Érico Rolim
ef02e2d5ef
This also required a small change in where gemi outputs the page's contents, to avoid requiring multiple wait_for_pager() calls in the code. This also allows it to show the redirect page's contents. |
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|---|---|---|
| extern/libbaseencode | ||
| .gitignore | ||
| LICENSE | ||
| README.md | ||
| comm.c | ||
| configure | ||
| cproc-make | ||
| encrypt.c | ||
| files.c | ||
| formats.c | ||
| gemi.c | ||
| gemini.c | ||
| gemini.h | ||
| makefile | ||
| mmap_file.c | ||
| mmap_file.h | ||
| pager.c | ||
| pager.h | ||
| purr.c | ||
| purr.h | ||
| read_certs.c | ||
| read_certs.h | ||
| socket.c | ||
| tests.c | ||
| urls.c | ||
README.md
purr-c
This repository holds some loosely related networking projects of mine. This is mainly a learning exercise for network, crypto and SSL programming, and all of the programs inside should be treated as such.
The BearSSL library was chosen as the crypto and SSL implementation.
libbaseencode has been
vendored in (can be found in external/libbaseencode), but has also gone
through some changes, namely removing null-byte checking from the base64
encoding function, adding an output length parameter to the base64 decoding
function and fixing Valgrind warnings about out-of-bounds accesses.
The code has a few instances of // TODO: remove hack comments and the like,
which I hope to get to someday.
Building
The only external dependency is BearSSL - on Void Linux, this can be obtained
with the bearssl-devel package. GNU Make and a C99 compiler, such as
cproc, are required for building.
You can build and install the project with the commands below:
$ ./configure # creates config.mk
$ make
$ make install PREFIX=$HOME/.local/bin
Programs
purr
This is a pure C client for the PurritoBin pastebin server, and uses PurritoBin's author's instance in https://bsd.ac by default.
It supports symmetric paste encryption (as supported by PurritoBin's online interface and its suggested clients). This makes it possible to share paste links that can only be decrypted by someone who has the keys to them. The key and IV are stored in the url's hash property, and are never sent to the server.
It can also work as a very limited curl alternative, due to its support of
both HTTP and HTTPS. It uses HTTP/1.0 for communication, but requires the
Content-Length field in the response header - this is done because I have
found servers that don't send notify_close when their transmission is done,
instead relying on the Content-Length field to provide enough information for
the client to determine if the transmission was sucessful or if the connection
was terminated before it should have been.
This program can use either Linux's getrandom(2) system call or BSD's
arc4random_buf(3) function for key generation.
Usage
Usage information can be viewed with purr -h. There are two symlinks to the
purr executable, meow and meowd, which are used as shortcuts to send and
receive encrypted pastes, respectively.
gemi
This is a (kind of) dumb Gemini client. For now, it requires servers with certificates that can be verified by the client's trust anchors, which means it isn't fully compliant with the Gemini spec, since it requires support for self-signed certificates via the TOFU (Trust On First Use) system.
It has a built-in "navigation" mechanism via the -b command line flag, which
parses the received page, finds links, asks the user to select one, and execs
into itself with the new link. This method of operation is currently quite
limited, due to lacking path normalization functions that deal with more complex
links (such as ../../docs).
It now supports parsing server messages, including redirects. However, these mechanisms are currently quite verbose.
Usage
Usage information can be viewed with gemi -h.
Acknowledgements
- Thomas Pornin for BearSSL
- Laurent Bercot for s6-networking (even though it's no longer in use here)
- epsilon-0 for PurritoBin (and the valuable help while I was testing this program)
- paolostivanin for libbaseencode