sha256

Documentation

Overview

Package sha256 implements the SHA-256 hashing algorithm for crypt(3).

Index

• Constants
• func Check(hash, password string) error
• func Key(password, salt []byte, rounds uint32) ([]byte, error)
• func NewHash(password string, rounds uint32) (string, error)
• func Params(hash string) (salt []byte, rounds uint32, err error)
• type InvalidRoundsError
  • func (e InvalidRoundsError) Error() string
• type InvalidSaltError
  • func (e InvalidSaltError) Error() string
• type InvalidSaltLengthError
  • func (e InvalidSaltLengthError) Error() string
• type UnsupportedPrefixError
  • func (e UnsupportedPrefixError) Error() string

Examples

• Check
• Key
• Params

Constants

const (
	MaxSaltLength     = 16
	DefaultSaltLength = MaxSaltLength
)

const (
	MinRounds      = 1000
	MaxRounds      = 999999999
	DefaultRounds  = 535000
	ImplicitRounds = 5000 // the value if the rounds parameter is omitted from the hash string
)

const Prefix = "$5$"

Functions

func Check

func Check(hash, password string) error

Check compares the given crypt(3) SHA-256 hash with a new hash derived from the password. Returns nil on success, or an error on failure.

Example

package main

import (
	"fmt"

	"github.com/sergeymakinen/go-crypt/sha256"
)

func main() {
	hash := "$5$rounds=505000$.HnFpd3anFzRwVj5$EdcK/Q9wfmq1XsG5OTKP0Ns.ZlN9DRHslblcgCLtXY5"
	fmt.Println(sha256.Check(hash, "password"))
	fmt.Println(sha256.Check(hash, "test"))
}

Output:

<nil>
hash and password mismatch

func Key

func Key(password, salt []byte, rounds uint32) ([]byte, error)

Key returns a SHA-256 key derived from the password, salt and rounds.

Example

package main

import (
	"fmt"

	"github.com/sergeymakinen/go-crypt/hash"
	"github.com/sergeymakinen/go-crypt/sha256"
)

func main() {
	salt, rounds, _ := sha256.Params("$5$rounds=505000$.HnFpd3anFzRwVj5$EdcK/Q9wfmq1XsG5OTKP0Ns.ZlN9DRHslblcgCLtXY5")
	fmt.Println(string(salt))
	fmt.Println(rounds)

	key, _ := sha256.Key([]byte("password"), salt, rounds)
	fmt.Println(hash.LittleEndianEncoding.EncodeToString(key))
}

Output:

.HnFpd3anFzRwVj5
505000
EdcK/Q9wfmq1XsG5OTKP0Ns.ZlN9DRHslblcgCLtXY5

func NewHash

func NewHash(password string, rounds uint32) (string, error)

NewHash returns the crypt(3) SHA-256 hash of the password with the given rounds.

func Params

func Params(hash string) (salt []byte, rounds uint32, err error)

Params returns the hashing salt and rounds used to create the given crypt(3) SHA-256 hash.

Example

package main

import (
	"fmt"

	"github.com/sergeymakinen/go-crypt/sha256"
)

func main() {
	salt, rounds, _ := sha256.Params("$5$rounds=505000$.HnFpd3anFzRwVj5$EdcK/Q9wfmq1XsG5OTKP0Ns.ZlN9DRHslblcgCLtXY5")
	fmt.Println(string(salt))
	fmt.Println(rounds)
}

Output:

.HnFpd3anFzRwVj5
505000

Types

type InvalidRoundsError

type InvalidRoundsError uint32

InvalidRoundsError values describe errors resulting from an invalid round count.

func (InvalidRoundsError) Error

func (e InvalidRoundsError) Error() string

type InvalidSaltError

type InvalidSaltError byte

InvalidSaltError values describe errors resulting from an invalid character in a hash string.

func (InvalidSaltError) Error

func (e InvalidSaltError) Error() string

type InvalidSaltLengthError

type InvalidSaltLengthError int

InvalidSaltLengthError values describe errors resulting from an invalid length of a salt.

func (InvalidSaltLengthError) Error

func (e InvalidSaltLengthError) Error() string

type UnsupportedPrefixError

type UnsupportedPrefixError string

UnsupportedPrefixError values describe errors resulting from an unsupported prefix string.

func (UnsupportedPrefixError) Error

func (e UnsupportedPrefixError) Error() string