NeilMadden

#!/usr/bin/env python3
# Copyright 2024 Neil Madden.
# License: https://creativecommons.org/licenses/by-sa/4.0/deed.en.

# Like this? I do training courses & consultancy:
# https://illuminated-security.com/

import hashlib
import math
import os

NeilMadden

        // Shared context of the request:
        String accessToken = "an_access_token";
        String origin = "https://api.example.com:443";
        JweHeader header = new JweHeader();
        header.setAgreementPartyUInfo(Base64url.encode(accessToken));
        header.setAgreementPartyVInfo(Base64url.encode(origin));

        // Server - generate challenge
        OkpJWK ephemeral = OkpJWK.generateKeyPair(X25519);
        String challenge = Base64url.encode(ephemeral.toPublicJwk().get().toJsonValue().toString());

NeilMadden

const crypto = window.crypto.subtle;
const UTF8 = new TextEncoder('utf-8');

function genKeyPair() {
    return crypto.generateKey({
            name: "ECDH",
            namedCurve: "P-256"
        }, false, ['deriveKey', 'deriveBits']);
}

NeilMadden

0x70000d039000 11:12:31.767 [opensc-pkcs11] ctx.c:792:sc_context_create: ===================================
0x70000d039000 11:12:31.767 [opensc-pkcs11] ctx.c:793:sc_context_create: opensc version: 0.17.0
0x70000d039000 11:12:31.767 [opensc-pkcs11] reader-pcsc.c:815:pcsc_init: PC/SC options: connect_exclusive=0 disconnect_action=1 transaction_end_action=0 reconnect_action=0 enable_pinpad=1 enable_pace=1
0x70000d039000 11:12:31.768 [opensc-pkcs11] reader-pcsc.c:1283:pcsc_detect_readers: called
0x70000d039000 11:12:31.768 [opensc-pkcs11] reader-pcsc.c:1302:pcsc_detect_readers: Probing PC/SC readers
0x70000d039000 11:12:31.768 [opensc-pkcs11] reader-pcsc.c:1330:pcsc_detect_readers: Establish PC/SC context
0x70000d039000 11:12:31.768 [opensc-pkcs11] reader-pcsc.c:1242:pcsc_add_reader: Adding new PC/SC reader 'Nitrokey Nitrokey HSM'
0x70000d039000 11:12:31.768 [opensc-pkcs11] reader-pcsc.c:319:refresh_attributes: Nitrokey Nitrokey HSM check
0x70000d039000 11:12:31.769 [opensc-pkcs11] reader-pcsc.c:347:refresh_attr

NeilMadden

1. Explicitly spell out the ECDH-ES public key validation routines from NIST. I have a blog post summarising them: https://neilmadden.wordpress.com/2017/05/17/so-how-do-you-validate-nist-ecdh-public-keys/
2. Recommend that (despite the -ES) ECDH is safest when both keys are ephemeral (eg you use some initial step to retrieve a fresh authenticated ephemeral key from the other party).
3. Spell out how to authenticate ECDH ephemeral keys. For instance, include an inner signed JWT that repeats the epk and possibly the apu/apv claims too.
4. Recommend that the apu and apv claims as a bare minimum include a hash of both public keys and SHOULD include any other known identifiers.
5. Recommend that the receiving party recalculates the apu and apv claims from known inputs to check they match. (Or leave these out of the JWT and require the other party to recalculate them).
6. Provide explicit key lifetime requirements. E.g., for AES GCM this should not exceed 2^32 messages for randomly-generated IVs, and not exce

NeilMadden

-module(index).
-export([index_file/1,get_file_contents/1,show_file_contents/1]).

% Used to read a file into a list of lines.
% Example files available in:
%   gettysburg-address.txt (short)
%   dickens-christmas.txt  (long)
  

% Get the contents of a text file into a list of lines.

NeilMadden

% Functional Programming in Erlang MOOC
% Week 1 assignment submission - Neil Madden
-module(ex).
-export([perimeter/1,area/1,enclose/1,bits/1]).

% Type definitions! Found out Erlang supports these...
-type point()       :: {number(), number()}.
-type circle()      :: {circle, point(), number()}.
-type rectangle()   :: {rectangle, point(), number(), number()}.
-type triangle()    :: {triangle, point(), point(), point()}.

NeilMadden

Keybase proof

I hereby claim:

• I am neilmadden on github.
• I am neilmadden (https://keybase.io/neilmadden) on keybase.
• I have a public key ASBcU_6xkYIeml3XZUbGrLB9LgOAcrvKGTZB55p-6JTyogo

To claim this, I am signing this object: