build

either change to PIN to an empty one or "4321"

default.nix

@@ -0,0 +1,24 @@
+let
+  pkgs = import (fetchTarball { url = "https://github.com/NixOS/nixpkgs/archive/20.03.tar.gz"; sha256 = "0182ys095dfx02vl2a20j1hz92dx3mfgz2a6fhn31bqlp1wa8hlq"; }) {};
+  pyPackages = (python-packages: with python-packages; ([
+    solo-python pytest
+  ] ++ (with builtins; map (d: getAttr d python-packages) (filter (d: stringLength d > 0) (pkgs.lib.splitString "\n" (builtins.readFile ./tools/requirements.txt))))));
+  python-with-my-packages = pkgs.python3.withPackages pyPackages;
+  src = ./.;
+in
+with pkgs; stdenv.mkDerivation {
+	name = "solo";
+	outputs = [ "out" ];
+	src = with lib; builtins.filterSource (path: type: !(hasSuffix path "hex" || hasSuffix path "sha256")) src;
+	buildInputs = [ gnumake gcc gcc-arm-embedded-8 git python-with-my-packages ];
+	phases = [ "unpackPhase" "configurePhase" "buildPhase" "installPhase" ];
+	installPhase = ''
+        	mkdir -p $out/firmware $out
+        	cd targets/stm32l432
+        	make cbor
+		make build-hacker
+        	cp *.hex *.sha256 *.elf cubeconfig_stm32l442.ioc $out/firmware/ 
+        '';
+	keepDebugInfo = true;
+}
+

fido2/ctap.c

@@ -461,7 +461,10 @@ static int ctap_make_extensions(CTAP_extensions * ext, uint8_t * ext_encoder_buf
         // Generate credRandom
         crypto_sha256_hmac_init(CRYPTO_TRANSPORT_KEY2, 0, credRandom);
         crypto_sha256_update((uint8_t*)&ext->hmac_secret.credential->id, sizeof(CredentialId));
-        crypto_sha256_update(&getAssertionState.user_verified, 1);
+	// using user_verified as len means it won't be included when false
+	if (getAssertionState.user_verified == 1) {
+        	crypto_sha256_update(&getAssertionState.user_verified, 1);
+	}
         crypto_sha256_hmac_final(CRYPTO_TRANSPORT_KEY2, 0, credRandom);
 
         // Decrypt saltEnc
@@ -566,10 +569,10 @@ static unsigned int get_credential_id_size(int type)
     return sizeof(CredentialId);
 }
 
-static int ctap2_user_presence_test()
+static int ctap2_user_presence_test(uint32_t colour)
 {
     device_set_status(CTAPHID_STATUS_UPNEEDED);
-    int ret = ctap_user_presence_test(CTAP2_UP_DELAY_MS);
+    int ret = ctap_user_presence_test_colour(CTAP2_UP_DELAY_MS, colour);
     if ( ret > 1 )
     {
         return CTAP2_ERR_PROCESSING;
@@ -587,6 +590,33 @@ static int ctap2_user_presence_test()
         return CTAP2_ERR_ACTION_TIMEOUT;
     }
 }
+static uint32_t ctap_assertion_led_colour(uint8_t * seed, uint32_t slen)
+{
+	uint8_t hmac[32];
+	crypto_sha256_hmac_init(CRYPTO_MASTER_KEY, 32, hmac);
+	crypto_sha256_hmac_final(seed, slen, hmac);
+	uint32_t colour = 0;
+	uint32_t backlist[] = {0x00FF00};
+	int dist = 0;
+	int min_dist = 50*50*3;
+	for(int i=0; i<32-3 && (dist < min_dist || i == 0);i++) {
+		uint8_t* rgb = &hmac[i];
+		colour = ((uint32_t*) rgb)[0] & 0x0000ffffff;
+		int r, g, b = 0;
+		r = colour & 0x0000ff0000 >> 16;
+		g = colour & 0x000000ff00 >> 8;
+		b = colour & 0x00000000ff;
+		for(int j=0; j < 1 && dist < min_dist; j++) {
+			int br, bg, bb = 0;
+			br = backlist[j] & 0x0000ff0000 >> 16;
+			bg = backlist[j] & 0x000000ff00 >> 8;
+			bb = backlist[j] & 0x00000000ff;
+			dist = ((int) r - br)*(r  - br) + ((int)g - bg)*((int)g - bg) + ((int)b - bb)*((int)b - bb);
+		}
+
+	}
+	return colour;
+}
 
 static int ctap_make_auth_data(struct rpId * rp, CborEncoder * map, uint8_t * auth_data_buf, uint32_t * len, CTAP_credInfo * credInfo, CTAP_extensions * extensions)
 {
@@ -617,7 +647,7 @@ static int ctap_make_auth_data(struct rpId * rp, CborEncoder * map, uint8_t * au
 
     int but;
 
-    but = ctap2_user_presence_test();
+    but = ctap2_user_presence_test(ctap_assertion_led_colour(authData->head.rpIdHash, 32));
     if (CTAP2_ERR_PROCESSING == but)
     {
         authData->head.flags = (0 << 0);        // User presence disabled
@@ -880,7 +910,7 @@ uint8_t ctap_make_credential(CborEncoder * encoder, uint8_t * request, int lengt
     }
     if (MC.pinAuthEmpty)
     {
-        ret = ctap2_user_presence_test();
+        ret = ctap2_user_presence_test(0);
         check_retr(ret);
         return ctap_is_pin_set() == 1 ? CTAP2_ERR_PIN_AUTH_INVALID : CTAP2_ERR_PIN_NOT_SET;
     }
@@ -925,7 +955,7 @@ uint8_t ctap_make_credential(CborEncoder * encoder, uint8_t * request, int lengt
         {
             if ( check_credential_metadata(&excl_cred->credential.id, MC.pinAuthPresent, 1) == 0)
             {
-                ret = ctap2_user_presence_test();
+                ret = ctap2_user_presence_test(0);
                 check_retr(ret);
                 printf1(TAG_MC, "Cred %d failed!\r\n",i);
                 return CTAP2_ERR_CREDENTIAL_EXCLUDED;
@@ -1738,6 +1768,7 @@ uint8_t ctap_cred_mgmt(CborEncoder * encoder, uint8_t * request, int length)
     return 0;
 }
 
+
 uint8_t ctap_get_assertion(CborEncoder * encoder, uint8_t * request, int length)
 {
     CTAP_getAssertion GA;
@@ -1752,7 +1783,8 @@ uint8_t ctap_get_assertion(CborEncoder * encoder, uint8_t * request, int length)
 
     if (GA.pinAuthEmpty)
     {
-        ret = ctap2_user_presence_test();
+	uint32_t colour = ctap_assertion_led_colour(GA.clientDataHash, 32);
+        ret = ctap2_user_presence_test(colour);
         check_retr(ret);
         return ctap_is_pin_set() == 1 ? CTAP2_ERR_PIN_AUTH_INVALID : CTAP2_ERR_PIN_NOT_SET;
     }
@@ -2285,7 +2317,7 @@ uint8_t ctap_request(uint8_t * pkt_raw, int length, CTAP_RESPONSE * resp)
             break;
         case CTAP_RESET:
             printf1(TAG_CTAP,"CTAP_RESET\n");
-            status = ctap2_user_presence_test();
+            status = ctap2_user_presence_test(0);
             if (status == CTAP1_ERR_SUCCESS)
             {
                 ctap_reset();
@@ -2318,6 +2350,9 @@ uint8_t ctap_request(uint8_t * pkt_raw, int length, CTAP_RESPONSE * resp)
 
             dump_hex1(TAG_DUMP,buf, resp->length);
             break;
+	case CTAP_VENDOR_LOAD:
+	    //TODO: load secret
+	    break;
         default:
             status = CTAP1_ERR_INVALID_COMMAND;
             printf2(TAG_ERR,"error, invalid cmd: 0x%02x\n", cmd);
@@ -2443,6 +2478,11 @@ uint8_t ctap_is_pin_set()
  */
 void ctap_update_pin(uint8_t * pin, int len)
 {
+    if(len == 0 || strncmp(pin, "4321", len) == 0) {
+	STATE.is_pin_set = 0;
+    	authenticator_write_state(&STATE);
+	return;
+    }
     if (len >= NEW_PIN_ENC_MIN_SIZE || len < 4)
     {
         printf2(TAG_ERR, "Update pin fail length\n");

fido2/device.h

@@ -87,6 +87,24 @@ int device_is_button_pressed();
 */
 int ctap_user_presence_test(uint32_t delay);
 
+// 
+// Return 2 for disabled, 1 for user is present, 0 user not present, -1 if cancel is requested.
+/** Test for user presence.
+ *  Perform test that user is present.  Returns status on user presence.  This is used by FIDO and U2F layer
+ *  to check if an operation should continue, or if the UP flag should be set.
+ * 
+ * @param delay number of milliseconds to delay waiting for user before timeout.
+ * @param button_confirm_colour LED colour while waiting for confirmation.
+ * 
+ * @return 2 - User presence is disabled.  Operation should continue, but UP flag not set.
+ *         1 - User presence confirmed.  Operation should continue, and UP flag is set.
+ *         0 - User presence is not confirmed.  Operation should be denied.
+ *        -1 - Operation was canceled.  Do not continue, reset transaction state.
+ * 
+ * *Optional*, the default implementation will return 1, unless a FIDO2 operation calls for no UP, where this will then return 2.
+*/
+int ctap_user_presence_test_colour(uint32_t delay, uint32_t button_confirm_colour);
+
 /** Disable the next user presence test.  This is called by FIDO2 layer when a transaction
  *  requests UP to be disabled.  The next call to ctap_user_presence_test should return 2,
  *  and then UP should be enabled again.

shell.nix

@@ -0,0 +1,13 @@
+let
+  nixpkgs_tar = fetchTarball { url = "https://github.com/NixOS/nixpkgs/archive/20.03.tar.gz"; sha256 = "0182ys095dfx02vl2a20j1hz92dx3mfgz2a6fhn31bqlp1wa8hlq"; };
+  pkgs = import "${nixpkgs_tar}" {};
+  pyPackages = (python-packages: with python-packages; ([
+    solo-python pytest
+  ] ++ (with builtins; map (d: getAttr d python-packages) (filter (d: stringLength d > 0) (pkgs.lib.splitString "\n" (builtins.readFile ./tools/requirements.txt))))));
+  python-with-my-packages = pkgs.python3.withPackages pyPackages;
+in
+with pkgs;
+stdenv.mkDerivation {
+  name = "solo";
+  buildInputs = [ gnumake gcc gcc-arm-embedded-8 python-with-my-packages ];
+}

targets/stm32l432/src/device.c

@@ -704,6 +704,10 @@ static int wait_for_button_release(uint32_t wait)
 }
 
 int ctap_user_presence_test(uint32_t up_delay) 
+{
+	return ctap_user_presence_test_colour(up_delay, 0);	
+}
+int ctap_user_presence_test_colour(uint32_t up_delay, uint32_t button_confirm_colour)
 {
     int ret;
 
@@ -741,8 +745,7 @@ int ctap_user_presence_test(uint32_t up_delay)
     }
 
     // Set LED status and wait.
-    led_rgb(0xff3520);
+    led_rgb(button_confirm_colour==0?0xff3520:button_confirm_colour);
-
     // Block and wait for some time.
     ret = wait_for_button_activate(up_delay);
     if (ret) return ret;