diff -up ./src/coolkey/slot.cpp.coolkey-more-keys ./src/coolkey/slot.cpp
--- ./src/coolkey/slot.cpp.coolkey-more-keys	2016-01-20 11:04:38.507533104 -0800
+++ ./src/coolkey/slot.cpp	2016-01-20 12:14:21.429947833 -0800
@@ -32,6 +32,8 @@
 
 #define MIN(x, y) ((x) < (y) ? (x) : (y))
 
+#define MAX_NUM_KEYS 32
+#define MAX_NUM_CERTS 32
 
 
 #ifdef DEBUG
@@ -3458,7 +3460,7 @@ Slot::loadObjects()
         } else if( type == 'c' ) {
             // cert attribute object. find the DER encoding
             unsigned short certnum = getObjectIndex(iter->obj.objectID);
-            if( certnum > 9 ) {
+            if( certnum > MAX_NUM_CERTS ) {
                 //invalid object id
                 throw PKCS11Exception(CKR_DEVICE_ERROR,
                     "Invalid object id %08x",iter->obj.objectID);
@@ -4154,7 +4156,7 @@ Slot::objectToKeyNum(const PKCS11Object
         throw PKCS11Exception(CKR_KEY_HANDLE_INVALID);
     }
     unsigned short keyNum = getObjectIndex(id);
-    if( keyNum > 9 ) {
+    if( keyNum > MAX_NUM_KEYS ) {
         throw PKCS11Exception(CKR_KEY_HANDLE_INVALID);
     }
     return keyNum & 0xFF;
@@ -4911,7 +4913,6 @@ Slot::generateRandom(SessionHandleSuffix
     }
 }
 
-#define MAX_NUM_KEYS 8
 unsigned int
 Slot::getRSAKeySize(PKCS11Object *key)
 {
diff -up ./src/coolkey/slot.h.coolkey-more-keys ./src/coolkey/slot.h
--- ./src/coolkey/slot.h.coolkey-more-keys	2016-01-20 11:04:45.610475971 -0800
+++ ./src/coolkey/slot.h	2016-01-20 11:43:09.981528125 -0800
@@ -511,9 +511,20 @@ class Slot {
     char getObjectClass(unsigned long objectID) const {
         return (char) (objectID >> 24) & 0xff;
     }
+
     unsigned short getObjectIndex(unsigned long objectID) const {
-        return (char )((objectID >> 16) & 0xff) - '0';
-    }
+       char char_index = (char) ((objectID >> 16) & 0xff);
+       if (char_index >= '0' && char_index <= '9') {
+           return char_index - '0';
+       }
+       if (char_index >= 'A' && char_index <= 'Z') {
+           return char_index - 'A' + 10;
+       }
+       if (char_index >= 'a' && char_index <= 'z') {
+           return char_index - 'a' + 26;
+       }
+        return 0x0100 + char_index;
+     }
 
     // actually get the size of a key in bits from the card
     unsigned int getRSAKeySize(PKCS11Object *key);