Skip to content

Fix bad numbering in BIP340Signer comment #2340

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
liamgilligan wants to merge 1 commit into
base: main
Choose a base branch
from
+5 −5
Open

Fix bad numbering in BIP340Signer comment #2340

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 5 additions & 5 deletions core/src/main/java/org/bouncycastle/crypto/signers/BIP340Signer.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -206,7 +206,7 @@ private static byte[] sign(ECPrivateKeyParameters privateKey, byte[] m, byte[] a
{
BigInteger n = SECP256K1.getN();

// Step 1: d' = int(sk); fail if d' = 0 or d' >= n.
// Step 1-2: d' = int(sk); fail if d' = 0 or d' >= n.
BigInteger d = privateKey.getD();
if (d.signum() <= 0 || d.compareTo(n) >= 0)
{
Expand All @@ -215,15 +215,15 @@ private static byte[] sign(ECPrivateKeyParameters privateKey, byte[] m, byte[] a

ECMultiplier mult = new FixedPointCombMultiplier();

// Steps 4-5: P = d' * G; d = d' if has_even_y(P) else n - d'.
// Steps 3-4: P = d' * G; d = d' if has_even_y(P) else n - d'.
ECPoint P_pt = mult.multiply(SECP256K1.getG(), d).normalize();
if (!hasEvenY(P_pt))
{
d = n.subtract(d);
}
byte[] pBytes = xBytes(P_pt);

// Steps 6-8: t = bytes(d) XOR H_aux(a); k' = int(H_nonce(t || bytes(P) || m)) mod n; fail if k' = 0.
// Steps 5-7: t = bytes(d) XOR H_aux(a); k' = int(H_nonce(t || bytes(P) || m)) mod n; fail if k' = 0.
byte[] t = BigIntegers.asUnsignedByteArray(X_SIZE, d);
Bytes.xorTo(X_SIZE, taggedHash(TAG_HASH_AUX, auxRand), t);

Expand All @@ -240,15 +240,15 @@ private static byte[] sign(ECPrivateKeyParameters privateKey, byte[] m, byte[] a
throw new IllegalStateException("BIP-340 nonce derivation produced zero");
}

// Steps 9-10: R = k' * G; k = k' if has_even_y(R) else n - k'.
// Steps 8-9: R = k' * G; k = k' if has_even_y(R) else n - k'.
ECPoint R_pt = mult.multiply(SECP256K1.getG(), k).normalize();
if (!hasEvenY(R_pt))
{
k = n.subtract(k);
}
byte[] rBytes = xBytes(R_pt);

// Steps 11-12: e = int(H_challenge(bytes(R) || bytes(P) || m)) mod n; sig = bytes(R) || bytes((k + e*d) mod n).
// Steps 10-11: e = int(H_challenge(bytes(R) || bytes(P) || m)) mod n; sig = bytes(R) || bytes((k + e*d) mod n).
BigInteger e = challengeScalar(rBytes, pBytes, m);
BigInteger s = k.add(e.multiply(d)).mod(n);

Expand Down