Handle additional signature component lengths (#4230)

* Added ledger support

* Fixed block explorer

* Added CL args

* Added a flag to ignore balance check

* Fixed explorer test

* Minor changes as per feedback

* Minor changes as per feedback

* Added global.json to lock the version

* DOwngraded to 2.1

* Removed unused tests

* Added keypath param for advanced users

* Fixed address scanning

* Fix for index

* Added more logs

* Added more logs

* Added logic to scan change addresses

* Added more logs

* Added ability to output signature

* Added minimum balance check

* Handle case where the signature R component is only 31 bytes

* Handle R and S values of length 31, 32 or 33

* Fix brace

Co-authored-by: Igor Goldobin <igor.goldobin@bhp.com>
Co-authored-by: Igor Goldobin <igor.goldobin@gmail.com>

src/AddressOwnershipTool/LedgerService.cs

@@ -138,59 +138,80 @@ private string GetSignature(string address, byte[] resp, PubKey pubKey)
                     Console.WriteLine($@"Signature response from ledger: {BitConverter.ToString(resp)}");
                 }
 
-                if (resp[0] != (byte)(48 + recId))
+                if (resp[0] != (byte) (48 + recId))
                     continue; //throw new Exception("Unexpected signature encoding - outer type not SET");
 
                 if (resp[2] != 0x02)
                     throw new Exception("Invalid signature encoding - type not integer");
 
                 int rLength = resp[3];
 
-                var rBytes = new byte[32];
-                Array.Resize(ref rBytes, rLength); // can be 33
+                byte[] rBytes = new byte[rLength];
                 Array.Copy(resp, 4, rBytes, 0, rLength);
 
                 if (resp[4 + rLength] != 0x02)
                     throw new Exception("Invalid signature encoding - type not integer");
 
                 int sLength = resp[5 + rLength];
 
-                var sBytes = new byte[32];
+                byte[] sBytes = new byte[sLength];
                 Array.Copy(resp, 6 + rLength, sBytes, 0, sLength);
 
                 // Now we have to work backwards to figure out the recId needed to recover the signature.
 
                 int headerByte = recId + 27 + (pubKey.IsCompressed ? 4 : 0);
 
-                var sigData = new byte[1 + rLength + sLength];  // 1 header + 32 bytes for R + 32 bytes for S
+                byte[] sigData = new byte[1 + 32 + 32]; // 1 header + 32 bytes for R + 32 bytes for S
 
-                sigData[0] = (byte)headerByte;
+                sigData[0] = (byte) headerByte;
 
-                if (rLength == 31)
+                switch (rLength)
                 {
-                    Array.Copy(rBytes, 0, sigData, 1, 31);
-                    Array.Copy(sBytes, sLength == 33 ? 1 : 0, sigData, 32, 32);
+                    case 31:
+                        // Add 1 to destination index as there will be a leading zero to make up the 32 bytes
+                        Array.Copy(rBytes, 0, sigData, 1 + 1, rLength);
+                        break;
+                    case 32:
+                        // The 'typical' case - no additional offsets
+                        Array.Copy(rBytes, 0, sigData, 1 + 0, rLength);
+                        break;
+                    case 33:
+                        // Use sourceIndex = 1 as we trim off the leading byte
+                        Array.Copy(rBytes, 1, sigData, 1 + 0, rLength - 1);
+                        break;
+                    default:
+                        throw new Exception("Unexpected rLength: " + rLength);
                 }
-                else
+
+                switch (sLength)
                 {
-                    Array.Copy(rBytes, rLength == 33 ? 1 : 0, sigData, 1, 32);
-                    Array.Copy(sBytes, sLength == 33 ? 1 : 0, sigData, 33, 32);
+                    case 31:
+                        Array.Copy(sBytes, 0, sigData, 33 + 1, sLength);
+                        break;
+                    case 32:
+                        Array.Copy(sBytes, 0, sigData, 33 + 0, sLength);
+                        break;
+                    case 33:
+                        Array.Copy(sBytes, 1, sigData, 33 + 0, sLength - 1);
+                        break;
+                    default:
+                        throw new Exception("Unexpected sLength: " + sLength);
                 }
 
-                var specialBytes = 0x18;
-                var prefixBytes = Encoding.UTF8.GetBytes("Stratis Signed Message:\n");
-                var lengthBytes = BitConverter.GetBytes((char)address.Length).Take(1).ToArray();
-                var addressBytes = Encoding.UTF8.GetBytes(address);
+                int specialBytes = 0x18;
+                byte[] prefixBytes = Encoding.UTF8.GetBytes("Stratis Signed Message:\n");
+                byte[] lengthBytes = BitConverter.GetBytes((char) address.Length).Take(1).ToArray();
+                byte[] addressBytes = Encoding.UTF8.GetBytes(address);
 
                 byte[] dataBytes = new byte[1 + prefixBytes.Length + lengthBytes.Length + addressBytes.Length];
-                dataBytes[0] = (byte)specialBytes;
+                dataBytes[0] = (byte) specialBytes;
                 Buffer.BlockCopy(prefixBytes, 0, dataBytes, 1, prefixBytes.Length);
                 Buffer.BlockCopy(lengthBytes, 0, dataBytes, prefixBytes.Length + 1, lengthBytes.Length);
                 Buffer.BlockCopy(addressBytes, 0, dataBytes, prefixBytes.Length + lengthBytes.Length + 1, addressBytes.Length);
 
                 uint256 messageHash = NBitcoin.Crypto.Hashes.Hash256(dataBytes);
-                var recovered = PubKey.RecoverCompact(messageHash, sigData);
-                var recoveredAddress = recovered.Hash.ScriptPubKey.GetDestinationAddress(this.network).ToString();
+                PubKey recovered = PubKey.RecoverCompact(messageHash, sigData);
+                string recoveredAddress = recovered.Hash.ScriptPubKey.GetDestinationAddress(this.network).ToString();
                 bool foundMatch = recoveredAddress == address;
 
                 if (foundMatch)