Mercurial > gemma
view pkg/common/random.go @ 3241:ecfa09241437
client: pdf-template: add a set of template-elements (fairwayprofile)
author | Fadi Abbud <fadi.abbud@intevation.de> |
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date | Fri, 10 May 2019 13:11:24 +0200 |
parents | 6a021108410b |
children | 810b28f59b8b |
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// This is Free Software under GNU Affero General Public License v >= 3.0 // without warranty, see README.md and license for details. // // SPDX-License-Identifier: AGPL-3.0-or-later // License-Filename: LICENSES/AGPL-3.0.txt // // Copyright (C) 2018 by via donau // – Österreichische Wasserstraßen-Gesellschaft mbH // Software engineering by Intevation GmbH // // Author(s): // * Sascha L. Teichmann <sascha.teichmann@intevation.de> package common import ( "bytes" "crypto/rand" "io" "log" "math/big" ) // GenerateRandomKey generates a cryptographically secure random key // of a given length. func GenerateRandomKey(length int) []byte { k := make([]byte, length) if _, err := io.ReadFull(rand.Reader, k); err != nil { return nil } return k } // RandomString generates a cryptographically secure password // of a given length which consists of alpha numeric characters // and at least one 'special' one. 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.ContainsAny(out, special) { return string(out) } } log.Println("warn: Your random generator may be broken.") out[0] = special[0] return string(out) }