From b8a56288be4f747f7ae626923a3786a6c36ccfdc Mon Sep 17 00:00:00 2001
From: Anon2026 <anon2026@nobody.org>
Date: Wed, 7 Jan 2026 20:24:59 +0300
Subject: [PATCH] Fix thread-unsafe localtime()

---
 daemon/HTTPServer.cpp | 10 ++++++++--
 libi2pd/Log.cpp       | 10 +++++++++-
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/daemon/HTTPServer.cpp b/daemon/HTTPServer.cpp
index 148d6ad7..934f726b 100644
--- a/daemon/HTTPServer.cpp
+++ b/daemon/HTTPServer.cpp
@@ -6,6 +6,7 @@
 * See full license text in LICENSE file at top of project tree
 */
 
+#include <time.h>
 #include <iomanip>
 #include <sstream>
 #include <thread>
@@ -93,11 +94,16 @@ namespace http {
 
 	static std::string ConvertTime (uint64_t time)
 	{
+		struct tm caltime;
 		lldiv_t divTime = lldiv(time, 1000);
 		time_t t = divTime.quot;
-		struct tm *tm = localtime(&t);
+#ifdef _WIN32
+		localtime_s(&caltime, &t);
+#else
+		localtime_r(&t, &caltime);
+#endif
 		char date[128];
-		snprintf(date, sizeof(date), "%02d/%02d/%d %02d:%02d:%02d.%03lld", tm->tm_mday, tm->tm_mon + 1, tm->tm_year + 1900, tm->tm_hour, tm->tm_min, tm->tm_sec, divTime.rem);
+		snprintf(date, sizeof(date), "%02d/%02d/%d %02d:%02d:%02d.%03lld", caltime.tm_mday, caltime.tm_mon + 1, caltime.tm_year + 1900, caltime.tm_hour, caltime.tm_min, caltime.tm_sec, divTime.rem);
 		return date;
 	}
 
diff --git a/libi2pd/Log.cpp b/libi2pd/Log.cpp
index 76e85d4a..eef5d196 100644
--- a/libi2pd/Log.cpp
+++ b/libi2pd/Log.cpp
@@ -6,6 +6,8 @@
 * See full license text in LICENSE file at top of project tree
 */
 
+#include <time.h>
+
 #include "Log.h"
 #include "util.h"
 
@@ -140,8 +142,14 @@ namespace log {
 	}
 
 	const char * Log::TimeAsString(std::time_t t) {
+		struct tm caltime;
 		if (t != m_LastTimestamp) {
-			strftime(m_LastDateTime, sizeof(m_LastDateTime), m_TimeFormat.c_str(), localtime(&t));
+#ifdef _WIN32
+			localtime_s(&caltime, &t);
+#else
+			localtime_r(&t, &caltime);
+#endif
+			strftime(m_LastDateTime, sizeof(m_LastDateTime), m_TimeFormat.c_str(), &caltime);
 			m_LastTimestamp = t;
 		}
 		return m_LastDateTime;