Rustls is ready for use. There are no major breaking interface changes envisioned after the set included in the 0.20 release.
If you'd like to help out, please see CONTRIBUTING.md.
- Next release
- Planned: removal of unused signature verification schemes at link-time.
- Expose AlertDescription, ContentType, and HandshakeType, SignatureAlgorithm, and NamedGroup as part of the stable API. Previously they were part of the unstable internals API, but were referenced by parts of the stable API.
- 0.20.6 (2022-05-18)
- 0.20.5 included a change to track more context for the
Error::CorruptMessagewhich made API-incompatible changes to the
Errortype. We yanked 0.20.5 and have reverted that change as part of 0.20.6.
- 0.20.5 included a change to track more context for the
- 0.20.5 (2022-05-14)
- Correct compatbility with servers which return no TLS extensions and take advantage of a special case encoding.
- Remove spurious warn-level logging introduced in 0.20.3.
- Expose cipher suites in
- Allow verification of IP addresses with
- Retry I/O operations in
- Fix server::ResolvesServerCertUsingSni case sensitivity.
- 0.20.4 (2022-02-19)
- Correct regression in QUIC 0-RTT support.
- 0.20.3 (2022-02-13)
- Support loading ECDSA keys in SEC1 format.
- Support receipt of 0-RTT "early data" in TLS1.3 servers. It is not enabled
by default; opt in by setting
ServerConfig::max_early_data_sizeto a non-zero value.
- Support sending of data with the first server flight. This is also not
enabled by default either: opt in by setting
read_bufinterface when compiled with nightly. This means data can be safely read out of a rustls connection into a buffer without the buffer requiring initialisation first. Set the
read_buffeature to use this.
- Improve efficiency when writing vectors of TLS types.
- Reduce copying and improve efficiency in TLS1.2 handshake.
- 0.20.2 (2021-11-21)
CipherSuite::as_str()value (as introduced in 0.20.1).
- 0.20.1 (2021-11-14)
- Allow cipher suite enum items to be stringified.
- Improve documentation of configuration builder types.
- Ensure unused cipher suites can be removed at link-time.
- Ensure single-use error types implement
std::error::Error, and are public.
See RELEASE_NOTES.md for further change history.
Lives here: https://docs.rs/rustls/
Rustls is a TLS library that aims to provide a good level of cryptographic security, requires no configuration to achieve that security, and provides no unsafe features or obsolete cryptography.
- TLS1.2 and TLS1.3.
- ECDSA, Ed25519 or RSA server authentication by clients.
- ECDSA, Ed25519 or RSA server authentication by servers.
- Forward secrecy using ECDHE; with curve25519, nistp256 or nistp384 curves.
- AES128-GCM and AES256-GCM bulk encryption, with safe nonces.
- ChaCha20-Poly1305 bulk encryption (RFC7905).
- ALPN support.
- SNI support.
- Tunable fragment size to make TLS messages match size of underlying transport.
- Optional use of vectored IO to minimise system calls.
- TLS1.2 session resumption.
- TLS1.2 resumption via tickets (RFC5077).
- TLS1.3 resumption via tickets or session storage.
- TLS1.3 0-RTT data for clients.
- TLS1.3 0-RTT data for servers.
- Client authentication by clients.
- Client authentication by servers.
- Extended master secret support (RFC7627).
- Exporters (RFC5705).
- OCSP stapling by servers.
- SCT stapling by servers.
- SCT verification by clients.
Possible future features
- PSK support.
- OCSP verification by clients.
- Certificate pinning.
For reasons explained in the manual, rustls does not and will not support:
- SSL1, SSL2, SSL3, TLS1 or TLS1.1.
- DES or triple DES.
- EXPORT ciphersuites.
- MAC-then-encrypt ciphersuites.
- Ciphersuites without forward secrecy.
- Discrete-log Diffie-Hellman.
- Automatic protocol version downgrade.
There are plenty of other libraries that provide these features should you need them.
Rustls requires Rust 1.56 or later.
There are two example programs which use mio to do asynchronous IO.
Client example program
The client example program is named
tlsclient. The interface looks like:
Connects to the TLS server at hostname:PORT. The default PORT is 443. By default, this reads a request from stdin (to EOF) before making the connection. --http replaces this with a basic HTTP GET request for /. If --cafile is not supplied, a built-in set of CA certificates are used from the webpki-roots crate. Usage: tlsclient [options] [--suite SUITE ...] [--proto PROTO ...] <hostname> tlsclient (--version | -v) tlsclient (--help | -h) Options: -p, --port PORT Connect to PORT [default: 443]. --http Send a basic HTTP GET request for /. --cafile CAFILE Read root certificates from CAFILE. --auth-key KEY Read client authentication key from KEY. --auth-certs CERTS Read client authentication certificates from CERTS. CERTS must match up with KEY. --protover VERSION Disable default TLS version list, and use VERSION instead. May be used multiple times. --suite SUITE Disable default cipher suite list, and use SUITE instead. May be used multiple times. --proto PROTOCOL Send ALPN extension containing PROTOCOL. May be used multiple times to offer several protocols. --cache CACHE Save session cache to file CACHE. --no-tickets Disable session ticket support. --no-sni Disable server name indication support. --insecure Disable certificate verification. --verbose Emit log output. --max-frag-size M Limit outgoing messages to M bytes. --version, -v Show tool version. --help, -h Show this screen.
Some sample runs:
$ cargo run --example tlsclient -- --http mozilla-modern.badssl.com HTTP/1.1 200 OK Server: nginx/1.6.2 (Ubuntu) Date: Wed, 01 Jun 2016 18:44:00 GMT Content-Type: text/html Content-Length: 644 (...)
$ cargo run --example tlsclient -- --http expired.badssl.com TLS error: WebPkiError(CertExpired, ValidateServerCert) Connection closed
Server example program
The server example program is named
tlsserver. The interface looks like:
Runs a TLS server on :PORT. The default PORT is 443. `echo' mode means the server echoes received data on each connection. `http' mode means the server blindly sends a HTTP response on each connection. `forward' means the server forwards plaintext to a connection made to localhost:fport. `--certs' names the full certificate chain, `--key' provides the RSA private key. Usage: tlsserver --certs CERTFILE --key KEYFILE [--suite SUITE ...] [--proto PROTO ...] [options] echo tlsserver --certs CERTFILE --key KEYFILE [--suite SUITE ...] [--proto PROTO ...] [options] http tlsserver --certs CERTFILE --key KEYFILE [--suite SUITE ...] [--proto PROTO ...] [options] forward <fport> tlsserver (--version | -v) tlsserver (--help | -h) Options: -p, --port PORT Listen on PORT [default: 443]. --certs CERTFILE Read server certificates from CERTFILE. This should contain PEM-format certificates in the right order (the first certificate should certify KEYFILE, the last should be a root CA). --key KEYFILE Read private key from KEYFILE. This should be a RSA private key or PKCS8-encoded private key, in PEM format. --ocsp OCSPFILE Read DER-encoded OCSP response from OCSPFILE and staple to certificate. Optional. --auth CERTFILE Enable client authentication, and accept certificates signed by those roots provided in CERTFILE. --require-auth Send a fatal alert if the client does not complete client authentication. --resumption Support session resumption. --tickets Support tickets. --protover VERSION Disable default TLS version list, and use VERSION instead. May be used multiple times. --suite SUITE Disable default cipher suite list, and use SUITE instead. May be used multiple times. --proto PROTOCOL Negotiate PROTOCOL using ALPN. May be used multiple times. --verbose Emit log output. --version, -v Show tool version. --help, -h Show this screen.
Here's a sample run; we start a TLS echo server, then connect to it with openssl and tlsclient:
$ cargo run --example tlsserver -- --certs test-ca/rsa/end.fullchain --key test-ca/rsa/end.rsa -p 8443 echo & $ echo hello world | openssl s_client -ign_eof -quiet -connect localhost:8443 depth=2 CN = ponytown RSA CA verify error:num=19:self signed certificate in certificate chain hello world ^C $ echo hello world | cargo run --example tlsclient -- --cafile test-ca/rsa/ca.cert -p 8443 localhost hello world ^C
Rustls is distributed under the following three licenses:
- Apache License version 2.0.
- MIT license.
- ISC license.
These are included as LICENSE-APACHE, LICENSE-MIT and LICENSE-ISC respectively. You may use this software under the terms of any of these licenses, at your option.