diff --git a/src/common/common.vcxproj b/src/common/common.vcxproj
index ab83e2e5..4f4c6407 100644
--- a/src/common/common.vcxproj
+++ b/src/common/common.vcxproj
@@ -71,6 +71,7 @@
     <ClCompile Include="servlist.c" />
     <ClCompile Include="ssl.c" />
     <ClCompile Include="scram.c" />
+    <ClCompile Include="sts.c" />
     <ClCompile Include="sysinfo\win32\backend.c" />
     <ClCompile Include="text.c" />
     <ClCompile Include="tree.c" />
diff --git a/src/common/common.vcxproj.filters b/src/common/common.vcxproj.filters
index d3d87016..f3b3b822 100644
--- a/src/common/common.vcxproj.filters
+++ b/src/common/common.vcxproj.filters
@@ -172,6 +172,9 @@
     <ClCompile Include="ssl.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="sts.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="text.c">
       <Filter>Source Files</Filter>
     </ClCompile>
diff --git a/src/common/meson.build b/src/common/meson.build
index 76a3c5ca..f5556fe4 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -18,6 +18,7 @@ common_sources = [
   'scram.c',
   'server.c',
   'servlist.c',
+  'sts.c',
 	'text.c',
   'tree.c',
   'url.c',
diff --git a/src/common/sts.c b/src/common/sts.c
new file mode 100644
index 00000000..d529945d
--- /dev/null
+++ b/src/common/sts.c
@@ -0,0 +1,152 @@
+/* ZoiteChat
+ * Copyright (C) 2024
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#include <glib.h>
+
+#include "sts.h"
+
+static gboolean
+sts_parse_bool (const char *value)
+{
+	if (!value || !*value)
+	{
+		return FALSE;
+	}
+
+	return g_ascii_strcasecmp (value, "1") == 0 ||
+		g_ascii_strcasecmp (value, "true") == 0 ||
+		g_ascii_strcasecmp (value, "yes") == 0;
+}
+
+sts_profile *
+sts_profile_new (const char *host, guint16 port, time_t expires_at, gboolean preload)
+{
+	sts_profile *profile = g_new0 (sts_profile, 1);
+
+	profile->host = g_strdup (host);
+	profile->port = port;
+	profile->expires_at = expires_at;
+	profile->preload = preload;
+
+	return profile;
+}
+
+void
+sts_profile_free (sts_profile *profile)
+{
+	if (!profile)
+	{
+		return;
+	}
+
+	g_free (profile->host);
+	g_free (profile);
+}
+
+char *
+sts_profile_serialize (const sts_profile *profile)
+{
+	GString *serialized;
+	char *escaped_host;
+	char *result;
+
+	if (!profile || !profile->host || !*profile->host)
+	{
+		return NULL;
+	}
+
+	escaped_host = g_strdup (profile->host);
+	serialized = g_string_new (escaped_host);
+	g_free (escaped_host);
+
+	g_string_append_printf (serialized, " %u %" G_GINT64_FORMAT,
+								profile->port, (gint64) profile->expires_at);
+
+	if (profile->preload)
+	{
+		g_string_append (serialized, " 1");
+	}
+
+	result = g_string_free (serialized, FALSE);
+	return result;
+}
+
+sts_profile *
+sts_profile_deserialize (const char *serialized)
+{
+	char *host = NULL;
+	guint16 port = 0;
+	gint64 expires_at = -1;
+	gboolean preload = FALSE;
+	gchar **pairs = NULL;
+	int i = 0;
+
+	if (!serialized || !*serialized)
+	{
+		return NULL;
+	}
+
+	pairs = g_strsplit_set (serialized, " \t", -1);
+	{
+		const char *fields[4] = {0};
+		int field_count = 0;
+
+		for (i = 0; pairs[i]; i++)
+		{
+			if (!pairs[i][0])
+			{
+				continue;
+			}
+
+			if (field_count < 4)
+			{
+				fields[field_count++] = pairs[i];
+			}
+		}
+
+		if (field_count >= 3)
+		{
+			host = g_strdup (fields[0]);
+
+			gint64 port_value = g_ascii_strtoll (fields[1], NULL, 10);
+			if (port_value > 0 && port_value <= G_MAXUINT16)
+			{
+				port = (guint16) port_value;
+			}
+
+			expires_at = g_ascii_strtoll (fields[2], NULL, 10);
+
+			if (field_count >= 4)
+			{
+				preload = sts_parse_bool (fields[3]);
+			}
+		}
+	}
+
+	if (!host || !*host || expires_at < 0)
+	{
+		g_free (host);
+		g_strfreev (pairs);
+		return NULL;
+	}
+
+	sts_profile *profile = sts_profile_new (host, port, (time_t) expires_at, preload);
+	g_free (host);
+	g_strfreev (pairs);
+	return profile;
+}
diff --git a/src/common/sts.h b/src/common/sts.h
new file mode 100644
index 00000000..2e60bae3
--- /dev/null
+++ b/src/common/sts.h
@@ -0,0 +1,43 @@
+/* ZoiteChat
+ * Copyright (C) 2024
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#ifndef HEXCHAT_STS_H
+#define HEXCHAT_STS_H
+
+#include <glib.h>
+#include <time.h>
+
+G_BEGIN_DECLS
+
+typedef struct sts_profile
+{
+	char *host;
+	guint16 port;
+	time_t expires_at;
+	gboolean preload;
+} sts_profile;
+
+sts_profile *sts_profile_new (const char *host, guint16 port, time_t expires_at, gboolean preload);
+void sts_profile_free (sts_profile *profile);
+
+char *sts_profile_serialize (const sts_profile *profile);
+sts_profile *sts_profile_deserialize (const char *serialized);
+
+G_END_DECLS
+
+#endif