mirror of
https://github.com/rclone/rclone.git
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e43b5ce5e5
This is possible now that we no longer support go1.12 and brings rclone into line with standard practices in the Go world. This also removes errors.New and errors.Errorf from lib/errors and prefers the stdlib errors package over lib/errors.
79 lines
2.0 KiB
Go
79 lines
2.0 KiB
Go
// Package random holds a few functions for working with random numbers
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package random
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import (
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cryptorand "crypto/rand"
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"encoding/base64"
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"encoding/binary"
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"fmt"
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mathrand "math/rand"
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)
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// StringFn create a random string for test purposes using the random
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// number generator function passed in.
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//
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// Do not use these for passwords.
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func StringFn(n int, randIntn func(n int) int) string {
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const (
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vowel = "aeiou"
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consonant = "bcdfghjklmnpqrstvwxyz"
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digit = "0123456789"
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)
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pattern := []string{consonant, vowel, consonant, vowel, consonant, vowel, consonant, digit}
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out := make([]byte, n)
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p := 0
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for i := range out {
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source := pattern[p]
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p = (p + 1) % len(pattern)
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out[i] = source[randIntn(len(source))]
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}
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return string(out)
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}
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// String create a random string for test purposes.
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//
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// Do not use these for passwords.
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func String(n int) string {
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return StringFn(n, mathrand.Intn)
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}
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// Password creates a crypto strong password which is just about
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// memorable. The password is composed of printable ASCII characters
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// from the base64 alphabet.
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//
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// Requires password strength in bits.
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// 64 is just about memorable
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// 128 is secure
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func Password(bits int) (password string, err error) {
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bytes := bits / 8
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if bits%8 != 0 {
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bytes++
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}
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var pw = make([]byte, bytes)
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n, err := cryptorand.Read(pw)
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if err != nil {
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return "", fmt.Errorf("password read failed: %w", err)
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}
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if n != bytes {
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return "", fmt.Errorf("password short read: %d", n)
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}
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password = base64.RawURLEncoding.EncodeToString(pw)
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return password, nil
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}
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// Seed the global math/rand with crypto strong data
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//
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// This doesn't make it OK to use math/rand in crypto sensitive
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// environments - don't do that! However it does help to mitigate the
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// problem if that happens accidentally. This would have helped with
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// CVE-2020-28924 - #4783
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func Seed() error {
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var seed int64
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err := binary.Read(cryptorand.Reader, binary.LittleEndian, &seed)
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if err != nil {
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return fmt.Errorf("failed to read random seed: %w", err)
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}
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mathrand.Seed(seed)
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return nil
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}
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