From d44da54b36490146b1136b867f8f010be057f18c Mon Sep 17 00:00:00 2001
From: Connor Olding <cloningdonor@gmail.com>
Date: Mon, 2 Aug 2021 13:49:38 -0700
Subject: [PATCH] add some pretty lame security checks to stfu

---
 sh/stfu | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/sh/stfu b/sh/stfu
index 03f1f58..bffa2dd 100644
--- a/sh/stfu
+++ b/sh/stfu
@@ -43,7 +43,30 @@ stfu() { ### @-
     ### ```
     [ $# -gt 0 ] || { printf "%s\n" "$0: too few arguments" >&2; return 1; }
 
-    local temp="${TMP:-/tmp}/stfu"
+    local dirty=0 temp="$STFU_DIR"
+    if [ -z "$temp" ]; then
+        temp="$(mktemp -dt stfu.XXXXXXXXXX)"
+        [ $? -eq 0 ] || { printf "%s\n" "$0: failed create temporary directory" >&2; return 1; }
+        dirty=1
+    fi
+
+    # NOTE: this stat command will not work on BSD-likes,
+    #       but it will work with GNU coreutils and busybox.
+    local perms="$(stat -c '%a' "$temp")"
+    local realtemp="$(readlink -f "$temp")"
+    [ -z "$MSYSTEM" ] || perms=700 # MSYS2 is insecure, oh well.
+    if [ -d "$temp" ] && [ "$realtemp" = "$temp" ] && [ "$perms" = 700 ]; then
+        if [ $dirty -ne 0 ]; then
+            export STFU_DIR="$temp"
+        fi
+    else
+        if [ -n "$STFU_DIR" ]; then
+            printf "%s\n" "$0: invalid temporary directory, please unset STFU_DIR" >&2;
+        else
+            printf "%s\n" "$0: something went horribly wrong, maybe you can tell?" "$perms" "$realtemp"
+        fi
+        return 1
+    fi
 
     local time="$(date -u '+%s')"
     [ $? -eq 0 ] || { printf "%s\n" "$0: failed to get current time" >&2; return 1; }
@@ -54,6 +77,8 @@ stfu() { ### @-
     local out="$temp/out_$time"
     local err="$temp/err_$time"
 
+    touch "$out" && touch "$err" || { printf "%s\n" "$0: failed to create temp files" >&2; return 1; }
+
     #local out="$(mktemp -t -p "$temp" out_XXXXXX)"
     #[ $? -eq 0 ] || { printf "%s\n" "$0: failed to create temp file" >&2; return 1; }
     #local err="$(mktemp -t -p "$temp" err_XXXXXX)"