From 5ae21fb5bead4d013bd2606bdc9ee1143674a13d Mon Sep 17 00:00:00 2001
From: Grzegorz Tworek <gtworek@users.noreply.github.com>
Date: Sun, 29 Dec 2024 00:32:42 +0100
Subject: [PATCH] Create ISAPINSRL.c

---
 HashSrv/ISAPINSRL.c | 207 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 207 insertions(+)
 create mode 100644 HashSrv/ISAPINSRL.c

diff --git a/HashSrv/ISAPINSRL.c b/HashSrv/ISAPINSRL.c
new file mode 100644
index 0000000..5565aa4
--- /dev/null
+++ b/HashSrv/ISAPINSRL.c
@@ -0,0 +1,207 @@
+#include <Windows.h>
+#include <tchar.h>
+#include <HttpExt.h>
+#include <strsafe.h>
+#include "sqlite3.h"
+
+
+#define SHA256LEN 64
+#define ALGONAMELEN 6
+#define ISAPIDESCRITPIONA "MySRL_ISAPI"
+#define VERMAJOR 1
+#define VERMINOR 0
+#define MAXQUERYLEN 256
+
+#define DBGOUT
+
+#ifdef DBGOUT
+#define MAXDBGLENGTH 2048
+#define DBGTMPL _T("[") ## _T(ISAPIDESCRITPIONA) ## _T("][%i] (%hs / %i) %s")
+
+#define DBGPRINT(dbgText) { \
+    TCHAR* macroStrMsg; \
+    macroStrMsg = HeapAlloc(GetProcessHeap(), 0, MAXDBGLENGTH*sizeof(TCHAR)); \
+    if (macroStrMsg) \
+    { \
+        (void)_stprintf_s(macroStrMsg, MAXDBGLENGTH, DBGTMPL, GetCurrentThreadId(), __FUNCTION__, __LINE__, (dbgText)); \
+        (void)OutputDebugString(macroStrMsg); \
+        HeapFree(GetProcessHeap(), 0, macroStrMsg); \
+    } \
+} __noop
+#else
+#define DBGPRINT(dbgText) __noop
+#endif
+
+
+sqlite3* g_db = NULL; //global db handle
+
+
+BOOL APIENTRY DllMain(HMODULE hModule, DWORD ul_reason_for_call, LPVOID lpReserved)
+{
+	UNREFERENCED_PARAMETER(lpReserved);
+
+	DisableThreadLibraryCalls(hModule);
+
+	switch (ul_reason_for_call)
+	{
+		case DLL_PROCESS_ATTACH:
+			DBGPRINT(_T("Attach."));
+			int rc;
+			rc = sqlite3_open("S:\\SqliteDB\\DB\\RDS_2024.03.1_modern_minimal.db", &g_db);
+			if (SQLITE_OK != rc)
+			{
+				DBGPRINT(_T("Can't open database")); //, sqlite3_errmsg(db)
+				sqlite3_close(g_db);
+				return FALSE;
+			}
+			break;
+
+		case DLL_PROCESS_DETACH:
+			DBGPRINT(_T("Detach."));
+			sqlite3_close(g_db);
+			break;
+
+		default:
+			break;
+	}
+
+	return TRUE;
+}
+
+
+BOOL WINAPI GetExtensionVersion(_Out_ HSE_VERSION_INFO* pVer)
+{
+	DBGPRINT(_T("Entering."));
+	pVer->dwExtensionVersion = MAKELONG(VERMINOR, VERMAJOR);
+	strcpy_s(pVer->lpszExtensionDesc, _countof(pVer->lpszExtensionDesc), ISAPIDESCRITPIONA);
+	return TRUE;
+}
+
+
+BOOL execute_query(sqlite3* db, const char* sql)
+{
+	BOOL bRes;
+	char** results;
+	int rows;
+	int columns;
+	char* zErrMsg = 0;
+	int rc = sqlite3_get_table(db, sql, &results, &rows, &columns, &zErrMsg);
+	if (rc != SQLITE_OK)
+	{
+		DBGPRINT(_T("query fail..."));
+		sqlite3_free(zErrMsg);
+		return FALSE;
+	}
+	else
+	{
+		if (rows > 0 && columns > 0)
+		{
+			DBGPRINT(_T("some results."));
+			bRes = TRUE;
+		}
+		else
+		{
+			DBGPRINT(_T("no results."));
+			bRes = FALSE;
+		}
+		sqlite3_free_table(results);
+	}
+	return bRes;
+}
+
+
+BOOL isAlphanumeric(const char* str)
+{
+	while (*str)
+	{
+		if (!isalnum((unsigned char)*str))
+		{
+			return FALSE;
+		}
+		str++;
+	}
+	return TRUE;
+}
+
+
+DWORD WINAPI HttpExtensionProc(_In_ EXTENSION_CONTROL_BLOCK* pECB)
+{
+	DBGPRINT(_T("Entering."));
+
+	HSE_SEND_HEADER_EX_INFO HeaderExInfo;
+
+	// prepare headers
+	HeaderExInfo.pszStatus = "200 OK";
+	HeaderExInfo.pszHeader = "Content-Type: text/plain\r\nCache-Control: no-cache\r\nPragma: no-cache\r\n\r\n";
+	HeaderExInfo.cchStatus = (DWORD)strlen(HeaderExInfo.pszStatus);
+	HeaderExInfo.cchHeader = (DWORD)strlen(HeaderExInfo.pszHeader);
+	HeaderExInfo.fKeepConn = TRUE;
+
+	pECB->ServerSupportFunction(pECB->ConnID, HSE_REQ_SEND_RESPONSE_HEADER_EX, &HeaderExInfo, NULL, NULL);
+
+	// we should ask for server variable len, allocate buffer, and ask for server variable again. But the valid buffer is always 1+ALGONAMELEN+1+SHA256LEN+1.
+
+	CHAR chOriginalUrl[1 + ALGONAMELEN + 1 + SHA256LEN + 1] = {0};
+	DWORD dwOriginalUrlSize;
+	dwOriginalUrlSize = _countof(chOriginalUrl);
+
+	pECB->GetServerVariable(pECB->ConnID, "HTTP_X_ORIGINAL_URL", chOriginalUrl, &dwOriginalUrlSize);
+
+	char* chContext = NULL;
+	char* chHash;
+	(void)strtok_s(chOriginalUrl, "/", &chContext);
+	chHash = strtok_s(NULL, "/", &chContext);
+
+
+#ifdef DBGOUT
+	TCHAR strMsg[MAXDBGLENGTH];
+	_stprintf_s(
+		strMsg,
+		MAXDBGLENGTH,
+		TEXT("[%hs][%d] (%hs / %i) HASH: %hs"),
+		ISAPIDESCRITPIONA,
+		GetCurrentThreadId(),
+		__FUNCTION__,
+		__LINE__,
+		chHash);
+	OutputDebugString(strMsg);
+#endif
+
+	BOOL bQueryResult;
+
+	if (!chHash)
+	{
+		DBGPRINT(_T("hash null fail..."));
+		bQueryResult = FALSE;
+	}
+	else if (strlen(chHash) != SHA256LEN)
+	{
+		DBGPRINT(_T("hash len fail..."));
+		bQueryResult = FALSE;
+	}
+	else if (!isAlphanumeric(chHash))
+	{
+		DBGPRINT(_T("hash alnum fail..."));
+		bQueryResult = FALSE;
+	}
+	else
+	{
+		char chQuery[MAXQUERYLEN] = {0};
+		(void)strcpy_s(chQuery, _countof(chQuery), "SELECT * FROM FILE WHERE sha256='");
+		(void)strcat_s(chQuery, _countof(chQuery), chHash);
+		(void)strcat_s(chQuery, _countof(chQuery), "' LIMIT 1");
+		bQueryResult = execute_query(g_db, chQuery);
+	}
+
+	DBGPRINT(_T("Serving data."));
+
+	BYTE bBuffer = '0';
+	if (bQueryResult)
+	{
+		bBuffer = '1';
+	}
+
+	DWORD dwBytesToWrite = 1;
+	pECB->WriteClient(pECB->ConnID, &bBuffer, &dwBytesToWrite, 0);
+	return HSE_STATUS_SUCCESS;
+}