Generate passwords using Diceware

Diceware passwords are easier to remember and communicate :
https://github.com/holizz/diceware/
via https://firstlook.org/theintercept/2015/03/26/passphrases-can-memorize-attackers-cant-guess/

We could improve the entropy per character by removing numbers and
symbols from the wordlist, and randomly adding them as delimiters
instead.

diceware/diceware.go

@@ -0,0 +1,22 @@
+package diceware
+
+import (
+	"io"
+	"math/big"
+	"crypto/rand"
+	"strings"
+)
+
+func DicewareWords(r io.Reader, delim string, count int) string {
+	l := big.NewInt(int64( len(diceware_words) ));
+	words := []string{}
+	for i := 0; i < count; i++ {
+		j,err := rand.Int(r,l)
+		if err != nil {
+			panic("error reading from rand: " + err.Error())
+		}
+		words = append(words, diceware_words[j.Int64()])
+	}
+	return strings.Join(words, delim)
+}
+

diceware/diceware/diceware.go

@@ -0,0 +1,12 @@
+package main
+
+import (
+	"fmt"
+	"crypto/rand"
+	"github.com/agl/pond/diceware"
+)
+
+func main() {
+	fmt.Println(diceware.DicewareWords(rand.Reader," ",6))
+}
+