password_hasher Class Reference

Manages password hashing and verification using the scrypt algorithm. More...

#include <password_hasher.hpp>

Collaboration diagram for password_hasher:

Static Public Member Functions
static std::string	hash (const std::string &password)
	Creates a password hash from the given password.
static bool	verify (const std::string &password, const std::string &hash)
	Verifies a password against a stored hash.

Detailed Description

Manages password hashing and verification using the scrypt algorithm.

The password_hasher class provides static methods to securely hash passwords and verify them against stored hashes. It uses the scrypt key derivation function from OpenSSL to generate and validate password hashes, ensuring strong security through configurable CPU/memory cost parameters.

Member Function Documentation

hash()

std::string hash ( const std::string &  password )

static

Creates a password hash from the given password.

Generates a secure hash of the provided password using the scrypt algorithm with predefined parameters (CPU/memory cost, block size, and parallelisation). The hash is formatted as a string containing the algorithm identifier, parameters, salt, and hash, all Base64-encoded.

Parameters

password

The plaintext password to hash.

Returns

A string containing the formatted hash (e.g., "$scrypt$ln=14,r=8,p=1$<salt>$<hash>").

Exceptions

std::invalid_argument	If the password is empty.
std::runtime_error	If hash generation fails (e.g., due to random salt generation or scrypt errors).

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verify()

bool verify ( const std::string &  password, const std::string &  hash  )

static

Verifies a password against a stored hash.

Checks if the provided password matches the given hash by recomputing the hash with the same salt and scrypt parameters extracted from the hash string. Uses constant-time comparison to prevent timing attacks.

Parameters

password	The plaintext password to verify.
hash	The stored hash string to verify against (e.g., "$scrypt$ln=14,r=8,p=1$<salt>$<hash>").

Returns

True if the password matches the hash, false otherwise.