peroxide-user: Implement credential key generation

cmd/peroxide-user/main.go

@@ -0,0 +1,51 @@
+// Copyright (c) 2022 Lukasz Janyst <lukasz@jany.st>
+//
+// This file is part of Peroxide.
+//
+// Peroxide is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Peroxide 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Peroxide.  If not, see <https://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+)
+
+var genKey = flag.Bool("gen-key", false, "generate a random key for the encryption of credentials")
+
+func main() {
+	flag.Parse()
+	done := false
+
+	if *genKey {
+		var key [32]byte
+		if _, err := io.ReadFull(rand.Reader, key[:]); err != nil {
+			fmt.Fprintf(os.Stderr, "Can't read random bytes: %s:\n", err)
+			os.Exit(1)
+		}
+		password := base64.StdEncoding.EncodeToString(key[:])
+		fmt.Println(password)
+		done = true
+	}
+
+	if !done {
+		fmt.Fprintf(os.Stderr, "Usage of %s:\n", os.Args[0])
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+}