diff --git a/cpp_ext/tcp_ssl_password.cpp b/cpp_ext/tcp_ssl_password.cpp
new file mode 100644
index 0000000..525e9aa
--- /dev/null
+++ b/cpp_ext/tcp_ssl_password.cpp
@@ -0,0 +1,33 @@
+#include "tcp_ssl_password.hpp"
+
+#include <openssl/md5.h>
+#include <sstream>
+#include <iomanip>
+
+namespace netcore {
+
+static std::string md5_hex(const std::string& input) {
+    MD5_CTX ctx;
+    MD5_Init(&ctx);
+    MD5_Update(&ctx, input.data(), input.size());
+
+    unsigned char digest[MD5_DIGEST_LENGTH];
+    MD5_Final(digest, &ctx);
+
+    std::ostringstream oss;
+    oss << std::hex << std::setfill('0');
+    for (int i = 0; i < MD5_DIGEST_LENGTH; ++i) {
+        oss << std::setw(2) << static_cast<unsigned int>(digest[i]);
+    }
+    return oss.str();
+}
+
+std::string calculate_tcp_ssl_password(const std::string& device_id, const std::string& iccid) {
+    std::string md5_device_hex = md5_hex(device_id);
+    if (!iccid.empty()) {
+        md5_device_hex += iccid;
+    }
+    return md5_hex(md5_device_hex);
+}
+
+} // namespace netcore
diff --git a/cpp_ext/tcp_ssl_password.hpp b/cpp_ext/tcp_ssl_password.hpp
new file mode 100644
index 0000000..71ecbfd
--- /dev/null
+++ b/cpp_ext/tcp_ssl_password.hpp
@@ -0,0 +1,7 @@
+#pragma once
+
+#include <string>
+
+namespace netcore {
+    std::string calculate_tcp_ssl_password(const std::string& device_id, const std::string& iccid);
+}