Initial Commit

packages/identity/auth/webauthn/src/__fixtures__/deterministic-keys.ts

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+/**
+ * Deterministic test keys for the webauthn fixture suite.
+ *
+ * ES256 (P-256), ES384, ES512 use hardcoded scalars; ECDSA via
+ * `@noble/curves` uses RFC 6979 deterministic-k so signatures round-trip
+ * byte-stably given the same message. Ed25519 is deterministic by spec.
+ * Public keys are memoised across the suite.
+ *
+ * `@noble/curves` is added as a devDependency on `@suaveplan/webauthn`
+ * specifically for these fixtures (it is the same transitive dep that
+ * `@suaveplan/crypto-curve` already depends on; fixture-only).
+ */
+import { p256 as nobleP256 } from "@noble/curves/p256";
+import { p384 as nobleP384 } from "@noble/curves/p384";
+import { p521 as nobleP521 } from "@noble/curves/p521";
+import type { Ec2Key, OkpKey } from "@suaveplan/cbor/cose";
+import { ed25519 } from "@suaveplan/crypto-curve";
+
+const P256_PRIV = Uint8Array.from([
+    0x70, 0x83, 0x95, 0xab, 0x2c, 0x46, 0x3d, 0x68, 0xa1, 0x10, 0x4f, 0x37,
+    0x29, 0xb5, 0xd5, 0x42, 0x0c, 0x18, 0x21, 0x9f, 0xa0, 0x60, 0xff, 0xff,
+    0x5c, 0x4d, 0x16, 0x97, 0x21, 0x83, 0x9b, 0x55,
+]);
+
+const P384_PRIV = Uint8Array.from(
+    Array.from({ length: 48 }, (_v, i) => (i * 7 + 3) & 0xff)
+);
+
+const P521_PRIV = Uint8Array.from([
+    0x00, 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0x01, 0x23, 0x45,
+    0x67, 0x89, 0xab, 0xcd, 0xef, 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd,
+    0xef, 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0x01, 0x23, 0x45,
+    0x67, 0x89, 0xab, 0xcd, 0xef, 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd,
+    0xef, 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0x01, 0x23, 0x45,
+    0x67, 0x89, 0xab, 0xcd, 0xef, 0x77,
+]);
+
+const ED25519_PRIV = new Uint8Array(32).fill(0xa5);
+
+export interface EcTestKey {
+    readonly priv: Uint8Array;
+    readonly pubUncompressed: Uint8Array;
+    readonly x: Uint8Array;
+    readonly y: Uint8Array;
+    readonly coseKey: Ec2Key;
+}
+
+export interface EddsaTestKey {
+    readonly priv: Uint8Array;
+    readonly pub: Uint8Array;
+    readonly coseKey: OkpKey;
+}
+
+let p256Cache: EcTestKey | undefined;
+let p384Cache: EcTestKey | undefined;
+let p521Cache: EcTestKey | undefined;
+let edCache: EddsaTestKey | undefined;
+
+function ecBuild(
+    priv: Uint8Array,
+    pubUncompressed: Uint8Array,
+    coordLen: number,
+    crv: "P-256" | "P-384" | "P-521",
+    alg: "ES256" | "ES384" | "ES512"
+): EcTestKey {
+    const x = pubUncompressed.slice(1, 1 + coordLen);
+    const y = pubUncompressed.slice(1 + coordLen, 1 + 2 * coordLen);
+    return {
+        priv,
+        pubUncompressed,
+        x,
+        y,
+        coseKey: {
+            kty: "EC2",
+            crv,
+            alg,
+            x,
+            y,
+        },
+    };
+}
+
+/** Deterministic P-256 keypair for ES256 webauthn tests. */
+export function getEcdsaP256TestKey(): EcTestKey {
+    if (p256Cache !== undefined) {
+        return p256Cache;
+    }
+    const pub = nobleP256.getPublicKey(P256_PRIV, false);
+    p256Cache = ecBuild(P256_PRIV, pub, 32, "P-256", "ES256");
+    return p256Cache;
+}
+
+/** Deterministic P-384 keypair for ES384 webauthn tests. */
+export function getEcdsaP384TestKey(): EcTestKey {
+    if (p384Cache !== undefined) {
+        return p384Cache;
+    }
+    const pub = nobleP384.getPublicKey(P384_PRIV, false);
+    p384Cache = ecBuild(P384_PRIV, pub, 48, "P-384", "ES384");
+    return p384Cache;
+}
+
+/** Deterministic P-521 keypair for ES512 webauthn tests. */
+export function getEcdsaP521TestKey(): EcTestKey {
+    if (p521Cache !== undefined) {
+        return p521Cache;
+    }
+    const pub = nobleP521.getPublicKey(P521_PRIV, false);
+    p521Cache = ecBuild(P521_PRIV, pub, 66, "P-521", "ES512");
+    return p521Cache;
+}
+
+/** Deterministic Ed25519 keypair for EdDSA webauthn tests. */
+export function getEd25519TestKey(): EddsaTestKey {
+    if (edCache !== undefined) {
+        return edCache;
+    }
+    const pub = ed25519.getPublicKey(ED25519_PRIV);
+    edCache = {
+        priv: ED25519_PRIV,
+        pub,
+        coseKey: {
+            kty: "OKP",
+            crv: "Ed25519",
+            alg: "EdDSA",
+            x: pub,
+        },
+    };
+    return edCache;
+}
+
+/** ECDSA-sign a digest with P-256. Returns DER signature. */
+export function signEcdsaP256Der(
+    digest: Uint8Array,
+    priv: Uint8Array
+): Uint8Array {
+    return nobleP256.sign(digest, priv).toBytes("der");
+}
+
+export function signEcdsaP384Der(
+    digest: Uint8Array,
+    priv: Uint8Array
+): Uint8Array {
+    return nobleP384.sign(digest, priv).toBytes("der");
+}
+
+export function signEcdsaP521Der(
+    digest: Uint8Array,
+    priv: Uint8Array
+): Uint8Array {
+    return nobleP521.sign(digest, priv).toBytes("der");
+}