PKCS11 Python FindObjects in available slots - python-3.x

Question

I wrote a script in python that gets info from a Cryptoki library. From there I can make (only)LowLevel API calls such as:
C_getInfo
C_GetSlotList
C_SlotInfo
C_OpenSession
C_GetTokenInfo
C_Logout
C_CloseSession
C_Initialize
Here's a few examples on their implementation
a.C_Initialize()
print("C_GetInfo:", hex(a.C_GetInfo(info)))
print("Library manufacturerID:", info.GetManufacturerID())
del info
print("C_GetSlotList(NULL): " + hex(a.C_GetSlotList(0, slotList)))
print("\tAvailable Slots: " + str(len(slotList)))
for x in range(len(slotList)):
print("\tC_SlotInfo(): " + hex(a.C_GetSlotInfo(slotList[x], slotInfo)))
print("\t\tSlot N." + str(x) + ": ID=" + str(slotList[x]) + ", name='" + slotInfo.GetSlotDescription() + "'")
print("\tC_OpenSession(): " + hex(a.C_OpenSession(slotList[x], CKF_SERIAL_SESSION | CKF_RW_SESSION, session)))
print("\t\tSession:" + str(session))
#print("\tMechList:" + hex(a.C_GetMechanismList(0, slotList[x])))
print("\tC_GetTokenInfo(): " + hex(a.C_GetTokenInfo(slotList[x], tokenInfo)))
print("\t\tTokenInfo: Label=" + tokenInfo.GetLabel() + ", ManufacturerID=" + tokenInfo.GetManufacturerID())
print("\t\tTokenInfo: flags=" + hex(tokenInfo.flags) + ", Model=" + tokenInfo.GetModel())
print("\tC_Login(): " + hex(a.C_Login(session, CKU_USER, pin)))
print("\t\tSessionInfo: state=" + hex(sessionInfo.state) + ", flags=" + hex(sessionInfo.flags))
QUESTION
I can't seem to figure out what api call is needed to find objects in the slot list.. i have something like print("Finding objects: " + hex(a.C_FindObjects(slotList[x], CKA_CLASS, CKO_CERTIFICATE)))
I'm not sure what arguments to pass or if it's structured the right way.
Im using this documentation LowLevel API pkcs11
Ultimately I'm trying to extract the specific omnikey smart card token.. use its private key and cert to sign and verify data..

Answer 1

SearchResult = PyKCS11.LowLevel.ckobjlist(10)
SearchTemplate = PyKCS11.LowLevel.ckattrlist(0)
print "C_FindObjectsInit: " + hex(a.C_FindObjectsInit(session,SearchTemplate))
print "C_FindObjects: " + hex(a.C_FindObjects(session, SearchResult))
print "C_FindObjectsFinal: " + hex(a.C_FindObjectsFinal(session))
First you have to make a result variable and use it to search the object list. I passed 10 in, as I knew there were only a handful of objects and tokens within the list. You can construct a template variable that searches each object for specific attributes, such if it is Private, Modifiable, Key Type, Encrypt, etc. Then you have to make (a.C_FindObjectsInit(session,SearchTemplate)) call to initialize the search in the session by template specifications. Working with the LowLevel API can be confusing, there is virtually no documentation. Hope this helps.