Converted validate module.

src/constants.ts

@@ -0,0 +1,11 @@
+/**
+ * Matches 64-character lowercase hexadecimal strings.
+ * Used for validating event IDs and cryptographic keys.
+ */
+export const HEX_64_PATTERN = /^[a-f0-9]{64}$/;
+
+/**
+ * Matches 128-character lowercase hexadecimal strings.
+ * Used for validating signatures.
+ */
+export const HEX_128_PATTERN = /^[a-f0-9]{128}$/;

src/crypto_init.ts

@@ -0,0 +1,11 @@
+/**
+ * Configures @noble/secp256k1 to use synchronous hash functions.
+ * Required for Schnorr signing and verification operations.
+ * Must be imported before any secp256k1 operations execute.
+ */
+import { hmac } from "@noble/hashes/hmac.js";
+import { sha256 } from "@noble/hashes/sha2.js";
+import { hashes as secp_hashes } from "@noble/secp256k1";
+
+secp_hashes.hmacSha256 = (key, msg) => hmac(sha256, key, msg);
+secp_hashes.sha256 = sha256;

src/errors.ts

@@ -1,3 +1,43 @@
+/**
+ * Public key is not 64 lowercase hex characters.
+ */
+export class MalformedPubKeyError extends Error {
+  constructor() {
+    super("public key must be 64 lowercase hex characters");
+    this.name = "MalformedPubKeyError";
+  }
+}
+
+/**
+ * Private key is not 64 lowercase hex characters.
+ */
+export class MalformedPrivKeyError extends Error {
+  constructor() {
+    super("private key must be 64 lowercase hex characters");
+    this.name = "MalformedPrivKeyError";
+  }
+}
+
+/**
+ * Event ID is not 64 hex characters.
+ */
+export class MalformedIDError extends Error {
+  constructor() {
+    super("event id must be 64 hex characters");
+    this.name = "MalformedIDError";
+  }
+}
+
+/**
+ * Event signature is not 128 hex characters.
+ */
+export class MalformedSigError extends Error {
+  constructor() {
+    super("event signature must be 128 hex characters");
+    this.name = "MalformedSigError";
+  }
+}
+
 /**
  * Event tag contains fewer than two elements.
  */

src/keys.test.ts

@@ -1,10 +1,9 @@
 import { describe, expect, test } from "vitest";
 
+import { HEX_64_PATTERN } from "./constants";
 import { Keys } from "./keys";
 import { testPK, testSK } from "./util.test";
 
-const HEX_64_PATTERN = /^[a-f0-9]{64}$/;
-
 describe("Keys.generatePrivate", () => {
   test("returns 64 hex characters", () => {
     const privateKey = Keys.generatePrivateKey();

src/sign.ts

@@ -1,11 +1,8 @@
-import { hmac } from "@noble/hashes/hmac.js";
 import { sha256 } from "@noble/hashes/sha2.js";
 import { bytesToHex, hexToBytes } from "@noble/hashes/utils.js";
-import { hashes as secp_hashes } from "@noble/secp256k1";
 import { schnorr } from "@noble/secp256k1";
 
-secp_hashes.hmacSha256 = (key, msg) => hmac(sha256, key, msg);
-secp_hashes.sha256 = sha256;
+import "./crypto_init";
 
 /**
  * Generates a Schnorr signature for the given event ID using the provided private key.

src/validate.test.ts

@@ -1,3 +1,225 @@
-import { test } from "vitest";
+import { describe, expect, test } from "vitest";
 
-test("placeholder", () => {});
+import type { EventData } from "./types";
+import { testEvent, testPK } from "./util.test";
+import { EventValidation } from "./validate";
+
+interface ValidateEventTestCase {
+  name: string;
+  event: EventData;
+  expectedError: string;
+}
+
+const structureTestCases: ValidateEventTestCase[] = [
+  {
+    name: "empty pubkey",
+    event: {
+      ...testEvent,
+      pubkey: "",
+    },
+    expectedError: "public key must be 64 lowercase hex characters",
+  },
+  {
+    name: "short pubkey",
+    event: {
+      ...testEvent,
+      pubkey: "abc123",
+    },
+    expectedError: "public key must be 64 lowercase hex characters",
+  },
+  {
+    name: "long pubkey",
+    event: {
+      ...testEvent,
+      pubkey:
+        "c7a702e6158744ca03508bbb4c90f9dbb0d6e88fefbfaa511d5ab24b4e3c48adabc",
+    },
+    expectedError: "public key must be 64 lowercase hex characters",
+  },
+  {
+    name: "non-hex pubkey",
+    event: {
+      ...testEvent,
+      pubkey:
+        "zyx-!2e6158744ca03508bbb4c90f9dbb0d6e88fefbfaa511d5ab24b4e3c48ad",
+    },
+    expectedError: "public key must be 64 lowercase hex characters",
+  },
+  {
+    name: "uppercase pubkey",
+    event: {
+      ...testEvent,
+      pubkey:
+        "C7A702E6158744CA03508BBB4C90F9DBB0D6E88FEFBFAA511D5AB24B4E3C48AD",
+    },
+    expectedError: "public key must be 64 lowercase hex characters",
+  },
+  {
+    name: "empty id",
+    event: {
+      ...testEvent,
+      id: "",
+    },
+    expectedError: "id must be 64 hex characters",
+  },
+  {
+    name: "short id",
+    event: {
+      ...testEvent,
+      id: "abc123",
+    },
+    expectedError: "id must be 64 hex characters",
+  },
+  {
+    name: "empty signature",
+    event: {
+      ...testEvent,
+      sig: "",
+    },
+    expectedError: "signature must be 128 hex characters",
+  },
+  {
+    name: "short signature",
+    event: {
+      ...testEvent,
+      sig: "abc123",
+    },
+    expectedError: "signature must be 128 hex characters",
+  },
+  {
+    name: "empty tag",
+    event: {
+      ...testEvent,
+      tags: [[]],
+    },
+    expectedError: "tags must contain at least two elements",
+  },
+  {
+    name: "single element tag",
+    event: {
+      ...testEvent,
+      tags: [["a"]],
+    },
+    expectedError: "tags must contain at least two elements",
+  },
+  {
+    name: "one good tag, one single element tag",
+    event: {
+      ...testEvent,
+      tags: [["a", "value"], ["b"]],
+    },
+    expectedError: "tags must contain at least two elements",
+  },
+];
+
+describe("EventValidation.validateStructure", () => {
+  test.each(structureTestCases)("$name", ({ event, expectedError }) => {
+    expect(() => EventValidation.validateStructure(event)).toThrow(
+      expectedError,
+    );
+  });
+});
+
+describe("EventValidation.validateID", () => {
+  test("detects ID mismatch", () => {
+    const event: EventData = {
+      ...testEvent,
+      id: "7f661c2a3c1ed67dc959d6cd968d743d5e6e334313df44724bca939e2aa42c9e",
+    };
+    expect(() => EventValidation.validateID(event)).toThrow(
+      "does not match computed id",
+    );
+  });
+});
+
+describe("EventValidation.validateSignature", () => {
+  test("accepts valid signature", () => {
+    expect(() => EventValidation.validateSignature(testEvent)).not.toThrow();
+  });
+
+  test("rejects invalid signature", () => {
+    const event: EventData = {
+      ...testEvent,
+      sig: "9e43cbcf7e828a21c53fa35371ee79bffbfd7a3063ae46fc05ec623dd3186667c57e3d006488015e19247df35eb41c61013e051aa87860e23fa5ffbd44120482",
+    };
+    expect(() => EventValidation.validateSignature(event)).toThrow(
+      "event signature is invalid",
+    );
+  });
+});
+
+interface ValidateSignatureTestCase {
+  name: string;
+  id: string;
+  sig: string;
+  pubkey: string;
+  expectedError: string | RegExp;
+}
+
+const validateSignatureTestCases: ValidateSignatureTestCase[] = [
+  {
+    name: "bad event id",
+    id: "badeventid",
+    sig: testEvent.sig,
+    pubkey: testEvent.pubkey,
+    expectedError: /hex string expected.*/,
+  },
+  {
+    name: "bad event signature",
+    id: testEvent.id,
+    sig: "badeventsignature",
+    pubkey: testEvent.pubkey,
+    expectedError: /hex string expected.*/,
+  },
+  {
+    name: "bad public key",
+    id: testEvent.id,
+    sig: testEvent.sig,
+    pubkey: "badpublickey",
+    expectedError: /hex string expected.*/,
+  },
+  {
+    name: "malformed event signature",
+    id: testEvent.id,
+    sig: "abc123",
+    pubkey: testEvent.pubkey,
+    expectedError: /"signature" expected.*/,
+  },
+  {
+    name: "malformed public key",
+    id: testEvent.id,
+    sig: testEvent.sig,
+    pubkey: "abc123",
+    expectedError: /"publicKey" expected.*/,
+  },
+];
+
+describe("EventValidation.validateSignature - malformed inputs", () => {
+  test.each(validateSignatureTestCases)(
+    "$name",
+    ({ id, sig, pubkey, expectedError }) => {
+      const event: EventData = { ...testEvent, id, sig, pubkey };
+      expect(() => EventValidation.validateSignature(event)).toThrow(
+        expectedError,
+      );
+    },
+  );
+});
+
+describe("EventValidation.validate", () => {
+  test("validates complete event", () => {
+    const event: EventData = {
+      id: "c9a0f84fcaa889654da8992105eb122eb210c8cbd58210609a5ef7e170b51400",
+      pubkey: testPK,
+      created_at: testEvent.created_at,
+      kind: testEvent.kind,
+      tags: [
+        ["a", "value"],
+        ["b", "value", "optional"],
+      ],
+      content: "valid event",
+      sig: "668a715f1eb983172acf230d17bd283daedb2598adf8de4290bcc7eb0b802fdb60669d1e7d1104ac70393f4dbccd07e8abf897152af6ce6c0a75499874e27f14",
+    };
+    expect(() => EventValidation.validate(event)).not.toThrow();
+  });
+});

src/validate.ts

@@ -0,0 +1,101 @@
+import { hexToBytes } from "@noble/hashes/utils.js";
+import { schnorr } from "@noble/secp256k1";
+
+import { HEX_64_PATTERN, HEX_128_PATTERN } from "./constants";
+import "./crypto_init";
+import {
+  FailedIDCompError,
+  InvalidSigError,
+  MalformedIDError,
+  MalformedPubKeyError,
+  MalformedSigError,
+  MalformedTagError,
+  NoEventIDError,
+} from "./errors";
+import { EventID } from "./id";
+import type { EventData } from "./types";
+
+/**
+ * Checks event field formats and lengths conform to protocol specification.
+ * @throws {MalformedPubKeyError} If pubkey is not 64 lowercase hex characters
+ * @throws {MalformedIDError} If id is not 64 hex characters
+ * @throws {MalformedSigError} If sig is not 128 hex characters
+ * @throws {MalformedTagError} If any tag has fewer than 2 elements
+ */
+function validateStructure(event: EventData): void {
+  if (!HEX_64_PATTERN.test(event.pubkey)) {
+    throw new MalformedPubKeyError();
+  }
+
+  if (!HEX_64_PATTERN.test(event.id)) {
+    throw new MalformedIDError();
+  }
+
+  if (!HEX_128_PATTERN.test(event.sig)) {
+    throw new MalformedSigError();
+  }
+
+  for (const tag of event.tags) {
+    if (tag.length < 2) {
+      throw new MalformedTagError();
+    }
+  }
+}
+
+/**
+ * Verifies the event ID matches the computed hash of the serialized event.
+ * @throws {FailedIDCompError} If ID computation fails
+ * @throws {NoEventIDError} If event.id is empty
+ * @throws {Error} If computed ID does not match stored ID
+ */
+function validateID(event: EventData): void {
+  let computedID: string;
+  try {
+    computedID = EventID.getID(event);
+  } catch (err) {
+    throw new FailedIDCompError();
+  }
+
+  if (event.id === "") {
+    throw new NoEventIDError();
+  }
+
+  if (computedID !== event.id) {
+    throw new Error(
+      `event id "${event.id}" does not match computed id "${computedID}"`,
+    );
+  }
+}
+
+/**
+ * Verifies the cryptographic signature using Schnorr verification.
+ * @throws {InvalidSigError} If signature verification fails
+ */
+function validateSignature(event: EventData): void {
+  const idBytes = hexToBytes(event.id);
+  const sigBytes = hexToBytes(event.sig);
+  const pubkeyBytes = hexToBytes(event.pubkey);
+
+  const isValid = schnorr.verify(sigBytes, idBytes, pubkeyBytes);
+
+  if (!isValid) {
+    throw new InvalidSigError();
+  }
+}
+
+/**
+ * Performs complete event validation: structure, ID, and signature.
+ * @throws First validation error encountered
+ */
+function validate(event: EventData): void {
+  validateStructure(event);
+  validateID(event);
+  validateSignature(event);
+}
+
+export const EventValidation = {
+  validate,
+  validateStructure,
+  validateID,
+  validateSignature,
+};