tag	08fcfaa96a9d7b5c988444282a0bad6a056b73aa
tagger	The Android Open Source Project <initial-contribution@android.com>	Fri May 26 06:20:16 2023 -0700
object	4742293d9c966485fdb0c11abbead402779fb525

commit	4742293d9c966485fdb0c11abbead402779fb525	[log] [tgz]
author	Joel Galenson <jgalenson@google.com>	Wed Dec 15 18:07:20 2021 +0000
committer	Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>	Wed Dec 15 18:07:20 2021 +0000
tree	c9278f52ec614b19d52386d5b40b15a17d324a21
parent	f178953783bbea245b936866a429f99215c4e607 [diff]
parent	f9dd168e8101466a9a63d2f26772e66f69f6b535 [diff]

tree: c9278f52ec614b19d52386d5b40b15a17d324a21

README.md

X.509 Parser

A X.509 v3 (RFC5280) parser, implemented with the nom parser combinator framework.

It is written in pure Rust, fast, and makes extensive use of zero-copy. A lot of care is taken to ensure security and safety of this crate, including design (recursion limit, defensive programming), tests, and fuzzing. It also aims to be panic-free.

The code is available on Github and is part of the Rusticata project.

Certificates are usually encoded in two main formats: PEM (usually the most common format) or DER. A PEM-encoded certificate is a container, storing a DER object. See the pem module for more documentation.

To decode a DER-encoded certificate, the main parsing method is [X509Certificate::from_der] ( part of the FromDer trait ), which builds a X509Certificate object.

An alternative method is to use X509CertificateParser, which allows specifying parsing options (for example, not automatically parsing option contents).

The returned objects for parsers follow the definitions of the RFC. This means that accessing fields is done by accessing struct members recursively. Some helper functions are provided, for example X509Certificate::issuer() returns the same as accessing <object>.tbs_certificate.issuer.

For PEM-encoded certificates, use the pem module.

Examples

Parsing a certificate in DER format:

use x509_parser::prelude::*;

static IGCA_DER: &[u8] = include_bytes!("../assets/IGC_A.der");

let res = X509Certificate::from_der(IGCA_DER);
match res {
    Ok((rem, cert)) => {
        assert!(rem.is_empty());
        //
        assert_eq!(cert.version(), X509Version::V3);
    },
    _ => panic!("x509 parsing failed: {:?}", res),
}

To parse a CRL and print information about revoked certificates:

#
#
let res = CertificateRevocationList::from_der(DER);
match res {
    Ok((_rem, crl)) => {
        for revoked in crl.iter_revoked_certificates() {
            println!("Revoked certificate serial: {}", revoked.raw_serial_as_string());
            println!("  Reason: {}", revoked.reason_code().unwrap_or_default().1);
        }
    },
    _ => panic!("CRL parsing failed: {:?}", res),
}

Features

The verify feature adds support for (cryptographic) signature verification, based on ring. It adds the X509Certificate::verify_signature() to X509Certificate.

/// Cryptographic signature verification: returns true if certificate was signed by issuer
#[cfg(feature = "verify")]
pub fn check_signature(cert: &X509Certificate<'_>, issuer: &X509Certificate<'_>) -> bool {
    let issuer_public_key = issuer.public_key();
    cert
        .verify_signature(Some(issuer_public_key))
        .is_ok()
}

The validate features add methods to run more validation functions on the certificate structure and values using the Validate trait. It does not validate any cryptographic parameter (see verify above).

Rust version requirements

x509-parser requires Rustc version 1.46 or greater, based on nom 7 dependencies and for proc-macro attributes support.

Changes

See CHANGELOG.md

License

Licensed under either of

Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.