The secp256k1 algorithm signature result is one byte less.

[sujiulong]

@test
public void verifyTest() {
String pri = "87385e10d018f971f66cf2c065663d4aa427286f259f85bb8b2438130f4f1ee7";
String sourceHash = "7d50e029128286afba20cb62cf1b874d76a527a896f3d39167289a9b0446c518";
ECKey ecKey = ECKey.fromPrivate(Hex.decode(pri));
byte[] sign = ecKey.sign(Hex.decode(sourceHash)).toByteArray();
System.out.println(sign.length);
}

The result is always 64 not 65 bytes.

[mkalinin]

65 on my side for this particular test.

[sujiulong]

Thank you very much for your reply. My code is too old.
This is my local code.
public byte[] toByteArray() {
final byte fixedV = this.v >= 27
? (byte) (this.v - 27)
: this.v;

        return ByteUtil.merge(
                ByteUtil.bigIntegerToBytes(this.r),
                ByteUtil.bigIntegerToBytes(this.s),
                new byte[]{fixedV});
    }

This is latest code.
public byte[] toByteArray() {
final byte fixedV = this.v >= 27
? (byte) (this.v - 27)
: this.v;

        return ByteUtil.merge(
                ByteUtil.bigIntegerToBytes(this.r, 32),
                ByteUtil.bigIntegerToBytes(this.s, 32),
                new byte[]{fixedV});
    }