codeberg-forgejo/modules/auth/password/hash/hash.go

148 lines
4.2 KiB
Go

// Copyright 2023 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package hash
import (
"crypto/subtle"
"encoding/hex"
"fmt"
"strings"
"sync/atomic"
"code.gitea.io/gitea/modules/log"
)
// This package takes care of hashing passwords, verifying passwords, defining
// available password algorithms, defining recommended password algorithms and
// choosing the default password algorithm.
// PasswordSaltHasher will hash a provided password with the provided saltBytes
type PasswordSaltHasher interface {
HashWithSaltBytes(password string, saltBytes []byte) string
}
// PasswordHasher will hash a provided password with the salt
type PasswordHasher interface {
Hash(password, salt string) (string, error)
}
// PasswordVerifier will ensure that a providedPassword matches the hashPassword when hashed with the salt
type PasswordVerifier interface {
VerifyPassword(providedPassword, hashedPassword, salt string) bool
}
// PasswordHashAlgorithms are named PasswordSaltHashers with a default verifier and hash function
type PasswordHashAlgorithm struct {
PasswordSaltHasher
Name string
}
// Hash the provided password with the salt and return the hash
func (algorithm *PasswordHashAlgorithm) Hash(password, salt string) (string, error) {
var saltBytes []byte
// There are two formats for the salt value:
// * The new format is a (32+)-byte hex-encoded string
// * The old format was a 10-byte binary format
// We have to tolerate both here.
if len(salt) == 10 {
saltBytes = []byte(salt)
} else {
var err error
saltBytes, err = hex.DecodeString(salt)
if err != nil {
return "", err
}
}
return algorithm.HashWithSaltBytes(password, saltBytes), nil
}
// Verify the provided password matches the hashPassword when hashed with the salt
func (algorithm *PasswordHashAlgorithm) VerifyPassword(providedPassword, hashedPassword, salt string) bool {
// The bcrypt package has its own specialized compare function that takes into
// account the stored password's bcrypt parameters.
if verifier, ok := algorithm.PasswordSaltHasher.(PasswordVerifier); ok {
return verifier.VerifyPassword(providedPassword, hashedPassword, salt)
}
// Compute the hash of the password.
providedPasswordHash, err := algorithm.Hash(providedPassword, salt)
if err != nil {
log.Error("passwordhash: %v.Hash(): %v", algorithm.Name, err)
return false
}
// Compare it against the hashed password in constant-time.
return subtle.ConstantTimeCompare([]byte(hashedPassword), []byte(providedPasswordHash)) == 1
}
var (
lastNonDefaultAlgorithm atomic.Value
availableHasherFactories = map[string]func(string) PasswordSaltHasher{}
)
// Register registers a PasswordSaltHasher with the availableHasherFactories
// This is not thread safe.
func Register[T PasswordSaltHasher](name string, newFn func(config string) T) {
if _, has := availableHasherFactories[name]; has {
panic(fmt.Errorf("duplicate registration of password salt hasher: %s", name))
}
availableHasherFactories[name] = func(config string) PasswordSaltHasher {
n := newFn(config)
return n
}
}
// In early versions of gitea the password hash algorithm field could be empty
// At that point the default was `pbkdf2` without configuration values
// Please note this is not the same as the DefaultAlgorithm
const defaultEmptyHashAlgorithmName = "pbkdf2"
func Parse(algorithm string) *PasswordHashAlgorithm {
if algorithm == "" {
algorithm = defaultEmptyHashAlgorithmName
}
if DefaultHashAlgorithm != nil && algorithm == DefaultHashAlgorithm.Name {
return DefaultHashAlgorithm
}
ptr := lastNonDefaultAlgorithm.Load()
if ptr != nil {
hashAlgorithm, ok := ptr.(*PasswordHashAlgorithm)
if ok && hashAlgorithm.Name == algorithm {
return hashAlgorithm
}
}
vals := strings.SplitN(algorithm, "$", 2)
var name string
var config string
if len(vals) == 0 {
return nil
}
name = vals[0]
if len(vals) > 1 {
config = vals[1]
}
newFn, has := availableHasherFactories[name]
if !has {
return nil
}
ph := newFn(config)
if ph == nil {
return nil
}
hashAlgorithm := &PasswordHashAlgorithm{
PasswordSaltHasher: ph,
Name: algorithm,
}
lastNonDefaultAlgorithm.Store(hashAlgorithm)
return hashAlgorithm
}