caddy/modules/caddyhttp/caddyauth/hashes.go
2019-10-30 13:56:27 -06:00

118 lines
3.0 KiB
Go

// Copyright 2015 Matthew Holt and The Caddy Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package caddyauth
import (
"crypto/subtle"
"github.com/caddyserver/caddy/v2"
"golang.org/x/crypto/bcrypt"
"golang.org/x/crypto/scrypt"
)
func init() {
caddy.RegisterModule(BcryptHash{})
caddy.RegisterModule(ScryptHash{})
}
// BcryptHash implements the bcrypt hash.
type BcryptHash struct{}
// CaddyModule returns the Caddy module information.
func (BcryptHash) CaddyModule() caddy.ModuleInfo {
return caddy.ModuleInfo{
Name: "http.handlers.authentication.hashes.bcrypt",
New: func() caddy.Module { return new(BcryptHash) },
}
}
// Compare compares passwords.
func (BcryptHash) Compare(hashed, plaintext, _ []byte) (bool, error) {
err := bcrypt.CompareHashAndPassword(hashed, plaintext)
if err == bcrypt.ErrMismatchedHashAndPassword {
return false, nil
}
if err != nil {
return false, err
}
return true, nil
}
// ScryptHash implements the scrypt KDF as a hash.
type ScryptHash struct {
N int `json:"N,omitempty"`
R int `json:"r,omitempty"`
P int `json:"p,omitempty"`
KeyLength int `json:"key_length,omitempty"`
}
// CaddyModule returns the Caddy module information.
func (ScryptHash) CaddyModule() caddy.ModuleInfo {
return caddy.ModuleInfo{
Name: "http.handlers.authentication.hashes.scrypt",
New: func() caddy.Module { return new(ScryptHash) },
}
}
// Provision sets up s.
func (s *ScryptHash) Provision(_ caddy.Context) error {
s.SetDefaults()
return nil
}
// SetDefaults sets safe default parameters, but does
// not overwrite existing values. Each default parameter
// is set independently; it does not check to ensure
// that r*p < 2^30. The defaults chosen are those as
// recommended in 2019 by
// https://godoc.org/golang.org/x/crypto/scrypt.
func (s *ScryptHash) SetDefaults() {
if s.N == 0 {
s.N = 32768
}
if s.R == 0 {
s.R = 8
}
if s.P == 0 {
s.P = 1
}
if s.KeyLength == 0 {
s.KeyLength = 32
}
}
// Compare compares passwords.
func (s ScryptHash) Compare(hashed, plaintext, salt []byte) (bool, error) {
ourHash, err := scrypt.Key(plaintext, salt, s.N, s.R, s.P, s.KeyLength)
if err != nil {
return false, err
}
if hashesMatch(hashed, ourHash) {
return true, nil
}
return false, nil
}
func hashesMatch(pwdHash1, pwdHash2 []byte) bool {
return subtle.ConstantTimeCompare(pwdHash1, pwdHash2) == 1
}
// Interface guards
var (
_ Comparer = (*BcryptHash)(nil)
_ Comparer = (*ScryptHash)(nil)
_ caddy.Provisioner = (*ScryptHash)(nil)
)