-help mentions SHA512 hash

[balloon.git] / cmd / balloon / main.go

diff --git a/cmd/balloon/main.go b/cmd/balloon/main.go
index 0c737c9dd794dfe9e6b5e095328e519e71fa4f5a..b7fd973b5874af07430ffca10b3420f1f8bc9e24 100644 (file)
--- a/cmd/balloon/main.go
+++ b/cmd/balloon/main.go
@@ -1,3 +1,21 @@
+/*
+balloon -- Balloon password hashing function
+Copyright (C) 2016-2019 Sergey Matveev <stargrave@stargrave.org>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as
+the Free Software Foundation, version 3 of the License.
+
+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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with this program.  If not, see
+<http://www.gnu.org/licenses/>.
+*/
+
 package main
 
 import (
@@ -7,6 +25,7 @@ import (
        "flag"
        "fmt"
        "io"
+       "os"
 
        "go.cypherpunks.ru/balloon"
 )
@@ -17,6 +36,10 @@ func main() {
        p := flag.Int("p", 4, "Number of threads")
        saltHex := flag.String("salt", "", "Salt, hexadecimal, optional")
        passwd := flag.String("passwd", "", "Password")
+       flag.Usage = func() {
+               fmt.Fprintf(os.Stderr, "balloon -- Strengthen password with Balloon+SHA512\n\n")
+               flag.PrintDefaults()
+       }
        flag.Parse()
        var salt []byte
        var err error