Bump backoffAlgorithm submodule for API change and update demos (#426)

The API of FreeRTOS/backoffAlgorithm library has changed to remove dependency on random number generator; instead require the caller to generate the random number and pass it to the BackoffAlgorithm_GetNextBackoff API for backoff period calculation. This PR updates the submodule pointer commit, and updates the demos and tests to use the simplied library API

9 files changed, 120 insertions, 286 deletions

diff --git a/FreeRTOS-Plus/Demo/AWS/Mqtt_Demo_Helpers/mqtt_demo_helpers.c b/FreeRTOS-Plus/Demo/AWS/Mqtt_Demo_Helpers/mqtt_demo_helpers.c
index 20c3b3e11..a2751e88b 100755
--- a/FreeRTOS-Plus/Demo/AWS/Mqtt_Demo_Helpers/mqtt_demo_helpers.c
+++ b/FreeRTOS-Plus/Demo/AWS/Mqtt_Demo_Helpers/mqtt_demo_helpers.c
@@ -359,15 +359,11 @@ static TlsTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkContext
     #endif
     xNetworkCredentials.pAlpnProtos = pcAlpnProtocols;
 
-    /* Initialize reconnect attempts and interval.
-     * Note: This utility uses a pseudo random number generator for use with the backoff
-     * algorithm. However, it is recommended to use a True Random Number generator to
-     * avoid possibility of collisions between multiple devices retrying connection. */
+    /* Initialize reconnect attempts and interval.*/
     BackoffAlgorithm_InitializeParams( &xReconnectParams,
                                        RETRY_BACKOFF_BASE_MS,
                                        RETRY_MAX_BACKOFF_DELAY_MS,
-                                       RETRY_MAX_ATTEMPTS,
-                                       prvGenerateRandomNumber );
+                                       RETRY_MAX_ATTEMPTS );
 
     /* Attempt to connect to MQTT broker. If connection fails, retry after
      * a timeout. Timeout value will exponentially increase until maximum
@@ -390,9 +386,12 @@ static TlsTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkContext
 
         if( xNetworkStatus != TLS_TRANSPORT_SUCCESS )
         {
-            /* Get back-off value (in milliseconds) for the next connection retry. */
-            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, &usNextRetryBackOff );
-            configASSERT( xBackoffAlgStatus != BackoffAlgorithmRngFailure );
+            /* Generate a random number and calculate backoff value (in milliseconds) for
+             * the next connection retry.
+             * Note: It is recommended to seed the random number generator with a device-specific
+             * entropy source so that possibility of multiple devices retrying failed network operations
+             * at similar intervals can be avoided. */
+            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, uxRand(), &usNextRetryBackOff );
 
             if( xBackoffAlgStatus == BackoffAlgorithmRetriesExhausted )
             {
diff --git a/FreeRTOS-Plus/Demo/coreHTTP_Windows_Simulator/Common/http_demo_utils.c b/FreeRTOS-Plus/Demo/coreHTTP_Windows_Simulator/Common/http_demo_utils.c
index 7ae825c7e..bbbbef353 100644
--- a/FreeRTOS-Plus/Demo/coreHTTP_Windows_Simulator/Common/http_demo_utils.c
+++ b/FreeRTOS-Plus/Demo/coreHTTP_Windows_Simulator/Common/http_demo_utils.c
@@ -59,31 +59,6 @@
 extern UBaseType_t uxRand();
 
 /*-----------------------------------------------------------*/
-
-/**
- * @brief A wrapper to the "uxRand()" random number generator so that it
- * can be passed to the backoffAlgorithm library for retry logic.
- *
- * This function implements the #BackoffAlgorithm_RNG_T type interface
- * in the backoffAlgorithm library API.
- *
- * @note The "uxRand" function represents a pseudo random number generator.
- * However, it is recommended to use a True Randon Number Generator (TRNG)
- * for generating unique device-specific random values to avoid possibility
- * of network collisions from multiple devices retrying network operations.
- *
- * @return The generated randon number. This function ALWAYS succeeds.
- */
-static int32_t prvGenerateRandomNumber();
-
-/*-----------------------------------------------------------*/
-
-static int32_t prvGenerateRandomNumber()
-{
-    return( uxRand() & INT32_MAX );
-}
-
-/*-----------------------------------------------------------*/
 BaseType_t connectToServerWithBackoffRetries( TransportConnect_t connectFunction,
                                               NetworkContext_t * pxNetworkContext )
 {
@@ -100,8 +75,7 @@ BaseType_t connectToServerWithBackoffRetries( TransportConnect_t connectFunction
     BackoffAlgorithm_InitializeParams( &xReconnectParams,
                                        RETRY_BACKOFF_BASE_MS,
                                        RETRY_MAX_BACKOFF_DELAY_MS,
-                                       RETRY_MAX_ATTEMPTS,
-                                       prvGenerateRandomNumber );
+                                       RETRY_MAX_ATTEMPTS );
 
     /* Attempt to connect to the HTTP server. If connection fails, retry after a
      * timeout. The timeout value will exponentially increase until either the
@@ -118,7 +92,13 @@ BaseType_t connectToServerWithBackoffRetries( TransportConnect_t connectFunction
             LogInfo( ( "Retry attempt %lu out of maximum retry attempts %lu.",
                        ( xReconnectParams.attemptsDone + 1 ),
                        RETRY_MAX_ATTEMPTS ) );
-            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, &usNextBackoff );
+
+            /* Generate a random number and calculate backoff value (in milliseconds) for
+             * the next connection retry.
+             * Note: It is recommended to seed the random number generator with a device-specific
+             * entropy source so that possibility of multiple devices retrying failed network operations
+             * at similar intervals can be avoided. */
+            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, uxRand(), &usNextBackoff );
         }
     } while( ( xReturn == pdFAIL ) && ( xBackoffAlgStatus == BackoffAlgorithmSuccess ) );
 
diff --git a/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Basic_TLS/DemoTasks/BasicTLSMQTTExample.c b/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Basic_TLS/DemoTasks/BasicTLSMQTTExample.c
index d797f2743..473f5b2ec 100644
--- a/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Basic_TLS/DemoTasks/BasicTLSMQTTExample.c
+++ b/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Basic_TLS/DemoTasks/BasicTLSMQTTExample.c
@@ -1,5 +1,5 @@
 /*
- * FreeRTOS Kernel V10.3.0
+ * FreeRTOS V202011.00
  * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
@@ -19,8 +19,8 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
- * http://www.FreeRTOS.org
- * http://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
  *
  */
 
@@ -193,21 +193,6 @@
  */
 static void prvMQTTDemoTask( void * pvParameters );
 
-/**
- * @brief A wrapper to the "uxRand()" random number generator so that it
- * can be passed to the backoffAlgorithm library for retry logic.
- *
- * This function implements the #BackoffAlgorithm_RNG_T type interface
- * in the backoffAlgorithm library API.
- *
- * @note The "uxRand" function represents a pseudo random number generator.
- * However, it is recommended to use a True Randon Number Generator (TRNG)
- * for generating unique device-specific random values to avoid possibility
- * of network collisions from multiple devices retrying network operations.
- *
- * @return The generated randon number. This function ALWAYS succeeds.
- */
-static int32_t prvGenerateRandomNumber();
 
 /**
  * @brief Connect to MQTT broker with reconnection retries.
@@ -508,13 +493,6 @@ static void prvMQTTDemoTask( void * pvParameters )
 }
 /*-----------------------------------------------------------*/
 
-static int32_t prvGenerateRandomNumber()
-{
-    return( uxRand() & INT32_MAX );
-}
-
-/*-----------------------------------------------------------*/
-
 static TlsTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkCredentials_t * pxNetworkCredentials,
                                                                   NetworkContext_t * pxNetworkContext )
 {
@@ -528,15 +506,11 @@ static TlsTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkCredent
     pxNetworkCredentials->rootCaSize = sizeof( democonfigROOT_CA_PEM );
     pxNetworkCredentials->disableSni = democonfigDISABLE_SNI;
 
-    /* Initialize reconnect attempts and interval.
-     * Note: This demo is using pseudo random number generator for the backoff
-     * algorithm. However, it is recommended to use a True Random Number generator to
-     * avoid possibility of collisions between multiple devices retrying connection. */
+    /* Initialize reconnect attempts and interval.*/
     BackoffAlgorithm_InitializeParams( &xReconnectParams,
                                        mqttexampleRETRY_BACKOFF_BASE_MS,
                                        mqttexampleRETRY_MAX_BACKOFF_DELAY_MS,
-                                       mqttexampleRETRY_MAX_ATTEMPTS,
-                                       prvGenerateRandomNum );
+                                       mqttexampleRETRY_MAX_ATTEMPTS );
 
     /* Attempt to connect to the MQTT broker. If connection fails, retry after
      * a timeout. Timeout value will exponentially increase until maximum
@@ -560,9 +534,9 @@ static TlsTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkCredent
 
         if( xNetworkStatus != TLS_TRANSPORT_SUCCESS )
         {
-            /* Get back-off value (in milliseconds) for the next connection retry. */
-            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, &usNextRetryBackOff );
-            configASSERT( xBackoffAlgStatus != BackoffAlgorithmRngFailure );
+            /* Generate a random number and calculate backoff value (in milliseconds) for
+             * the next connection retry. */
+            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, uxRand(), &usNextRetryBackOff );
 
             if( xBackoffAlgStatus == BackoffAlgorithmRetriesExhausted )
             {
@@ -678,15 +652,11 @@ static void prvMQTTSubscribeWithBackoffRetries( MQTTContext_t * pxMQTTContext )
     xMQTTSubscription[ 0 ].pTopicFilter = mqttexampleTOPIC;
     xMQTTSubscription[ 0 ].topicFilterLength = ( uint16_t ) strlen( mqttexampleTOPIC );
 
-    /* Initialize context for backoff retry attempts if SUBSCRIBE request fails.
-     * Note: This demo is using pseudo random number generator for the backoff
-     * algorithm. However, it is recommended to use a True Random Number generator to
-     * avoid possibility of collisions between multiple devices retrying network operations. */
+    /* Initialize context for backoff retry attempts if SUBSCRIBE request fails. */
     BackoffAlgorithm_InitializeParams( &xRetryParams,
                                        mqttexampleRETRY_BACKOFF_BASE_MS,
                                        mqttexampleRETRY_MAX_BACKOFF_DELAY_MS,
-                                       mqttexampleRETRY_MAX_ATTEMPTS,
-                                       prvGenerateRandomNum );
+                                       mqttexampleRETRY_MAX_ATTEMPTS );
 
     do
     {
@@ -729,9 +699,12 @@ static void prvMQTTSubscribeWithBackoffRetries( MQTTContext_t * pxMQTTContext )
             {
                 xFailedSubscribeToTopic = true;
 
-                /* Get back-off value (in milliseconds) for the next connection retry. */
-                xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xRetryParams, &usNextRetryBackOff );
-                configASSERT( xBackoffAlgStatus != BackoffAlgorithmRngFailure );
+                /* Generate a random number and calculate backoff value (in milliseconds) for
+                 * the next connection retry.
+                 * Note: It is recommended to seed the random number generator with a device-specific
+                 * entropy source so that possibility of multiple devices retrying failed network operations
+                 * at similar intervals can be avoided. */
+                xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xRetryParams, uxRand(), &usNextRetryBackOff );
 
                 if( xBackoffAlgStatus == BackoffAlgorithmRetriesExhausted )
                 {
diff --git a/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Keep_Alive/DemoTasks/KeepAliveMQTTExample.c b/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Keep_Alive/DemoTasks/KeepAliveMQTTExample.c
index aade4aece..5e1673fca 100644
--- a/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Keep_Alive/DemoTasks/KeepAliveMQTTExample.c
+++ b/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Keep_Alive/DemoTasks/KeepAliveMQTTExample.c
@@ -1,5 +1,5 @@
 /*
- * FreeRTOS Kernel V10.3.0
+ * FreeRTOS V202011.00
  * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
@@ -19,8 +19,8 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
- * http://www.FreeRTOS.org
- * http://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
  *
  */
 
@@ -215,21 +215,6 @@
  */
 static void prvMQTTDemoTask( void * pvParameters );
 
-/**
- * @brief A wrapper to the "uxRand()" random number generator so that it
- * can be passed to the backoffAlgorithm library for retry logic.
- *
- * This function implements the #BackoffAlgorithm_RNG_T type interface
- * in the backoffAlgorithm library API.
- *
- * @note The "uxRand" function represents a pseudo random number generator.
- * However, it is recommended to use a True Randon Number Generator (TRNG)
- * for generating unique device-specific random values to avoid possibility
- * of network collisions from multiple devices retrying network operations.
- *
- * @return The generated randon number. This function ALWAYS succeeds.
- */
-static int32_t prvGenerateRandomNumber();
 
 /**
  * @brief Connect to MQTT broker with reconnection retries.
@@ -634,13 +619,6 @@ static void prvMQTTDemoTask( void * pvParameters )
 }
 /*-----------------------------------------------------------*/
 
-static int32_t prvGenerateRandomNumber()
-{
-    return( uxRand() & INT32_MAX );
-}
-
-/*-----------------------------------------------------------*/
-
 static PlaintextTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkContext_t * pxNetworkContext )
 {
     PlaintextTransportStatus_t xNetworkStatus;
@@ -648,15 +626,11 @@ static PlaintextTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkC
     BackoffAlgorithmContext_t xReconnectParams;
     uint16_t usNextRetryBackOff = 0U;
 
-    /* Initialize reconnect attempts and interval.
-     * Note: This demo is using pseudo random number generator for the backoff
-     * algorithm. However, it is recommended to use a True Random Number generator to
-     * avoid possibility of collisions between multiple devices retrying connection. */
+    /* Initialize reconnect attempts and interval. */
     BackoffAlgorithm_InitializeParams( &xReconnectParams,
                                        mqttexampleRETRY_BACKOFF_BASE_MS,
                                        mqttexampleRETRY_MAX_BACKOFF_DELAY_MS,
-                                       mqttexampleRETRY_MAX_ATTEMPTS,
-                                       prvGenerateRandomNumber );
+                                       mqttexampleRETRY_MAX_ATTEMPTS );
 
     /* Attempt to connect to MQTT broker. If connection fails, retry after
      * a timeout. Timeout value will exponentially increase till maximum
@@ -678,9 +652,12 @@ static PlaintextTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkC
 
         if( xNetworkStatus != PLAINTEXT_TRANSPORT_SUCCESS )
         {
-            /* Get back-off value (in milliseconds) for the next connection retry. */
-            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, &usNextRetryBackOff );
-            configASSERT( xBackoffAlgStatus != BackoffAlgorithmRngFailure );
+            /* Generate a random number and calculate backoff value (in milliseconds) for
+             * the next connection retry.
+             * Note: It is recommended to seed the random number generator with a device-specific
+             * entropy source so that possibility of multiple devices retrying failed network operations
+             * at similar intervals can be avoided. */
+            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, uxRand(), &usNextRetryBackOff );
 
             if( xBackoffAlgStatus == BackoffAlgorithmRetriesExhausted )
             {
@@ -796,15 +773,11 @@ static void prvMQTTSubscribeWithBackoffRetries( MQTTContext_t * pxMQTTContext )
     xMQTTSubscription[ 0 ].pTopicFilter = mqttexampleTOPIC;
     xMQTTSubscription[ 0 ].topicFilterLength = ( uint16_t ) strlen( mqttexampleTOPIC );
 
-    /* Initialize context for backoff retry attempts if SUBSCRIBE request fails.
-     * Note: This demo is using pseudo random number generator for the backoff
-     * algorithm. However, it is recommended to use a True Random Number generator to
-     * avoid possibility of collisions between multiple devices retrying network operations. */
+    /* Initialize context for backoff retry attempts if SUBSCRIBE request fails. */
     BackoffAlgorithm_InitializeParams( &xRetryParams,
                                        mqttexampleRETRY_BACKOFF_BASE_MS,
                                        mqttexampleRETRY_MAX_BACKOFF_DELAY_MS,
-                                       mqttexampleRETRY_MAX_ATTEMPTS,
-                                       prvGenerateRandomNumber );
+                                       mqttexampleRETRY_MAX_ATTEMPTS );
 
     do
     {
@@ -864,9 +837,12 @@ static void prvMQTTSubscribeWithBackoffRetries( MQTTContext_t * pxMQTTContext )
             {
                 xFailedSubscribeToTopic = true;
 
-                /* Get back-off value (in milliseconds) for the next connection retry. */
-                xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xRetryParams, &usNextRetryBackOff );
-                configASSERT( xBackoffAlgStatus != BackoffAlgorithmRngFailure );
+                /* Generate a random number and calculate backoff value (in milliseconds) for
+                 * the next connection retry.
+                 * Note: It is recommended to seed the random number generator with a device-specific
+                 * entropy source so that possibility of multiple devices retrying failed network operations
+                 * at similar intervals can be avoided. */
+                xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xRetryParams, uxRand(), &usNextRetryBackOff );
 
                 if( xBackoffAlgStatus == BackoffAlgorithmRetriesExhausted )
                 {
diff --git a/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Multitask/DemoTasks/MultitaskMQTTExample.c b/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Multitask/DemoTasks/MultitaskMQTTExample.c
index d4cd4f96b..afabdeeb7 100644
--- a/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Multitask/DemoTasks/MultitaskMQTTExample.c
+++ b/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Multitask/DemoTasks/MultitaskMQTTExample.c
@@ -1,5 +1,5 @@
 /*
- * FreeRTOS Kernel V10.3.0
+ * FreeRTOS V202011.00
  * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
@@ -19,8 +19,9 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
- * http://www.FreeRTOS.org
- * http://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
+ *
  */
 
 /*
@@ -409,21 +410,6 @@ static MQTTStatus_t prvMQTTConnect( MQTTContext_t * pxMQTTContext,
  */
 static MQTTStatus_t prvResumeSession( bool xSessionPresent );
 
-/**
- * @brief A wrapper to the "uxRand()" random number generator so that it
- * can be passed to the backoffAlgorithm library for retry logic.
- *
- * This function implements the #BackoffAlgorithm_RNG_T type interface
- * in the backoffAlgorithm library API.
- *
- * @note The "uxRand" function represents a pseudo random number generator.
- * However, it is recommended to use a True Randon Number Generator (TRNG)
- * for generating unique device-specific random values to avoid possibility
- * of network collisions from multiple devices retrying network operations.
- *
- * @return The generated randon number. This function ALWAYS succeeds.
- */
-static int32_t prvGenerateRandomNumber();
 
 /**
  * @brief Form a TCP connection to a server.
@@ -988,13 +974,6 @@ static MQTTStatus_t prvResumeSession( bool xSessionPresent )
 
 /*-----------------------------------------------------------*/
 
-static int32_t prvGenerateRandomNumber()
-{
-    return( uxRand() & INT32_MAX );
-}
-
-/*-----------------------------------------------------------*/
-
 static BaseType_t prvSocketConnect( NetworkContext_t * pxNetworkContext )
 {
     BaseType_t xConnected = pdFAIL;
@@ -1037,15 +1016,11 @@ static BaseType_t prvSocketConnect( NetworkContext_t * pxNetworkContext )
     #endif /* if defined( democonfigUSE_TLS ) && ( democonfigUSE_TLS == 1 ) */
 
     /* We will use a retry mechanism with an exponential backoff mechanism and
-     * jitter. We initialize the context required for backoff period calculation here.
-     * Note: This demo is using pseudo random number generator for the backoff
-     * algorithm. However, it is recommended to use a True Random Number generator to
-     * avoid possibility of collisions between multiple devices retrying connection. */
+     * jitter. We initialize the context required for backoff period calculation here. */
     BackoffAlgorithm_InitializeParams( &xReconnectParams,
                                        mqttexampleRETRY_BACKOFF_BASE_MS,
                                        mqttexampleRETRY_MAX_BACKOFF_DELAY_MS,
-                                       mqttexampleRETRY_MAX_ATTEMPTS,
-                                       prvGenerateRandomNumber );
+                                       mqttexampleRETRY_MAX_ATTEMPTS );
 
     /* Attempt to connect to MQTT broker. If connection fails, retry after a
      * timeout. Timeout value will exponentially increase until the maximum
@@ -1081,9 +1056,12 @@ static BaseType_t prvSocketConnect( NetworkContext_t * pxNetworkContext )
 
         if( !xConnected )
         {
-            /* Get back-off value (in milliseconds) for the next connection retry. */
-            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, &usNextRetryBackOff );
-            configASSERT( xBackoffAlgStatus != BackoffAlgorithmRngFailure );
+            /* Generate a random number and calculate backoff value (in milliseconds) for
+             * the next connection retry.
+             * Note: It is recommended to seed the random number generator with a device-specific
+             * entropy source so that possibility of multiple devices retrying failed network operations
+             * at similar intervals can be avoided. */
+            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, uxRand(), &usNextRetryBackOff );
 
             if( xBackoffAlgStatus == BackoffAlgorithmRetriesExhausted )
             {
diff --git a/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Mutual_Auth/DemoTasks/MutualAuthMQTTExample.c b/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Mutual_Auth/DemoTasks/MutualAuthMQTTExample.c
index 785b52c2d..ddc94a2b8 100644
--- a/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Mutual_Auth/DemoTasks/MutualAuthMQTTExample.c
+++ b/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Mutual_Auth/DemoTasks/MutualAuthMQTTExample.c
@@ -1,5 +1,5 @@
 /*
- * FreeRTOS Kernel V10.3.0
+ * FreeRTOS V202011.00
  * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
@@ -19,8 +19,8 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
- * http://www.FreeRTOS.org
- * http://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
  *
  */
 
@@ -282,21 +282,6 @@
  */
 static void prvMQTTDemoTask( void * pvParameters );
 
-/**
- * @brief A wrapper to the "uxRand()" random number generator so that it
- * can be passed to the backoffAlgorithm library for retry logic.
- *
- * This function implements the #BackoffAlgorithm_RNG_T type interface
- * in the backoffAlgorithm library API.
- *
- * @note The "uxRand" function represents a pseudo random number generator.
- * However, it is recommended to use a True Randon Number Generator (TRNG)
- * for generating unique device-specific random values to avoid possibility
- * of network collisions from multiple devices retrying network operations.
- *
- * @return The generated randon number. This function ALWAYS succeeds.
- */
-static int32_t prvGenerateRandomNumber();
 
 /**
  * @brief Connect to MQTT broker with reconnection retries.
@@ -590,13 +575,6 @@ static void prvMQTTDemoTask( void * pvParameters )
 }
 /*-----------------------------------------------------------*/
 
-static int32_t prvGenerateRandomNumber()
-{
-    return( uxRand() & INT32_MAX );
-}
-
-/*-----------------------------------------------------------*/
-
 static TlsTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkCredentials_t * pxNetworkCredentials,
                                                                   NetworkContext_t * pxNetworkContext )
 {
@@ -632,15 +610,11 @@ static TlsTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkCredent
         pxNetworkCredentials->privateKeySize = sizeof( democonfigCLIENT_PRIVATE_KEY_PEM );
     #endif
 
-    /* Initialize reconnect attempts and interval.
-     * Note: This demo is using pseudo random number generator for the backoff
-     * algorithm. However, it is recommended to use a True Random Number generator to
-     * avoid possibility of collisions between multiple devices retrying connection. */
+    /* Initialize reconnect attempts and interval. */
     BackoffAlgorithm_InitializeParams( &xReconnectParams,
                                        mqttexampleRETRY_BACKOFF_BASE_MS,
                                        mqttexampleRETRY_MAX_BACKOFF_DELAY_MS,
-                                       mqttexampleRETRY_MAX_ATTEMPTS,
-                                       prvGenerateRandomNumber );
+                                       mqttexampleRETRY_MAX_ATTEMPTS );
 
     /* Attempt to connect to MQTT broker. If connection fails, retry after
      * a timeout. Timeout value will exponentially increase till maximum
@@ -664,9 +638,12 @@ static TlsTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkCredent
 
         if( xNetworkStatus != TLS_TRANSPORT_SUCCESS )
         {
-            /* Get back-off value (in milliseconds) for the next connection retry. */
-            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, &usNextRetryBackOff );
-            configASSERT( xBackoffAlgStatus != BackoffAlgorithmRngFailure );
+            /* Generate a random number and calculate backoff value (in milliseconds) for
+             * the next connection retry.
+             * Note: It is recommended to seed the random number generator with a device-specific
+             * entropy source so that possibility of multiple devices retrying failed network operations
+             * at similar intervals can be avoided. */
+            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, uxRand(), &usNextRetryBackOff );
 
             if( xBackoffAlgStatus == BackoffAlgorithmRetriesExhausted )
             {
@@ -805,15 +782,11 @@ static void prvMQTTSubscribeWithBackoffRetries( MQTTContext_t * pxMQTTContext )
     xMQTTSubscription[ 0 ].pTopicFilter = mqttexampleTOPIC;
     xMQTTSubscription[ 0 ].topicFilterLength = ( uint16_t ) strlen( mqttexampleTOPIC );
 
-    /* Initialize context for backoff retry attempts if SUBSCRIBE request fails.
-     * Note: This demo is using pseudo random number generator for the backoff
-     * algorithm. However, it is recommended to use a True Random Number generator to
-     * avoid possibility of collisions between multiple devices retrying network operations. */
+    /* Initialize context for backoff retry attempts if SUBSCRIBE request fails. */
     BackoffAlgorithm_InitializeParams( &xRetryParams,
                                        mqttexampleRETRY_BACKOFF_BASE_MS,
                                        mqttexampleRETRY_MAX_BACKOFF_DELAY_MS,
-                                       mqttexampleRETRY_MAX_ATTEMPTS,
-                                       prvGenerateRandomNumber );
+                                       mqttexampleRETRY_MAX_ATTEMPTS );
 
     do
     {
@@ -856,9 +829,12 @@ static void prvMQTTSubscribeWithBackoffRetries( MQTTContext_t * pxMQTTContext )
             {
                 xFailedSubscribeToTopic = true;
 
-                /* Get back-off value (in milliseconds) for the next connection retry. */
-                xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xRetryParams, &usNextRetryBackOff );
-                configASSERT( xBackoffAlgStatus != BackoffAlgorithmRngFailure );
+                /* Generate a random number and calculate backoff value (in milliseconds) for
+                 * the next connection retry.
+                 * Note: It is recommended to seed the random number generator with a device-specific
+                 * entropy source so that possibility of multiple devices retrying failed network operations
+                 * at similar intervals can be avoided. */
+                xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xRetryParams, uxRand(), &usNextRetryBackOff );
 
                 if( xBackoffAlgStatus == BackoffAlgorithmRetriesExhausted )
                 {
diff --git a/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Plain_Text/DemoTasks/PlaintextMQTTExample.c b/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Plain_Text/DemoTasks/PlaintextMQTTExample.c
index da3975c76..a9f8fb95c 100644
--- a/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Plain_Text/DemoTasks/PlaintextMQTTExample.c
+++ b/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Plain_Text/DemoTasks/PlaintextMQTTExample.c
@@ -1,5 +1,5 @@
 /*
- * FreeRTOS Kernel V10.3.0
+ * FreeRTOS V202011.00
  * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
@@ -19,8 +19,8 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
- * http://www.FreeRTOS.org
- * http://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
  *
  */
 
@@ -184,21 +184,6 @@
  */
 static void prvMQTTDemoTask( void * pvParameters );
 
-/**
- * @brief A wrapper to the "uxRand()" random number generator so that it
- * can be passed to the backoffAlgorithm library for retry logic.
- *
- * This function implements the #BackoffAlgorithm_RNG_T type interface
- * in the backoffAlgorithm library API.
- *
- * @note The "uxRand" function represents a pseudo random number generator.
- * However, it is recommended to use a True Randon Number Generator (TRNG)
- * for generating unique device-specific random values to avoid possibility
- * of network collisions from multiple devices retrying network operations.
- *
- * @return The generated randon number. This function ALWAYS succeeds.
- */
-static int32_t prvGenerateRandomNumber();
 
 /**
  * @brief Connect to MQTT broker with reconnection retries.
@@ -468,13 +453,6 @@ static void prvMQTTDemoTask( void * pvParameters )
 }
 /*-----------------------------------------------------------*/
 
-static int32_t prvGenerateRandomNumber()
-{
-    return( uxRand() & INT32_MAX );
-}
-
-/*-----------------------------------------------------------*/
-
 static PlaintextTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkContext_t * pxNetworkContext )
 {
     PlaintextTransportStatus_t xNetworkStatus;
@@ -482,15 +460,11 @@ static PlaintextTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkC
     BackoffAlgorithmContext_t xReconnectParams;
     uint16_t usNextRetryBackOff = 0U;
 
-    /* Initialize reconnect attempts and interval.
-     * Note: This demo is using pseudo random number generator for the backoff
-     * algorithm. However, it is recommended to use a True Random Number generator to
-     * avoid possibility of collisions between multiple devices retrying connection. */
+    /* Initialize reconnect attempts and interval.*/
     BackoffAlgorithm_InitializeParams( &xReconnectParams,
                                        mqttexampleRETRY_BACKOFF_BASE_MS,
                                        mqttexampleRETRY_MAX_BACKOFF_DELAY_MS,
-                                       mqttexampleRETRY_MAX_ATTEMPTS,
-                                       prvGenerateRandomNumber );
+                                       mqttexampleRETRY_MAX_ATTEMPTS );
 
     /* Attempt to connect to MQTT broker. If connection fails, retry after
      * a timeout. Timeout value will exponentially increase till maximum
@@ -512,9 +486,12 @@ static PlaintextTransportStatus_t prvConnectToServerWithBackoffRetries( NetworkC
 
         if( xNetworkStatus != PLAINTEXT_TRANSPORT_SUCCESS )
         {
-            /* Get back-off value (in milliseconds) for the next connection retry. */
-            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, &usNextRetryBackOff );
-            configASSERT( xBackoffAlgStatus != BackoffAlgorithmRngFailure );
+            /* Generate a random number and calculate backoff value (in milliseconds) for
+             * the next connection retry.
+             * Note: It is recommended to seed the random number generator with a device-specific
+             * entropy source so that possibility of multiple devices retrying failed network operations
+             * at similar intervals can be avoided. */
+            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, uxRand(), &usNextRetryBackOff );
 
             if( xBackoffAlgStatus == BackoffAlgorithmRetriesExhausted )
             {
@@ -628,15 +605,11 @@ static void prvMQTTSubscribeWithBackoffRetries( MQTTContext_t * pxMQTTContext )
     xMQTTSubscription[ 0 ].pTopicFilter = mqttexampleTOPIC;
     xMQTTSubscription[ 0 ].topicFilterLength = ( uint16_t ) strlen( mqttexampleTOPIC );
 
-    /* Initialize context for backoff retry attempts if SUBSCRIBE request fails.
-     * Note: This demo is using pseudo random number generator for the backoff
-     * algorithm. However, it is recommended to use a True Random Number generator to
-     * avoid possibility of collisions between multiple devices retrying network operations. */
+    /* Initialize context for backoff retry attempts if SUBSCRIBE request fails. */
     BackoffAlgorithm_InitializeParams( &xRetryParams,
                                        mqttexampleRETRY_BACKOFF_BASE_MS,
                                        mqttexampleRETRY_MAX_BACKOFF_DELAY_MS,
-                                       mqttexampleRETRY_MAX_ATTEMPTS,
-                                       prvGenerateRandomNumber );
+                                       mqttexampleRETRY_MAX_ATTEMPTS );
 
     do
     {
@@ -679,9 +652,12 @@ static void prvMQTTSubscribeWithBackoffRetries( MQTTContext_t * pxMQTTContext )
             {
                 xFailedSubscribeToTopic = true;
 
-                /* Get back-off value (in milliseconds) for the next connection retry. */
-                xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xRetryParams, &usNextRetryBackOff );
-                configASSERT( xBackoffAlgStatus != BackoffAlgorithmRngFailure );
+                /* Generate a random number and calculate backoff value (in milliseconds) for
+                 * the next connection retry.
+                 * Note: It is recommended to seed the random number generator with a device-specific
+                 * entropy source so that possibility of multiple devices retrying failed network operations
+                 * at similar intervals can be avoided. */
+                xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xRetryParams, uxRand(), &usNextRetryBackOff );
 
                 if( xBackoffAlgStatus == BackoffAlgorithmRetriesExhausted )
                 {
diff --git a/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Serializer/DemoTasks/SerializerMQTTExample.c b/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Serializer/DemoTasks/SerializerMQTTExample.c
index b705eb5b8..1ea4eebec 100644
--- a/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Serializer/DemoTasks/SerializerMQTTExample.c
+++ b/FreeRTOS-Plus/Demo/coreMQTT_Windows_Simulator/MQTT_Serializer/DemoTasks/SerializerMQTTExample.c
@@ -1,5 +1,5 @@
 /*
- * FreeRTOS Kernel V10.3.0
+ * FreeRTOS V202011.00
  * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
@@ -19,8 +19,8 @@
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
- * http://www.FreeRTOS.org
- * http://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
  *
  */
 
@@ -189,21 +189,6 @@ static void prvMQTTDemoTask( void * pvParameters );
  */
 static Socket_t prvCreateTCPConnectionToBroker( void );
 
-/**
- * @brief A wrapper to the "uxRand()" random number generator so that it
- * can be passed to the backoffAlgorithm library for retry logic.
- *
- * This function implements the #BackoffAlgorithm_RNG_T type interface
- * in the backoffAlgorithm library API.
- *
- * @note The "uxRand" function represents a pseudo random number generator.
- * However, it is recommended to use a True Randon Number Generator (TRNG)
- * for generating unique device-specific random values to avoid possibility
- * of network collisions from multiple devices retrying network operations.
- *
- * @return The generated randon number. This function ALWAYS succeeds.
- */
-static int32_t prvGenerateRandomNumber();
 
 /**
  * @brief Connect to MQTT broker with reconnection retries.
@@ -643,13 +628,6 @@ static Socket_t prvCreateTCPConnectionToBroker( void )
 }
 /*-----------------------------------------------------------*/
 
-static int32_t prvGenerateRandomNumber()
-{
-    return( uxRand() & INT32_MAX );
-}
-
-/*-----------------------------------------------------------*/
-
 static Socket_t prvConnectToServerWithBackoffRetries()
 {
     Socket_t xSocket;
@@ -657,15 +635,11 @@ static Socket_t prvConnectToServerWithBackoffRetries()
     BackoffAlgorithmContext_t xReconnectParams;
     uint16_t usNextRetryBackOff = 0U;
 
-    /* Initialize reconnect attempts and interval.
-     * Note: This demo is using pseudo random number generator for the backoff
-     * algorithm. However, it is recommended to use a True Random Number generator to
-     * avoid possibility of collisions between multiple devices retrying connection. */
+    /* Initialize reconnect attempts and interval.*/
     BackoffAlgorithm_InitializeParams( &xReconnectParams,
                                        mqttexampleRETRY_BACKOFF_BASE_MS,
                                        mqttexampleRETRY_MAX_BACKOFF_DELAY_MS,
-                                       mqttexampleRETRY_MAX_ATTEMPTS,
-                                       prvGenerateRandomNumber );
+                                       mqttexampleRETRY_MAX_ATTEMPTS );
 
     /* Attempt to connect to MQTT broker. If connection fails, retry after
      * a timeout. Timeout value will exponentially increase till maximum
@@ -683,9 +657,12 @@ static Socket_t prvConnectToServerWithBackoffRetries()
 
         if( xSocket == FREERTOS_INVALID_SOCKET )
         {
-            /* Get back-off value (in milliseconds) for the next connection retry. */
-            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, &usNextRetryBackOff );
-            configASSERT( xBackoffAlgStatus != BackoffAlgorithmRngFailure );
+            /* Generate a random number and calculate backoff value (in milliseconds) for
+             * the next connection retry.
+             * Note: It is recommended to seed the random number generator with a device-specific
+             * entropy source so that possibility of multiple devices retrying failed network operations
+             * at similar intervals can be avoided. */
+            xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xReconnectParams, uxRand(), &usNextRetryBackOff );
 
             if( xBackoffAlgStatus == BackoffAlgorithmRetriesExhausted )
             {
@@ -870,15 +847,11 @@ static void prvMQTTSubscribeWithBackoffRetries( Socket_t xMQTTSocket )
     uint16_t usNextRetryBackOff = 0U;
     bool xFailedSubscribeToTopic = false;
 
-    /* Initialize context for backoff retry attempts if SUBSCRIBE request fails.
-     * Note: This demo is using pseudo random number generator for the backoff
-     * algorithm. However, it is recommended to use a True Random Number generator to
-     * avoid possibility of collisions between multiple devices retrying network operations. */
+    /* Initialize context for backoff retry attempts if SUBSCRIBE request fails. */
     BackoffAlgorithm_InitializeParams( &xRetryParams,
                                        mqttexampleRETRY_BACKOFF_BASE_MS,
                                        mqttexampleRETRY_MAX_BACKOFF_DELAY_MS,
-                                       mqttexampleRETRY_MAX_ATTEMPTS,
-                                       prvGenerateRandomNumber );
+                                       mqttexampleRETRY_MAX_ATTEMPTS );
 
     do
     {
@@ -916,9 +889,12 @@ static void prvMQTTSubscribeWithBackoffRetries( Socket_t xMQTTSocket )
             {
                 xFailedSubscribeToTopic = true;
 
-                /* Get back-off value (in milliseconds) for the next connection retry. */
-                xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xRetryParams, &usNextRetryBackOff );
-                configASSERT( xBackoffAlgStatus != BackoffAlgorithmRngFailure );
+                /* Generate a random number and calculate backoff value (in milliseconds) for
+                 * the next connection retry.
+                 * Note: It is recommended to seed the random number generator with a device-specific
+                 * entropy source so that possibility of multiple devices retrying failed network operations
+                 * at similar intervals can be avoided. */
+                xBackoffAlgStatus = BackoffAlgorithm_GetNextBackoff( &xRetryParams, uxRand(), &usNextRetryBackOff );
 
                 if( xBackoffAlgStatus == BackoffAlgorithmRetriesExhausted )
                 {
diff --git a/FreeRTOS-Plus/Source/Utilities/backoff_algorithm b/FreeRTOS-Plus/Source/Utilities/backoff_algorithm
-Subproject bc5ce2ed93ac063d75a4d3661e5253477c4e4fe
+Subproject 8a9a6654296a3b478785eb5de4025b6d073a1ec