From 0607f3a47b507cc5c1081fc8bef8639820ed3f32 Mon Sep 17 00:00:00 2001
From: iceman1001 <iceman@iuse.se>
Date: Mon, 15 Jan 2024 11:18:35 +0100
Subject: [PATCH] added some sanity checks for the person who enters too small
 blocksize

---
 client/src/cmdhf15.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/client/src/cmdhf15.c b/client/src/cmdhf15.c
index 6ce5a2d67..27d432a2f 100644
--- a/client/src/cmdhf15.c
+++ b/client/src/cmdhf15.c
@@ -1250,6 +1250,12 @@ static int CmdHF15ESave(const char *Cmd) {
     int count = arg_get_int_def(ctx, 3, -1);
     CLIParserFree(ctx);
 
+    // sanity checks
+    if (blocksize < 4) {
+        PrintAndLogEx(WARNING, "Blocksize too small, using default 4 bytes");
+        blocksize = 4;
+    }
+
     int bytes = CARD_MEMORY_SIZE;
     if (count > 0 && count * blocksize <= bytes) {
         bytes = count * blocksize;
@@ -1703,6 +1709,11 @@ static int CmdHF15Dump(const char *Cmd) {
         return PM3_EINVARG;
     }
 
+    if (blocksize < 4) {
+        PrintAndLogEx(WARNING, "Blocksize too small, using default 4 bytes");
+        blocksize = 4;
+    }
+
     // default fallback to scan for tag.
     // overriding unaddress parameter :)
     if (uidlen != HF15_UID_LENGTH) {
@@ -2054,6 +2065,11 @@ static int CmdHF15Readmulti(const char *Cmd) {
         return PM3_EINVARG;
     }
 
+    if (blocksize < 4) {
+        PrintAndLogEx(WARNING, "Blocksize too small, using default 4 bytes");
+        blocksize = 4;
+    }
+
     // enforcing add_option in order to get lock-info
     if (add_option == false) {
         if (verbose) {
@@ -2201,6 +2217,11 @@ static int CmdHF15Readblock(const char *Cmd) {
         return PM3_EINVARG;
     }
 
+    if (blocksize < 4) {
+        PrintAndLogEx(WARNING, "Blocksize too small, using default 4 bytes");
+        blocksize = 4;
+    }
+
     // enforcing add_option in order to get lock-info
     if (add_option == false) {
         if (verbose) {
@@ -2499,6 +2520,11 @@ static int CmdHF15Restore(const char *Cmd) {
         return PM3_EINVARG;
     }
 
+    if (blocksize < 4) {
+        PrintAndLogEx(WARNING, "Blocksize too small, using default 4 bytes");
+        blocksize = 4;
+    }
+
     // default fallback to scan for tag.
     // overriding unaddress parameter :)
     if (uidlen != HF15_UID_LENGTH) {