oem-factory-reset : Prompt user for any connected block device, give storage size and loop until none is connected to exit loop.

Warn user if connected usb block device is less then 128mb, since creating LUKS container of less then 8mb might cause issues.

Signed-off-by: Thierry Laurion <insurgo@riseup.net>

Author: tlaurion

initrd/bin/oem-factory-reset

@@ -326,12 +326,6 @@ prompt_insert_to_be_wiped_thumb_drive() {
         die "Error displaying warning about having only desired to be wiped thumb drive inserted"
 }
 
-#list blkid devices (removing partition numbers)
-list_blkid_devices() {
-    TRACE "Under oem-factory-reset:list_blkid_devices"
-    blkid | cut -d: -f1 | sed 's/[0-9]$//'
-}
-
 #export master key and subkeys to thumbdrive's private LUKS contained partition
 export_master_key_subkeys_and_revocation_key_to_private_LUKS_container() {
     TRACE "Under oem-factory-reset:export_master_key_subkeys_and_revocation_key_to_private_LUKS_container"
@@ -422,16 +416,59 @@ export_public_key_to_thumbdrive_public_partition() {
 wipe_thumb_drive_and_copy_gpg_key_material() {
     TRACE "Under oem-factory-reset:wipe_thumb_drive_and_copy_gpg_key_material"
     prompt_disconnect_external_USB_storage_device
-    actual_devices=$(list_blkid_devices)
     #enable usb storage
     enable_usb
     enable_usb_storage
-    prompt_insert_to_be_wiped_thumb_drive
-    new_devices=$(list_blkid_devices)
-    thumb_drive=$(echo "$new_devices" | grep -v "$actual_devices" | uniq)
-    if [ -z "$thumb_drive" ]; then
-        whiptail_error_die "No new thumb drive detected! Aborting."
-    fi
+
+    #loop until user chooses a disk
+    thumb_drive=""
+    while [ -z "$thumb_drive" ]; do
+        prompt_insert_to_be_wiped_thumb_drive
+        #list usb storage devices
+        list_usb_storage disks >/tmp/usb_disk_list
+        if [ $(cat /tmp/usb_disk_list | wc -l) -gt 0 ]; then
+            file_selector "/tmp/usb_disk_list" "Select USB device to partition"
+            if [ "$FILE" == "" ]; then
+                #No USB storage device selected
+                warn "No USB storage device selected!"
+            else
+                # Obtain size of thumb drive to be wiped with fdisk
+                disk_size_bytes="$(blockdev --getsize64 "$FILE")"
+                #Convert disk size to GB
+                thumb_drive_size_mb=$((disk_size_bytes / 1024 / 1024))
+                thumb_drive_size_gb=$((thumb_drive_size_mb / 1024 ))
+                
+                #if thumb_drive_size_gb is 0, then disk size is less than 1GB
+                thumb_drive_size_message=""
+                if [ "$thumb_drive_size_gb" -eq 0 ]; then
+                    thumb_drive_size_message="$thumb_drive_size_mb MB"
+                    if [ "$thumb_drive_size_mb" -lt 128 ]; then
+                        warn "Thumb drive size is less than 128MB!"
+                        warn "LUKS container needs to be at least 8mb!"
+                        warn "If the next operation fails, try with a bigger thumb drive"
+                    fi
+                else
+                    thumb_drive_size_message="$thumb_drive_size_gb GB"
+                fi
+                
+                # confirm with user size of thumb drive to be wiped
+                whiptail --title "Confirm thumb drive to be wiped" --yesno "Are you sure you want to wipe the following thumb drive?\n\n$FILE\n\nSize: $thumb_drive_size_message" 0 0
+                if [ $? -ne 0 ]; then
+                    warn "Thumb drive wipe aborted by user!"
+                    continue
+                fi
+
+                #User chose and confirmed a thumb drive and its size to be wiped
+                thumb_drive=$FILE
+            fi
+        else
+            #No USB storage device detected
+            warn "No USB storage device detected! Aborting OEM Factory Reset / Re-Ownership"
+            sleep 3
+            die "No USB storage device detected! User decided to not wipe any thumb drive"
+        fi
+    done
+
     select_luks_container_size_percent
     #Wipe thumb drive with a LUKS container of size $(cat /tmp/luks_container_size_percent)
     prepare_thumb_drive --device "$thumb_drive" --percentage "$(cat /tmp/luks_container_size_percent)" --pass "${ADMIN_PIN}"