RustCrypto: Constant-Time Base64

Pure Rust implementation of Base64 ([RFC 4648]).

Implements multiple Base64 variants without data-dependent branches or lookup tables, thereby providing portable "best effort" constant-time operation.

Supports no_std environments and avoids heap allocations in the core API (but also provides optional alloc support for convenience).

Documentation

Supported Base64 variants

• Standard Base64: [A-Z], [a-z], [0-9], +, /
• URL-safe Base64: [A-Z], [a-z], [0-9], -, _
• bcrypt Base64: ., /, [A-Z], [a-z], [0-9]
• crypt(3) Base64: ., -, [0-9], [A-Z], [a-z]

License

Licensed under either of:

• Apache License, Version 2.0
• MIT license

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.