Merge pull request #56 from CoinSpace/extraentropy

fix: check extraEntropy according to the spec
paulmillr · Jun 28, 2023 · 309d29a · 309d29a
2 parents 5609ec7 + d3aa051
commit 309d29a
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diff --git a/src/abstract/weierstrass.ts b/src/abstract/weierstrass.ts
@@ -964,7 +964,7 @@ export function weierstrass(curveDef: CurveType): CurveFn {
  if (ent != null) {
  // K = HMAC_K(V || 0x00 || int2octets(x) || bits2octets(h1) || k')
  const e = ent === true ? randomBytes(Fp.BYTES) : ent; // generate random bytes OR pass as-is
- seedArgs.push(ensureBytes('extraEntropy', e, Fp.BYTES)); // check for being of size BYTES
+ seedArgs.push(ensureBytes('extraEntropy', e)); // check for being bytes
  }
  const seed = ut.concatBytes(...seedArgs); // Step D of RFC6979 3.2
  const m = h1int; // NOTE: no need to call bits2int second time here, it is inside truncateHash!

diff --git a/test/secp256k1.test.js b/test/secp256k1.test.js
@@ -268,6 +268,33 @@ describe('secp256k1', () => {
  deepStrictEqual(sign(ent5), e.extraEntropyMax);
  }
  });
+
+ should('handle one byte {extraData}', () => {
+ const extraEntropy = '01';
+ const privKey = hexToBytes(
+ '0101010101010101010101010101010101010101010101010101010101010101'
+ );
+ const msg = 'd1a9dc8ed4e46a6a3e5e594615ca351d7d7ef44df1e4c94c1802f3592183794b';
+ const res = secp.sign(msg, privKey, { extraEntropy }).toCompactHex();
+ deepStrictEqual(
+ res,
+ 'a250ec23a54bfdecf0e924cbf484077c5044410f915cdba86731cb2e4e925aaa5b1e4e3553d88be2c48a9a0d8d849ce2cc5720d25b2f97473e02f2550abe9545'
+ );
+ });
+
+ should('handle 48 bytes {extraData}', () => {
+ const extraEntropy =
+ '000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000001';
+ const privKey = hexToBytes(
+ '0101010101010101010101010101010101010101010101010101010101010101'
+ );
+ const msg = 'd1a9dc8ed4e46a6a3e5e594615ca351d7d7ef44df1e4c94c1802f3592183794b';
+ const res = secp.sign(msg, privKey, { extraEntropy }).toCompactHex();
+ deepStrictEqual(
+ res,
+ '2bdf40f42ac0e42ee12750d03bb12b75306dae58eb3c961c5a80d78efae93e595295b66e8eb28f1eb046bb129a976340312159ec0c20b97342667572e4a8379a'
+ );
+ });
  });
 
  describe('verify()', () => {