pass

A password checking package based on Python's passlib, an amazing library. There is no password library with more thought put into it, or with more support for obscure password formats.

Currently, it supports:

• Argon2i
• scrypt-sha256
• sha512-crypt
• sha256-crypt
• bcrypt
• passlib's bcrypt-sha256 variant
• pbkdf2-sha512 (in passlib format)
• pbkdf2-sha256 (in passlib format)
• pbkdf2-sha1 (in passlib format)

By default, it will hash using scrypt-sha256 and verify existing hashes using any of these schemes.

Example Usage

There is a default context for ease of use. Most people only need to use the Hash and Verify functions:

// Hash gets the password in UTF-8 format and hashes it.
func Hash(password string) (hash string, err error)

// Verify verifies password in UTF-8 format using previously obtained hash.
// Returns an error if verification fails.
// Also returns updated password hash, if the provided hash is out of date.
func Verify(password string, hash string) (newHash string, err error)

import "gopkg.in/pchchv/pass"

func Register() {
    (...)
  
    var password string // get a (UTF-8, plaintext) password from somewhere
  
    hash, err := pass.Hash(password)
    if err != nil {
        // error handling...
    }
    
    (store hash in database, etc.)
}

func CheckPassword(password string, hash string) bool {
    newHash, err := pass.Verify(password, hash)
    if err != nil {
        // incorrect password, malformed hash, etc.
        // error handling...
    }
    if newHash != "" {
        // According to its policy,
        // the context decided that the hash that was used
        // to validate the password should be changed.
        // It updated the hash using the verified password.
        
        (store newHash in database, replacing old hash)
    }
    
    return true
}

scrypt Modular Crypt Format

Scrypt does not have an existing modular crypto-format standard. The format used in this library is as follows:

$s2$N$r$p$salt$hash

N, r and p are the corresponding complexity parameters for encryption in the form of positive decimal integers.