Ticket #179: gemsafeV1.key_ref.patch

pkcs15-gemsafeV1.c

@@ -114 +114 @@
         { NULL, NULL, 0, 0, NULL, 0, NULL, 0}
 };
 
-static int gemsafe_get_cert_len(sc_card_t *card, sc_path_t *path)
+static int gemsafe_get_cert_len(sc_card_t *card, sc_path_t *path, 
+        int *key_ref)
 {
         const char *fn_name = "gemsafe_get_cert_len";
         int r;
+        int ind;
         u8  ibuf[248];
         struct sc_file *file;
         size_t objlen, certlen;
@@ -146 +148 @@
             return 0;
         }
 
+        /*
+         * We need to find the private key associated with the cert
+         * It looks like the first thing in the block is a table of
+         * which keys are allocated. 
+         * We will look for the first allocated key, and save the 
+         * key_ref. The table is small and is in the first 248 bytes.
+         * If for some reason this is not true, we can still override
+         * the key_ref in the opensc.conf with flag = n.
+         */
+        ind = 2; /* skip length */
+        while (ibuf[ind] == 0x01) {
+                if (ibuf[ind+1] == 0xFE) {
+                        *key_ref = ibuf[ind+4];
+                        sc_debug(card->ctx, "Using key_ref %d found at offset %d\n",
+                                        *key_ref, ind);
+                        break;
+                }
+                ind = ind + 8;
+        }
+
         /* Using (block+1) in while loop avoids using final cert object data block */
         while (!found && ( (block+1) * 248 < objlen) ) {
             /* Check current buffer */
@@ -193 +215 @@
     const char *fn_name = "sc_pkcs15emu_gemsafe_init";
 
     int    r, i;
+        int        key_ref = 0x03; 
     struct sc_path path;
     struct sc_file *file = NULL;
     struct sc_card *card = p15card->card;
@@ -252 +275 @@
             struct sc_pkcs15_id  p15Id;
 
             sc_format_path(gemsafe_cert[i].path, &path);
-            if (!gemsafe_get_cert_len(card, &path))
+            if (!gemsafe_get_cert_len(card, &path, &key_ref))
                     /* skip errors */
                     continue;
             sc_pkcs15_format_id(gemsafe_cert[i].id, &p15Id);
@@ -284 +307 @@
                     pauthId = &authId;
             } else
                     pauthId = NULL;
+                        /*
+                         * the key ref may be different for different sites 
+                         * by adding flags=n where the low order 4 bits can be
+                         * the key ref we can force it. 
+                         */
+                        if ( p15card->card->flags & 0x0F) {
+                                key_ref = p15card->card->flags & 0x0F;
+                                sc_debug(p15card->card->ctx,
+                                        "Overriding key_ref  with %d\n", key_ref);
+                        } 
             sc_pkcs15emu_add_prkey(p15card, &p15Id, gemsafe_prkeys[i].label,
                             SC_PKCS15_TYPE_PRKEY_RSA,
                             gemsafe_prkeys[i].modulus_len, gemsafe_prkeys[i].usage,
-                            &path, gemsafe_prkeys[i].ref, pauthId,
+                            &path, key_ref, pauthId,
                             gemsafe_prkeys[i].obj_flags);
     }