# rsurl
A pure-Rust implementation of curl, built on top of [purecrypto](https://crates.io/crates/purecrypto)
for TLS — no OpenSSL, no system libcurl, no C dependencies.
`rsurl` ships in three forms:
1. **Rust library** (`rsurl` crate) — a small, ergonomic HTTP client API for Rust projects.
2. **C library** (`librsurl.so` / `rsurl.h`) — a curl-compatible C ABI for non-Rust consumers.
3. **`rsurl` CLI** — a drop-in-ish replacement for the `curl` command line.
## Status
Early, in active development.
| HTTP/1.1 (all methods) | working | Content-Length, chunked, read-to-EOF body modes |
| HTTPS via purecrypto | working | TLS 1.2/1.3, system roots, full cert verification |
| HTTP/2 (RFC 9113) | working* | ALPN h2, HPACK + Huffman decoder; single request/conn, no flow control yet |
| HTTP/3 over QUIC (RFC 9114) | partial | QUIC + frame layer wired; QPACK Huffman decoder still TODO |
| FTP / FTPS (RFC 959, 4217) | working | RETR + LIST, EPSV with PASV fallback, implicit FTPS |
| FILE (RFC 8089) | working | rejects non-local hosts |
| DICT (RFC 2229) | working | DEFINE, MATCH, SHOW DATABASES |
| GOPHER / GOPHERS (RFC 1436) | working | reads to EOF, item-type 7 search deferred |
| IMAP / IMAPS (RFC 9051) | working | LOGIN + LIST / SELECT+FETCH / UID FETCH BODY[] |
| LDAP / LDAPS (RFC 4511) | working | simple bind + search → LDIF; subset of filter syntax |
| MQTT / MQTTS (v3.1.1) | working | CONNECT, SUBSCRIBE, receive one PUBLISH (QoS 0) |
| POP3 / POP3S (RFC 1939) | working | LIST or RETR, USER/PASS auth |
| RTSP (RFC 7826) | working | DESCRIBE only; SETUP/PLAY session flow deferred |
| TFTP (RFC 1350) | working | read side with timeout/retry, 256 MiB cap |
| WS / WSS (RFC 6455) | working | reads one data frame then closes |
\* HTTP/2 verified live against nghttp2.org and cloudflare.com from the implementation
worktree. Available via `--http2` (force) or auto-negotiated via ALPN.
System CA bundle paths searched, in order: `/etc/ssl/certs/ca-certificates.crt`,
`/etc/pki/tls/certs/ca-bundle.crt`, `/etc/ssl/cert.pem`, `/etc/ssl/ca-bundle.pem`,
`/etc/ca-certificates/extracted/tls-ca-bundle.pem`.
## Rust usage
```rust
let resp = rsurl::get("http://example.com")?;
println!("{} {}", resp.status, resp.reason);
println!("{}", String::from_utf8_lossy(&resp.body));
```
## CLI usage
```sh
rsurl http://example.com
rsurl -o out.html -v http://example.com
rsurl https://example.com # HTTPS via purecrypto
rsurl -L http://github.com # follow redirects
rsurl -u alice:hunter2 http://api/... # HTTP Basic auth
rsurl -k https://expired.badssl.com # skip TLS verification (insecure!)
rsurl --cacert ./roots.pem https://... # custom trust anchors
rsurl --max-time 5 -O http://e/foo.bin # cap total time, save as foo.bin
rsurl file:///etc/hostname # local file
rsurl dict://dict.org/d:curl # dictionary lookup
rsurl gopher://gopher.floodgap.com/ # gopher menu
rsurl ftp://ftp.example.com/pub/file # FTP download
```
Supported curl-style flags include `-L`/`--location`, `--max-redirs`,
`-u`/`--user`, `-k`/`--insecure`, `--cacert`, `--max-time`,
`--connect-timeout`, and `-O`/`--remote-name`. Multiple URLs on one
command line are processed sequentially.
## C usage
```c
#include "rsurl.h"
RSURL *h = rsurl_easy_init();
rsurl_easy_setopt_str(h, RSURLOPT_URL, "http://example.com");
rsurl_easy_perform(h);
const uint8_t *body; size_t len;
rsurl_easy_response_body(h, &body, &len);
printf("%ld %.*s\n", rsurl_easy_response_status(h), (int)len, body);
rsurl_easy_cleanup(h);
```
Link with `-lrsurl`. Function names use a `rsurl_` prefix so the library
can coexist with libcurl in the same process.
## Build
```sh
cargo build --release
# Binary: target/release/rsurl
# Rust rlib: target/release/librsurl.rlib
# C cdylib: target/release/librsurl.so
# C header: include/rsurl.h
```
## License
MIT — Copyright © 2026 Karpelès Lab Inc. See [LICENSE](LICENSE).