From 2d9152d9b9f035f5bdad3a3160509dae8fd46d9d Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sun, 14 Sep 2025 17:35:18 -0500
Subject: [PATCH] [md5] Optimize MD5::get_hex() to eliminate sprintf dependency
 (#10710)

---
 esphome/components/md5/md5.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/esphome/components/md5/md5.cpp b/esphome/components/md5/md5.cpp
index 980cb98699..21bd2e1cab 100644
--- a/esphome/components/md5/md5.cpp
+++ b/esphome/components/md5/md5.cpp
@@ -1,4 +1,3 @@
-#include <cstdio>
 #include <cstring>
 #include "md5.h"
 #ifdef USE_MD5
@@ -44,7 +43,9 @@ void MD5Digest::get_bytes(uint8_t *output) { memcpy(output, this->digest_, 16);
 
 void MD5Digest::get_hex(char *output) {
   for (size_t i = 0; i < 16; i++) {
-    sprintf(output + i * 2, "%02x", this->digest_[i]);
+    uint8_t byte = this->digest_[i];
+    output[i * 2] = format_hex_char(byte >> 4);
+    output[i * 2 + 1] = format_hex_char(byte & 0x0F);
   }
 }