smoser · June 26, 2012 17:01 · Jun 26, 2012
diff --git a/rsa2azure b/rsa2azure
@@ -0,0 +1,55 @@
+#!/bin/sh
+# vi: ts=4 noexpandtab
+# rsa2azure
+
+Usage() {
+   cat <<EOF
+Usage: ${0##*/} [options] [private-key]
+   convert private-key in ssh private key format to the format
+   needed by windows azure as described at
+      http://utlemming.azurewebsites.net/?p=91
+
+   options:
+    -o | --output FILE    write output to F. default stdout.
+
+   Default private-key is ~/.ssh/id_rsa)
+EOF
+}
+fail() { echo "$@" 1>&2; exit 1; }
+
+short_opts="ho:"
+long_opts="output:,help"
+getopt_out=$(getopt --name "${0##*/}" \
+	--options "ho:" --long "output:,help" -- "$@") &&
+	eval set -- "${getopt_out}" ||
+	{ Usage 1>&2; fail "bad usage"; }
+
+umask 066
+
+outfile=/dev/stdout
+echo $@
+while [ $# -ne 0 ]; do
+	case "$1" in
+		-h|--help) Usage; exit 0;;
+		-o|--output) outfile=${2}; shift;;
+		   --) shift; break;;
+	esac
+	shift;
+done
+
+[ $# -eq 0 -o $# -eq 1 ] || { Usage 1>&2; exit 1; }
+
+key_in=$1
+if [ $# -eq 0 ]; then
+	key_in=~/.ssh/id_rsa
+	[ -f "$key_in" ] || fail "no default key found in $key_in";
+fi
+
+[ "$key_in" = "-" ] && key_in=/dev/stdin
+[ -f "$key_in" ] || fail "${key_in}: not a file"
+
+out=$(openssl rsa -in "$key_in" -out /dev/stdout 2>/dev/null) ||
+	fail "failed to decrypt private key in $key_in"
+printf "%s" "$out" |
+	openssl req -new -x509 -nodes -days 999 -batch -outform DER -batch \
+		-key /dev/stdin -out "${outfile}" 2>/dev/null