4 files changed, 113 insertions, 0 deletions
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..2149bd8
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2021 Wolfgang Müller
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..01de724
--- /dev/null
+++ b/README.md
@@ -0,0 +1,13 @@
+# git-helpers
+
+This is a collection of miscellaneous helper scripts for anything that has to
+do with [`git(1)`](https://git-scm.com/). These are first and foremost for
+personal use.
+
+## Scripts
+
+- git-init-shared: Initialize a bare repo that multiple users have write access
+  to. This uses `setfacl(1)` and thereby relies on ACL support.
+- git-sign-for-cgit: Generate a snapshot and store its signify signature for
+  [`cgit`](https://git.zx2c4.com/cgit/about/) using
+  [`git-notes(1)`](https://git-scm.com/docs/git-notes).
diff --git a/git-init-shared b/git-init-shared
new file mode 100755
index 0000000..ea18234
--- /dev/null
+++ b/git-init-shared
@@ -0,0 +1,25 @@
+#!/bin/sh
+
+set -e
+
+usage() {
+	printf "usage: git init-shared directory [user...]\n" >&2
+	exit 1
+}
+
+add_to_acl() {
+	setfacl -m "d:u:$2:rwx" "$1"
+	setfacl -m "u:$2:rwx" "$1"
+}
+
+test $# -ge 1 || usage
+dir=$1
+shift
+
+mkdir "$dir"
+
+for user in "$(id -un)" "$@"; do
+	add_to_acl "$dir" "$user"
+done
+
+exec git init --bare "$dir"
diff --git a/git-sign-for-cgit b/git-sign-for-cgit
new file mode 100755
index 0000000..fe127a8
--- /dev/null
+++ b/git-sign-for-cgit
@@ -0,0 +1,54 @@
+#!/bin/sh
+
+set -e
+
+errx() {
+	printf '%s\n' "$*" >&2
+	exit 1
+}
+
+usage() {
+	errx 'usage: git sign-for-cgit [-f format] <object>\n'
+}
+
+seckey=${SIGNIFY_SECKEY:-$HOME/.signify/release.sec}
+
+format="$(git config --get package.format)"
+: "${format:=tar.gz}"
+
+while getopts f: opt; do
+	case $opt in
+		f) format=$OPTARG;;
+		?) usage;;
+	esac
+done
+shift $((OPTIND - 1))
+test $# -eq 1 || usage
+
+git archive -l | grep -Fqx "$format" || errx "fatal: unknown format"
+
+name=$(basename "$(git rev-parse --show-toplevel)")
+object=$1
+
+tmpdir=$(mktemp -d --suffix .sign-for-cgit)
+
+# We do want to expand tmpdir now rather than later, 
+# and mktemp should give us a path without spaces.
+# shellcheck disable=SC2064
+trap "{ rm -r $tmpdir; }" EXIT
+
+archive_base=$name-$object.$format
+archive_path=$tmpdir/$archive_base
+
+git archive --prefix="$name-$object/" -o "$archive_path" -- "$object"
+
+(
+	cd "$tmpdir"
+	sha256sum --tag "$archive_base" > "${archive_base}.SHA256"
+	signify -Ses "$seckey" -m "${archive_base}.SHA256"
+)
+
+id=$(git hash-object -w "${archive_path}.SHA256.sig")
+
+# do not use exec here because otherwise the EXIT trap will not fire
+git notes --ref="refs/notes/signatures/$format" add -C "$id" "$object"