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-* Solutions to the [[https://cryptopals.com/][Cryptopals]] challenges
+* Cryptopals
 
 [[https://github.com/dlozeve/cryptopals/actions][https://github.com/dlozeve/cryptopals/workflows/CI/badge.svg]]
+
+Here are my solutions to the [[https://cryptopals.com/][cryptopals crypto challenges]], implemented
+in C.
+
+** Build
+
+You will need [[https://mesonbuild.com/][Meson]] and [[https://ninja-build.org/][Ninja]], and CMake for the mbedtls dependency,
+which is a [[https://mesonbuild.com/CMake-module.html][CMake subproject]].
+
+#+begin_src sh
+  meson build
+  cd build
+  ninja
+#+end_src
+
+Use e.g. ~CC=clang meson build~ if you want to use a different
+compiler.
+
+The build will generate one executable for each challenge, and an
+additional executable =tests=.
+
+Building will automatically pull and compile the dependencies: [[https://github.com/ARMmbed/mbedtls/][Mbed
+TLS]] and [[https://github.com/nemequ/munit/][µnit]].
+
+** Test
+
+After building, there is a =tests= executable in the =build=
+directory, that will run the unit tests. You can also run them with
+the built-in =ninja test= command.
+
+To test the challenges outputs, run the =tests/challenges.py= Python
+script, which will run the executable for each challenge and test it
+against the expected output.
+
+** Development
+
+For editor integration, you might want to link
+=compile_commands.json=, which is automatically generated by the build
+system, at the root of the project:
+#+begin_src sh
+  ln -s build/compile_commands.json
+#+end_src