Add convenience script for generating certificate fingerprints

1 files changed, 72 insertions, 0 deletions

diff --git a/.local/bin/crt-fp b/.local/bin/crt-fp
new file mode 100755
index 0000000..a764ba6
--- /dev/null
+++ b/.local/bin/crt-fp
@@ -0,0 +1,72 @@
+#! /usr/bin/env sh
+
+# This program is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your option) any
+# later version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+
+main()
+{
+	# Handle opts
+	opts "$@"
+	shift "$OPTS"
+	unset OPTS
+
+	# Show help
+	[ "$OPT_HELP_ONLY" ] && usage && exit 0
+	[ -z "$1" ] && usage && exit 1
+
+	# Generate fingerprint info for all certificates in question
+	for crt in "$@"
+	do
+		printf "%s: \n" "$crt"
+		for alg in md5 sha1 sha256
+		do
+			printf "  %-8s %s\n" "$alg" "$(fingerprint "$alg" "$crt")"
+		done
+	done
+}
+
+fingerprint()
+{
+	openssl x509 -noout -fingerprint "-$1" -inform pem -in "$2" \
+		| awk -F= '{ print $NF }'
+}
+
+opts()
+{
+	OPTS=0
+
+	while getopts ":h" opt
+	do
+		case "$opt" in
+			h) OPT_HELP_ONLY=1 ;;
+			*)
+				printf "Invalid option passed: %s\n" "$OPTARG" >&2
+				;;
+		esac
+	done
+
+	unset opt
+}
+
+usage()
+{
+	cat <<EOF
+Usage:
+	$(basename "$0") -h
+	$(basename "$0") [file [file...]]
+
+Generate common fingerprints for a certificate, using openssl.
+
+Options:
+	-h  Show this help text and exit.
+EOF
+}
+
+main "$@"