Added FIPS 140-2 sanity check to usbtrng-v2.0

3 files changed, 143 insertions, 4 deletions

diff --git a/src/drivers/ao_trng.c b/src/drivers/ao_trng.c
index db742928..b8e25e28 100644
--- a/src/drivers/ao_trng.c
+++ b/src/drivers/ao_trng.c
@@ -20,6 +20,120 @@
 #include <ao_crc.h>
 #include <ao_trng.h>
 
+
+static struct ao_task ao_blink_red_task;
+static uint8_t ao_failed = 0;
+
+static void
+ao_blink_red(void)
+{
+	for (;;) {
+		while (!ao_failed)
+			ao_sleep(&ao_failed);
+		while (ao_failed) {
+			ao_led_toggle(AO_LED_RED);
+			ao_delay(AO_MS_TO_TICKS(500));
+		}
+	}
+}
+
+static struct ao_task ao_blink_green_task;
+static uint8_t ao_blinking_green = 0;
+
+static void
+ao_blink_green(void)
+{
+	for (;;) {
+		while (!ao_blinking_green)
+			ao_sleep(&ao_blinking_green);
+		while (ao_blinking_green) {
+			ao_led_toggle(AO_LED_GREEN);
+			ao_delay(AO_MS_TO_TICKS(1000));
+		}
+	}
+}
+
+
+static void
+ao_blink_green_toggle(void)
+{
+	ao_blinking_green = !ao_blinking_green;
+	if (!ao_blinking_green)
+		ao_led_off(AO_LED_GREEN);
+	ao_wakeup(&ao_blinking_green);
+}
+
+#define ADC_WORDS (AO_USB_IN_SIZE / sizeof (uint16_t))
+static uint16_t prev16 = 0;
+static uint16_t	adc_values[ADC_WORDS];
+static uint8_t	adc_i = ADC_WORDS;
+
+static uint16_t
+fetch16(uint8_t initialize)
+{
+	uint32_t	*rnd;
+	uint8_t		i;
+
+	if (ao_failed)
+		return 0;
+	if (initialize)
+		adc_i = ADC_WORDS;
+	if (adc_i == ADC_WORDS) {
+		rnd = (uint32_t *) ao_adc_get(AO_USB_IN_SIZE);	/* one 16-bit value per output byte */
+		adc_i = 0;
+		for (i = 0; i < ADC_WORDS; i++) {
+			adc_values[i] = ao_crc_in_32_out_16(*rnd++);
+		}
+	}
+	if (initialize)
+		prev16 = adc_values[adc_i++];
+	if (adc_values[adc_i] == prev16) {
+		/* FAILED: how do we prevent spewing bad data? */
+		printf("FAILED value %d repeated\n", prev16);
+		ao_failed = 1;
+		ao_wakeup(&ao_failed);
+		return 0;
+	}
+	prev16 = adc_values[adc_i];
+	adc_i++;
+	return prev16;
+}
+
+static void
+ao_simulate_failure(void)
+{
+	if (adc_i == ADC_WORDS)
+		fetch16(0);
+	prev16 = adc_values[adc_i];
+}
+
+/* NOTE: the reset function also functions as the Power On Self Test */
+void
+ao_reset(void)
+{
+	uint32_t	count;
+
+	printf("Power On Self Test\n"); /* DEBUGGING */
+	ao_failed = 0;
+	ao_led_off(AO_LED_RED);
+	ao_wakeup(&ao_failed);
+	fetch16(1);
+	/* get the first 1k bits and ensure there are no duplicates */
+	count = 1024 / sizeof (uint16_t);
+	while (count-- && !ao_failed) {
+		fetch16(0);
+	}
+	if (ao_failed) { /* show failure */
+		printf("FAILED self test\n");
+	} else { /* show success */
+		printf("PASS - operation NOMINAL\n");
+		/* this blocks! */
+		ao_led_on(AO_LED_GREEN);
+		ao_delay(AO_MS_TO_TICKS(1000));
+		ao_led_off(AO_LED_GREEN);
+	}
+}
+
 static void
 ao_trng_fetch(void)
 {
@@ -29,7 +143,6 @@ ao_trng_fetch(void)
 	int		usb_buf_id;
 	uint16_t	i;
 	uint16_t	*buf;
-	uint32_t	*rnd;
 
 	if (!buffer[0]) {
 		buffer[0] = ao_usb_alloc();
@@ -50,10 +163,9 @@ ao_trng_fetch(void)
 
 	ao_led_on(AO_LED_TRNG_READ);
 	while (count--) {
-		rnd = (uint32_t *) ao_adc_get(AO_USB_IN_SIZE);	/* one 16-bit value per output byte */
 		buf = buffer[usb_buf_id];
 		for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++)
-			*buf++ = ao_crc_in_32_out_16(*rnd++);
+			*buf++ = fetch16(0);
 		ao_adc_ack(AO_USB_IN_SIZE);
 		ao_led_toggle(AO_LED_TRNG_READ|AO_LED_TRNG_WRITE);
 		ao_usb_write(buffer[usb_buf_id], AO_USB_IN_SIZE);
@@ -64,13 +176,35 @@ ao_trng_fetch(void)
 	flush();
 }
 
+static void
+ao_trng_word(void)
+{
+	printf("%d\n", fetch16(0));
+}
+
+static void
+ao_status(void)
+{
+	if (ao_failed)
+		printf("FAILED\n");
+	else
+		printf("NOMINAL\n");
+}
+
 static const struct ao_cmds ao_trng_cmds[] = {
-	{ ao_trng_fetch,	"f <kbytes>\0Fetch a block of numbers" },
+	{ ao_trng_fetch, "f <kbytes>\0Fetch a block of numbers" },
+	{ ao_trng_word, "F\0Fetch 16 bit unsigned int" },
+	{ ao_reset, "R\0reset" },
+	{ ao_blink_green_toggle, "G\0Toggle green LED blinking" },
+	{ ao_status, "s\0show status" },
+	{ ao_simulate_failure, "z\0simulate failure" },
 	{ 0, NULL },
 };
 
 void
 ao_trng_init(void)
 {
+	ao_add_task(&ao_blink_red_task, ao_blink_red, "blink_red");
+	ao_add_task(&ao_blink_green_task, ao_blink_green, "blink_green");
 	ao_cmd_register(ao_trng_cmds);
 }
diff --git a/src/drivers/ao_trng.h b/src/drivers/ao_trng.h
index 78577428..089c70c6 100644
--- a/src/drivers/ao_trng.h
+++ b/src/drivers/ao_trng.h
@@ -21,4 +21,7 @@
 void
 ao_trng_init(void);
 
+void
+ao_reset(void);
+
 #endif /* _AO_TRNG_H_ */
diff --git a/src/usbtrng-v2.0/ao_usbtrng.c b/src/usbtrng-v2.0/ao_usbtrng.c
index 42713b6e..d4a75197 100644
--- a/src/usbtrng-v2.0/ao_usbtrng.c
+++ b/src/usbtrng-v2.0/ao_usbtrng.c
@@ -40,4 +40,6 @@ void main(void)
 	ao_led_off(AO_LED_RED);
 
 	ao_start_scheduler();
+
+	ao_reset(); /* Power On Self Test */
 }