From a4ef5e6d172eda105445dee50dd278f6ecc3622d Mon Sep 17 00:00:00 2001
From: Pol Henarejos <pol.henarejos@cttc.es>
Date: Thu, 24 Feb 2022 16:22:05 +0100
Subject: [PATCH] Adding delete file command.

Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>
---
 file.c    | 12 ++++++++++++
 file.h    |  1 +
 hsm2040.h |  1 +
 sc_hsm.c  | 22 ++++++++++++++++++++++
 4 files changed, 36 insertions(+)

diff --git a/file.c b/file.c
index dcc04f5..bb2dcb1 100644
--- a/file.c
+++ b/file.c
@@ -392,6 +392,18 @@ file_t *search_dynamic_file(uint16_t fid) {
     return NULL;
 }
 
+int delete_dynamic_file(file_t *f) {
+    for (int i = 0; i < dynamic_files; i++) {
+        if (dynamic_file[i].fid == f->fid) {
+            for (int j = i+1; j < dynamic_files; j++)
+                memcpy(&dynamic_file[j-1], &dynamic_file[j], sizeof(file_t));
+            dynamic_files--;
+            return HSM_OK;
+        }
+    }
+    return HSM_ERR_FILE_NOT_FOUND;
+}
+
 file_t *file_new(uint16_t fid) {
     file_t *f;
     if ((f = search_dynamic_file(fid)))
diff --git a/file.h b/file.h
index f5005b8..f153c9f 100644
--- a/file.h
+++ b/file.h
@@ -94,6 +94,7 @@ extern file_t *file_new(uint16_t);
 extern uint16_t dynamic_files;
 extern file_t dynamic_file[];
 extern file_t *search_dynamic_file(uint16_t);
+extern int delete_dynamic_file(file_t *f);
 
 extern file_chain_t *add_file_to_chain(file_t *file, file_chain_t **chain);
 extern file_t *search_file_chain(uint16_t fid, file_chain_t *chain);
diff --git a/hsm2040.h b/hsm2040.h
index 0caebcf..a59f4d9 100644
--- a/hsm2040.h
+++ b/hsm2040.h
@@ -112,6 +112,7 @@ void put_binary (const char *s, int len);
 
 extern int flash_write_data_to_file(file_t *file, const uint8_t *data, uint16_t len);
 extern void low_flash_available();
+extern int flash_clear_file(file_t *file);
 
 extern pico_unique_board_id_t unique_id;
 #endif
\ No newline at end of file
diff --git a/sc_hsm.c b/sc_hsm.c
index 658c841..c367af5 100644
--- a/sc_hsm.c
+++ b/sc_hsm.c
@@ -1071,6 +1071,26 @@ int cmd_update_ef() {
     return SW_OK(); 
 }
 
+int cmd_delete_file() {
+    file_t *ef = NULL;
+    if (apdu.cmd_apdu_data_len == 0) {
+        ef = currentEF;
+        if (!(ef = search_dynamic_file(ef->fid)))
+            return SW_FILE_INVALID();
+    }
+    else {
+        uint16_t fid = (apdu.cmd_apdu_data[0] << 8) | apdu.cmd_apdu_data[1];
+        if (!(ef = search_dynamic_file(fid)))
+            return SW_FILE_NOT_FOUND();
+    }
+    if (flash_clear_file(ef) != HSM_OK)
+        return SW_EXEC_ERROR();
+    if (delete_dynamic_file(ef) != HSM_OK)
+        return SW_EXEC_ERROR();
+    
+    return SW_OK();
+}
+
 typedef struct cmd
 {
   uint8_t ins;
@@ -1088,6 +1108,7 @@ typedef struct cmd
 #define INS_LIST_KEYS               0x58
 #define INS_KEYPAIR_GEN             0x46
 #define INS_UPDATE_EF               0xD7
+#define INS_DELETE_FILE             0xE4
 
 static const cmd_t cmds[] = {
     { INS_SELECT_FILE, cmd_select },
@@ -1101,6 +1122,7 @@ static const cmd_t cmds[] = {
     { INS_IMPORT_DKEK, cmd_import_dkek },
     { INS_KEYPAIR_GEN, cmd_keypair_gen },
     { INS_UPDATE_EF, cmd_update_ef },
+    { INS_DELETE_FILE, cmd_delete_file },
     { 0x00, 0x0}
 };