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+\documentclass[12pt]{beamer}
+\usetheme{metropolis}
+\newenvironment{code}{\ttfamily}{\par}
+\title{Where does \textit{your} compiler come from?}
+\date{2018-03-13}
+\author{Vincent Ambo}
+\institute{Norwegian Unix User Group}
+\begin{document}
+  \maketitle
+
+  %% Slide 1:
+  \section{Introduction}
+
+  %% Slide 2:
+  \begin{frame}{Chicken and egg}
+    Self-hosted compilers are often built using themselves, for example:
+
+    \begin{itemize}
+    \item C-family compilers bootstrap themselves \& each other
+    \item (Some!) Common Lisp compilers can bootstrap each other
+    \item \texttt{rustc} bootstraps itself with a previous version
+    \item ... same for many other languages!
+    \end{itemize}
+  \end{frame}
+
+  \begin{frame}{Chicken, egg and ... lizard?}
+    It's not just compilers: Languages have runtimes, too.
+
+    \begin{itemize}
+    \item JVM is implemented in C++
+    \item Erlang-VM is C
+    \item Haskell runtime is C
+    \end{itemize}
+
+    ... we can't ever get away from C, can we?
+  \end{frame}
+
+  %% Slide 3:
+  \begin{frame}{Trusting Trust}
+    \begin{center}
+      \huge{Could this be exploited?}
+    \end{center}
+  \end{frame}
+
+  %% Slide 4:
+  \begin{frame}{Short interlude: A quine}
+    \begin{center}
+      \begin{code}
+        ((lambda (x) (list x (list 'quote x)))
+        \newline\vspace*{6mm} '(lambda (x) (list x (list 'quote x))))
+      \end{code}
+    \end{center}
+  \end{frame}
+
+  %% Slide 5:
+  \begin{frame}{Short interlude: Quine Relay}
+    \begin{center}
+      \includegraphics[
+        keepaspectratio=true,
+        height=\textheight
+      ]{quine-relay.png}
+    \end{center}
+  \end{frame}
+
+  %% Slide 6:
+  \begin{frame}{Trusting Trust}
+    An attack described by Ken Thompson in 1983:
+
+    \begin{enumerate}
+    \item Modify a compiler to detect when it's compiling itself.
+    \item Let the modification insert \textit{itself} into the new compiler.
+    \item Add arbitrary attack code to the modification.
+    \item \textit{Optional!} Remove the attack from the source after compilation.
+    \end{enumerate}
+  \end{frame}
+
+  %% Slide 7:
+  \begin{frame}{Damage potential?}
+    \begin{center}
+      \large{Let your imagination run wild!}
+    \end{center}
+  \end{frame}
+
+  %% Slide 8:
+  \section{Countermeasures}
+
+  %% Slide 9:
+  \begin{frame}{Diverse Double-Compiling}
+    Assume we have:
+
+    \begin{itemize}
+    \item Target language compilers $A$ and $T$
+    \item The source code of $A$: $ S_{A} $
+    \end{itemize}
+  \end{frame}
+
+  %% Slide 10:
+  \begin{frame}{Diverse Double-Compiling}
+    Apply the first stage (functional equivalence):
+
+    \begin{itemize}
+    \item $ X = A(S_{A})$
+    \item $ Y = T(S_{A})$
+    \end{itemize}
+
+    Apply the second stage (bit-for-bit equivalence):
+
+    \begin{itemize}
+    \item $ V = X(S_{A})$
+    \item $ W = Y(S_{A})$
+    \end{itemize}
+
+    Now we have a new problem: Reproducibility!
+  \end{frame}
+
+  %% Slide 11:
+  \begin{frame}{Reproducibility}
+    Bit-for-bit equivalent output is hard, for example:
+
+    \begin{itemize}
+    \item Timestamps in output artifacts
+    \item Non-deterministic linking order in concurrent builds
+    \item Non-deterministic VM \& memory states in outputs
+    \item Randomness in builds (sic!)
+    \end{itemize}
+  \end{frame}
+
+  \begin{frame}{Reproducibility}
+    \begin{center}
+      Without reproducibility, we can never trust that any shipped
+      binary matches the source code!
+    \end{center}
+  \end{frame}
+
+  %% Slide 12:
+  \section{(Partial) State of the Union}
+
+  \begin{frame}{The Desired State}
+    \begin{center}
+      \begin{enumerate}
+      \item Full-source bootstrap!
+      \item All packages reproducible!
+      \end{enumerate}
+    \end{center}
+  \end{frame}
+
+  %% Slide 13:
+  \begin{frame}{Bootstrapping Debian}
+    \begin{itemize}
+    \item Sparse information on the Debian-wiki
+    \item Bootstrapping discussions mostly resolve around new architectures
+    \item GCC is compiled by depending on previous versions of GCC
+    \end{itemize}
+  \end{frame}
+
+  \begin{frame}{Reproducing Debian}
+    Debian has a very active effort for reproducible builds:
+
+    \begin{itemize}
+    \item Organised information about reproducibility status
+    \item Over 90\% reproducibility in Debian package base!
+    \end{itemize}
+  \end{frame}
+
+  \begin{frame}{Short interlude: Nix}
+    \begin{center}
+      \includegraphics[
+        keepaspectratio=true,
+        height=0.7\textheight
+      ]{nixos-logo.png}
+    \end{center}
+  \end{frame}
+
+  \begin{frame}{Short interlude: Nix}
+    \begin{center}
+      \includegraphics[
+        keepaspectratio=true,
+        height=0.90\textheight
+      ]{drake-meme.png}
+    \end{center}
+  \end{frame}
+
+  \begin{frame}{Short interlude: Nix}
+    \begin{center}
+      \includegraphics[
+        keepaspectratio=true,
+        height=0.7\textheight
+      ]{nixos-logo.png}
+    \end{center}
+  \end{frame}
+
+  \begin{frame}{Bootstrapping NixOS}
+    Nix evaluation can not recurse forever: The bootstrap can not
+    simply depend on a previous GCC.
+
+    Workaround: \texttt{bootstrap-tools} tarball from a previous
+    binary cache is fetched and used.
+
+    An unfortunate magic binary blob ...
+  \end{frame}
+
+  \begin{frame}{Reproducing NixOS}
+    Not all reproducibility patches have been ported from Debian.
+
+    However: Builds are fully repeatable via the Nix fundamentals!
+  \end{frame}
+
+  \section{Future Developments}
+
+  \begin{frame}{Bootstrappable: stage0}
+    Hand-rolled ``Cthulhu's Path to Madness'' hex-programs:
+
+    \begin{itemize}
+    \item No non-auditable binary blobs
+    \item Aims for understandability by 70\% of programmers
+    \item End goal is a full-source bootstrap of GCC
+    \end{itemize}
+  \end{frame}
+
+
+  \begin{frame}{Bootstrappable: MES}
+    Bootstrapping the ``Maxwell Equations of Software'':
+
+    \begin{itemize}
+    \item Minimal C-compiler written in Scheme
+    \item Minimal Scheme-interpreter (currently in C, but intended to
+      be rewritten in stage0 macros)
+    \item End goal is full-source bootstrap of the entire GuixSD
+    \end{itemize}
+  \end{frame}
+
+  \begin{frame}{Other platforms}
+    \begin{itemize}
+    \item Nix for Darwin is actively maintained
+    \item F-Droid Android repository works towards fully reproducible
+      builds of (open) Android software
+    \item Mobile devices (phones, tablets, etc.) are a lost cause at
+      the moment
+    \end{itemize}
+  \end{frame}
+
+  \begin{frame}{Thanks!}
+    Resources:
+    \begin{itemize}
+    \item bootstrappable.org
+    \item reproducible-builds.org
+    \end{itemize}
+
+    @tazjin | mail@tazj.in
+  \end{frame}
+\end{document}