fix crashing if wrong type of sig is entered in find input box

README.md

@@ -65,9 +65,5 @@ cmake -S . -B build
 ### Building using Github Actions
 - based on [binja-ci-tests](https://github.com/CouleeApps/binja-ci-tests)
 
-### Known issues
-- if a code signature is provided and the 'find norm signature' process is executed, Binary Ninja will freeze and crash, potentially caused by an infinite loop, similar issue may also occur in various other scenarios
-- creating signature from `Hex Editor` view within the main frame most likely causes crash as partial instructions might be selected
-
 ### Backstory
 I have been using IDA for majority of my reverse engineering career and recently decided to switch to Binary Ninja. I work with signatures on daily basis and this plugin is a must for me. Although there already is a community plugin for the exact same purpose, it is frankly unusable for binaries over 50KB in size as it is incredibly slow and on top of that contains two bugs causing creation of signatures with wrongly placed wild bytes resulting in signatures not being compatible with different compilations of the same binary. I still want to note that the python version was a nice resource in creation of this version.

sigscan.cpp

@@ -280,13 +280,15 @@ std::string exctract_sig(std::string str, sig_types type, bool scan_for_custom_w
 		// "48 89 5c 24 08 ? 9a
 		// 48 89 5C 24 08 ?? 9A'
 		bool have_byte = false;
+		int cur_byte_len = 0;
 		for (auto& c : str)
 		{
 			if (have_byte && c == ' ')
 			{
+				if (cur_byte_len > 2) { return ""; }
 				sig += " ";
 				have_byte = false;
-				continue;
+				cur_byte_len = 0;
 			}
 			else
 			{
@@ -297,6 +299,7 @@ std::string exctract_sig(std::string str, sig_types type, bool scan_for_custom_w
 				else if (c == '?')
 				{
 					sig += "?";
+					++cur_byte_len;
 					have_byte = true;
 				}
 				else
@@ -306,6 +309,7 @@ std::string exctract_sig(std::string str, sig_types type, bool scan_for_custom_w
 						have_byte = true;
 					}
 					sig += c;
+					++cur_byte_len;
 				}
 			}
 		}
@@ -341,27 +345,30 @@ std::string exctract_sig(std::string str, sig_types type, bool scan_for_custom_w
 		// MASK
 		// find the first occurrence of ',' after pos in str
 		pos = str.find(',', pos);
-		// read characters until is 'x' or '?'
-		while (pos < str.size() && str[pos] != 'x' && str[pos] != '?')
+		if (pos != std::string::npos)
 		{
-			++pos;
-		}
-		// read characters until the end of the string or a character that is not 'x' or '?'
-		for (size_t i = pos, j = 0; i < str.size() && j * 3 + 2 < sig.size(); ++i, ++j)
-		{
-			char c = str[i];
-			if (c == '?')
+			// read characters until is 'x' or '?'
+			while (pos < str.size() && str[pos] != 'x' && str[pos] != '?')
 			{
-				sig[j * 3] = '?';
-				sig[j * 3 + 1] = '?';
+				++pos;
 			}
-			else if (c != 'x')
+			// read characters until the end of the string or a character that is not 'x' or '?'
+			for (size_t i = pos, j = 0; i < str.size() && j * 3 + 2 < sig.size(); ++i, ++j)
 			{
-				break;
+				char c = str[i];
+				if (c == '?')
+				{
+					sig[j * 3] = '?';
+					sig[j * 3 + 1] = '?';
+				}
+				else if (c != 'x')
+				{
+					break;
+				}
 			}
 		}
-		sig.pop_back();
 	}
+	if (sig.back() == ' ') { sig.pop_back(); }
 	return sig;
 }
 
@@ -388,6 +395,7 @@ void find_sig(BinaryView* view, sig_types type)
 	if (sig.empty())
 	{
 		Log(ErrorLog, "INPUT IS NOT VALID SIG");
+		return;
 	}
 	// Log(InfoLog, "sig: %s", sig.c_str());