cargo / base64ct

base64ct

cargo

Pure Rust implementation of Base64 (RFC 4648) which avoids any usages of data-dependent branches/LUTs and thereby provides portable "best effort" constant-time operation and embedded-friendly no_std support

1 audit github.com/RustCrypto/formats

Audits

PE Patrick Elsen 2026-05-27

base64ct@1.8.3 · 2 findings

Pure-Rust constant-time Base64 codec for PEM-formatted cryptographic material. Branchless 6-bit decode/encode and deferred error accumulation preserve the data-independent timing claim. Two low-severity findings: decode_in_place diverges from decode on non-canonical trailing-bit inputs, and encoded_len silently returns 0 on usize overflow.

algorithm-impl-boundsalgorithm-impl-correctalgorithm-impl-safealgorithm-impl-testedhas-binarieshas-build-exechas-fuzz-testshas-install-exechas-integration-testshas-property-testshas-unit-testsimpl-algorithmimpl-concurrencyimpl-cryptoimpl-datastructureimpl-interpreterimpl-jitimpl-parserimpl-protocolis-benignparser-impl-correctparser-impl-safeparser-impl-testedunsafe-documentedunsafe-minimalunsafe-safeunsafe-testeduses-concurrencyuses-cryptouses-environmentuses-execuses-filesystemuses-interpreteruses-jituses-networkuses-unsafe