# RustCrypto: CTR
[![crate][crate-image]][crate-link]
[![Docs][docs-image]][docs-link]
![Apache2/MIT licensed][license-image]
![Rust Version][rustc-image]
[![Project Chat][chat-image]][chat-link]
[![Build Status][build-image]][build-link]
Generic implementation of the [Counter][CTR] (CTR) block cipher mode of operation.
<img src="https://raw.githubusercontent.com/RustCrypto/media/26acc39f/img/block-modes/ctr_enc.svg" width="50%"><img src="https://raw.githubusercontent.com/RustCrypto/media/26acc39f/img/block-modes/ctr_dec.svg" width="50%">
See [documentation][cipher-doc] of the `cipher` crate for additional information.
## Minimum Supported Rust Version
Rust **1.56** or higher.
Minimum supported Rust version can be changed in the future, but it will be
done with a minor version bump.
## SemVer Policy
- All on-by-default features of this library are covered by SemVer
- MSRV is considered exempt from SemVer as noted above
## License
Licensed under either of:
* [Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0)
* [MIT license](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.
[//]: # (badges)
[crate-image]: https://img.shields.io/crates/v/ctr.svg
[crate-link]: https://crates.io/crates/ctr
[docs-image]: https://docs.rs/ctr/badge.svg
[docs-link]: https://docs.rs/ctr/
[license-image]: https://img.shields.io/badge/license-Apache2.0/MIT-blue.svg
[rustc-image]: https://img.shields.io/badge/rustc-1.56+-blue.svg
[chat-image]: https://img.shields.io/badge/zulip-join_chat-blue.svg
[chat-link]: https://rustcrypto.zulipchat.com/#narrow/stream/308460-block-modes
[build-image]: https://github.com/RustCrypto/block-modes/workflows/ctr/badge.svg?branch=master&event=push
[build-link]: https://github.com/RustCrypto/block-modes/actions?query=workflow%3Actr+branch%3Amaster
[//]: # (general links)
[CTR]: https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Counter_(CTR)
[cipher-doc]: https://docs.rs/cipher/