Verify a Password against an Argon2 Hash

Demonstrates Crypt2.Argon2VerifyPassword, which verifies a password against a PHC-format Argon2 hash string. The cost parameters are read from the hash string, so none need to be supplied.

integer li_rc
oleobject loo_Crypt
string ls_Password
string ls_PhcHash
integer li_VerifyResult

loo_Crypt = create oleobject
li_rc = loo_Crypt.ConnectToNewObject("Chilkat.Crypt2")
if li_rc < 0 then
    destroy loo_Crypt
    MessageBox("Error","Connecting to COM object failed")
    return
end if

//  The password should come from a secure source rather than being hard-coded.
ls_Password = "correct horse battery staple"

//  A PHC-format Argon2 hash string previously produced by Argon2HashPassword.  All cost options
//  (variant, version, memory cost, iterations, parallelism, salt, hash length) are read from this
//  string, so none need to be supplied.
ls_PhcHash = "$argon2id$v=19$m=65536,t=3,p=1$c29tZXJhbmRvbXNhbHQ$3fJ7v1qKcVJ0lHqXjBQZ8mYm3sNTfSPRt0bqDl9kEyM"

//  Verify the password.  Pass an empty options string when no secret (pepper) or ad was used.
//  The method returns one of three values:  1 = the password matched, 0 = it did not match, and
//  -1 = the verification could not be performed (the hash string was invalid or unusable).
//  Always test for a match with == 1.
li_VerifyResult = loo_Crypt.Argon2VerifyPassword(ls_Password,"",ls_PhcHash)
if li_VerifyResult = 1 then
    Write-Debug "The password is verified."
else
    if li_VerifyResult = 0 then
        Write-Debug "The password does not match."
    else
        Write-Debug "The verification could not be performed: " + loo_Crypt.LastErrorText
    end if

end if



destroy loo_Crypt