# `keys/serialize`

## Purpose

Public dispatcher entry-point inverse of `parse`. Selects the per-format
serialiser via the same `format` discriminator. Returns `Uint8Array` for
binary formats (`pkcs1`, `spki`, `pkcs8`) and a structured `RsaJwk` object
for JWK so consumers can post-process the result without re-parsing JSON.

## Features

- `serializeRsaPublicKey(key, { format })` over the PKCS#1 / SPKI / JWK set.
- `serializeRsaPrivateKey(key, { format })` over the PKCS#1 / PKCS#8 / JWK set.
- `default` branch surfaces `CRYPTO_RSA.UNSUPPORTED_FORMAT` for safety.

## Usage: Basic Example

```ts
import { serializeRsaPublicKey } from "@suaveplan/crypto-rsa";

const der = serializeRsaPublicKey(key, { format: "spki" });
```

## Usage: Advanced Example

```ts
import {
    serializeRsaPrivateKey,
    serializeRsaPublicKey,
} from "@suaveplan/crypto-rsa";

const jwk = serializeRsaPublicKey(key, { format: "jwk" });
const pkcs8 = serializeRsaPrivateKey(key, { format: "pkcs8" });
```

## API Reference

### `serializeRsaPublicKey(key, options): Uint8Array | RsaJwk`

Returns bytes for `pkcs1` / `spki`, a structured `RsaJwk` for `jwk`.

### `serializeRsaPrivateKey(key, options): Uint8Array | RsaJwk`

Returns bytes for `pkcs1` / `pkcs8`, a structured `RsaJwk` for `jwk`.

## Implementation Notes

The mixed `Uint8Array | RsaJwk` return type intentionally pushes the
discrimination back to the caller — picking `format: "jwk"` is a deliberate
choice and the caller already knows the result will be an object. Type
narrowing on the `format` literal is left to consumer-side discriminated
union helpers because Stage 1 deliberately keeps the dispatcher minimal.