nstdlib-nightly/lib/internal/crypto/ec.mjs

Node.js standard library converted to runtime-agnostic ES modules.

// Source: https://github.com/nodejs/node/blob/65eff1eb/lib/internal/crypto/ec.js

import {
  ECKeyExportJob,
  KeyObjectHandle,
  SignJob,
  kCryptoJobAsync,
  kKeyTypePrivate,
  kSignJobModeSign,
  kSignJobModeVerify,
  kSigEncP1363,
} from "nstdlib/stub/binding/crypto";
import {
  getUsagesUnion,
  hasAnyNotIn,
  jobPromise,
  normalizeHashName,
  validateKeyOps,
  kHandle,
  kKeyObject,
  kNamedCurveAliases,
} from "nstdlib/lib/internal/crypto/util";
import { lazyDOMException, promisify } from "nstdlib/lib/internal/util";
import { generateKeyPair as _generateKeyPair } from "nstdlib/lib/internal/crypto/keygen";
import {
  InternalCryptoKey,
  PrivateKeyObject,
  PublicKeyObject,
  createPrivateKey,
  createPublicKey,
} from "nstdlib/lib/internal/crypto/keys";

const generateKeyPair = promisify(_generateKeyPair);

function verifyAcceptableEcKeyUse(name, isPublic, usages) {
  let checkSet;
  switch (name) {
    case "ECDH":
      checkSet = isPublic ? [] : ["deriveKey", "deriveBits"];
      break;
    case "ECDSA":
      checkSet = isPublic ? ["verify"] : ["sign"];
      break;
    default:
      throw lazyDOMException(
        "The algorithm is not supported",
        "NotSupportedError",
      );
  }
  if (hasAnyNotIn(usages, checkSet)) {
    throw lazyDOMException(
      `Unsupported key usage for a ${name} key`,
      "SyntaxError",
    );
  }
}

function createECPublicKeyRaw(namedCurve, keyData) {
  const handle = new KeyObjectHandle();

  if (!handle.initECRaw(kNamedCurveAliases[namedCurve], keyData)) {
    throw lazyDOMException("Invalid keyData", "DataError");
  }

  return new PublicKeyObject(handle);
}

async function ecGenerateKey(algorithm, extractable, keyUsages) {
  const { name, namedCurve } = algorithm;

  if (
    !Array.prototype.includes.call(Object.keys(kNamedCurveAliases), namedCurve)
  ) {
    throw lazyDOMException("Unrecognized namedCurve", "NotSupportedError");
  }

  const usageSet = new Set(keyUsages);
  switch (name) {
    case "ECDSA":
      if (hasAnyNotIn(usageSet, ["sign", "verify"])) {
        throw lazyDOMException(
          "Unsupported key usage for an ECDSA key",
          "SyntaxError",
        );
      }
      break;
    case "ECDH":
      if (hasAnyNotIn(usageSet, ["deriveKey", "deriveBits"])) {
        throw lazyDOMException(
          "Unsupported key usage for an ECDH key",
          "SyntaxError",
        );
      }
    // Fall through
  }

  const keypair = await generateKeyPair("ec", { namedCurve }).catch((err) => {
    throw lazyDOMException(
      "The operation failed for an operation-specific reason",
      { name: "OperationError", cause: err },
    );
  });

  let publicUsages;
  let privateUsages;
  switch (name) {
    case "ECDSA":
      publicUsages = getUsagesUnion(usageSet, "verify");
      privateUsages = getUsagesUnion(usageSet, "sign");
      break;
    case "ECDH":
      publicUsages = [];
      privateUsages = getUsagesUnion(usageSet, "deriveKey", "deriveBits");
      break;
  }

  const keyAlgorithm = { name, namedCurve };

  const publicKey = new InternalCryptoKey(
    keypair.publicKey,
    keyAlgorithm,
    publicUsages,
    true,
  );

  const privateKey = new InternalCryptoKey(
    keypair.privateKey,
    keyAlgorithm,
    privateUsages,
    extractable,
  );

  return { __proto__: null, publicKey, privateKey };
}

function ecExportKey(key, format) {
  return jobPromise(
    () => new ECKeyExportJob(kCryptoJobAsync, format, key[kKeyObject][kHandle]),
  );
}

async function ecImportKey(format, keyData, algorithm, extractable, keyUsages) {
  const { name, namedCurve } = algorithm;

  if (
    !Array.prototype.includes.call(Object.keys(kNamedCurveAliases), namedCurve)
  ) {
    throw lazyDOMException("Unrecognized namedCurve", "NotSupportedError");
  }

  let keyObject;
  const usagesSet = new Set(keyUsages);
  switch (format) {
    case "spki": {
      verifyAcceptableEcKeyUse(name, true, usagesSet);
      try {
        keyObject = createPublicKey({
          key: keyData,
          format: "der",
          type: "spki",
        });
      } catch (err) {
        throw lazyDOMException("Invalid keyData", {
          name: "DataError",
          cause: err,
        });
      }
      break;
    }
    case "pkcs8": {
      verifyAcceptableEcKeyUse(name, false, usagesSet);
      try {
        keyObject = createPrivateKey({
          key: keyData,
          format: "der",
          type: "pkcs8",
        });
      } catch (err) {
        throw lazyDOMException("Invalid keyData", {
          name: "DataError",
          cause: err,
        });
      }
      break;
    }
    case "jwk": {
      if (!keyData.kty) throw lazyDOMException("Invalid keyData", "DataError");
      if (keyData.kty !== "EC")
        throw lazyDOMException('Invalid JWK "kty" Parameter', "DataError");
      if (keyData.crv !== namedCurve)
        throw lazyDOMException(
          'JWK "crv" does not match the requested algorithm',
          "DataError",
        );

      verifyAcceptableEcKeyUse(name, keyData.d === undefined, usagesSet);

      if (usagesSet.size > 0 && keyData.use !== undefined) {
        const checkUse = name === "ECDH" ? "enc" : "sig";
        if (keyData.use !== checkUse)
          throw lazyDOMException('Invalid JWK "use" Parameter', "DataError");
      }

      validateKeyOps(keyData.key_ops, usagesSet);

      if (
        keyData.ext !== undefined &&
        keyData.ext === false &&
        extractable === true
      ) {
        throw lazyDOMException(
          'JWK "ext" Parameter and extractable mismatch',
          "DataError",
        );
      }

      if (algorithm.name === "ECDSA" && keyData.alg !== undefined) {
        let algNamedCurve;
        switch (keyData.alg) {
          case "ES256":
            algNamedCurve = "P-256";
            break;
          case "ES384":
            algNamedCurve = "P-384";
            break;
          case "ES512":
            algNamedCurve = "P-521";
            break;
        }
        if (algNamedCurve !== namedCurve)
          throw lazyDOMException(
            'JWK "alg" does not match the requested algorithm',
            "DataError",
          );
      }

      const handle = new KeyObjectHandle();
      const type = handle.initJwk(keyData, namedCurve);
      if (type === undefined)
        throw lazyDOMException("Invalid JWK", "DataError");
      keyObject =
        type === kKeyTypePrivate
          ? new PrivateKeyObject(handle)
          : new PublicKeyObject(handle);
      break;
    }
    case "raw": {
      verifyAcceptableEcKeyUse(name, true, usagesSet);
      keyObject = createECPublicKeyRaw(namedCurve, keyData);
      break;
    }
  }

  switch (algorithm.name) {
    case "ECDSA":
    // Fall through
    case "ECDH":
      if (keyObject.asymmetricKeyType !== "ec")
        throw lazyDOMException("Invalid key type", "DataError");
      break;
  }

  if (!keyObject[kHandle].checkEcKeyData()) {
    throw lazyDOMException("Invalid keyData", "DataError");
  }

  const { namedCurve: checkNamedCurve } = keyObject[kHandle].keyDetail({});
  if (kNamedCurveAliases[namedCurve] !== checkNamedCurve)
    throw lazyDOMException("Named curve mismatch", "DataError");

  return new InternalCryptoKey(
    keyObject,
    { name, namedCurve },
    keyUsages,
    extractable,
  );
}

function ecdsaSignVerify(key, data, { name, hash }, signature) {
  const mode = signature === undefined ? kSignJobModeSign : kSignJobModeVerify;
  const type = mode === kSignJobModeSign ? "private" : "public";

  if (key.type !== type)
    throw lazyDOMException(`Key must be a ${type} key`, "InvalidAccessError");

  const hashname = normalizeHashName(hash.name);

  return jobPromise(
    () =>
      new SignJob(
        kCryptoJobAsync,
        mode,
        key[kKeyObject][kHandle],
        undefined,
        undefined,
        undefined,
        data,
        hashname,
        undefined, // Salt length, not used with ECDSA
        undefined, // PSS Padding, not used with ECDSA
        kSigEncP1363,
        signature,
      ),
  );
}

export { ecExportKey };
export { ecImportKey };
export { ecGenerateKey };
export { ecdsaSignVerify };