then dump the certificate in PEM format.

ticket 473

ipalib/errors.py

@@ -1110,6 +1110,39 @@ class ManagedPolicyError(ExecutionError):
     errno = 4021
     format = _('A managed group cannot have a password policy.')
 
+
+class FileError(ExecutionError):
+    """
+    **4022** Errors when dealing with files
+
+    For example:
+
+    >>> raise FileError('cannot write file \'test\'')
+    Traceback (most recent call last):
+      ...
+    FileError: cannot write file 'test'
+    """
+
+    errno = 4022
+    format = _('%(reason)s')
+
+
+class NoCertificateError(ExecutionError):
+    """
+    **4023** Raised when trying to retrieve a certificate that doesn't exist.
+
+    For example:
+
+    >>> raise NoCertificateError('\'ipa.example.com\' doesn't have a certificate.')
+    Traceback (most recent call last):
+      ...
+    NoCertificateError: 'ipa.example.com' doesn't have a certificate
+    """
+
+    errno = 4023
+    format = _('\'%(entry)s\' doesn\'t have a certificate.')
+
+
 class ManagedGroupExistsError(ExecutionError):
     """
     **4024** Raised when adding a user and its managed group exists

ipalib/plugins/cert.py

@@ -71,6 +71,8 @@ from ipalib import pkcs10
 from ipalib import x509
 from ipalib.plugins.virtual import *
 from ipalib.plugins.service import split_principal
+from ipalib.plugins.service import make_pem, check_writable_file
+from ipalib.plugins.service import write_certificate
 import base64
 import logging
 import traceback
@@ -414,6 +416,12 @@ class cert_show(VirtualCommand):
         ),
     )
 
+    takes_options = (
+        Str('out?',
+            doc=_('file to store certificate in'),
+        ),
+    )
+
     operation="retrieve certificate"
 
     def execute(self, serial_number):
@@ -443,6 +451,20 @@ class cert_show(VirtualCommand):
 
         return dict(result=result)
 
+    def forward(self, *keys, **options):
+        if 'out' in options:
+            check_writable_file(options['out'])
+            result = super(cert_show, self).forward(*keys, **options)
+            if 'usercertificate' in result['result']:
+                write_certificate(result['result']['usercertificate'][0], options['out'])
+                result['summary'] = _('Certificate stored in file \'%(file)s\'') % dict(file=options['out'])
+                return result
+            else:
+                raise errors.NoCertificateError(entry=keys[-1])
+        else:
+            return super(cert_show, self).forward(*keys, **options)
+
+
 api.register(cert_show)
 
 

ipalib/plugins/host.py

@@ -81,6 +81,8 @@ from ipalib.plugins.service import split_principal
 from ipalib.plugins.service import validate_certificate
 from ipalib.plugins.service import normalize_certificate
 from ipalib.plugins.service import set_certificate_attrs
+from ipalib.plugins.service import make_pem, check_writable_file
+from ipalib.plugins.service import write_certificate
 from ipalib.plugins.dns import dns_container_exists, _attribute_types
 from ipalib import _, ngettext
 from ipalib import x509
@@ -577,6 +579,12 @@ class host_show(LDAPRetrieve):
     Display information about a host.
     """
     has_output_params = LDAPRetrieve.has_output_params + host_output_params
+    takes_options = LDAPRetrieve.takes_options + (
+        Str('out?',
+            doc=_('file to store certificate in'),
+        ),
+    )
+
     member_attributes = ['managedby']
 
     def post_callback(self, ldap, dn, entry_attrs, *keys, **options):
@@ -591,6 +599,19 @@ class host_show(LDAPRetrieve):
 
         return dn
 
+    def forward(self, *keys, **options):
+        if 'out' in options:
+            check_writable_file(options['out'])
+            result = super(host_show, self).forward(*keys, **options)
+            if 'usercertificate' in result['result']:
+                write_certificate(result['result']['usercertificate'][0], options['out'])
+                result['summary'] = _('Certificate stored in file \'%(file)s\'') % dict(file=options['out'])
+                return result
+            else:
+                raise errors.NoCertificateError(entry=keys[-1])
+        else:
+            return super(host_show, self).forward(*keys, **options)
+
 api.register(host_show)
 
 

ipalib/plugins/service.py

@@ -69,6 +69,7 @@ EXAMPLES:
 
 """
 import base64
+import os
 
 from ipalib import api, errors, util
 from ipalib import Str, Flag, Bytes
@@ -78,6 +79,7 @@ from ipalib import _, ngettext
 from ipalib import util
 import nss.nss as nss
 from nss.error import NSPRError
+from ipapython.ipautil import file_exists
 
 
 output_params = (
@@ -219,6 +221,41 @@ def set_certificate_attrs(entry_attrs):
     entry_attrs['md5_fingerprint'] = unicode(nss.data_to_hex(nss.md5_digest(cert.der_data), 64)[0])
     entry_attrs['sha1_fingerprint'] = unicode(nss.data_to_hex(nss.sha1_digest(cert.der_data), 64)[0])
 
+def check_writable_file(filename):
+    """
+    Determine if the file is writable. If the file doesn't exist then
+    open the file to test writability.
+    """
+    try:
+        if file_exists(filename):
+            if not os.access(filename, os.W_OK):
+                raise errors.FileError(reason=_('Permission denied: %(file)s') % dict(file=filename))
+        else:
+            fp = open(filename, 'w')
+            fp.close()
+    except (IOError, OSError), e:
+        raise errors.FileError(reason=str(e))
+
+def make_pem(data):
+    """
+    Convert a raw base64-encoded blob into something that looks like a PE
+    file with lines split to 64 characters and proper headers.
+    """
+    cert = '\n'.join([data[x:x+64] for x in range(0, len(data), 64)])
+    return '-----BEGIN CERTIFICATE-----\n' + \
+    cert + \
+    '\n-----END CERTIFICATE-----'
+
+def write_certificate(cert, filename):
+    """
+    Check to see if the certificate should be written to a file and do so.
+    """
+    try:
+        fp = open(filename, 'w')
+        fp.write(make_pem(base64.b64encode(cert)))
+        fp.close()
+    except (IOError, OSError), e:
+        raise errors.FileError(reason=str(e))
 
 class service(LDAPObject):
     """
@@ -411,7 +448,11 @@ class service_show(LDAPRetrieve):
     Display information about an IPA service.
     """
     member_attributes = ['managedby']
-    takes_options = LDAPRetrieve.takes_options
+    takes_options = LDAPRetrieve.takes_options + (
+        Str('out?',
+            doc=_('file to store certificate in'),
+        ),
+    )
 
     def post_callback(self, ldap, dn, entry_attrs, *keys, **options):
         if 'krblastpwdchange' in entry_attrs:
@@ -425,6 +466,19 @@ class service_show(LDAPRetrieve):
 
         return dn
 
+    def forward(self, *keys, **options):
+        if 'out' in options:
+            check_writable_file(options['out'])
+            result = super(service_show, self).forward(*keys, **options)
+            if 'usercertificate' in result['result']:
+                write_certificate(result['result']['usercertificate'][0], options['out'])
+                result['summary'] = _('Certificate stored in file \'%(file)s\'') % dict(file=options['out'])
+                return result
+            else:
+                raise errors.NoCertificateError(entry=keys[-1])
+        else:
+            return super(service_show, self).forward(*keys, **options)
+
 api.register(service_show)
 
 class service_add_host(LDAPAddMember):