add two new functions

sc_reader_t *sc_ctx_get_reader(sc_context_t *ctx, unsigned int i);
	unsigned int sc_ctx_get_reader_count(sc_context_t *ctx);
to access the reader_count and the sc_reader objects (to avoid accessing
the sc_context members directly).
Use these functions in src/pkcs11 + error checking to avoid accessing
invalid sc_reader objects.


git-svn-id: https://www.opensc-project.org/svnp/opensc/trunk@2595 c6295689-39f2-0310-b995-f0e70906c6a9

src/libopensc/ctx.c

@@ -643,6 +643,18 @@ static void process_config_file(sc_context_t *ctx, struct _sc_ctx_options *opts)
 		load_parameters(ctx, ctx->conf_blocks[i], opts);
 }
 
+sc_reader_t *sc_ctx_get_reader(sc_context_t *ctx, unsigned int i)
+{
+	if (i >= (unsigned int)ctx->reader_count || i >= SC_MAX_READERS)
+		return NULL;
+	return ctx->reader[i];
+}
+
+unsigned int sc_ctx_get_reader_count(sc_context_t *ctx)
+{
+	return (unsigned int)ctx->reader_count;
+}
+
 int sc_establish_context(sc_context_t **ctx_out, const char *app_name)
 {
 	const char *default_app = "default";

src/libopensc/opensc.h

@@ -678,6 +678,23 @@ int sc_establish_context(sc_context_t **ctx, const char *app_name);
  * @param ctx A pointer to the context structure to be released
  */
 int sc_release_context(sc_context_t *ctx);
+
+/**
+ * Returns a pointer to the specified sc_reader_t object
+ * @param  ctx  OpenSC context
+ * @param  i    number of the reader structure to return (starting with 0)
+ * @return the requested sc_reader object or NULL if the index is
+ *         not available
+ */
+sc_reader_t *sc_ctx_get_reader(sc_context_t *ctx, unsigned int i);
+
+/**
+ * Returns the number a available sc_reader objects
+ * @param  ctx  OpenSC context
+ * @return the number of available reader objects
+ */
+unsigned int sc_ctx_get_reader_count(sc_context_t *ctx);
+
 /**
  * Forces the use of a specified card driver
  * @param ctx OpenSC context

src/pkcs11/pkcs11-global.c

@@ -84,7 +84,7 @@ CK_RV C_Finalize(CK_VOID_PTR pReserved)
 	}
 
 	sc_debug(context, "Shutting down Cryptoki\n");
-	for (i=0; i<context->reader_count; i++)
+	for (i=0; i < (int)sc_ctx_get_reader_count(context); i++)
 		card_removed(i);
 
 	sc_release_context(context);
@@ -361,8 +361,12 @@ CK_RV C_WaitForSlotEvent(CK_FLAGS flags,   /* blocking/nonblocking flag */
 	 || (flags & CKF_DONT_BLOCK))
 		goto out;
 
-	for (i = k = 0; i < context->reader_count; i++) {
-		reader = context->reader[i];
+	for (i = k = 0; i < (int)sc_ctx_get_reader_count(context); i++) {
+		reader = sc_ctx_get_reader(context, i);
+		if (reader == NULL) {
+			rv = CKR_GENERAL_ERROR;
+			goto out;
+		}
 		for (j = 0; j < reader->slot_count; j++, k++) {
 			readers[k] = reader;
 			slots[k] = j;

src/pkcs11/slot.c

@@ -83,10 +83,12 @@ CK_RV card_detect(int reader)
 	sc_debug(context, "%d: Detecting smart card\n", reader);
 	for (i = card->max_slots; i--; ) {
 		struct sc_pkcs11_slot *slot;
+		sc_reader_t *rdr = sc_ctx_get_reader(context, (unsigned int)reader);
 
+		if (rdr == NULL)
+			return CKR_GENERAL_ERROR;
 		slot = virtual_slots + card->first_slot + i;
-		strcpy_bp(slot->slot_info.slotDescription,
-				context->reader[reader]->name, 64);
+		strcpy_bp(slot->slot_info.slotDescription, rdr->name, 64);
 		slot->reader = reader;
 	}
 
@@ -119,7 +121,7 @@ again:	rc = sc_detect_card_presence(context->reader[reader], 0);
 	/* Detect the card if it's not known already */
 	if (card->card == NULL) {
 		sc_debug(context, "%d: Connecting to smart card\n", reader);
-		rc = sc_connect_card(context->reader[reader], 0, &card->card);
+		rc = sc_connect_card(sc_ctx_get_reader(context, reader), 0, &card->card);
 		if (rc != SC_SUCCESS)
 			return sc_to_cryptoki_error(rc, reader);
 	}
@@ -158,7 +160,7 @@ CK_RV __card_detect_all(int report_events)
 
 	if (context == NULL_PTR)
 		return CKR_CRYPTOKI_NOT_INITIALIZED;
-	for (i = 0; i < context->reader_count; i++)
+	for (i = 0; i < (int)sc_ctx_get_reader_count(context); i++)
 		card_detect(i);
 	if (!report_events) {
 		CK_SLOT_ID id;