Invocation of noise.c from demo.c mostly proving in frama-c

5 files changed, 53 insertions, 31 deletions

diff --git a/src/demo.c b/src/demo.c
index 0e16d5e..4d6a040 100644
--- a/src/demo.c
+++ b/src/demo.c
@@ -20,20 +20,6 @@
  *

  */

 

-#include "usart_helpers.h"

-#include "usbh_core.h"

-#include "usbh_lld_stm32f4.h"

-#include "usbh_driver_hid.h"

-#include "usbh_driver_hub.h"

-#include "rand_stm32.h"

-#include "packet_interface.h"

-#include "noise.h"

-#include "hid_keycodes.h"

-#include "words.h"

-#include "tracing.h"

-

-#include "crypto/noise-c/src/protocol/internal.h"

-

 #include <libopencm3/stm32/rcc.h>

 #include <libopencm3/stm32/gpio.h>

 #include <libopencm3/stm32/usart.h>

@@ -49,6 +35,20 @@
 #include <stdlib.h>

 #include <string.h>

 

+#include "usart_helpers.h"

+#include "usbh_core.h"

+#include "usbh_lld_stm32f4.h"

+#include "usbh_driver_hid.h"

+#include "usbh_driver_hub.h"

+#include "rand_stm32.h"

+#include "packet_interface.h"

+#include "noise.h"

+#include "hid_keycodes.h"

+#include "words.h"

+#include "tracing.h"

+

+#include "crypto/noise-c/src/protocol/internal.h"

+

 #ifndef USE_STM32F4_USBH_DRIVER_FS

 #error The full-speed USB driver must be enabled with USE_STM32F4_USBH_DRIVER_FS in usbh_config.h!

 #endif

@@ -439,7 +439,8 @@ void usart1_isr(void) {
     if (USART1_SR & USART_SR_ORE) { /* Overrun handling */

         LOG_PRINTF("USART1 data register overrun\n");

         /* Clear interrupt flag */

-        return (void)USART1_DR;

+        int dummy = USART1_DR;

+        return;

     }

 

     uint8_t data = USART1_DR; /* This automatically acknowledges the IRQ */

@@ -487,7 +488,17 @@ void DMA_ISR(DEBUG_USART_DMA_NUM, DEBUG_USART_DMA_STREAM_NUM)(void) {
     TRACING_CLEAR(TR_DEBUG_OUT_DMA_IRQ);

 }

 

-void handle_host_packet(struct control_packet *pkt, size_t payload_length) {

+/*@ requires \valid_read(&pkt->type) && \valid_read(pkt->payload + (0..payload_length-1));

+    requires \valid(st);

+    requires \valid(st->handshake);

+    requires \separated(st, st->rx_cipher, st->tx_cipher, st->handshake, (uint8_t *)pkt->payload, &usart2_out, &st->handshake_hash);

+    requires \valid(usart2_out);

+

+    assigns pairing_buf_pos, *usart2_out, *st;

+

+    assigns st->handshake, st->handshake_state, st->rx_cipher, st->tx_cipher;

+  @*/

+void handle_host_packet(struct NoiseState *st, const struct control_packet *pkt, size_t payload_length) {

     TRACING_SET(TR_HOST_PKT_HANDLER);

     if (pkt->type == HOST_INITIATE_HANDSHAKE) {

         /* It is important that we acknowledge this command right away. Starting the handshake involves key

@@ -496,9 +507,9 @@ void handle_host_packet(struct control_packet *pkt, size_t payload_length) {
 

         if (payload_length > 0) {

             LOG_PRINTF("Extraneous data in INITIATE_HANDSHAKE message\n");

-        } else if (noise_state.failed_handshakes < MAX_FAILED_HANDSHAKES) {

+        } else if (st->failed_handshakes < MAX_FAILED_HANDSHAKES) {

             LOG_PRINTF("Starting noise protocol handshake...\n");

-            if (reset_protocol_handshake(&noise_state))

+            if (reset_protocol_handshake(st))

                 LOG_PRINTF("Error starting protocol handshake.\n");

             pairing_buf_pos = 0; /* Reset channel binding keyboard input buffer */

         } else {

@@ -510,7 +521,7 @@ void handle_host_packet(struct control_packet *pkt, size_t payload_length) {
     } else if (pkt->type == HOST_HANDSHAKE) {

         LOG_PRINTF("Handling handshake packet of length %d\n", payload_length);

         TRACING_SET(TR_NOISE_HANDSHAKE);

-        if (try_continue_noise_handshake(&noise_state, pkt->payload, payload_length)) {

+        if (try_continue_noise_handshake(st, pkt->payload, payload_length)) {

             TRACING_CLEAR(TR_NOISE_HANDSHAKE);

             LOG_PRINTF("Reporting handshake error to host\n");

             struct control_packet out = { .type=HOST_CRYPTO_ERROR };

@@ -565,7 +576,11 @@ int main(void)
 	LOG_PRINTF("Initializing RNG...\n");

     rand_init();

 

+    //@ assert \valid(&noise_state);

+    //@ assert \valid((uint8_t *)keystore.keys.remote_key_reference + (0..31)) && \valid((uint8_t *)keystore.keys.local_key + (0..31));

     noise_state_init(&noise_state, keystore.keys.remote_key_reference, keystore.keys.local_key);

+

+    //@ assert \valid(noise_state.local_key + (0..31));

     /* FIXME load remote key from backup memory */

     /* FIXME only run this on first boot and persist key in backup sram. Allow reset via jumper-triggered factory reset function. */

     if (!keystore.mgmt.identity_key_valid) {

@@ -633,13 +648,13 @@ int main(void)
         }

 

         if (host_packet_length > 0) {

-            handle_host_packet((struct control_packet *)host_packet_buf, host_packet_length - 1);

+            handle_host_packet(&noise_state, (struct control_packet *)host_packet_buf, host_packet_length - 1);

             host_packet_length = 0; /* Acknowledge to USART ISR the buffer has been handled */

 

         } else if (host_packet_length < 0) { /* USART error */

             host_packet_length = 0; /* Acknowledge to USART ISR the error has been handled */

             if (noise_state.handshake_state < HANDSHAKE_DONE_UNKNOWN_HOST) {

-                LOG_PRINTF("USART error, aborting handshake\n")

+                LOG_PRINTF("USART error, aborting handshake\n");

 

                 struct control_packet pkt = { .type=HOST_COMM_ERROR };

                 send_packet(usart2_out, (uint8_t *)&pkt, sizeof(pkt));

diff --git a/src/frama_c_cmdline b/src/frama_c_cmdline
new file mode 100644
index 0000000..d6c6adc
--- /dev/null
+++ b/src/frama_c_cmdline
@@ -0,0 +1 @@
+frama-c-gui -c11 -cpp-extra-args="-DVERIFICATION -DSTM32F4 -DUSE_STM32F4_USBH_DRIVER_FS -DDEBUG_USART=USART1 -DDEBUG_USART_BAUDRATE=115200 -DDEBUG_USART_DMA_CHANNEL_NUM=4 -DDEBUG_USART_DMA_NUM=2 -DDEBUG_USART_DMA_STREAM_NUM=7 -I. -I"(frama-c -print-path)"/libc -I crypto/noise-c/include -I../include -I../libopencm3/include" -wp -wp-rte -wp-model +cint -wp-verbose 2 -slevel 8 -wp-out goals noise.c demo.c -wp-fct try_continue_noise_handshake
diff --git a/src/noise.c b/src/noise.c
index e03fc45..890b5b5 100644
--- a/src/noise.c
+++ b/src/noise.c
@@ -52,9 +52,8 @@ volatile int host_packet_length = 0;
 
 /*@
     requires \valid(st);
-    requires \valid_read(remote_key_reference + (0..31)) && \valid_read(local_key + (0..31));
 
-    ensures \valid_read(st->remote_key_reference + (0..31)) && \valid_read(st->local_key + (0..31));
+    ensures st->remote_key_reference == remote_key_reference && st->local_key == local_key;
     ensures st->handshake_state == HANDSHAKE_UNINITIALIZED;
     ensures st->failed_handshakes == 0;
     ensures st->tx_cipher == NULL && st->rx_cipher == NULL && st->handshake == NULL;
@@ -74,7 +73,7 @@ void noise_state_init(struct NoiseState *st, uint8_t *remote_key_reference, uint
 /*@
     requires \valid(st);
     requires \valid(st->handshake_hash + (0..31));
-    requires \separated(st->handshake_hash + (0..31), st, st->rx_cipher, st->tx_cipher, st->handshake);
+    requires \separated(st, st->rx_cipher, st->tx_cipher, st->handshake);
 
     ensures \result == 0 ==> (
         \valid(st->handshake) &&
@@ -188,9 +187,9 @@ void uninit_handshake(struct NoiseState *st, enum handshake_state new_state) {
     arm_key_scrubber();
 }
 
-//@ ghost int key_checked_trace = 0;
-//@ ghost int key_match_trace = 0;
-/*@ requires empty_trace: key_checked_trace == 0;
+//@ ghost int key_checked_trace;
+//@ ghost int key_match_trace;
+/*@ 
     requires \valid(st);
     requires \valid(usart2_out);
     requires \valid(st->handshake);
@@ -198,15 +197,17 @@ void uninit_handshake(struct NoiseState *st, enum handshake_state new_state) {
     requires \valid(st->remote_key + (0..sizeof(st->remote_key)-1));
     requires \valid(st->handshake_hash + (0..sizeof(st->handshake_hash)-1));
 
-    requires \separated(st, buf);
-    requires \separated(&usart2_out, \union(st, buf));
-    requires \separated(&st->handshake, st);
+    requires \separated(&usart2_out, st, buf, st->handshake, &st->handshake_hash);
+
     assigns key_checked_trace;
+
     ensures (st->handshake_state == HANDSHAKE_DONE_KNOWN_HOST) ==> key_checked_trace == 1;
     ensures (st->handshake_state != HANDSHAKE_IN_PROGRESS) ==>
         key_match_trace == 1 || (st->failed_handshakes > \old(st->failed_handshakes));
   @*/
 int try_continue_noise_handshake(struct NoiseState * const st, uint8_t *buf, size_t len) {
+    //@ ghost key_checked_trace = 0;
+    //@ ghost key_match_trace = 0;
     int err;
     struct {
         struct control_packet header;
diff --git a/src/packet_interface.h b/src/packet_interface.h
index 86afb0e..35e9758 100644
--- a/src/packet_interface.h
+++ b/src/packet_interface.h
@@ -51,7 +51,7 @@ struct control_packet {
     requires \valid_read(data + (0..len-1));
     requires len > 0;
 
-    assigns \nothing;
+    assigns *f;
  */
 void send_packet(struct dma_usart_file *f, const uint8_t *data, size_t len);
 
diff --git a/src/tracing.h b/src/tracing.h
index 9aa9216..1970556 100644
--- a/src/tracing.h
+++ b/src/tracing.h
@@ -3,8 +3,13 @@
 
 #include <libopencm3/stm32/gpio.h>
 
+#ifndef VERIFICATION
 #define TRACING_SET(i) gpio_set(GPIOD, (1<<i))
 #define TRACING_CLEAR(i) gpio_clear(GPIOD, (1<<i))
+#else
+#define TRACING_SET(i) ((void)0)
+#define TRACING_CLEAR(i) ((void)0)
+#endif
 
 enum tracing_channels {
     TR_HID_MESSAGE_HANDLER = 0,