From 30ace5a3f39fa2a463b29eab329fd8de55a92bbb Mon Sep 17 00:00:00 2001
From: s-hadinger <49731213+s-hadinger@users.noreply.github.com>
Date: Sat, 17 Dec 2022 23:38:57 +0100
Subject: [PATCH] Berry support for `crypto.SHA256` (#17430)

---
 CHANGELOG.md                                  |  1 +
 .../berry_tasmota/src/be_crypto_lib.c         | 14 ++++
 tasmota/my_user_config.h                      |  1 +
 .../xdrv_52_3_berry_crypto.ino                | 77 +++++++++++++++++++
 4 files changed, 93 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e4981bc39..b7736a4eb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ All notable changes to this project will be documented in this file.
 ## [12.3.1.1] 20221216
 ### Added
 - Support for IPv6 DNS records (AAAA) and IPv6 ``Ping`` for ESP32 and ESP8266
+- Berry support for ``crypto.SHA256``
 
 ### Breaking Changed
 
diff --git a/lib/libesp32/berry_tasmota/src/be_crypto_lib.c b/lib/libesp32/berry_tasmota/src/be_crypto_lib.c
index 5e6818a00..3889e750c 100644
--- a/lib/libesp32/berry_tasmota/src/be_crypto_lib.c
+++ b/lib/libesp32/berry_tasmota/src/be_crypto_lib.c
@@ -15,8 +15,13 @@ extern int m_aes_gcm_tag(bvm *vm);
 extern int m_ec_c25519_pubkey(bvm *vm);
 extern int m_ec_c25519_sharedkey(bvm *vm);
 
+extern int m_hash_sha256_init(bvm *vm);
+extern int m_hash_sha256_update(bvm *vm);
+extern int m_hash_sha256_out(bvm *vm);
+
 #include "be_fixed_be_class_aes_gcm.h"
 #include "be_fixed_be_class_ec_c25519.h"
+#include "be_fixed_be_class_sha256.h"
 #include "be_fixed_crypto.h"
 
 /* @const_object_info_begin
@@ -36,9 +41,18 @@ class be_class_ec_c25519 (scope: global, name: EC_C25519) {
     shared_key, func(m_ec_c25519_sharedkey)
 }
 
+class be_class_sha256 (scope: global, name: SHA256) {
+    .p, var
+
+    init, func(m_hash_sha256_init)
+    update, func(m_hash_sha256_update)
+    out, func(m_hash_sha256_out)
+}
+
 module crypto (scope: global) {
   AES_GCM, class(be_class_aes_gcm)
   EC_C25519, class(be_class_ec_c25519)
+  SHA256, class(be_class_sha256)
 }
 
 @const_object_info_end */
diff --git a/tasmota/my_user_config.h b/tasmota/my_user_config.h
index 6ca0fa850..f00cc476a 100644
--- a/tasmota/my_user_config.h
+++ b/tasmota/my_user_config.h
@@ -1107,6 +1107,7 @@
   // Berry crypto extensions below:
   #define USE_BERRY_CRYPTO_AES_GCM               // enable AES GCM 256 bits
   // #define USE_BERRY_CRYPTO_EC_C25519             // enable Elliptic Curve C C25519
+  #define USE_BERRY_CRYPTO_SHA256                // enable SHA256 hash function
 #define USE_CSE7761                              // Add support for CSE7761 Energy monitor as used in Sonoff Dual R3
 
 // -- LVGL Graphics Library ---------------------------------
diff --git a/tasmota/tasmota_xdrv_driver/xdrv_52_3_berry_crypto.ino b/tasmota/tasmota_xdrv_driver/xdrv_52_3_berry_crypto.ino
index 2c89fb30a..83094ff5d 100644
--- a/tasmota/tasmota_xdrv_driver/xdrv_52_3_berry_crypto.ino
+++ b/tasmota/tasmota_xdrv_driver/xdrv_52_3_berry_crypto.ino
@@ -158,6 +158,83 @@ extern "C" {
 #endif // USE_BERRY_CRYPTO_AES_GCM
   }
 }
+/*********************************************************************************************\
+ * SHA256 class
+ * 
+\*********************************************************************************************/
+extern "C" {
+
+  // `SHA256.init() -> nil`
+  int32_t m_hash_sha256_init(struct bvm *vm);
+  int32_t m_hash_sha256_init(struct bvm *vm) {
+#ifdef USE_BERRY_CRYPTO_SHA256
+    // Initialize a SHA256 context
+    br_sha256_context * ctx = (br_sha256_context *) be_os_malloc(sizeof(br_sha256_context));
+    if (!ctx) {
+      be_throw(vm, BE_MALLOC_FAIL);
+    }
+    br_sha256_init(ctx);
+
+    be_newcomobj(vm, ctx, &be_commonobj_destroy_generic);
+    be_setmember(vm, 1, ".p");
+    be_return_nil(vm);
+#else // USE_BERRY_CRYPTO_SHA256
+    be_raise(vm, "Not implemented", nullptr);
+#endif // USE_BERRY_CRYPTO_SHA256
+  }
+
+  // `<instance:SHA256>.update(content:bytes()) -> nil`
+  //
+  // Add raw bytes to the hash calculation
+  int32_t m_hash_sha256_update(struct bvm *vm);
+  int32_t m_hash_sha256_update(struct bvm *vm) {
+#ifdef USE_BERRY_CRYPTO_SHA256
+    int32_t argc = be_top(vm); // Get the number of arguments
+    if (argc >= 2 && be_isinstance(vm, 2)) {
+      do {
+        be_getglobal(vm, "bytes"); /* get the bytes class */ /* TODO eventually replace with be_getbuiltin */
+        if (!be_isderived(vm, 2)) break;
+        size_t length = 0;
+        const void * bytes = be_tobytes(vm, 2, &length);
+        if (!bytes) break;
+
+        be_getmember(vm, 1, ".p");
+        br_sha256_context * ctx;
+        ctx = (br_sha256_context *) be_tocomptr(vm, -1);
+        if (!ctx) break;
+
+        if (length > 0) {
+          br_sha256_update(ctx, bytes, length);
+        }
+        be_return_nil(vm);
+        // success
+      } while (0);
+    }
+    be_raise(vm, "value_error", NULL);
+#else // USE_BERRY_CRYPTO_SHA256
+    be_raise(vm, "Not implemented", nullptr);
+#endif // USE_BERRY_CRYPTO_SHA256
+  }
+
+  // `<instance:SHA256>.finish() -> bytes()`
+  //
+  // Add raw bytes to the MD5 calculation
+  int32_t m_hash_sha256_out(struct bvm *vm);
+  int32_t m_hash_sha256_out(struct bvm *vm) {
+#ifdef USE_BERRY_CRYPTO_SHA256
+    be_getmember(vm, 1, ".p");
+    br_sha256_context * ctx;
+    ctx = (br_sha256_context *) be_tocomptr(vm, -1);
+
+    uint8_t output[32];
+    br_sha256_out(ctx, output);
+    be_pushbytes(vm, output, sizeof(output));
+    be_return(vm);
+#else // USE_BERRY_CRYPTO_SHA256
+    be_raise(vm, "Not implemented", nullptr);
+#endif // USE_BERRY_CRYPTO_SHA256
+  }
+}
 
 /*********************************************************************************************\
  * EC C25519 class