From 8d1d0706679062a5bd3257727af46f66a65e1b5f Mon Sep 17 00:00:00 2001
From: Jonas Gunz <himself@jonasgunz.de>
Date: Sun, 19 Jul 2020 01:34:53 +0200
Subject: gitwrapper

---
 gitwrapper.sh | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100755 gitwrapper.sh

diff --git a/gitwrapper.sh b/gitwrapper.sh
new file mode 100755
index 0000000..f619143
--- /dev/null
+++ b/gitwrapper.sh
@@ -0,0 +1,39 @@
+#!/bin/bash
+
+# gitwrapper.sh
+#
+# A wrapper for the 'git upload-pack' command
+# to automatically create repositories if they are
+# pushed to
+#
+# Set command="" in .ssh/authorized_keys:
+#
+#	command="/path/to/wrapper.sh myrepos" ssh-rsa ... user@example
+#
+
+[ -z "$1" ] && >&2 echo Invalid configuration in authorized_keys && exit 1
+ALLOWED_REPODIR="$1"
+
+if [ -z "$SSH_ORIGINAL_COMMAND" ]; then
+	bash
+	exit $?
+fi
+
+repo_path=$(sed -n 's/^git upload-pack \(.*\)$/\1/p' <<< "$SSH_ORIGINAL_COMMAND")
+if [ ! -z "$repo_path" ]; then
+	if grep -q '\.\.' <<< "$repo_path"; then
+		>&2 echo Invalid file name.
+		exit 1
+	fi
+
+	reponame_regex='^\w+\.git$'
+	if [ "$(dirname "$repo_path")" != "$ALLOWED_REPODIR" ] || \
+	   [[ ! "$(basename "$repo_path")" =~ $reponame_regex ]]; then
+		>&2 echo Invalid repository
+		exit 1
+	fi
+
+	[ ! -e "$repo_path" ] && git init --bare "$repo_path"
+fi
+
+eval $SSH_ORIGINAL_COMMAND
-- 
cgit v1.2.3