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.

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoCrypt
    String sPassword
    String sPhcHash
    Integer iVerifyResult
    String sTemp1

    Get Create (RefClass(cComChilkatCrypt2)) To hoCrypt
    If (Not(IsComObjectCreated(hoCrypt))) Begin
        Send CreateComObject of hoCrypt
    End

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

    //  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.
    Move "$argon2id$v=19$m=65536,t=3,p=1$c29tZXJhbmRvbXNhbHQ$3fJ7v1qKcVJ0lHqXjBQZ8mYm3sNTfSPRt0bqDl9kEyM" To sPhcHash

    //  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.
    Get ComArgon2VerifyPassword Of hoCrypt sPassword "" sPhcHash To iVerifyResult
    If (iVerifyResult = 1) Begin
        Showln "The password is verified."
    End
    Else Begin
        If (iVerifyResult = 0) Begin
            Showln "The password does not match."
        End
        Else Begin
            Get ComLastErrorText Of hoCrypt To sTemp1
            Showln "The verification could not be performed: " sTemp1
        End

    End



End_Procedure