19 lines
721 B
TypeScript
19 lines
721 B
TypeScript
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import { ed25519 } from '@noble/curves/ed25519.js';
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/**
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* Deterministically derive an Ed25519 public key from a 32-byte seed.
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*
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* In the @noble/curves convention the "private key" *is* the seed —
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* `sign(seed, msg)` works directly, and `getPublicKey(seed)` recovers
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* the matching public key. V4.9's encrypted-blob primitive uses this
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* to mint a per-slot signing keypair from an HKDF output rooted at the
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* user's master key, so the same credentials always reproduce the same
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* keypair.
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*/
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export function ed25519PublicKeyFromSeed(seed: Uint8Array): Uint8Array {
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if (seed.length !== 32) {
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throw new Error(`Ed25519 seed must be 32 bytes, got ${seed.length}`);
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}
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return ed25519.getPublicKey(seed);
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}
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