Add minimal Huawei Hagrid WSP support

android_app/app/src/main/java/com/health/openscale/core/bluetooth/ScaleFactory.kt

@@ -41,6 +41,7 @@ import com.health.openscale.core.bluetooth.scales.HesleyHandler
 import com.health.openscale.core.bluetooth.scales.HoffenBbs8107Handler
 import com.health.openscale.core.bluetooth.scales.HuaweiAhCh100Handler
 import com.health.openscale.core.bluetooth.scales.HuaweiCH100SHandler
+import com.health.openscale.core.bluetooth.scales.HuaweiHagridWspHandler
 import com.health.openscale.core.bluetooth.scales.IHealthHS3Handler
 import com.health.openscale.core.bluetooth.scales.InlifeHandler
 import com.health.openscale.core.bluetooth.scales.LinkMode
@@ -134,6 +135,7 @@ class ScaleFactory @Inject constructor(
         IHealthHS3Handler(),
         HuaweiAhCh100Handler(),
         HuaweiCH100SHandler(),
+        HuaweiHagridWspHandler(),
         HoffenBbs8107Handler(),
         HesleyHandler(),
         ExingtechY1Handler(),

android_app/app/src/main/java/com/health/openscale/core/bluetooth/libs/HuaweiHagridSecretProvider.kt

@@ -0,0 +1,84 @@
+/*
+ * openScale
+ * Copyright (C) 2026 openScale contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.health.openscale.core.bluetooth.libs
+
+/**
+ * Replaceable source for Huawei Hagrid CAK/C1/C2 key material.
+ *
+ * Implementations must not log raw secret values. The upstream app only uses
+ * explicitly configured settings here; private Huawei Health extraction tools
+ * are outside this boundary.
+ */
+interface HuaweiHagridSecretProvider {
+    val id: String
+
+    fun load(
+        getString: (String) -> String?,
+        warn: (String) -> Unit
+    ): HuaweiHagridWspLib.HagridSecrets?
+
+    class DriverSettings(
+        private val cakKey: String,
+        private val c1Key: String,
+        private val c2Key: String
+    ) : HuaweiHagridSecretProvider {
+        override val id: String = "driver-settings"
+
+        override fun load(
+            getString: (String) -> String?,
+            warn: (String) -> Unit
+        ): HuaweiHagridWspLib.HagridSecrets? {
+            val cak = settingsHexOrNull(getString, warn, cakKey, 16)
+            val c1 = settingsHexOrNull(getString, warn, c1Key, 16)
+            val c2 = settingsHexOrNull(getString, warn, c2Key, 16)
+            if (cak == null && c1 == null && c2 == null) return null
+            if (cak == null || c1 == null || c2 == null) {
+                warn("Incomplete Huawei Hagrid secrets; require CAK, C1, and C2 hex settings")
+                return null
+            }
+            return runCatching { HuaweiHagridWspLib.HagridSecrets(cak, c1, c2) }
+                .getOrElse { error ->
+                    warn("Invalid Huawei Hagrid secrets: ${error.message}")
+                    null
+                }
+        }
+
+        private fun settingsHexOrNull(
+            getString: (String) -> String?,
+            warn: (String) -> Unit,
+            key: String,
+            expectedBytes: Int
+        ): ByteArray? {
+            val raw = getString(key)?.trim().orEmpty()
+            if (raw.isEmpty()) return null
+            val hex = raw.filter { it.isDigit() || it.lowercaseChar() in 'a'..'f' }
+            if (hex.length != expectedBytes * 2) {
+                warn("Ignoring Huawei Hagrid setting $key: expected ${expectedBytes * 2} hex digits, got ${hex.length}")
+                return null
+            }
+            return runCatching {
+                ByteArray(expectedBytes) { index ->
+                    hex.substring(index * 2, index * 2 + 2).toInt(16).toByte()
+                }
+            }.getOrElse { error ->
+                warn("Ignoring Huawei Hagrid setting $key: ${error.message}")
+                null
+            }
+        }
+    }
+}