CCID: App changes (#3837)

- Keep ccid_callback and buffer as private to the iso7816_handler
- set usb ccid callback from iso7816_handler (to ensure the right structure is being passed)
- make iso7816 related code independent from furi related code (goal is to make it independently testable)
- rename vars

Co-authored-by: あく <alleteam@gmail.com>

applications/debug/ccid_test/ccid_test_app.c

@@ -105,7 +105,7 @@ void ccid_test_app_free(CcidTestApp* app) {
     furi_record_close(RECORD_GUI);
     app->gui = NULL;
 
-    free(app->iso7816_handler);
+    iso7816_handler_free(app->iso7816_handler);
 
     // Free rest
     free(app);
@@ -121,8 +121,7 @@ int32_t ccid_test_app(void* p) {
     furi_hal_usb_unlock();
 
     furi_check(furi_hal_usb_set_config(&usb_ccid, &app->ccid_cfg) == true);
-    furi_hal_usb_ccid_set_callbacks(
+    iso7816_handler_set_usb_ccid_callbacks();
-        (CcidCallbacks*)&app->iso7816_handler->ccid_callbacks, app->iso7816_handler);
     furi_hal_usb_ccid_insert_smartcard();
 
     //handle button events
@@ -142,7 +141,7 @@ int32_t ccid_test_app(void* p) {
     }
 
     //tear down USB
-    furi_hal_usb_ccid_set_callbacks(NULL, NULL);
+    iso7816_handler_reset_usb_ccid_callbacks();
     furi_hal_usb_set_config(usb_mode_prev, NULL);
 
     //teardown view

applications/debug/ccid_test/iso7816/iso7816_handler.c

@@ -6,11 +6,17 @@
 #include <furi.h>
 #include <furi_hal.h>
 
+#include "iso7816_handler.h"
+
 #include "iso7816_t0_apdu.h"
 #include "iso7816_atr.h"
-#include "iso7816_handler.h"
 #include "iso7816_response.h"
 
+static Iso7816Handler* iso7816_handler;
+static CcidCallbacks* ccid_callbacks;
+static uint8_t* command_apdu_buffer;
+static uint8_t* response_apdu_buffer;
+
 void iso7816_icc_power_on_callback(uint8_t* atr_data, uint32_t* atr_data_len, void* context) {
     furi_check(context);
 
@@ -40,12 +46,11 @@ void iso7816_xfr_datablock_callback(
 
     Iso7816Handler* handler = (Iso7816Handler*)context;
 
-    ISO7816_Response_APDU* response_apdu = (ISO7816_Response_APDU*)&handler->response_apdu_buffer;
+    ISO7816_Response_APDU* response_apdu = (ISO7816_Response_APDU*)response_apdu_buffer;
-
+    ISO7816_Command_APDU* command_apdu = (ISO7816_Command_APDU*)command_apdu_buffer;
-    ISO7816_Command_APDU* command_apdu = (ISO7816_Command_APDU*)&handler->command_apdu_buffer;
 
     uint8_t result = iso7816_read_command_apdu(
-        command_apdu, pc_to_reader_datablock, pc_to_reader_datablock_len);
+        command_apdu, pc_to_reader_datablock, pc_to_reader_datablock_len, CCID_SHORT_APDU_SIZE);
 
     if(result == ISO7816_READ_COMMAND_APDU_OK) {
         handler->iso7816_process_command(command_apdu, response_apdu);
@@ -61,8 +66,31 @@ void iso7816_xfr_datablock_callback(
 }
 
 Iso7816Handler* iso7816_handler_alloc() {
-    Iso7816Handler* handler = malloc(sizeof(Iso7816Handler));
+    iso7816_handler = malloc(sizeof(Iso7816Handler));
-    handler->ccid_callbacks.icc_power_on_callback = iso7816_icc_power_on_callback;
+
-    handler->ccid_callbacks.xfr_datablock_callback = iso7816_xfr_datablock_callback;
+    command_apdu_buffer = malloc(sizeof(ISO7816_Command_APDU) + CCID_SHORT_APDU_SIZE);
-    return handler;
+    response_apdu_buffer = malloc(sizeof(ISO7816_Response_APDU) + CCID_SHORT_APDU_SIZE);
+
+    ccid_callbacks = malloc(sizeof(CcidCallbacks));
+    ccid_callbacks->icc_power_on_callback = iso7816_icc_power_on_callback;
+    ccid_callbacks->xfr_datablock_callback = iso7816_xfr_datablock_callback;
+
+    return iso7816_handler;
+}
+
+void iso7816_handler_set_usb_ccid_callbacks() {
+    furi_hal_usb_ccid_set_callbacks(ccid_callbacks, iso7816_handler);
+}
+
+void iso7816_handler_reset_usb_ccid_callbacks() {
+    furi_hal_usb_ccid_set_callbacks(NULL, NULL);
+}
+
+void iso7816_handler_free(Iso7816Handler* handler) {
+    free(ccid_callbacks);
+
+    free(command_apdu_buffer);
+    free(response_apdu_buffer);
+
+    free(handler);
 }

applications/debug/ccid_test/iso7816/iso7816_handler.h

@@ -5,14 +5,14 @@
 #include "iso7816_t0_apdu.h"
 
 typedef struct {
-    CcidCallbacks ccid_callbacks;
     void (*iso7816_answer_to_reset)(Iso7816Atr* atr);
     void (*iso7816_process_command)(
         const ISO7816_Command_APDU* command,
         ISO7816_Response_APDU* response);
-
-    uint8_t command_apdu_buffer[sizeof(ISO7816_Command_APDU) + CCID_SHORT_APDU_SIZE];
-    uint8_t response_apdu_buffer[sizeof(ISO7816_Response_APDU) + CCID_SHORT_APDU_SIZE];
 } Iso7816Handler;
 
 Iso7816Handler* iso7816_handler_alloc();
+
+void iso7816_handler_free(Iso7816Handler* handler);
+void iso7816_handler_set_usb_ccid_callbacks();
+void iso7816_handler_reset_usb_ccid_callbacks();

applications/debug/ccid_test/iso7816/iso7816_t0_apdu.c

@@ -1,49 +1,48 @@
 /* Implements rudimentary iso7816-3 support for APDU (T=0) */
 #include <stdint.h>
 #include <string.h>
-#include <furi.h>
-#include <furi_hal.h>
 #include "iso7816_t0_apdu.h"
 
-//reads dataBuffer with dataLen size, translate it into a ISO7816_Command_APDU type
+//reads pc_to_reader_datablock_len with pc_to_reader_datablock_len size, translate it into a ISO7816_Command_APDU type
 //extra data will be pointed to commandDataBuffer
 uint8_t iso7816_read_command_apdu(
     ISO7816_Command_APDU* command,
-    const uint8_t* dataBuffer,
+    const uint8_t* pc_to_reader_datablock,
-    uint32_t dataLen) {
+    uint32_t pc_to_reader_datablock_len,
-    command->CLA = dataBuffer[0];
+    uint32_t max_apdu_size) {
-    command->INS = dataBuffer[1];
+    command->CLA = pc_to_reader_datablock[0];
-    command->P1 = dataBuffer[2];
+    command->INS = pc_to_reader_datablock[1];
-    command->P2 = dataBuffer[3];
+    command->P1 = pc_to_reader_datablock[2];
+    command->P2 = pc_to_reader_datablock[3];
 
-    if(dataLen == 4) {
+    if(pc_to_reader_datablock_len == 4) {
         command->Lc = 0;
         command->Le = 0;
         command->LePresent = false;
 
         return ISO7816_READ_COMMAND_APDU_OK;
-    } else if(dataLen == 5) {
+    } else if(pc_to_reader_datablock_len == 5) {
         //short le
 
         command->Lc = 0;
-        command->Le = dataBuffer[4];
+        command->Le = pc_to_reader_datablock[4];
         command->LePresent = true;
 
         return ISO7816_READ_COMMAND_APDU_OK;
-    } else if(dataLen > 5 && dataBuffer[4] != 0x00) {
+    } else if(pc_to_reader_datablock_len > 5 && pc_to_reader_datablock[4] != 0x00) {
         //short lc
 
-        command->Lc = dataBuffer[4];
+        command->Lc = pc_to_reader_datablock[4];
-        if(command->Lc > 0 && command->Lc < CCID_SHORT_APDU_SIZE) { //-V560
+        if(command->Lc > 0 && command->Lc < max_apdu_size) { //-V560
-            memcpy(command->Data, &dataBuffer[5], command->Lc);
+            memcpy(command->Data, &pc_to_reader_datablock[5], command->Lc);
 
             //does it have a short le too?
-            if(dataLen == (uint32_t)(command->Lc + 5)) {
+            if(pc_to_reader_datablock_len == (uint32_t)(command->Lc + 5)) {
                 command->Le = 0;
                 command->LePresent = false;
                 return ISO7816_READ_COMMAND_APDU_OK;
-            } else if(dataLen == (uint32_t)(command->Lc + 6)) {
+            } else if(pc_to_reader_datablock_len == (uint32_t)(command->Lc + 6)) {
-                command->Le = dataBuffer[dataLen - 1];
+                command->Le = pc_to_reader_datablock[pc_to_reader_datablock_len - 1];
                 command->LePresent = true;
 
                 return ISO7816_READ_COMMAND_APDU_OK;

applications/debug/ccid_test/iso7816/iso7816_t0_apdu.h

@@ -34,7 +34,8 @@ typedef struct {
 uint8_t iso7816_read_command_apdu(
     ISO7816_Command_APDU* command,
     const uint8_t* pc_to_reader_datablock,
-    uint32_t pc_to_reader_datablock_len);
+    uint32_t pc_to_reader_datablock_len,
+    uint32_t max_apdu_size);
 void iso7816_write_response_apdu(
     const ISO7816_Response_APDU* response,
     uint8_t* reader_to_pc_datablock,