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stevecheckoway / keybase.md
Last active August 3, 2017 17:20

Keybase proof

I hereby claim:

  • I am stevecheckoway on github.
  • I am stevecheckoway (https://keybase.io/stevecheckoway) on keybase.
  • I have a public key ASDmRS21uuyoSF8fbJpR5c8MWoHaZlc3DOeEyrJsK59VZAo

To claim this, I am signing this object:

@stevecheckoway
stevecheckoway / smalloc.c
Created January 9, 2016 17:05
Malloc implementation designed to be vulnerable to buffer overflows on the heap.
#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
/* glibc's malloc hooks. Silence warnings about deprecated hooks (see
* bottom of this file). */
@stevecheckoway
stevecheckoway / skramdown.rb
Last active October 24, 2018 21:29
Simple Jekyll plugin to 1. parse `$…$` or `\(…\)` as inline math; 2. parse `$$…$$` as display math both inside and outside paragraphs.
# This is a (more) sane math parsing scheme.
require 'kramdown/parser/kramdown'
require 'kramdown/parser/kramdown/block_boundary'
module Kramdown
module Parser
class Skramdown < Kramdown::Parser::GFM
def initialize(source, options)
super
idx = @span_parsers.index(:inline_math)
@stevecheckoway
stevecheckoway / fa.sty
Created March 10, 2018 22:54
Finite automata and (deterministic) Turing machine running/drawing.
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{fa}
[2018/03/09 v0.3 Construct finite automata and Turing machines]
\RequirePackage{tikz}
\RequirePackage{etoolbox}
\usetikzlibrary{arrows.meta,automata,calc,chains,positioning}
% Define \emptystring to \varepsilon
@stevecheckoway
stevecheckoway / notes.md
Created May 29, 2019 18:30
Installing Ghidra Server on Ubuntu 18.04.2 LTS

Installation on Ubuntu 18.04.2 LTS

  1. Install the jdk.

    $ sudo apt update
$ sudo apt install default-jdk

  2. Create a new user.

@stevecheckoway
stevecheckoway / quiz-checklist.md
Last active September 12, 2019 18:00
Checklist for making a quiz on Blackboard
  • reading quizzes > Assessments > Test
  • Create a New Test with questions
  • Set all point values to 1
  • Make test available to students
  • Allow unlimited attempts
  • Display after the previous class
  • Set the due date to the beginning of class
  • Do not allow students to start the Test if the due date has passed
  • After submission show all answers and submitted
  • After due date, show everything
@stevecheckoway
stevecheckoway / verify.py
Created October 30, 2020 05:06
DKIM signature verification
#!/usr/bin/env python3
from dkim import DKIM
import sys
def get_txt(*args, **kwargs):
return b'k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA1Kd87/UeJjenpabgbFwh+eBCsSTrqmwIYYvywlbhbqoo2DymndFkbjOVIPIldNs/m40KF+yzMn1skyoxcTUGCQs8g3FgD2Ap3ZB5DekAo5wMmk4wimDO+U8QzI3SD0" "7y2+07wlNWwIt8svnxgdxGkVbbhzY8i+RQ9DpSVpPbF7ykQxtKXkv/ahW3KjViiAH+ghvvIhkx4xYSIc9oSwVmAl5OctMEeWUwg8Istjqz8BZeTWbf41fbNhte7Y+YqZOwq1Sd0DbvYAD9NOZK9vlfuac0598HY+vtSBczUiKERHv1yRbcaQtZFh5wtiRrN04BLUTD21MycBX5jYchHjPY/wIDAQAB'
failed = False
@stevecheckoway
stevecheckoway / fpuzzles-copyselection.js
Created July 16, 2021 15:31
Tampermonkey script to copy the selection in f-puzzles.com
// ==UserScript==
// @name Copy selection
// @namespace http://tampermonkey.net/
// @version 0.1
// @description Copy the value of selected cells
// @author Stephen Checkoway
// @match https://*.f-puzzles.com/*
// @match https://f-puzzles.com/*
// @icon https://www.google.com/s2/favicons?domain=f-puzzles.com
// @grant none
@stevecheckoway
stevecheckoway / Notes.md
Created May 3, 2022 19:10
Script to create client certificates for Ghidra Server

${HOME}/ghidra-current is a symlink to the currently active Ghidra directory. That is, I have several versions of Ghidra installed in ${HOME} and ghidra-current points to the one I'm using.

I'm keeping the cacerts and keystore outside of the Ghidra directory to make upgrading Ghidra easier. (I also keep the repositories directory outside of the Ghidra directory for the same reason.)

The directory for the keystore and cacerts should exist and the directory for the keystore should have permissions 0700. This isn't checked.

For this to work, you need to enable PKI authentication in server.conf by setting

wrapper.app.parameter.1=-a2
wrapper.app.parameter.2=${ghidra.repositories.dir}
@stevecheckoway
stevecheckoway / shell_output.txt
Created July 15, 2025 15:14
Example showing strncpy not working as desired
root@53a1a0150ee1:~/api_key_manager# make
gcc -Wall -Wextra -O2 -o api_key_manager api_key_manager.c -lsqlite3 -lsodium
api_key_manager.c: In function 'add_key':
api_key_manager.c:97:5: warning: '__builtin_strncpy' specified bound 256 equals destination size [-Wstringop-truncation]
97 | strncpy(new_key.description, description, MAX_DESC_LEN);
| ^
root@53a1a0150ee1:~/api_key_manager# ./api_key_manager
No master key set. Please set a master key:
Master key set successfully
root@53a1a0150ee1:~/api_key_manager# ./api_key_manager -a "Encrypted key in description: $(perl -e 'print "A" x 256')"