forgejo-federation/modules/password/password.go

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// Copyright 2019 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package password
import (
"crypto/rand"
"math/big"
"strings"
"sync"
"code.gitea.io/gitea/modules/setting"
)
var (
matchComplexityOnce sync.Once
validChars string
requiredChars []string
charComplexities = map[string]string{
"lower": `abcdefghijklmnopqrstuvwxyz`,
"upper": `ABCDEFGHIJKLMNOPQRSTUVWXYZ`,
"digit": `0123456789`,
"spec": ` !"#$%&'()*+,-./:;<=>?@[\]^_{|}~` + "`",
}
)
// NewComplexity for preparation
func NewComplexity() {
matchComplexityOnce.Do(func() {
setupComplexity(setting.PasswordComplexity)
})
}
func setupComplexity(values []string) {
if len(values) != 1 || values[0] != "off" {
for _, val := range values {
if chars, ok := charComplexities[val]; ok {
validChars += chars
requiredChars = append(requiredChars, chars)
}
}
if len(requiredChars) == 0 {
// No valid character classes found; use all classes as default
for _, chars := range charComplexities {
validChars += chars
requiredChars = append(requiredChars, chars)
}
}
}
if validChars == "" {
// No complexities to check; provide a sensible default for password generation
validChars = charComplexities["lower"] + charComplexities["upper"] + charComplexities["digit"]
}
}
// IsComplexEnough return True if password meets complexity settings
func IsComplexEnough(pwd string) bool {
NewComplexity()
if len(validChars) > 0 {
for _, req := range requiredChars {
if !strings.ContainsAny(req, pwd) {
return false
}
}
}
return true
}
// Generate a random password
func Generate(n int) (string, error) {
NewComplexity()
buffer := make([]byte, n)
max := big.NewInt(int64(len(validChars)))
for {
for j := 0; j < n; j++ {
rnd, err := rand.Int(rand.Reader, max)
if err != nil {
return "", err
}
buffer[j] = validChars[rnd.Int64()]
}
if IsComplexEnough(string(buffer)) && string(buffer[0]) != " " && string(buffer[n-1]) != " " {
return string(buffer), nil
}
}
}