@danzy/starkware-crypto-utils

StarkWare Crypto Utils

Signatures, keys and Pedersen hash on STARK friendly elliptic curve

Example: Signing a StarkEx Order

const starkwareCrypto = require('@starkware-libs/starkware-crypto-utils');
const testData = require('test/config/signature_test_data.json');

const privateKey = testData.meta_data.party_a_order.private_key.substring(2);
const keyPair = starkwareCrypto.ec.keyFromPrivate(privateKey, 'hex');
const publicKey = starkwareCrypto.ec.keyFromPublic(
  keyPair.getPublic(true, 'hex'),
  'hex'
);
const publicKeyX = publicKey.pub.getX();

assert(
  publicKeyX.toString(16) ===
    testData.settlement.party_a_order.public_key.substring(2),
  `Got: ${publicKeyX.toString(16)}.
        Expected: ${testData.settlement.party_a_order.public_key.substring(2)}`
);

const {party_a_order: partyAOrder} = testData.settlement;
const msgHash = starkwareCrypto.getLimitOrderMsgHash(
  partyAOrder.vault_id_sell, // - vault_sell (uint31)
  partyAOrder.vault_id_buy, // - vault_buy (uint31)
  partyAOrder.amount_sell, // - amount_sell (uint63 decimal str)
  partyAOrder.amount_buy, // - amount_buy (uint63 decimal str)
  partyAOrder.token_sell, // - token_sell (hex str with 0x prefix < prime)
  partyAOrder.token_buy, // - token_buy (hex str with 0x prefix < prime)
  partyAOrder.nonce, // - nonce (uint31)
  partyAOrder.expiration_timestamp // - expiration_timestamp (uint22)
);

assert(
  msgHash === testData.meta_data.party_a_order.message_hash.substring(2),
  `Got: ${msgHash}. Expected: ` +
    testData.meta_data.party_a_order.message_hash.substring(2)
);

const msgSignature = starkwareCrypto.sign(keyPair, msgHash);
const {r, s} = msgSignature;

assert(starkwareCrypto.verify(publicKey, msgHash, msgSignature));
assert(
  r.toString(16) === partyAOrder.signature.r.substring(2),
  `Got: ${r.toString(16)}. Expected: ${partyAOrder.signature.r.substring(2)}`
);
assert(
  s.toString(16) === partyAOrder.signature.s.substring(2),
  `Got: ${s.toString(16)}. Expected: ${partyAOrder.signature.s.substring(2)}`
);

// The following is the JSON representation of an order:
console.log('Order JSON representation: ');
console.log(partyAOrder);
console.log('\n');

Example: StarkEx key serialization

const starkwareCrypto = require('@starkware-libs/starkware-crypto-utils');

const pubXStr = publicKey.pub.getX().toString('hex');
const pubYStr = publicKey.pub.getY().toString('hex');

// Verify Deserialization.
const pubKeyDeserialized = starkwareCrypto.ec.keyFromPublic(
  {x: pubXStr, y: pubYStr},
  'hex'
);
assert(starkwareCrypto.verify(pubKeyDeserialized, msgHash, msgSignature));

Example: StarkEx Transfer

const starkwareCrypto = require('@starkware-libs/starkware-crypto-utils');
const testData = require('test/config/signature_test_data.json');

const privateKey = testData.meta_data.transfer_order.private_key.substring(2);
const keyPair = starkwareCrypto.ec.keyFromPrivate(privateKey, 'hex');
const publicKey = starkwareCrypto.ec.keyFromPublic(
  keyPair.getPublic(true, 'hex'),
  'hex'
);
const publicKeyX = publicKey.pub.getX();

assert(
  publicKeyX.toString(16) === testData.transfer_order.public_key.substring(2),
  `Got: ${publicKeyX.toString(16)}.
            Expected: ${testData.transfer_order.public_key.substring(2)}`
);

const transfer = testData.transfer_order;
const msgHash = starkwareCrypto.getTransferMsgHash(
  transfer.amount, // - amount (uint63 decimal str)
  transfer.nonce, // - nonce (uint31)
  transfer.sender_vault_id, // - sender_vault_id (uint31)
  transfer.token, // - token (hex str with 0x prefix < prime)
  transfer.target_vault_id, // - target_vault_id (uint31)
  transfer.target_public_key, // - target_public_key (hex str with 0x prefix < prime)
  transfer.expiration_timestamp // - expiration_timestamp (uint22)
);

assert(
  msgHash === testData.meta_data.transfer_order.message_hash.substring(2),
  `Got: ${msgHash}. Expected: ` +
    testData.meta_data.transfer_order.message_hash.substring(2)
);

// The following is the JSON representation of a transfer:
console.log('Transfer JSON representation: ');
console.log(transfer);
console.log('\n');

Example: StarkEx Conditional Transfer

const starkwareCrypto = require('@starkware-libs/starkware-crypto-utils');
const testData = require('test/config/signature_test_data.json');

const privateKey =
  testData.meta_data.conditional_transfer_order.private_key.substring(2);
const keyPair = starkwareCrypto.ec.keyFromPrivate(privateKey, 'hex');
const publicKey = starkwareCrypto.ec.keyFromPublic(
  keyPair.getPublic(true, 'hex'),
  'hex'
);
const publicKeyX = publicKey.pub.getX();

assert(
  publicKeyX.toString(16) ===
    testData.conditional_transfer_order.public_key.substring(2),
  `Got: ${publicKeyX.toString(16)}.
        Expected: ${testData.conditional_transfer_order.public_key.substring(
          2
        )}`
);

const transfer = testData.conditional_transfer_order;
const msgHash = starkwareCrypto.getTransferMsgHash(
  transfer.amount, // - amount (uint63 decimal str)
  transfer.nonce, // - nonce (uint31)
  transfer.sender_vault_id, // - sender_vault_id (uint31)
  transfer.token, // - token (hex str with 0x prefix < prime)
  transfer.target_vault_id, // - target_vault_id (uint31)
  transfer.target_public_key, // - target_public_key (hex str with 0x prefix < prime)
  transfer.expiration_timestamp, // - expiration_timestamp (uint22)
  transfer.condition // - condition (hex str with 0x prefix < prime)
);

assert(
  msgHash ===
    testData.meta_data.conditional_transfer_order.message_hash.substring(2),
  `Got: ${msgHash}. Expected: ` +
    testData.meta_data.conditional_transfer_order.message_hash.substring(2)
);

// The following is the JSON representation of a transfer:
console.log('Transfer JSON representation: ');
console.log(transfer);
console.log('\n');

Example: And adding a matching order to create a settlement

const starkwareCrypto = require('@starkware-libs/starkware-crypto-utils');
const testData = require('test/config/signature_test_data.json');

const privateKey = testData.meta_data.party_b_order.private_key.substring(2);
const keyPair = starkwareCrypto.ec.keyFromPrivate(privateKey, 'hex');
const publicKey = starkwareCrypto.ec.keyFromPublic(
  keyPair.getPublic(true, 'hex'),
  'hex'
);
const publicKeyX = publicKey.pub.getX();

assert(
  publicKeyX.toString(16) ===
    testData.settlement.party_b_order.public_key.substring(2),
  `Got: ${publicKeyX.toString(16)}.
        Expected: ${testData.settlement.party_b_order.public_key.substring(2)}`
);

const {party_b_order: partyBOrder} = testData.settlement;
const msgHash = starkwareCrypto.getLimitOrderMsgHash(
  partyBOrder.vault_id_sell, // - vault_sell (uint31)
  partyBOrder.vault_id_buy, // - vault_buy (uint31)
  partyBOrder.amount_sell, // - amount_sell (uint63 decimal str)
  partyBOrder.amount_buy, // - amount_buy (uint63 decimal str)
  partyBOrder.token_sell, // - token_sell (hex str with 0x prefix < prime)
  partyBOrder.token_buy, // - token_buy (hex str with 0x prefix < prime)
  partyBOrder.nonce, // - nonce (uint31)
  partyBOrder.expiration_timestamp // - expiration_timestamp (uint22)
);

assert(
  msgHash === testData.meta_data.party_b_order.message_hash.substring(2),
  `Got: ${msgHash}. Expected: ` +
    testData.meta_data.party_b_order.message_hash.substring(2)
);

const msgSignature = starkwareCrypto.sign(keyPair, msgHash);
const {r, s} = msgSignature;

assert(starkwareCrypto.verify(publicKey, msgHash, msgSignature));
assert(
  r.toString(16) === partyBOrder.signature.r.substring(2),
  `Got: ${r.toString(16)}. Expected: ${partyBOrder.signature.r.substring(2)}`
);
assert(
  s.toString(16) === partyBOrder.signature.s.substring(2),
  `Got: ${s.toString(16)}. Expected: ${partyBOrder.signature.s.substring(2)}`
);

// The following is the JSON representation of a settlement:
console.log('Settlement JSON representation: ');
console.log(testData.settlement);

API

{
    prime,
    ec: starkEc,
    constantPoints,
    shiftPoint,
    maxEcdsaVal, // Data.
    pedersen,
    getLimitOrderMsgHash,
    getTransferMsgHash,
    sign,
    verify // Function.
    asset: {
        getAssetType, 
        getAssetId // Function.
     },
    keyDerivation: {
        StarkExEc: ec.n, // Data.
        getKeyPairFromPath,
        getAccountPath,
        grindKey // Function.
   }
}

License

Apache License 2.0