Merge pull request #3 from tectrolabs/add_device_validation_feature

Add device validation feature

Author: tectrolabs

mcrng/MicroRngSPI.cpp

@@ -1,5 +1,5 @@
 /**
- *   Copyright (C) 2014-2020 TectroLabs LLC, https://tectrolabs.com
+ *   Copyright (C) 2014-2022 TectroLabs LLC, https://tectrolabs.com
  *
  *    Permission is hereby granted, free of charge, to any person obtaining
  *    a copy of this software and associated documentation files (the "Software"),
@@ -23,8 +23,8 @@
 /**
  *    @file MicroRngSPI.cpp
  *    @author Andrian Belinski
- *    @date 04/21/2020
- *    @version 1.0
+ *    @date 06/07/2022
+ *    @version 1.1
  *
  *    @brief communicates with MicroRNG device through SPI interface on Raspberry PI 3+ or other Linux-based single-board computers.
  *
@@ -220,6 +220,41 @@ bool MicroRngSPI::executeCommand(char cmd, uint8_t *rx)
     return exhangeByte(cmd, rx);
 }
 
+/**
+ * Check to see if the MicroRNG device is actually responding to requests.
+ *
+ * @return true when validated successfully
+ */
+bool MicroRngSPI::validateDevice()
+{
+    if (!isConnected())
+    {
+        return false;
+    }
+
+    uint8_t beginTransactionID;
+    for (int i = 1; i <= 257; ++i)
+    {
+    	uint8_t transactionID;
+        if (!executeCommand('t', &transactionID))
+        {
+        	return false;
+        }
+
+    	if (i == 1)
+    	{
+    		beginTransactionID = transactionID;
+    	}
+
+        if ( i != 1 && transactionID != ++beginTransactionID)
+        {
+        	sprintf(lastError, "MicroRNG device not found");
+        	return false;
+        }
+    }
+    return true;
+}
+
 /**
  * Retrieve MicroRNG internal status.
  *

mcrng/MicroRngSPI.h

@@ -1,5 +1,5 @@
 /**
- *   Copyright (C) 2014-2020 TectroLabs LLC, https://tectrolabs.com
+ *   Copyright (C) 2014-2022 TectroLabs LLC, https://tectrolabs.com
  *
  *    Permission is hereby granted, free of charge, to any person obtaining
  *    a copy of this software and associated documentation files (the "Software"),
@@ -23,8 +23,8 @@
 /**
  *    @file MicroRngSPI.h
  *    @author Andrian Belinski
- *    @date 04/21/2020
- *    @version 1.0
+ *    @date 06/07/2022
+ *    @version 1.1
  *
  *    @brief communicates with MicroRNG device through SPI interface on Raspberry PI 3+ or other Linux-based single-board computers.
  *
@@ -53,6 +53,7 @@ class MicroRngSPI
     virtual ~MicroRngSPI();
     bool isConnected();
     bool connect(const char *devicePath);
+    bool validateDevice();
     bool disconnect();
     bool executeCommand(char cmd, uint8_t *rx);
     const char* getLastErrMsg();

mcrng/mcrng.cpp

@@ -1,5 +1,5 @@
 /**
- *   Copyright (C) 2014-2020 TectroLabs LLC, https://tectrolabs.com
+ *   Copyright (C) 2014-2022 TectroLabs LLC, https://tectrolabs.com
  *
  *    Permission is hereby granted, free of charge, to any person obtaining
  *    a copy of this software and associated documentation files (the "Software"),
@@ -23,8 +23,8 @@
 /**
  *    @file mcrng.cpp
  *    @author Andrian Belinski
- *    @date 04/21/2020
- *    @version 1.0
+ *    @date 06/-7/2022
+ *    @version 1.1
  *
  *    @brief downloads random bytes from MicroRNG device through SPI interface on Raspberry PI 3+ or other Linux-based single-board computers.
  *
@@ -220,15 +220,20 @@ int handleDownloadRequest()
 
     uint8_t receiveByteBuffer[MCR_BUFF_FILE_SIZE_BYTES];
 
-    bool status = spi.connect(devicePath);
-    if (!status)
+    if (!spi.connect(devicePath))
     {
         fprintf(stderr, " Cannot open SPI device %s, error: %s ... \n", devicePath, spi.getLastErrMsg());
         return -1;
     }
 
     spi.setMaxClockFrequency(maxSpiMasterClock);
 
+    if (!spi.validateDevice())
+    {
+        fprintf(stderr, " Cannot access device, error: %s ... \n", spi.getLastErrMsg());
+        return -1;
+    }
+
     if (filePathName == NULL)
     {
         fprintf(stderr, "No file name defined.\n");
@@ -253,8 +258,7 @@ int handleDownloadRequest()
     while (numGenBytes == -1)
     {
         // Infinite loop for downloading unlimited random bytes
-        status = spi.retrieveRandomBytes(MCR_BUFF_FILE_SIZE_BYTES, receiveByteBuffer);
-        if (!status)
+        if (!spi.retrieveRandomBytes(MCR_BUFF_FILE_SIZE_BYTES, receiveByteBuffer))
         {
             fprintf(stderr,
                     "Failed to receive %d bytes for unlimited download, error: %s. \n",
@@ -274,8 +278,7 @@ int handleDownloadRequest()
     int64_t chunkNum;
     for (chunkNum = 0; chunkNum < numCompleteChunks; chunkNum++)
     {
-        status = spi.retrieveRandomBytes(MCR_BUFF_FILE_SIZE_BYTES, receiveByteBuffer);
-        if (!status)
+        if (!spi.retrieveRandomBytes(MCR_BUFF_FILE_SIZE_BYTES, receiveByteBuffer))
         {
             fprintf(stderr, "Failed to receive %d bytes, error: %s. \n",
                     MCR_BUFF_FILE_SIZE_BYTES, spi.getLastErrMsg());
@@ -287,8 +290,7 @@ int handleDownloadRequest()
     if (chunkRemaindBytes > 0)
     {
         //Process incomplete chunk
-        status = spi.retrieveRandomBytes(chunkRemaindBytes, receiveByteBuffer);
-        if (!status)
+        if (!spi.retrieveRandomBytes(chunkRemaindBytes, receiveByteBuffer))
         {
             fprintf(stderr, "Failed to receive %d bytes for last chunk, error: code %s. ",
                     chunkRemaindBytes,spi.getLastErrMsg());

mcrng/sample.cpp

@@ -1,5 +1,5 @@
 /**
- *   Copyright (C) 2014-2020 TectroLabs LLC, https://tectrolabs.com
+ *   Copyright (C) 2014-2022 TectroLabs LLC, https://tectrolabs.com
  *
  *    Permission is hereby granted, free of charge, to any person obtaining
  *    a copy of this software and associated documentation files (the "Software"),
@@ -23,8 +23,8 @@
 /**
  *    @file sample.cpp
  *    @author Andrian Belinski
- *    @date 04/21/2020
- *    @version 1.0
+ *    @date 06/07/2022
+ *    @version 1.1
  *
  *    @brief a sample C program that demonstrates how to retrieve random bytes from MicroRNG device through SPI interface on Raspberry PI 3+ or other Linux-based single-board computers.
  *
@@ -49,23 +49,29 @@ int main(int argc, char **argv) {
 	printf("--------------------------------------------------------------------------\n");
 	printf("--- Sample C program for retrieving random bytes from MicroRNG device ----\n");
 	printf("---    Use with RPI 3+ or other Linux-based single-board computers     ---\n");
-    	printf("--------------------------------------------------------------------------\n");
+	printf("--------------------------------------------------------------------------\n");
 
-    	setbuf(stdout, NULL);
+	setbuf(stdout, NULL);
 
-    	if (argc < 2)
-    	{
-        	printf("Usage: sample <spi device>\n");
-        	printf("Example: sample /dev/spidev0.0\n");
-        	return -1;
-    	}
+	if (argc < 2)
+	{
+		printf("Usage: sample <spi device>\n");
+		printf("Example: sample /dev/spidev0.0\n");
+		return -1;
+	}
 
     	char *devicePath = argv[1];
 
 	if (!spi.connect(devicePath)) {
 		printf("%s\n", spi.getLastErrMsg());
 		return -1;
 	}
+
+	if (!spi.validateDevice()) {
+		printf("%s\n", spi.getLastErrMsg());
+		return -1;
+	}
+
 	printf("\nMicroRNG device open successfully, SPI clock frequency: %8ld Hz\n\n", (long)spi.getMaxClockFrequency());
 
 	// Retrieve random bytes from device