THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

What is webpki?

webpki is a library that validates Web PKI (TLS/SSL) certificates. webpki is designed to provide a full implementation of the client side of the Web PKI to a diverse range of applications and devices, including embedded (IoT) applications, mobile apps, desktop applications, and server infrastructure. webpki is intended to not only be the best implementation of the Web PKI, but to also precisely define what the Web PKI is.

webpki is written in Rust and uses ring for signature verification.

webpki is strongly influenced by mozilla::pkix. You can read a little about the ideas underlying both mozilla::pkix and webpki in insanity::pkix: A New Certificate Path Building & Validation Library.

The Rust compiler statically guarantees there are no buffer overflows, uses-after-free, double-frees, data races, etc. in webpki. webpki takes advantage of Rust's borrow checker to ensure that its zero-copy parsing strategy is safe and efficient. webpki never allocates memory on the heap, and it maintains a tight bound on the amount of stack memory it uses. webpki avoids all superfluous PKIX features in order to keep its object code size small. Further reducing the code size of webpki is an important goal.

This release is the very first prototype. Lots of improvements are planned, including:

• An extensive automated test suite.
• Key pinning.
• Certificate Transparency support.
• Short-lived certificate, OCSP stapling, and CRLSet support.
• Customization of the supported algorithms, key sizes, and elliptic curves allowed during a validation.
• A C language wrapper interface to allow using webpki in non-Rust applications.
• A specification of precisely what the Web PKI is.

About this fork

This is a fork of the original webpki project which adds a number of features required by the rustls project. This fork is released as the rustls-webpki crate, with versions starting 0.100.0 so as to not confusingly overlap with webpki versions.

Changelog

• 0.100.0 (2023-01-xx) - first release of rustls-webpki crate.
  • Allow verification of certificates with IP address subjectAltNames. EndEntityCert::verify_is_valid_for_subject_name was added, and EndEntityCert::verify_is_valid_for_dns_name was removed.
  • Make Error type non-exhaustive.
  • Reject non-contiguous netmasks in IP address name constraints.
  • Name constraints of type dNSName and iPAddress now work and are tested. directoryName name constraints are not implemented and will prevent path building where they appear.
• 0.22.0 (2021-04-10) - last upstream release of webpki crate.

Demo

See https://github.com/ctz/rustls#example-code for an example of using webpki.

License

See LICENSE. This project happily accepts pull requests without any formal copyright/contributor license agreement. Pull requests must explicitly indicate who owns the copyright to the code being contributed and that the code is being licensed under the same terms as the existing webpki code.

Bug Reporting

Please report bugs either as pull requests or as issues in the issue tracker. webpki has a full disclosure vulnerability policy. Please do NOT attempt to report any security vulnerability in this code privately to anybody.