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Code Issues Releases Wiki Activity

cleanup

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This commit is contained in:
J. Nick Koston
2026-01-06 00:48:40 -10:00
parent 3e6d777439
commit b40de61224
1 changed files with 14 additions and 4 deletions
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18
esphome/components/sha256/sha256.h
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@@ -22,6 +22,18 @@
namespace esphome::sha256 {
/// SHA256 hash implementation.
///
/// CRITICAL for ESP32-S3 with IDF 5.5.x hardware SHA acceleration:
/// 1. SHA256 objects MUST be declared with `alignas(32)` for proper DMA alignment
/// 2. The object MUST stay in the same stack frame (no passing to other functions)
/// 3. NO Variable Length Arrays (VLAs) in the same function
///
/// Example usage:
/// alignas(32) sha256::SHA256 hasher;
/// hasher.init();
/// hasher.add(data, len);
/// hasher.calculate();
class SHA256 : public esphome::HashBase {
public:
SHA256() = default;
@@ -39,10 +51,8 @@ class SHA256 : public esphome::HashBase {
protected:
#if defined(USE_ESP32) || defined(USE_LIBRETINY)
// CRITICAL: The mbedtls context MUST be stack-allocated (not a pointer) for ESP32-S3 hardware SHA acceleration.
// The ESP32-S3 DMA engine references this structure's memory addresses. If the context is passed to another
// function (crossing stack frames) or if VLAs are present, the DMA operations will corrupt memory and produce
// truncated/incorrect hash results.
// The mbedtls context for ESP32-S3 hardware SHA requires proper alignment and stack frame constraints.
// See class documentation above for critical requirements.
mbedtls_sha256_context ctx_{};
#elif defined(USE_ESP8266) || defined(USE_RP2040)
br_sha256_context ctx_{};