Initialize CHIP stack before running app tests (#29092)

* Initialize CHIP stack before running app tests

* Patch add_entropy_source() to make it idempotent

* Do not add entropy source more than once

src/app/tests/AppTestContext.cpp

@@ -41,6 +41,7 @@ namespace Test {
 CHIP_ERROR AppContext::Init()
 {
     ReturnErrorOnFailure(Super::Init());
+    ReturnErrorOnFailure(chip::DeviceLayer::PlatformMgr().InitChipStack());
     ReturnErrorOnFailure(chip::app::InteractionModelEngine::GetInstance()->Init(&GetExchangeManager(), &GetFabricTable(),
                                                                                 app::reporting::GetDefaultReportScheduler()));
 
@@ -57,6 +58,7 @@ void AppContext::Shutdown()
     Access::ResetAccessControlToDefault();
 
     chip::app::InteractionModelEngine::GetInstance()->Shutdown();
+    chip::DeviceLayer::PlatformMgr().Shutdown();
     Super::Shutdown();
 }
 

src/crypto/CHIPCryptoPAL.h

@@ -967,6 +967,13 @@ CHIP_ERROR DRBG_get_bytes(uint8_t * out_buffer, size_t out_length);
 typedef int (*entropy_source)(void * data, uint8_t * output, size_t len, size_t * olen);
 
 /** @brief A function to add entropy sources to crypto library
+ *
+ * This function can be called multiple times to add multiple entropy sources. However,
+ * once the entropy source is added, it cannot be removed. Please make sure that the
+ * entropy source is valid for the lifetime of the application. Also, make sure that the
+ * same entropy source is not added multiple times, e.g.: by calling this function
+ * in class constructor or initialization function.
+ *
  * @param fn_source Function pointer to the entropy source
  * @param p_source  Data that should be provided when fn_source is called
  * @param threshold Minimum required from source before entropy is released

src/platform/Zephyr/PlatformManagerImpl.cpp

@@ -46,6 +46,7 @@ PlatformManagerImpl PlatformManagerImpl::sInstance{ sChipThreadStack };
 static k_timer sOperationalHoursSavingTimer;
 
 #if !defined(CONFIG_NORDIC_SECURITY_BACKEND) && !defined(CONFIG_MBEDTLS_ZEPHYR_ENTROPY)
+static bool sChipStackEntropySourceAdded = false;
 static int app_entropy_source(void * data, unsigned char * output, size_t len, size_t * olen)
 {
     const struct device * entropy = DEVICE_DT_GET(DT_CHOSEN(zephyr_entropy));
@@ -118,9 +119,13 @@ CHIP_ERROR PlatformManagerImpl::_InitChipStack(void)
     SuccessOrExit(err);
 
 #if !defined(CONFIG_NORDIC_SECURITY_BACKEND) && !defined(CONFIG_MBEDTLS_ZEPHYR_ENTROPY)
-    // Add entropy source based on Zephyr entropy driver
-    err = chip::Crypto::add_entropy_source(app_entropy_source, NULL, kThreshold);
-    SuccessOrExit(err);
+    if (!sChipStackEntropySourceAdded)
+    {
+        // Add entropy source based on Zephyr entropy driver
+        err = chip::Crypto::add_entropy_source(app_entropy_source, NULL, kThreshold);
+        SuccessOrExit(err);
+        sChipStackEntropySourceAdded = true;
+    }
 #endif // !defined(CONFIG_NORDIC_SECURITY_BACKEND) && !defined(CONFIG_MBEDTLS_ZEPHYR_ENTROPY)
 
     // Call _InitChipStack() on the generic implementation base class to finish the initialization process.