gemma: pkg/common/random.go comparison

Moved project specific Go packages to new pkg folder.

author	Sascha L. Teichmann <sascha.teichmann@intevation.de>
date	Wed, 15 Aug 2018 17:30:50 +0200
parents	common/random.go@ac23905e64b1
children	a244b18cb916

comparison

equal deleted inserted replaced

-:a9440a4826aa
+:c1047fd04a3a
+package common
+import (
+	"bytes"
+	"crypto/rand"
+	"io"
+	"log"
+	"math/big"
+)
+func GenerateRandomKey(length int) []byte {
+	k := make([]byte, length)
+	if _, err := io.ReadFull(rand.Reader, k); err != nil {
+		return nil
+	}
+	return k
+}
+func RandomString(n int) string {
+	const (
+		special  = "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~"
+		alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" +
+			"abcdefghijklmnopqrstuvwxyz" +
+			"0123456789" +
+			special
+	)
+	max := big.NewInt(int64(len(alphabet)))
+	out := make([]byte, n)
+	for i := 0; i < 1000; i++ {
+		for i := range out {
+			v, err := rand.Int(rand.Reader, max)
+			if err != nil {
+				log.Panicf("error: %v\n", err)
+			}
+			out[i] = alphabet[v.Int64()]
+		}
+		// Ensure at least one special char.
+		if bytes.IndexAny(out, special) >= 0 {
+			return string(out)
+		}
+	}
+	log.Println("warn: Your random generator may be broken.")
+	out[0] = special[0]
+	return string(out)
+}

Mercurial > gemma