Add platformIO files and adapt file structure

.gitignore

@@ -1 +1,47 @@
 build/
+
+# Random seed file created by test scripts and sample programs
+seedfile
+
+# CMake build artifacts:
+CMakeCache.txt
+CMakeFiles
+CTestTestfile.cmake
+cmake_install.cmake
+Testing
+# CMake generates *.dir/ folders for in-tree builds (used by MSVC projects), ignore all of those:
+*.dir/
+# MSVC files generated by CMake:
+/*.sln
+/*.vcxproj
+/*.filters
+
+# Test coverage build artifacts:
+Coverage
+*.gcno
+*.gcda
+
+# generated by scripts/memory.sh
+massif-*
+
+# MSVC build artifacts:
+*.exe
+*.pdb
+*.ilk
+*.lib
+
+# Python build artifacts:
+*.pyc
+
+# Generated documentation:
+/apidoc
+
+# Editor navigation files:
+/GPATH
+/GRTAGS
+/GSYMS
+/GTAGS
+/TAGS
+/tags
+.pio
+.vscode

CMakeLists.txt

@@ -1,13 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-
-cmake_minimum_required(VERSION 3.13.1)
-find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
-project(bluecovid)
-
-target_sources(app PRIVATE src/main.c src/contacts.c src/exposure-notification.c src/gatt-service.c src/covid.c) 
-
-zephyr_include_directories(${APPLICATION_SOURCE_DIR}/src/tls_config)
-
-#use for testing only, will update keys every X seconds, default is 600
-#add_definitions(-DEN_INTERVAL_LENGTH=11)
-#add_definitions(-DEN_INTERVAL_LENGTH=1)

lib/README

@@ -0,0 +1,46 @@
+
+This directory is intended for project specific (private) libraries.
+PlatformIO will compile them to static libraries and link into executable file.
+
+The source code of each library should be placed in a an own separate directory
+("lib/your_library_name/[here are source files]").
+
+For example, see a structure of the following two libraries `Foo` and `Bar`:
+
+|--lib
+|  |
+|  |--Bar
+|  |  |--docs
+|  |  |--examples
+|  |  |--src
+|  |     |- Bar.c
+|  |     |- Bar.h
+|  |  |- library.json (optional, custom build options, etc) https://docs.platformio.org/page/librarymanager/config.html
+|  |
+|  |--Foo
+|  |  |- Foo.c
+|  |  |- Foo.h
+|  |
+|  |- README --> THIS FILE
+|
+|- platformio.ini
+|--src
+   |- main.c
+
+and a contents of `src/main.c`:
+```
+#include <Foo.h>
+#include <Bar.h>
+
+int main (void)
+{
+  ...
+}
+
+```
+
+PlatformIO Library Dependency Finder will find automatically dependent
+libraries scanning project source files.
+
+More information about PlatformIO Library Dependency Finder
+- https://docs.platformio.org/page/librarymanager/ldf.html

lib/exposure-notification/examples/tracking.c

@@ -0,0 +1,52 @@
+#include "exposure-notification.h"
+#include "time.h"
+
+
+int main(int argc, char **argv) {
+
+    // first init everything
+    // TODO: More randomization, we init with NULL to let en init mbdet entropy for us
+    en_init(NULL);
+
+    // get the currentTime
+    time_t currentTime = time(NULL);
+
+    // The periodKey changes each EN_TEK_ROLLING_PERIOD intervals
+    ENIntervalNumber periodInterval = en_get_interval_number_at_period_start(currentTime);
+
+    ENPeriodKey periodKey;
+    ENPeriodIdentifierKey periodIdentifierKey;
+    ENPeriodMetadataEncryptionKey periodMetadaEncryptionKey;
+
+    // setup period keys at the beginning
+    // in theory you could let them generate automatically setting periodInterval to 0
+    en_generate_and_derive_period_keys(&periodKey, &periodIdentifierKey, &periodMetadaEncryptionKey);
+
+    char metadata[128] = "";
+
+    while(1) {
+        // we check the current time to know if we actually need to regenerate anything
+        currentTime = time(NULL);
+        ENIntervalNumber currentInterval = en_get_interval_number(currentTime);
+
+        // we check if we need to generate new keys
+        if (currentInterval - periodInterval >= EN_TEK_ROLLING_PERIOD) {
+            periodInterval = en_get_interval_number_at_period_start(currentTime);
+            en_generate_and_derive_period_keys(&periodKey, &periodIdentifierKey, &periodMetadaEncryptionKey);
+            // TODO: Store new periodKey with periodInterval
+        }
+
+        // we now generate the new interval identifier and re-encrypt the metadata
+        ENIntervalIdentifier intervalIdentifier;
+        en_derive_interval_identifier(&intervalIdentifier, &periodIdentifierKey, currentInterval);
+
+        char encryptedMetadata[sizeof(metadata)];
+        en_encrypt_interval_metadata(&periodMetadaEncryptionKey, &intervalIdentifier, metadata, encryptedMetadata, sizeof(metadata));
+
+        // broadcast intervalIdentifier plus encryptedMetada according to specs
+        // TODO: receive packets and store them
+        // repeat for 10-20 minutes
+    }
+
+    return 0;
+}

lib/exposure-notification/library.json

@@ -0,0 +1,14 @@
+{
+    "description": "exposure-notification",
+    "frameworks": "*",
+    "keywords": "exposure, notification, contact, tracking, tracing",
+    "name": "exposure-notification",
+    "platforms": "*",
+    "version": "0.1",
+    "dependencies":  [
+        {
+            "name": "mbedtls",
+            "version": "^2.16.4"
+        }
+    ]
+}

lib/exposure-notification/src/exposure-notification.c

@@ -4,22 +4,27 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+
+#if EN_INCLUDE_ZEPHYR_DEPS
 #include <zephyr.h>
 #include <zephyr/types.h>
 #include <stddef.h>
 #include <sys/printk.h>
 #include <sys/util.h>
+#endif
+
 #include <string.h>
 
-#include <mbedtls/entropy.h>
-#include <mbedtls/ctr_drbg.h>
-#include <mbedtls/hkdf.h>
-#include <mbedtls/sha256.h>
-#include <mbedtls/aes.h>
+#include "mbedtls/entropy.h"
+#include "mbedtls/ctr_drbg.h"
+#include "mbedtls/hkdf.h"
+#include "mbedtls/sha256.h"
+#include "mbedtls/aes.h"
 
 #include "exposure-notification.h"
 
 
+
 static mbedtls_ctr_drbg_context ctr_drbg;
 static ENRandomBytesCallback random_bytes_callback = NULL;
 

platformio.ini

@@ -0,0 +1,36 @@
+; PlatformIO Project Configuration File
+;
+;   Build options: build flags, source filter
+;   Upload options: custom upload port, speed and extra flags
+;   Library options: dependencies, extra library storages
+;   Advanced options: extra scripting
+;
+; Please visit documentation for the other options and examples
+; https://docs.platformio.org/page/projectconf.html
+
+
+[env:nrf52840_dk]
+platform = nordicnrf52
+board = nrf52840_dk
+framework = zephyr
+monitor_speed = 115200
+test_ignore = test_desktop
+build_flags = 
+    -Iinclude/tls_config
+    # For testing: -DUNITY_EXCLUDE_SETJMP_H=1
+    -DEN_INCLUDE_ZEPHYR_DEPS=1
+    -DEN_INIT_MBEDTLS_ENTROPY=0
+lib_deps = exposure-notification
+
+    
+[env:desktop]
+platform = native
+test_ignore = test_embedded
+lib_compat_mode = off
+lib_deps = mbedtls@~2
+build_flags = 
+    -Iinclude/desktop
+    -Iinclude/tls_config
+    -Wno-nullability-completeness
+    -DMBEDTLS_USER_CONFIG_FILE='"user-tls.conf"'
+src_filter = --<.src/>   

test/README

@@ -0,0 +1,11 @@
+
+This directory is intended for PIO Unit Testing and project tests.
+
+Unit Testing is a software testing method by which individual units of
+source code, sets of one or more MCU program modules together with associated
+control data, usage procedures, and operating procedures, are tested to
+determine whether they are fit for use. Unit testing finds problems early
+in the development cycle.
+
+More information about PIO Unit Testing:
+- https://docs.platformio.org/page/plus/unit-testing.html

test/test_common/test_common.cpp

@@ -0,0 +1,222 @@
+#include <unity.h>
+
+#include <string.h>
+
+#include "exposure-notification.h"
+
+#define TEST_ASSERT_EQUAL_KEY(k1, k2) TEST_ASSERT_EQUAL(0, memcmp(k1.b, k2.b, sizeof(k1.b)))
+#define TEST_ASSERT_NOT_EQUAL_KEY(k1, k2) TEST_ASSERT_NOT_EQUAL(0, memcmp(k1.b, k2.b, sizeof(k1.b)))
+
+
+void test_init(void) {
+    int ret = en_init(NULL);   
+    TEST_ASSERT_EQUAL(0, ret);
+}
+
+void test_get_interval_number(void) {
+    TEST_ASSERT_EQUAL(0, en_get_interval_number(0));       
+    TEST_ASSERT_EQUAL(0, en_get_interval_number(EN_INTERVAL_LENGTH-1));       
+    TEST_ASSERT_EQUAL(1, en_get_interval_number(EN_INTERVAL_LENGTH));
+    TEST_ASSERT_EQUAL(42, en_get_interval_number(EN_INTERVAL_LENGTH*42));       
+}
+
+void test_get_interval_number_at_period_start(void) {
+    TEST_ASSERT_EQUAL(0, en_get_interval_number_at_period_start(0));       
+    TEST_ASSERT_EQUAL(0, en_get_interval_number_at_period_start(EN_INTERVAL_LENGTH-1));       
+    TEST_ASSERT_EQUAL(0, en_get_interval_number_at_period_start(EN_INTERVAL_LENGTH));
+    TEST_ASSERT_EQUAL(0, en_get_interval_number_at_period_start(EN_INTERVAL_LENGTH*42));       
+    TEST_ASSERT_EQUAL(EN_TEK_ROLLING_PERIOD, en_get_interval_number_at_period_start(EN_INTERVAL_LENGTH*EN_TEK_ROLLING_PERIOD));
+    TEST_ASSERT_EQUAL(EN_TEK_ROLLING_PERIOD, en_get_interval_number_at_period_start(EN_INTERVAL_LENGTH*EN_TEK_ROLLING_PERIOD+1));
+}
+
+void test_generate_period_key(void) {
+    ENPeriodKey p1, p2;
+    en_generate_period_key(&p1);
+    en_generate_period_key(&p2);
+    // yes there is a minimal chance that both are the same ;)
+    TEST_ASSERT_NOT_EQUAL_KEY(p1, p2);
+}
+
+void test_get_period_identifier_key(void) {
+
+    ENPeriodKey pk;
+    en_generate_period_key(&pk);
+
+    ENPeriodIdentifierKey k1, k2;
+    en_derive_period_identifier_key(&k1, &pk);
+    en_derive_period_identifier_key(&k2, &pk);
+
+    // This time both should be the same key as the depent on the period key
+    TEST_ASSERT_EQUAL_KEY(k1, k2);
+    
+    // BUT: they should be different than the period key itself
+    TEST_ASSERT_NOT_EQUAL_KEY(k1, pk);
+}
+
+
+void test_get_interval_identifier(void) {
+
+    ENPeriodKey pk;
+    en_generate_period_key(&pk);
+
+    ENIntervalNumber iv = en_get_interval_number(0);
+
+    ENIntervalIdentifier id1, id2;
+    en_derive_interval_identifier(&id1, &pk, iv);
+    en_derive_interval_identifier(&id2, &pk, iv);
+
+    // identities should be the same for the same intervalnumber and period key
+
+    TEST_ASSERT_EQUAL_KEY(id1, id2);
+
+    iv = en_get_interval_number(EN_INTERVAL_LENGTH);
+    en_derive_interval_identifier(&id2, &pk, iv);
+
+    // BUT: they should be different when we are using another interval number
+    TEST_ASSERT_NOT_EQUAL_KEY(id1, id2);
+
+    // They should also be different for another period key but the the same interval number
+    en_generate_period_key(&pk);
+    en_derive_interval_identifier(&id1, &pk, iv);
+
+    en_generate_period_key(&pk);
+    en_derive_interval_identifier(&id2, &pk, iv);
+
+    TEST_ASSERT_NOT_EQUAL_KEY(id1, id2);
+}
+
+void test_get_period_metadata_encryption_key(void) {
+
+    ENPeriodKey pk;
+    en_generate_period_key(&pk);
+    ENPeriodMetadataEncryptionKey k1, k2;
+    en_derive_period_metadata_encryption_key(&k1, &pk);
+    en_derive_period_metadata_encryption_key(&k2, &pk);
+
+    // This time both should be the same key as the depent on the period key
+    TEST_ASSERT_EQUAL_KEY(k1, k2);
+    
+    // BUT: they should be different than the period key itself
+    TEST_ASSERT_NOT_EQUAL_KEY(k1, pk);
+
+    // and they should also be different than the periodIdentifierKey
+    ENPeriodIdentifierKey pik;
+    en_derive_period_identifier_key(&pik, &pk);
+    TEST_ASSERT_NOT_EQUAL_KEY(k1, pik);
+}
+
+
+void test_en_encrypt_interval_metadata(void) {
+
+    ENPeriodKey pk;
+    en_generate_period_key(&pk);
+    ENPeriodMetadataEncryptionKey k1;
+    en_derive_period_metadata_encryption_key(&k1, &pk);
+
+    ENIntervalNumber iv = en_get_interval_number(0);
+    ENIntervalIdentifier id;
+    en_derive_interval_identifier(&id, &pk, iv);
+
+    unsigned char testData[42] = "This is some test data :)";
+    unsigned char encryptedData[42] = "";
+
+    en_encrypt_interval_metadata(&k1, &id, testData, encryptedData, sizeof(testData));
+
+    // the original data should not be changed
+    TEST_ASSERT_EQUAL_CHAR_ARRAY("This is some test data :)", testData, sizeof("This is some test data :)")-1);
+
+    // but the encrypted one should be changed
+    TEST_ASSERT_NOT_EQUAL(0, memcmp(testData, encryptedData, sizeof(testData)));
+    
+    unsigned char decryptedData[42] = "";
+    en_decrypt_interval_metadata(&k1, &id, encryptedData, decryptedData, sizeof(testData));
+    
+    // the decrypted metadata should be the same as the testData
+    TEST_ASSERT_EQUAL_CHAR_ARRAY(testData, decryptedData, sizeof(testData));
+}
+
+void test_identifier_generation_performance(void) {
+
+    int runs = 1000000;
+
+    for(int i = 0; i < runs; i++) {
+        ENPeriodKey pk;
+        en_generate_period_key(&pk);
+        ENPeriodIdentifierKey ik;
+        en_derive_period_identifier_key(&ik, &pk);
+
+        for(int iv = 0; iv < EN_TEK_ROLLING_PERIOD; iv++) {
+            ENIntervalNumber intervalNumber = en_get_interval_number(iv);
+            ENIntervalIdentifier id;
+            en_derive_interval_identifier(&id, &ik, intervalNumber);
+        }
+    }
+}
+
+void test_generate_and_derive_period_keys(void) {
+    // Test multiple generation
+    ENPeriodKey periodKey;
+    ENPeriodIdentifierKey periodIdentifierKey;
+    ENPeriodMetadataEncryptionKey periodMetadaEncryptionKey;
+    for(int i = 0; i < 10; i++) {
+        en_generate_and_derive_period_keys(&periodKey, &periodIdentifierKey, &periodMetadaEncryptionKey);
+    }
+}
+
+
+void test_against_fixtures(void) {
+    // First define base values
+    ENIntervalNumber intervalNumber = 2642976;
+    ENPeriodKey periodKey = {.b = {0x75, 0xc7, 0x34, 0xc6, 0xdd, 0x1a, 0x78, 0x2d, 0xe7, 0xa9, 0x65, 0xda, 0x5e, 0xb9, 0x31, 0x25}};
+    unsigned char metadata[4] = {0x40, 0x08, 0x00, 0x00};
+
+    // define the expected values
+    ENPeriodIdentifierKey expectedPIK = {.b = {0x18, 0x5a, 0xd9, 0x1d, 0xb6, 0x9e, 0xc7, 0xdd, 0x04, 0x89, 0x60, 0xf1, 0xf3, 0xba, 0x61, 0x75}};
+    ENPeriodMetadataEncryptionKey expectedPMEK = {.b = {0xd5, 0x7c, 0x46, 0xaf, 0x7a, 0x1d, 0x83, 0x96, 0x5b, 0x9b, 0xed, 0x8b, 0xd1, 0x52, 0x93, 0x6a}};
+
+    ENIntervalIdentifier expectedIntervalIdentifier = {.b = {0x8b, 0xe6, 0xcd, 0x37, 0x1c, 0x5c, 0x89, 0x16, 0x04, 0xbf, 0xbe, 0x49, 0xdf, 0x84, 0x50, 0x96}};
+    unsigned char expectedEncryptedMetadata[4] = {0x72, 0x03, 0x38, 0x74};
+
+
+    ENPeriodIdentifierKey pik;
+    en_derive_period_identifier_key(&pik, &periodKey);
+    TEST_ASSERT_EQUAL_KEY(expectedPIK, pik);
+
+    ENPeriodMetadataEncryptionKey pmek;
+    en_derive_period_metadata_encryption_key(&pmek, &periodKey);
+    TEST_ASSERT_EQUAL_KEY(expectedPMEK, pmek);
+
+    ENIntervalIdentifier intervalIdentifier;
+    en_derive_interval_identifier(&intervalIdentifier, &pik, intervalNumber);
+    TEST_ASSERT_EQUAL_KEY(expectedIntervalIdentifier, intervalIdentifier);
+
+
+    unsigned char encryptedMetadata[sizeof(metadata)] = {0};
+    en_encrypt_interval_metadata(&pmek, &intervalIdentifier, metadata, encryptedMetadata, sizeof(metadata));
+    TEST_ASSERT_EQUAL_CHAR_ARRAY(expectedEncryptedMetadata, encryptedMetadata, sizeof(expectedEncryptedMetadata));
+}
+
+
+void test_exposure_notification() {
+    UNITY_BEGIN();
+    RUN_TEST(test_init);
+    RUN_TEST(test_get_interval_number);
+    RUN_TEST(test_get_interval_number_at_period_start);
+    RUN_TEST(test_generate_period_key);
+    RUN_TEST(test_get_period_identifier_key);
+    RUN_TEST(test_get_interval_identifier);
+    RUN_TEST(test_get_period_metadata_encryption_key);
+    RUN_TEST(test_en_encrypt_interval_metadata);
+    RUN_TEST(test_generate_and_derive_period_keys);
+    RUN_TEST(test_against_fixtures);
+    //RUN_TEST(test_identifier_generation_performance);
+    UNITY_END();
+}
+
+
+
+
+int main(int argc, char **argv) {
+    test_exposure_notification();
+    return 0;
+}

zephyr/CMakeLists.txt

@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.13.1)
+include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
+project(test)
+
+FILE(GLOB app_sources ../src/*.c*)
+target_sources(app PRIVATE ${app_sources})

zephyr/prj.conf

@@ -8,8 +8,6 @@ CONFIG_BT_DEVICE_NAME="BlueCovid"
 CONFIG_ENTROPY_GENERATOR=y
 
 CONFIG_MBEDTLS=y
-#CONFIG_MBEDTLS_USER_CONFIG_ENABLE=y
-#CONFIG_MBEDTLS_CFG_FILE="mbedtls_config.h"
 CONFIG_MBEDTLS_USER_CONFIG_ENABLE=y
 CONFIG_MBEDTLS_USER_CONFIG_FILE="user-tls.conf"