code/refactor: Deduplicate sigscan code

> cleanup unnecessary code, should break nothing
> probably will cause merge issues someday
> add missing `replace_pattern_from`

util/sigscan.cpp

@@ -13,85 +13,19 @@ intptr_t find_pattern(std::vector<uint8_t> &data, intptr_t base, const uint8_t *
         const char *mask, intptr_t offset, intptr_t usage)
 {
 
-    // build pattern
-    std::vector<std::pair<uint8_t, bool>> pattern_vector;
-    size_t mask_size = strlen(mask);
-    for (size_t i = 0; i < mask_size; i++) {
-        pattern_vector.emplace_back(pattern[i], mask[i] == 'X');
-    }
-
-    // the scan loop
-    auto data_begin = data.begin();
-    auto cur_usage = 0;
-    while (true) {
-
-        // search for the pattern
-        auto search_result = std::search(data_begin, data.end(), pattern_vector.begin(), pattern_vector.end(),
-                               [&](uint8_t c, std::pair<uint8_t, bool> pat) {
-                                   return (!pat.second) || c == pat.first;
-                               });
-
-        // check for a match
-        if (search_result != data.end()) {
-
-            // return the result if we hit the usage count
-            if (cur_usage == usage) {
-                return (std::distance(data.begin(), search_result) + base) + offset;
-            }
-
-            // increment the found count
-            ++cur_usage;
-            data_begin = ++search_result;
-        } else {
-            break;
-        }
-    }
-
-    return 0;
+    return find_pattern_from(data, base, pattern, mask, offset, usage, 0);
 }
 
 intptr_t find_pattern(HMODULE module, const uint8_t *pattern, const char *mask,
         intptr_t offset, intptr_t result_usage)
 {
-    // get module information
-    MODULEINFO module_info {};
-    if (!GetModuleInformation(GetCurrentProcess(), module, &module_info, sizeof(module_info))) {
-        return 0;
-    }
-
-    auto size = static_cast<size_t>(module_info.SizeOfImage);
-
-    try {
-
-        // copy data
-        std::vector<uint8_t> data(size);
-        memcpy(data.data(), module_info.lpBaseOfDll, size);
-
-        // find pattern
-        return find_pattern(
-                data,
-                reinterpret_cast<intptr_t>(module_info.lpBaseOfDll),
-                pattern,
-                mask,
-                offset,
-                result_usage);
-    } catch (const std::bad_alloc &e) {
-        log_warning("sigscan", "failed to allocate buffer of size {} for image data", size);
-        return false;
-    }
+    return find_pattern_from(module, pattern, mask, offset, result_usage, 0);
 }
 
 intptr_t find_pattern(HMODULE module, const std::string &pattern, const char *mask,
         intptr_t offset, intptr_t result_usage)
 {
-    std::string pattern_str(pattern);
-    auto pattern_bin = std::make_unique<uint8_t[]>(pattern.length() / 2);
-    if (!hex2bin(pattern_str.c_str(), pattern_bin.get())) {
-        log_warning("sigscan", "hex2bin failed");
-        return false;
-    }
-
-    return find_pattern(module, pattern_bin.get(), mask, offset, result_usage);
+    return find_pattern_from(module, pattern, mask, offset, result_usage, 0);
 }
 
 ///
@@ -184,12 +118,12 @@ intptr_t find_pattern_from(HMODULE module, const std::string &pattern, const cha
 }
 
 
-intptr_t replace_pattern(HMODULE module, const uint8_t *pattern, const char *mask, intptr_t offset,
-        intptr_t usage, const uint8_t *replace_data, const char *replace_mask)
+intptr_t replace_pattern_from(HMODULE module, const uint8_t *pattern, const char *mask, intptr_t offset,
+        intptr_t usage, intptr_t start_from, const uint8_t *replace_data, const char *replace_mask)
 {
 
     // find result
-    auto result = find_pattern(module, pattern, mask, offset, usage);
+    auto result = find_pattern_from(module, pattern, mask, offset, usage, start_from);
 
     // check result
     if (!result) {
@@ -211,8 +145,8 @@ intptr_t replace_pattern(HMODULE module, const uint8_t *pattern, const char *mas
     return result;
 }
 
-intptr_t replace_pattern(HMODULE module, const std::string &signature,
-        const std::string &replacement, intptr_t offset, intptr_t usage)
+intptr_t replace_pattern_from(HMODULE module, const std::string &signature,
+        const std::string &replacement, intptr_t offset, intptr_t usage, intptr_t start_from)
 {
     // build pattern
     std::string pattern_str(signature);
@@ -259,17 +193,30 @@ intptr_t replace_pattern(HMODULE module, const std::string &signature,
     }
 
     // do the replacement
-    return replace_pattern(
+    return replace_pattern_from(
             module,
             pattern_bin.get(),
             signature_mask.str().c_str(),
             offset,
             usage,
+            start_from,
             replace_data_bin.get(),
             replace_mask.str().c_str()
     );
 }
 
+intptr_t replace_pattern(HMODULE module, const std::string &signature,
+        const std::string &replacement, intptr_t offset, intptr_t usage)
+{
+    return replace_pattern_from(module, signature, replacement, offset, usage, 0);
+}
+
+intptr_t replace_pattern(HMODULE module, const uint8_t *pattern, const char *mask, intptr_t offset,
+        intptr_t usage, const uint8_t *replace_data, const char *replace_mask)
+{
+    return replace_pattern_from(module, pattern, mask, offset, usage, 0, replace_data, replace_mask);
+}
+
 bool get_pe_identifier(const std::filesystem::path& dll_path, uint32_t* time_date_stamp, uint32_t* address_of_entry_point) {
     std::ifstream file(dll_path, std::ios::binary);
     if (!file) {

util/sigscan.h

@@ -71,4 +71,22 @@ intptr_t replace_pattern(
         intptr_t offset,
         intptr_t usage);
 
+intptr_t replace_pattern_from(
+        HMODULE module,
+        const unsigned char *pattern,
+        const char *mask,
+        intptr_t offset,
+        intptr_t usage,
+        intptr_t start_from,
+        const unsigned char *replace_data,
+        const char *replace_mask);
+
+intptr_t replace_pattern_from(
+        HMODULE module,
+        const std::string &signature,
+        const std::string &replacement,
+        intptr_t offset,
+        intptr_t usage,
+        intptr_t start_from);
+
 bool get_pe_identifier(const std::filesystem::path& dll_path, uint32_t* time_date_stamp, uint32_t* address_of_entry_point);