https://github.com/codesteak/self-modifying-elf-prototype
This is a **prototype/experiment** for an self modifying executable.
https://github.com/codesteak/self-modifying-elf-prototype
Last synced: 3 months ago
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This is a **prototype/experiment** for an self modifying executable.
- Host: GitHub
- URL: https://github.com/codesteak/self-modifying-elf-prototype
- Owner: CodeSteak
- License: mit
- Created: 2019-03-01T15:31:20.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2019-03-01T18:25:32.000Z (over 6 years ago)
- Last Synced: 2025-01-13T08:35:34.505Z (5 months ago)
- Language: Rust
- Size: 108 KB
- Stars: 2
- Watchers: 2
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: Readme.md
- License: LICENSE
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README
# A Self Modifying Binary
## What is this?
This is a **prototype / experiment** for an self modifying executable. It's inspired by
[tiddlywiki](https://tiddlywiki.com/). Instead of having a separat executable
and some files containing data, all data are appended to the executable.
---
## What can it do?
* You can dynamically add plugins. (It does IPC).
* You can bundle executables with their dynamic libraries.
### Commands
#### Add
Adds data to the executable. Each entry has some content, an name, an some tags
with optional string values.
* You can add files
`./microwiki add file --name "My Cat" cat-pic.png --tag lol --tag rating=5`
* You can add tags to existing entries.
`./microwiki add tag "My Cat" "Cat-Pics"`
* You can add executables or plugins.
`./microwiki add elf ${which nano} --name nano`
And run them via `microwiki nano`. (Dynamic libraries are bundled).
#### Web
This starts a half backed web ui for managing entries und tags. Only text
entries are supported.
#### Export
This is used for bootstrapping.
`./microwiki export -o microwiki.new && chmod +x microwiki.new` can be used
to clone the executable. Then this done, the new executable is garbage
collected. This may be necessary because data in the executable is append only.
### Special Tags
The `type`-tag is used to mark the type of an entry. The value of this tag
should be the file extension of the content. For Elf-Binaries `elf` is used.
For text `text` should be used.
When `microwiki` is run, the first argument is used to determene what
plugin/executable to run. For an entry to be selected, the `type` tag must be
`elf` and the `command` tag must equal the first command line argument.
The value of `lib` specifies a dynamic library to use. Multiple `lib` can
be used for a single entry. If none is set is `LD_LIBRARY_PATH` overwritten.
Every entry with the `web/style` is added as css when displaying an entry
via the `web` plugin. Similarly, `web/script` is included as javascript.
### Environment variables
When `OVERLAY` is provided, microwiki scans the directory for `*.entry` files
which are then loaded. _See entry files in repo._ This is used for bootstrapping.
When `OVERLAY` and `OVERLAY_WATCH` is provided, microwiki watches for changes
in the `OVERLAY_WATCH`, to reload the entry files in `OVERLAY_WATCH` and restart
the current plugin/command.
If `USE_STRIP` is set and `#cargo` is used in an entry file, the executable
gets stripped before loading.
If `USE_UPX` is set and `#cargo` is used in an entry file, the executable
gets compressed via upx before loading.
---
## Building
This runs only on linux.
Since some bootstrapping is needed, `build.sh` can be used to build the
executable. For building ~~`rust`~~ `cargo`, `clang`, `gnu-binutils` and `upx` are required.
The executable can be found at `out/microwiki`.
Or run in debug mode with `OVERLAY="." cargo run -p microwiki`.
---
## Known Bugs
* Web ui can't handle binary data.
* If `OVERLAY` used the dynamic libraries in `/tmp` are not deleted after the
programm exits.
* If you run `strip` on `out/microwiki` all data and the main programm is
deleted, since it's only append. Only the loader _(See loader/)_ is left.
---
## Lessons learned
* Rust web libraries are not major enough or too complicated because of
missing async/await.
* Set a clear focus for a project like this.
I'm still unsure what this is.
* Reuse and integrate existing software.
E.g. instead of building a web ui, a tiddywiki plugin could have been written.
### That programms like this could be useful for
* Exporting a single executable. Like shipping
scripts + payload + interpreter in one executable.
* Building a persistent REPL.
* Making a tiddywiki server thing like [TiddlyServer](https://github.com/Arlen22/TiddlyServer)