README.md

@@ -150,9 +150,13 @@ final EncryptedSubmissionPayload frontendEncryptedPayload = EncryptedSubmissionB
         .build();
 
 final SentSubmission sentSubmission = senderClient.submit(frontendEncryptedPayload);
-
 ```
 
+| **Important** |
+| ------------- |
+| If destination id (`destinationId`) and service type (`leikaKey`) are provided by a frontend component, they MUST NOT be blindly trusted. Instead, the sender's backend MUST check if sending submissions of this service type to the specified destination is allowed. |
+
+
 ### Hand in a new submission with unencrypted data
 
 If all data, metadata and attachments are encrypted in the sender using the SDK, the client automatically handles the encryption.

api/src/main/java/dev/fitko/fitconnect/api/config/BuildInfo.java

+package dev.fitko.fitconnect.api.config;
+
+import lombok.Data;
+
+@Data
+public class BuildInfo {
+
+    private String productName;
+    private String productVersion;
+    private String commit;
+}

api/src/main/java/dev/fitko/fitconnect/api/services/Sender.java

@@ -51,6 +51,17 @@ public interface Sender {
      */
     ValidationResult validateMetadata(Metadata metadata);
 
+    /**
+     * Checks if a received callback can be trusted by validating the provided request data
+     *
+     * @param hmac authentication code provided by the callback
+     * @param timestamp timestamp provided by the callback
+     * @param httpBody HTTP body provided by the callback
+     * @param callbackSecret secret owned by the client, which is used to calculate the hmac
+     * @return {@code true} if hmac and timestamp provided by the callback meet the required conditions
+     */
+    ValidationResult validateCallback(String hmac, Long timestamp, String httpBody, String callbackSecret);
+
     /**
      * Encrypts the submission data payload (json or xml) with JWE (JSON-Web-Encryption).
      *

api/src/main/java/dev/fitko/fitconnect/api/services/Subscriber.java

@@ -85,6 +85,17 @@ public interface Subscriber {
      */
     ValidationResult validateHashIntegrity(String originalHash, byte[] data);
 
+    /**
+     * Checks if a received callback can be trusted by validating the provided request data
+     *
+     * @param hmac authentication code provided by the callback
+     * @param timestamp timestamp provided by the callback
+     * @param httpBody HTTP body provided by the callback
+     * @param callbackSecret secret owned by the client, which is used to calculate the hmac
+     * @return {@code true} if hmac and timestamp provided by the callback meet the required conditions
+     */
+    ValidationResult validateCallback(String hmac, Long timestamp, String httpBody, String callbackSecret);
+
     /**
      * Sends a confirmation event if the received submission matches all validations.
      *

api/src/main/java/dev/fitko/fitconnect/api/services/crypto/MessageDigestService.java

@@ -37,4 +37,13 @@ public interface MessageDigestService {
      * @return byte[] of the given hex string
      */
     byte[] fromHexString(String hexString);
+
+    /**
+     * Creates an HMAC
+     *
+     * @param data raw data
+     * @param key secret key
+     * @return HMAC according to https://datatracker.ietf.org/doc/html/rfc2104
+     */
+    String calculateHMAC(String data, String key);
 }

api/src/main/java/dev/fitko/fitconnect/api/services/validation/ValidationService.java

@@ -80,5 +80,14 @@ public interface ValidationService {
      */
     ValidationResult validateXmlFormat(String xml);
 
-
+    /**
+     * Checks if a received callback can be trusted by validating the provided request data
+     *
+     * @param hmac authentication code provided by the callback
+     * @param timestamp timestamp provided by the callback
+     * @param httpBody HTTP body provided by the callback
+     * @param callbackSecret secret owned by the client, which is used to calculate the hmac
+     * @return {@code true} if hmac and timestamp provided by the callback meet the required conditions
+     */
+    ValidationResult validateCallback(String hmac, Long timestamp, String httpBody, String callbackSecret);
 }

client/pom.xml

@@ -71,6 +71,14 @@
     </dependencies>
 
     <build>
+
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+
         <plugins>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
@@ -105,8 +113,23 @@
                     </execution>
                 </executions>
             </plugin>
+            <plugin>
+                <groupId>io.github.git-commit-id</groupId>
+                <artifactId>git-commit-id-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>get-the-git-infos</id>
+                        <goals>
+                            <goal>revision</goal>
+                        </goals>
+                        <phase>initialize</phase>
+                    </execution>
+                </executions>
+                <configuration>
+                    <commitIdGenerationMode>full</commitIdGenerationMode>
+                </configuration>
+            </plugin>
         </plugins>
     </build>
 
-
 </project>
\ No newline at end of file

client/src/main/java/dev/fitko/fitconnect/client/SenderClient.java

@@ -8,6 +8,7 @@ import dev.fitko.fitconnect.api.domain.model.event.authtags.AuthenticationTags;
 import dev.fitko.fitconnect.api.domain.model.submission.SentSubmission;
 import dev.fitko.fitconnect.api.domain.model.submission.Submission;
 import dev.fitko.fitconnect.api.domain.model.submission.SubmitSubmission;
+import dev.fitko.fitconnect.api.domain.validation.ValidationResult;
 import dev.fitko.fitconnect.api.services.Sender;
 import dev.fitko.fitconnect.client.sender.model.EncryptedSubmissionPayload;
 import dev.fitko.fitconnect.client.sender.model.SubmissionPayload;
@@ -69,6 +70,10 @@ public class SenderClient {
         return sender.getLastedEvent(destinationId, caseId, submissionId, authenticationTags);
     }
 
+    public ValidationResult validateCallback(String hmac, Long timestamp, String httpBody, String callbackSecret) {
+        return this.sender.validateCallback(hmac, timestamp, httpBody, callbackSecret);
+    }
+
     /**
      * Send submission with attachments and data to FIT-Connect API. Encryption is handled by the SDK.
      *

client/src/main/java/dev/fitko/fitconnect/client/SubscriberClient.java

@@ -144,6 +144,10 @@ public class SubscriberClient {
         return null;
     }
 
+    public ValidationResult validateCallback(String hmac, Long timestamp, String httpBody, String callbackSecret) {
+        return this.subscriber.validateCallback(hmac, timestamp, httpBody, callbackSecret);
+    }
+
     private ReceivedSubmission buildReceivedSubmission(final Submission submission, final Metadata metadata, final byte[] decryptedData, final List<DecryptedAttachmentPayload> attachments) {
         final MimeType mimeType = metadata.getContentStructure().getData().getSubmissionSchema().getMimeType();
         final ReceivedData receivedData = new ReceivedData(new String(decryptedData, StandardCharsets.UTF_8), mimeType);

client/src/main/java/dev/fitko/fitconnect/client/factory/ApplicationConfigLoader.java

 package dev.fitko.fitconnect.client.factory;
 
 import dev.fitko.fitconnect.api.config.ApplicationConfig;
+import dev.fitko.fitconnect.api.config.BuildInfo;
 import dev.fitko.fitconnect.api.exceptions.InitializationException;
 import org.yaml.snakeyaml.Yaml;
 import org.yaml.snakeyaml.constructor.Constructor;
@@ -11,13 +12,15 @@ import java.nio.file.Path;
 
 public final class ApplicationConfigLoader {
 
-    private ApplicationConfigLoader() { }
+    private static final String BUILD_INFO_PATH = "buildinfo.yaml";
+
+    private ApplicationConfigLoader() {
+    }
 
     /**
      * Load ApplicationConfig from path.
      *
      * @param configPath path to config file
-     *
      * @return ApplicationConfig
      * @throws InitializationException if the config file could not be loaded
      */
@@ -33,24 +36,31 @@ public final class ApplicationConfigLoader {
      * Load ApplicationConfig from path string.
      *
      * @param configPath string of path to config file
-     *
      * @return ApplicationConfig
      * @throws InitializationException if the config file could not be loaded
      */
     public static ApplicationConfig loadConfig(final String configPath) {
-       return loadConfig(Path.of(configPath));
+        return loadConfig(Path.of(configPath));
     }
 
     /**
      * Load ApplicationConfig from yaml string.
      *
      * @param configYaml string content of the yaml config file
-     *
      * @return ApplicationConfig
      */
     public static ApplicationConfig loadConfigFromYaml(final String configYaml) {
-        final Constructor constructor = new Constructor(ApplicationConfig.class);
-        final Yaml yaml = new Yaml(constructor);
-        return yaml.load(configYaml);
+
+        final Yaml applicationPropertiesYaml = new Yaml(new Constructor(ApplicationConfig.class));
+        ApplicationConfig applicationConfig = applicationPropertiesYaml.load(configYaml);
+
+        return applicationConfig;
+    }
+
+    public static BuildInfo loadBuildInfo() {
+
+        final Yaml buildInfoYaml = new Yaml(new Constructor(BuildInfo.class));
+
+        return buildInfoYaml.load(ApplicationConfigLoader.class.getClassLoader().getResourceAsStream(BUILD_INFO_PATH));
     }
 }

client/src/main/java/dev/fitko/fitconnect/client/factory/ClientFactory.java

@@ -3,6 +3,7 @@ package dev.fitko.fitconnect.client.factory;
 import com.nimbusds.jose.jwk.JWK;
 import com.nimbusds.jose.jwk.RSAKey;
 import dev.fitko.fitconnect.api.config.ApplicationConfig;
+import dev.fitko.fitconnect.api.config.BuildInfo;
 import dev.fitko.fitconnect.api.config.SchemaConfig;
 import dev.fitko.fitconnect.api.config.SubscriberConfig;
 import dev.fitko.fitconnect.api.exceptions.InitializationException;
@@ -64,8 +65,7 @@ public final class ClientFactory {
      * @return the sender client
      */
     public static SenderClient senderClient() {
-        final ApplicationConfig config = loadConfig();
-        return senderClient(config);
+        return senderClient(loadConfig());
     }
 
     /**
@@ -75,7 +75,7 @@ public final class ClientFactory {
      */
     public static SenderClient senderClient(final ApplicationConfig config) {
         LOGGER.info("Initializing sender client ...");
-        return new SenderClient(getSender(config));
+        return new SenderClient(getSender(config, ApplicationConfigLoader.loadBuildInfo()));
     }
 
 
@@ -85,8 +85,7 @@ public final class ClientFactory {
      * @return the subscriber client
      */
     public static SubscriberClient subscriberClient() {
-        final ApplicationConfig config = loadConfig();
-        return subscriberClient(config);
+        return subscriberClient(loadConfig());
     }
 
     /**
@@ -96,7 +95,7 @@ public final class ClientFactory {
      */
     public static SubscriberClient subscriberClient(final ApplicationConfig config) {
         LOGGER.info("Initializing subscriber client ...");
-        final Subscriber subscriber = getSubscriber(config);
+        final Subscriber subscriber = getSubscriber(config, ApplicationConfigLoader.loadBuildInfo());
         final SubscriberConfig subscriberConfig = config.getSubscriberConfig();
 
         LOGGER.info("Reading private decryption key from {} ", subscriberConfig.getPrivateDecryptionKeyPath());
@@ -106,8 +105,8 @@ public final class ClientFactory {
         return new SubscriberClient(subscriber, privateKey);
     }
 
-    private static Subscriber getSubscriber(final ApplicationConfig config) {
-        final RestTemplate restTemplate = getRestTemplate(config);
+    private static Subscriber getSubscriber(final ApplicationConfig config, final BuildInfo buildInfo) {
+        final RestTemplate restTemplate = getRestTemplate(config, buildInfo);
         final SchemaProvider schemaProvider = getSchemaProvider();
         final MessageDigestService messageDigestService = getMessageDigestService();
 
@@ -124,8 +123,8 @@ public final class ClientFactory {
         return new SubmissionSubscriber(submissionService, eventLogService, cryptoService, validator, setService);
     }
 
-    private static Sender getSender(final ApplicationConfig config) {
-        final RestTemplate restTemplate = getRestTemplate(config);
+    private static Sender getSender(final ApplicationConfig config, final BuildInfo buildInfo) {
+        final RestTemplate restTemplate = getRestTemplate(config, buildInfo);
         final SchemaProvider schemaProvider = getSchemaProvider();
         final MessageDigestService messageDigestService = getMessageDigestService();
 
@@ -169,8 +168,8 @@ public final class ClientFactory {
         return new JWECryptoService(messageDigestService);
     }
 
-    private static RestTemplate getRestTemplate(final ApplicationConfig config) {
-        final ProxyConfig proxyConfig = new ProxyConfig(config.getHttpProxyHost(), config.getHttpProxyPort());
+    private static RestTemplate getRestTemplate(final ApplicationConfig config, final BuildInfo buildInfo) {
+        final ProxyConfig proxyConfig = new ProxyConfig(config.getHttpProxyHost(), config.getHttpProxyPort(), buildInfo);
         return proxyConfig.proxyRestTemplate();
     }
 

client/src/main/resources/buildinfo.yaml

+productName: "${project.name}"
+productVersion: "${project.version}"
+commit: "${git.commit.id.full}"
\ No newline at end of file

client/src/test/java/dev/fitko/fitconnect/client/ClientIntegrationTest.java

@@ -22,8 +22,8 @@ import dev.fitko.fitconnect.api.services.crypto.CryptoService;
 import dev.fitko.fitconnect.client.factory.ClientFactory;
 import dev.fitko.fitconnect.client.sender.EncryptedSubmissionBuilder;
 import dev.fitko.fitconnect.client.sender.SubmissionBuilder;
-import dev.fitko.fitconnect.client.subscriber.ReceivedSubmission;
 import dev.fitko.fitconnect.client.sender.model.AttachmentPayload;
+import dev.fitko.fitconnect.client.subscriber.ReceivedSubmission;
 import dev.fitko.fitconnect.client.util.SubmissionUtil;
 import dev.fitko.fitconnect.core.auth.DefaultOAuthService;
 import dev.fitko.fitconnect.core.crypto.HashService;

client/src/test/java/dev/fitko/fitconnect/client/SenderClientTest.java

@@ -18,12 +18,7 @@ import dev.fitko.fitconnect.api.domain.model.submission.SentSubmission;
 import dev.fitko.fitconnect.api.domain.model.submission.Submission;
 import dev.fitko.fitconnect.api.domain.model.submission.SubmissionForPickup;
 import dev.fitko.fitconnect.api.domain.validation.ValidationResult;
-import dev.fitko.fitconnect.api.exceptions.EncryptionException;
-import dev.fitko.fitconnect.api.exceptions.EventLogException;
-import dev.fitko.fitconnect.api.exceptions.KeyNotRetrievedException;
-import dev.fitko.fitconnect.api.exceptions.RestApiException;
-import dev.fitko.fitconnect.api.exceptions.SubmissionNotCreatedException;
-import dev.fitko.fitconnect.api.exceptions.ValidationException;
+import dev.fitko.fitconnect.api.exceptions.*;
 import dev.fitko.fitconnect.api.services.Sender;
 import dev.fitko.fitconnect.client.sender.EncryptedSubmissionBuilder;
 import dev.fitko.fitconnect.client.sender.SubmissionBuilder;
@@ -35,24 +30,15 @@ import org.junit.jupiter.api.Test;
 
 import java.io.File;
 import java.net.URI;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-import java.util.Set;
-import java.util.UUID;
+import java.util.*;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.core.IsEqual.equalTo;
-import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.assertNull;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.*;
+import static org.mockito.Mockito.*;
 
 public class SenderClientTest {
 
@@ -636,6 +622,18 @@ public class SenderClientTest {
 
     }
 
+    @Test
+    void validateCallback() {
+
+        when(this.senderMock.validateCallback(anyString(), anyLong(), anyString(), anyString())).thenReturn(ValidationResult.ok());
+
+        ValidationResult validationResult = this.senderClient.validateCallback("hmac", 0L, "body", "secret");
+
+        verify(this.senderMock, times(1)).validateCallback(anyString(), anyLong(), anyString(), anyString());
+        assertTrue(validationResult.isValid());
+        assertFalse(validationResult.hasError());
+    }
+
     private UUID setupTestMocks() throws JOSEException {
         final var destinationId = UUID.randomUUID();
         final var destination = getDestination(destinationId);

client/src/test/java/dev/fitko/fitconnect/client/SubscriberClientTest.java

@@ -550,6 +550,18 @@ class SubscriberClientTest {
 
     }
 
+    @Test
+    void validateCallback() {
+
+        when(this.subscriberMock.validateCallback(anyString(), anyLong(), anyString(), anyString())).thenReturn(ValidationResult.ok());
+
+        ValidationResult validationResult = this.underTest.validateCallback("hmac", 0L, "body", "secret");
+
+        verify(this.subscriberMock, times(1)).validateCallback(anyString(), anyLong(), anyString(), anyString());
+        assertTrue(validationResult.isValid());
+        assertFalse(validationResult.hasError());
+    }
+
     private String getResourceAsString(final String name) throws IOException {
         final ClassLoader classLoader = getClass().getClassLoader();
         final File file = new File(Objects.requireNonNull(classLoader.getResource(name)).getFile());

client/src/test/java/dev/fitko/fitconnect/client/factory/ApplicationConfigLoaderTest.java

@@ -16,9 +16,7 @@ import java.nio.file.Path;
 import java.util.Objects;
 
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.containsString;
-import static org.hamcrest.Matchers.equalTo;
-import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.*;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 class ApplicationConfigLoaderTest {

client/src/test/java/dev/fitko/fitconnect/client/factory/ClientFactoryTest.java

 package dev.fitko.fitconnect.client.factory;
 
-import dev.fitko.fitconnect.api.config.ApplicationConfig;
-import dev.fitko.fitconnect.api.config.Environment;
-import dev.fitko.fitconnect.api.config.EnvironmentName;
-import dev.fitko.fitconnect.api.config.SenderConfig;
-import dev.fitko.fitconnect.api.config.SubscriberConfig;
+import dev.fitko.fitconnect.api.config.*;
 import dev.fitko.fitconnect.api.exceptions.InitializationException;
 import dev.fitko.fitconnect.api.exceptions.InvalidKeyException;
 import org.junit.jupiter.api.Test;

core/src/main/java/dev/fitko/fitconnect/core/SubmissionSender.java

@@ -59,6 +59,11 @@ public class SubmissionSender implements Sender {
         return validationService.validateMetadataSchema(metadata);
     }
 
+    @Override
+    public ValidationResult validateCallback(String hmac, Long timestamp, String httpBody, String callbackSecret) {
+        return this.validationService.validateCallback(hmac, timestamp, httpBody, callbackSecret);
+    }
+
     @Override
     public String encryptBytes(final RSAKey publicKey, final byte[] data) {
         LOGGER.info("Encrypting {} bytes", data.length);

core/src/main/java/dev/fitko/fitconnect/core/SubmissionSubscriber.java

@@ -85,6 +85,11 @@ public class SubmissionSubscriber implements Subscriber {
         return validationService.validateHashIntegrity(originalHash, data);
     }
 
+    @Override
+    public ValidationResult validateCallback(String hmac, Long timestamp, String httpBody, String callbackSecret) {
+        return this.validationService.validateCallback(hmac, timestamp, httpBody, callbackSecret);
+    }
+
     @Override
     public void acceptSubmission(final EventPayload eventPayload) {
         LOGGER.info("Accepting submission");

core/src/main/java/dev/fitko/fitconnect/core/crypto/HashService.java

 package dev.fitko.fitconnect.core.crypto;
 
+import dev.fitko.fitconnect.api.exceptions.EncryptionException;
 import dev.fitko.fitconnect.api.exceptions.InitializationException;
 import dev.fitko.fitconnect.api.services.crypto.MessageDigestService;
 import dev.fitko.fitconnect.core.util.StopWatch;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+import java.security.InvalidKeyException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 
 public class HashService implements MessageDigestService {
 
     static final String DEFAULT_ALGORITHM = "SHA-512"; // Currently, only SHA-512 is supported.
+    private static final String HMAC_SHA512 = "HmacSHA512";
 
     private static final Logger LOGGER = LoggerFactory.getLogger(HashService.class);
 
@@ -67,6 +72,19 @@ public class HashService implements MessageDigestService {
         return bytes;
     }
 
+    @Override
+    public String calculateHMAC(String data, String key) {
+
+        try {
+            SecretKeySpec secretKeySpec = new SecretKeySpec(key.getBytes(), HMAC_SHA512);
+            Mac mac = Mac.getInstance(HMAC_SHA512);
+            mac.init(secretKeySpec);
+            return toHexString(mac.doFinal(data.getBytes()));
+        } catch (NoSuchAlgorithmException | InvalidKeyException e) {
+            throw new EncryptionException("Calculation of HMAC failed.", e);
+        }
+    }
+
     private byte hexToByte(final String hexString) {
         final int firstDigit = toDigit(hexString.charAt(0));
         final int secondDigit = toDigit(hexString.charAt(1));