Remove gpg key within user control panel

src/freedombone-controlpanel-user

@@ -33,6 +33,8 @@ PROJECT_NAME='freedombone'
 export TEXTDOMAIN=${PROJECT_NAME}-controlpanel-user
 export TEXTDOMAINDIR="/usr/share/locale"
 
+MY_EMAIL_ADDRESS=$USER@$HOSTNAME
+
 function any_key {
     echo ' '
     read -n1 -r -p $"Press any key to continue..." key
@@ -345,7 +347,6 @@ function block_unblock_subject {
 }
 
 function show_gpg_key {
-    MY_EMAIL_ADDRESS=$USER@$HOSTNAME
     GPG_ID=$(gpg --fingerprint $MY_EMAIL_ADDRESS | grep -i "pub" | head -n 1 | awk -F '/' '{print $2}' | awk -F ' ' '{print $1}')
     GPG_FINGERPRINT=$(gpg --fingerprint $MY_EMAIL_ADDRESS | grep -i "key fingerprint" | head -n 1 | awk -F '= ' '{print $2}')
     GPG_DATE=$(gpg --fingerprint $MY_EMAIL_ADDRESS | grep -i "pub" | head -n 1 | awk -F '/' '{print $2}' | awk -F ' ' '{print $2}')
@@ -364,7 +365,7 @@ function add_gpg_key {
     case $sel in
         0)
             ADD_EMAIL_ADDRESS=$(<$data)
-            if [ ${#ADD_EMAIL_ADDRESS} -gt 1 ]; then
+            if [ ${#ADD_EMAIL_ADDRESS} -gt 2 ]; then
                 if [[ $ADD_EMAIL_ADDRESS == *"@"* && $ADD_EMAIL_ADDRESS == *"."* ]]; then
                     clear
                     gpg --search-keys $ADD_EMAIL_ADDRESS
@@ -376,10 +377,36 @@ function add_gpg_key {
             fi
             ;;
     esac
-
 }
 
 function remove_gpg_key {
+    data=$(tempfile 2>/dev/null)
+    trap "rm -f $data" 0 1 2 5 15
+    dialog --title $"Remove someone's PGP/GPG key" \
+           --backtitle $"Freedombone User Control Panel" \
+           --inputbox $"Enter their email address below" 8 60 2>$data
+    sel=$?
+    case $sel in
+        0)
+            REMOVE_EMAIL_ADDRESS=$(<$data)
+            if [ ${#REMOVE_EMAIL_ADDRESS} -gt 2 ]; then
+                if [[ $REMOVE_EMAIL_ADDRESS == *"@"* && $REMOVE_EMAIL_ADDRESS == *"."* ]]; then
+                    if [[ $REMOVE_EMAIL_ADDRESS != $MY_EMAIL_ADDRESS ]]; then
+                        clear
+                        gpg --delete-key $REMOVE_EMAIL_ADDRESS
+                    else
+                        dialog --title $"Remove someone's PGP/GPG key" \
+                               --backtitle $"Freedombone User Control Panel" \
+                               --msgbox $"It's not a good idea to remove your own encryption key" 6 65
+                    fi
+                else
+                    dialog --title $"Unrecognised email address" \
+                           --backtitle $"Freedombone User Control Panel" \
+                           --msgbox $"This doesn't look like an email address" 6 50
+                fi
+            fi
+            ;;
+    esac
 }
 
 function add_ssh_key {