Add keyword arguments to C_GenerateKeyPair() in an attempt to present

a saner API to the user.  This requires the library to know more than
it really should about which attributes go into the public and private
templates; if doing it this way proves infeasible, we may have to
parse more details out of attributes.yaml to support this feature.

1 files changed, 32 insertions, 3 deletions

diff --git a/py11/__init__.py b/py11/__init__.py
index ec51d19..9d3837e 100644
--- a/py11/__init__.py
+++ b/py11/__init__.py
@@ -140,10 +140,39 @@ class PKCS11 (object):
       for i in xrange(count.value):
         yield objects[i]
 
-  def C_GenerateKeyPair(self, session, mechanism_type, public_template, private_template):
+  def _parse_GenerateKeyPair_template(self,
+                                      # Attributes common to public and private templates
+                                      CKA_ID,
+                                      CKA_LABEL         = None,
+                                      CKA_TOKEN         = False,
+                                      # Attributes only in private template
+                                      CKA_SIGN          = False,
+                                      CKA_DECRYPT       = False,
+                                      CKA_UNWRAP        = False,
+                                      CKA_SENSITIVE     = True,
+                                      CKA_PRIVATE       = True,
+                                      CKA_EXTRACTABLE   = False,
+                                      # Finer-grained control for CKA_TOKEN
+                                      public_CKA_TOKEN  = False,
+                                      private_CKA_TOKEN = False,
+                                      # Anything else is only in public template
+                                      **kwargs):
+    if CKA_LABEL is None:
+      CKA_LABEL = CKA_ID
+    public = dict(kwargs, CKA_LABEL = CKA_LABEL, CKA_ID = CKA_ID, CKA_TOKEN = public_CKA_TOKEN or CKA_TOKEN)
+    private = dict(CKA_LABEL = CKA_LABEL, CKA_ID = CKA_ID, CKA_TOKEN = private_CKA_TOKEN or CKA_TOKEN,
+                   CKA_SIGN = CKA_SIGN, CKA_DECRYPT = CKA_DECRYPT, CKA_UNWRAP = CKA_UNWRAP,
+                   CKA_SENSITIVE = CKA_SENSITIVE, CKA_PRIVATE = CKA_PRIVATE, CKA_EXTRACTABLE = CKA_EXTRACTABLE)
+    return self.adb.to_ctypes(public), self.adb.to_ctypes(private)
+
+  def C_GenerateKeyPair(self, session, mechanism_type, public_template = None, private_template = None, **kwargs):
+    assert kwargs or (public_template and private_template)
+    if kwargs:
+      public_template, private_template = self._parse_GenerateKeyPair_template(**kwargs)
+    else:
+      public_template  = self.adb.to_ctypes(public_template)
+      private_template = self.adb.to_ctypes(private_template)
     mechanism = CK_MECHANISM(mechanism_type, None, 0)
-    public_template  = self.adb.to_ctypes(public_template)
-    private_template = self.adb.to_ctypes(private_template)
     public_handle  = CK_OBJECT_HANDLE()
     private_handle = CK_OBJECT_HANDLE()
     self.so.C_GenerateKeyPair(session, byref(mechanism),