Wt::Auth::PasswordVerifier Class Reference

Password hash computation and verification class. More...

#include <Wt/Auth/PasswordVerifier>

Inheritance diagram for Wt::Auth::PasswordVerifier:

Public Member Functions
	PasswordVerifier ()
	Constructor.
virtual	~PasswordVerifier ()
	Destructor.
void	setSaltLength (int words)
	Sets the salt length. More...
int	saltLength () const
	Returns the salt length.
void	addHashFunction (HashFunction *function)
	Adds a hash function. More...
const std::vector< HashFunction * > &	hashFunctions () const
	Returns the list of hash functions. More...
virtual bool	needsUpdate (const PasswordHash &hash) const
	Returns whether a password hash needs to be updated (recomputed). More...
virtual PasswordHash	hashPassword (const WString &password) const
	Computes the password hash for a clear text password. More...
virtual bool	verify (const WString &password, const PasswordHash &hash) const
	Verifies a password against a hash. More...
Public Member Functions inherited from Wt::Auth::PasswordService::AbstractVerifier
virtual	~AbstractVerifier ()
	Destructor.

Detailed Description

Password hash computation and verification class.

This class implements the logic for comparing passwords against password hashes, or computing a new password hash for a password.

One or more hash functions can be added, which allow you to introduce a new "preferred" hash function while maintaining support for verifying existing passwords hashes.

Member Function Documentation

void Wt::Auth::PasswordVerifier::addHashFunction

(

HashFunction *

function

)

Adds a hash function.

The first hash function added is the one that will be used for creating new password hashes, i.e. the "preferred" hash function. The other hash functions are used only for verifying existing hash passwords. This allows you to move to new hash functions as other ones are no longer deemed secure.

Each hash function has a unique name, which is annotated in the generated hash to identify the appropriate hash funtion to evaluate it.

Ownership of the hash functions is transferred.

See also

hashFunctions()

const std::vector<HashFunction *>& Wt::Auth::PasswordVerifier::hashFunctions

(

)

const

Returns the list of hash functions.

This returns a list with references to hashfunctions that have been added with addHashFunction().

PasswordHash Wt::Auth::PasswordVerifier::hashPassword ( const WString &  password ) const

virtual

Computes the password hash for a clear text password.

This creates new salt and applies the "preferred" hash function to the salt and clear text password to compute the hash.

See also

verify()

Implements Wt::Auth::PasswordService::AbstractVerifier.

bool Wt::Auth::PasswordVerifier::needsUpdate ( const PasswordHash &  hash ) const

virtual

Returns whether a password hash needs to be updated (recomputed).

A hash may need to be updated if it has been computed with a cryptographic method that is being disfavoured.

Implements Wt::Auth::PasswordService::AbstractVerifier.

void Wt::Auth::PasswordVerifier::setSaltLength

(

int

words

)

Sets the salt length.

The salt length is used to create new salt when a new password is being hashed.

The salt length is specified in bytes, but should be a multiple of 3 (so that Base64 encoding yields an integral number of bytes).

The default length is 12.

See also

hashPassword()

bool Wt::Auth::PasswordVerifier::verify ( const WString &  password, const PasswordHash &  hash  ) const

virtual

Verifies a password against a hash.

This verifies whether the password matches the hash.

See also

hashPassword()

Implements Wt::Auth::PasswordService::AbstractVerifier.