mirror of https://github.com/ergochat/ergo.git
122 lines
3.7 KiB
Go
122 lines
3.7 KiB
Go
// (C) Copyright 2013, Jonas mg. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license
|
|
// that can be found in the LICENSE file.
|
|
|
|
// Package crypt provides interface for password crypt functions and collects
|
|
// common constants.
|
|
package crypt
|
|
|
|
import (
|
|
"errors"
|
|
"strings"
|
|
|
|
"github.com/GehirnInc/crypt/common"
|
|
)
|
|
|
|
var ErrKeyMismatch = errors.New("hashed value is not the hash of the given password")
|
|
|
|
// Crypter is the common interface implemented by all crypt functions.
|
|
type Crypter interface {
|
|
// Generate performs the hashing algorithm, returning a full hash suitable
|
|
// for storage and later password verification.
|
|
//
|
|
// If the salt is empty, a randomly-generated salt will be generated with a
|
|
// length of SaltLenMax and number RoundsDefault of rounds.
|
|
//
|
|
// Any error only can be got when the salt argument is not empty.
|
|
Generate(key, salt []byte) (string, error)
|
|
|
|
// Verify compares a hashed key with its possible key equivalent.
|
|
// Returns nil on success, or an error on failure; if the hashed key is
|
|
// diffrent, the error is "ErrKeyMismatch".
|
|
Verify(hashedKey string, key []byte) error
|
|
|
|
// Cost returns the hashing cost (in rounds) used to create the given hashed
|
|
// key.
|
|
//
|
|
// When, in the future, the hashing cost of a key needs to be increased in
|
|
// order to adjust for greater computational power, this function allows one
|
|
// to establish which keys need to be updated.
|
|
//
|
|
// The algorithms based in MD5-crypt use a fixed value of rounds.
|
|
Cost(hashedKey string) (int, error)
|
|
|
|
// SetSalt sets a different salt. It is used to easily create derivated
|
|
// algorithms, i.e. "apr1_crypt" from "md5_crypt".
|
|
SetSalt(salt common.Salt)
|
|
}
|
|
|
|
// Crypt identifies a crypt function that is implemented in another package.
|
|
type Crypt uint
|
|
|
|
const (
|
|
APR1 Crypt = 1 + iota // import github.com/GehirnInc/crypt/apr1_crypt
|
|
MD5 // import github.com/GehirnInc/crypt/md5_crypt
|
|
SHA256 // import github.com/GehirnInc/crypt/sha256_crypt
|
|
SHA512 // import github.com/GehirnInc/crypt/sha512_crypt
|
|
maxCrypt
|
|
)
|
|
|
|
var crypts = make([]func() Crypter, maxCrypt)
|
|
|
|
// New returns new Crypter making the Crypt c.
|
|
// New panics if the Crypt c is unavailable.
|
|
func (c Crypt) New() Crypter {
|
|
if c > 0 && c < maxCrypt {
|
|
f := crypts[c]
|
|
if f != nil {
|
|
return f()
|
|
}
|
|
}
|
|
panic("crypt: requested crypt function is unavailable")
|
|
}
|
|
|
|
// Available reports whether the Crypt c is available.
|
|
func (c Crypt) Available() bool {
|
|
return c > 0 && c < maxCrypt && crypts[c] != nil
|
|
}
|
|
|
|
var cryptPrefixes = make([]string, maxCrypt)
|
|
|
|
// RegisterCrypt registers a function that returns a new instance of the given
|
|
// crypt function. This is intended to be called from the init function in
|
|
// packages that implement crypt functions.
|
|
func RegisterCrypt(c Crypt, f func() Crypter, prefix string) {
|
|
if c >= maxCrypt {
|
|
panic("crypt: RegisterHash of unknown crypt function")
|
|
}
|
|
crypts[c] = f
|
|
cryptPrefixes[c] = prefix
|
|
}
|
|
|
|
// New returns a new crypter.
|
|
func New(c Crypt) Crypter {
|
|
return c.New()
|
|
}
|
|
|
|
// IsHashSupported returns true if hashedKey has a supported prefix.
|
|
// NewFromHash will not panic for this hashedKey
|
|
func IsHashSupported(hashedKey string) bool {
|
|
for i := range cryptPrefixes {
|
|
prefix := cryptPrefixes[i]
|
|
if crypts[i] != nil && strings.HasPrefix(hashedKey, prefix) {
|
|
return true
|
|
}
|
|
}
|
|
|
|
return false
|
|
}
|
|
|
|
// NewFromHash returns a new Crypter using the prefix in the given hashed key.
|
|
func NewFromHash(hashedKey string) Crypter {
|
|
for i := range cryptPrefixes {
|
|
prefix := cryptPrefixes[i]
|
|
if crypts[i] != nil && strings.HasPrefix(hashedKey, prefix) {
|
|
crypt := Crypt(uint(i))
|
|
return crypt.New()
|
|
}
|
|
}
|
|
|
|
panic("crypt: unknown crypt function")
|
|
}
|