base64-swift

A small Swift library that provides explicit, predictable Base64 encoding and decoding.

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Why this exists

In real-world systems, Base64 handling tends to show up at boundaries: authentication flows, cryptographic payloads, API contracts, persistence layers.

In many codebases, this logic ends up:

• duplicated across projects
• mixed with unrelated string manipulation
• loosely validated or inconsistently encoded
• difficult to reason about at call sites

This library exists to make Base64 handling:

• explicit
• well-typed
• easy to audit
• hard to misuse

It pulls this logic into a single, focused abstraction that can be reused confidently across projects.

---

What it is

• A lightweight Swift wrapper around Base64 encoding and decoding
• Focused on clarity and correctness, not cleverness
• Designed to be used at system boundaries
• Small enough to read and understand end-to-end

---

What it deliberately avoids

• Convenience extensions that hide failure
• Silent coercion of invalid input
• Global helpers scattered across String or Data
• Over-generalised encoding utilities

If a value cannot be decoded, the API makes that explicit.

---

Example

let encoded = EncodedBase64("hello world")
let decoded = try encoded.decodedString()

The intent is visible at the call site: you are working with a Base64-encoded value, not an arbitrary string.

Design principles

• Explicit representation Encoded values are modelled intentionally, not inferred.
• Fail clearly Invalid input is surfaced immediately rather than silently ignored.
• Small surface area The library does one thing and stays out of the way.
• Production-oriented Suitable for authentication, cryptography, and API boundary code.

When to use this

Use this library when:

• Base64 values are part of your domain or protocol
• correctness matters more than convenience
• you want to make encoding/decoding intent obvious in code

If you only need a one-off helper, this may be more structure than you need.

Note

This logic was originally extracted from production WebAuthn-related code and simplified for general reuse. It remains intentionally minimal.

base64-swift

A small Swift library that provides explicit, predictable Base64 encoding and decoding.

Designed for production codebases that need to handle Base64 safely and consistently without scattering string utilities across the app.

---

Why this exists

In real-world systems, Base64 handling tends to show up at boundaries: authentication flows, cryptographic payloads, API contracts, persistence layers.

In many codebases, this logic ends up:

• duplicated across projects
• mixed with unrelated string manipulation
• loosely validated or inconsistently encoded
• difficult to reason about at call sites

This library exists to make Base64 handling:

• explicit
• well-typed
• easy to audit
• hard to misuse

It pulls this logic into a single, focused abstraction that can be reused confidently across projects.

---

What it is

• A lightweight Swift wrapper around Base64 encoding and decoding
• Focused on clarity and correctness, not cleverness
• Designed to be used at system boundaries
• Small enough to read and understand end-to-end

---

What it deliberately avoids

• Convenience extensions that hide failure
• Silent coercion of invalid input
• Global helpers scattered across String or Data
• Over-generalised encoding utilities

If a value cannot be decoded, the API makes that explicit.

---

Example

let encoded = EncodedBase64("hello world")
let decoded = try encoded.decodedString()

The intent is visible at the call site: you are working with a Base64-encoded value, not an arbitrary string.

Design principles

• Explicit representation Encoded values are modelled intentionally, not inferred.
• Fail clearly Invalid input is surfaced immediately rather than silently ignored.
• Small surface area The library does one thing and stays out of the way.
• Production-oriented Suitable for authentication, cryptography, and API boundary code.

When to use this

Use this library when:

• Base64 values are part of your domain or protocol
• correctness matters more than convenience
• you want to make encoding/decoding intent obvious in code

If you only need a one-off helper, this may be more structure than you need.

Acknowledgements

This library was extracted and adapted from Base64 handling logic originally implemented in webauthn-swift-models.

The original project implements parts of the WebAuthn specification in Swift. This package isolates and generalises the Base64-related components for reuse in non-WebAuthn contexts.

Credit and thanks to the original authors and contributors.