Verify an Argon2 Password with a Secret and Memory Guard

Demonstrates Crypt2.Argon2VerifyPassword when the hash was created with a secret (pepper) or ad, and the use of maxMemoryKb to guard against untrusted hash strings.

    crypt := chilkat.NewCrypt2()

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

    phcHash := "$argon2id$v=19$m=131072,t=4,p=2$c29tZXJhbmRvbXNhbHQ$3fJ7v1qKcVJ0lHqXjBQZ8mYm3sNTfSPRt0bqDl9kEyM"

    //  When the hash was created with a secret (pepper) or ad, the same values must be supplied to verify.
    //  Only the secret, ad, encoding, passwordCharset, and maxMemoryKb members of the options are used;
    //  everything else is ignored.
    json := chilkat.NewJsonObject()
    json.UpdateString("secret","application-wide-pepper")
    json.UpdateString("secretEncoding","utf-8")

    //  maxMemoryKb guards against a hash from an untrusted source claiming an enormous memory cost.  The
    //  memory cost is taken from the hash string, so this limit is checked before any memory is allocated.
    //  It defaults to 2 GB.
    json.UpdateInt("maxMemoryKb",262144)

    //  Argon2VerifyPassword returns 1 if the password matched, 0 if it did not match, and -1 if the
    //  verification could not be performed.  Always test for a match with == 1.
    verifyResult := crypt.Argon2VerifyPassword(password,*json.Emit(),phcHash)
    if verifyResult == 1 {
        fmt.Println("The password is verified.")
    } else {
        if verifyResult == 0 {
            fmt.Println("The password does not match.")
        } else {
            fmt.Println("The verification could not be performed: ", crypt.LastErrorText())
        }

    }


    crypt.DisposeCrypt2()
    json.DisposeJsonObject()