From 649ad47e628cb8f5ee965cda8da9f23a82ab2902 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Tue, 1 Jul 2025 10:05:23 -0500
Subject: [PATCH] web_server_ support for ota backend idf

---
 .../components/ota_base/ota_backend_esp_idf.cpp   | 15 ++++++++++-----
 esphome/components/ota_base/ota_backend_esp_idf.h |  1 +
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/esphome/components/ota_base/ota_backend_esp_idf.cpp b/esphome/components/ota_base/ota_backend_esp_idf.cpp
index eef4cb8026..b49a690a95 100644
--- a/esphome/components/ota_base/ota_backend_esp_idf.cpp
+++ b/esphome/components/ota_base/ota_backend_esp_idf.cpp
@@ -67,7 +67,10 @@ OTAResponseTypes IDFOTABackend::begin(size_t image_size) {
   return OTA_RESPONSE_OK;
 }
 
-void IDFOTABackend::set_update_md5(const char *expected_md5) { memcpy(this->expected_bin_md5_, expected_md5, 32); }
+void IDFOTABackend::set_update_md5(const char *expected_md5) {
+  memcpy(this->expected_bin_md5_, expected_md5, 32);
+  this->md5_set_ = true;
+}
 
 OTAResponseTypes IDFOTABackend::write(uint8_t *data, size_t len) {
   esp_err_t err = esp_ota_write(this->update_handle_, data, len);
@@ -84,10 +87,12 @@ OTAResponseTypes IDFOTABackend::write(uint8_t *data, size_t len) {
 }
 
 OTAResponseTypes IDFOTABackend::end() {
-  this->md5_.calculate();
-  if (!this->md5_.equals_hex(this->expected_bin_md5_)) {
-    this->abort();
-    return OTA_RESPONSE_ERROR_MD5_MISMATCH;
+  if (this->md5_set_) {
+    this->md5_.calculate();
+    if (!this->md5_.equals_hex(this->expected_bin_md5_)) {
+      this->abort();
+      return OTA_RESPONSE_ERROR_MD5_MISMATCH;
+    }
   }
   esp_err_t err = esp_ota_end(this->update_handle_);
   this->update_handle_ = 0;
diff --git a/esphome/components/ota_base/ota_backend_esp_idf.h b/esphome/components/ota_base/ota_backend_esp_idf.h
index a7e34cb5ae..3c760df1c8 100644
--- a/esphome/components/ota_base/ota_backend_esp_idf.h
+++ b/esphome/components/ota_base/ota_backend_esp_idf.h
@@ -24,6 +24,7 @@ class IDFOTABackend : public OTABackend {
   const esp_partition_t *partition_;
   md5::MD5Digest md5_{};
   char expected_bin_md5_[32];
+  bool md5_set_{false};
 };
 
 }  // namespace ota_base