Add random key padding (#609)

corona-warn-app · Jun 22, 2020 · 3d58c8f · 3d58c8f
1 parent e3d9044
commit 3d58c8f
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Showing 5 changed files with 85 additions and 21 deletions.
diff --git a/...c/main/java/app/coronawarn/server/services/submission/config/SubmissionServiceConfig.java b/...c/main/java/app/coronawarn/server/services/submission/config/SubmissionServiceConfig.java
@@ -21,18 +21,25 @@
 package app.coronawarn.server.services.submission.config;
 
 import java.io.File;
+import javax.validation.constraints.Max;
+import javax.validation.constraints.Min;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.stereotype.Component;
+import org.springframework.validation.annotation.Validated;
 
 @Component
 @ConfigurationProperties(prefix = "services.submission")
+@Validated
 public class SubmissionServiceConfig {
 
   // Exponential moving average of the last N real request durations (in ms), where
   // N = fakeDelayMovingAverageSamples.
   private Long initialFakeDelayMilliseconds;
   private Long fakeDelayMovingAverageSamples;
   private Integer retentionDays;
+  @Min(1)
+  @Max(100)
+  private Integer randomKeyPaddingMultiplier;
   private Integer connectionPoolSize;
   private Payload payload;
   private Verification verification;
@@ -63,6 +70,14 @@ public void setRetentionDays(Integer retentionDays) {
     this.retentionDays = retentionDays;
   }
 
+  public Integer getRandomKeyPaddingMultiplier() {
+    return randomKeyPaddingMultiplier;
+  }
+
+  public void setRandomKeyPaddingMultiplier(Integer randomKeyPaddingMultiplier) {
+    this.randomKeyPaddingMultiplier = randomKeyPaddingMultiplier;
+  }
+
   public Integer getConnectionPoolSize() {
     return connectionPoolSize;
   }

diff --git a/.../main/java/app/coronawarn/server/services/submission/controller/SubmissionController.java b/.../main/java/app/coronawarn/server/services/submission/controller/SubmissionController.java
@@ -29,8 +29,10 @@
 import app.coronawarn.server.services.submission.validation.ValidSubmissionPayload;
 import app.coronawarn.server.services.submission.verification.TanVerifier;
 import io.micrometer.core.annotation.Timed;
+import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.IntStream;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.http.HttpStatus;
@@ -59,6 +61,7 @@ public class SubmissionController {
   private final DiagnosisKeyService diagnosisKeyService;
   private final TanVerifier tanVerifier;
   private final Integer retentionDays;
+  private final Integer randomKeyPaddingMultiplier;
   private final FakeDelayManager fakeDelayManager;
 
   SubmissionController(
@@ -69,6 +72,7 @@ public class SubmissionController {
     this.submissionMonitor = submissionMonitor;
     this.fakeDelayManager = fakeDelayManager;
     retentionDays = submissionServiceConfig.getRetentionDays();
+    randomKeyPaddingMultiplier = submissionServiceConfig.getRandomKeyPaddingMultiplier();
   }
 
   /**
@@ -130,6 +134,26 @@ public void persistDiagnosisKeysPayload(SubmissionPayload protoBufDiagnosisKeys)
       }
     }
 
-    diagnosisKeyService.saveDiagnosisKeys(diagnosisKeys);
+    diagnosisKeyService.saveDiagnosisKeys(padDiagnosisKeys(diagnosisKeys));
+  }
+
+  private List<DiagnosisKey> padDiagnosisKeys(List<DiagnosisKey> diagnosisKeys) {
+    List<DiagnosisKey> paddedDiagnosisKeys = new ArrayList<>();
+    diagnosisKeys.forEach(diagnosisKey -> {
+      paddedDiagnosisKeys.add(diagnosisKey);
+      IntStream.range(1, randomKeyPaddingMultiplier)
+          .mapToObj(index -> {
+            byte[] randomKeyData = new byte[16];
+            new SecureRandom().nextBytes(randomKeyData);
+            return DiagnosisKey.builder()
+                .withKeyData(randomKeyData)
+                .withRollingStartIntervalNumber(diagnosisKey.getRollingStartIntervalNumber())
+                .withTransmissionRiskLevel(diagnosisKey.getTransmissionRiskLevel())
+                .withRollingPeriod(diagnosisKey.getRollingPeriod())
+                .build();
+          })
+          .forEach(paddedDiagnosisKeys::add);
+    });
+    return paddedDiagnosisKeys;
   }
 }
diff --git a/services/submission/src/main/resources/application.yaml b/services/submission/src/main/resources/application.yaml
@@ -15,6 +15,12 @@ services:
     fake-delay-moving-average-samples: 10
     # The retention threshold for acceptable diagnosis keys during submission.
     retention-days: 14
+    # The number of keys to save to the DB for every real submitted key.
+    # Example: If the 'random-key-padding-multiplier' is set to 10, and 5 keys are being submitted,
+    # then the 5 real submitted keys will be saved to the DB, plus an additional 45 keys with
+    # random 'key_data'. All properties, besides the 'key_data', of the additional keys will be
+    # identical to the real key.
+    random-key-padding-multiplier: ${RANDOM_KEY_PADDING_MULTIPLIER:1}
     # The ApacheHttpClient's connection pool size.
     connection-pool-size: 200
     payload:

diff --git a/...t/java/app/coronawarn/server/services/submission/controller/SubmissionControllerTest.java b/...t/java/app/coronawarn/server/services/submission/controller/SubmissionControllerTest.java
@@ -127,28 +127,28 @@ void singleKeyWithOutdatedRollingStartIntervalNumberDoesNotGetSaved() {
 
   @Test
   void keysWithOutdatedRollingStartIntervalNumberDoNotGetSaved() {
-    Collection<TemporaryExposureKey> keys = buildPayloadWithMultipleKeys();
+    Collection<TemporaryExposureKey> submittedKeys = buildPayloadWithMultipleKeys();
     TemporaryExposureKey outdatedKey = createOutdatedKey();
-    keys.add(outdatedKey);
+    submittedKeys.add(outdatedKey);
     ArgumentCaptor<Collection<DiagnosisKey>> argument = ArgumentCaptor.forClass(Collection.class);
 
-    executor.executePost(keys, buildOkHeaders());
+    executor.executePost(submittedKeys, buildOkHeaders());
 
     verify(diagnosisKeyService, atLeastOnce()).saveDiagnosisKeys(argument.capture());
-    keys.remove(outdatedKey);
-    assertElementsCorrespondToEachOther(keys, argument.getValue());
+    submittedKeys.remove(outdatedKey);
+    assertElementsCorrespondToEachOther(submittedKeys, argument.getValue());
   }
 
   @Test
   void checkSaveOperationCallAndFakeDelayUpdateForValidParameters() {
-    Collection<TemporaryExposureKey> keys = buildPayloadWithMultipleKeys();
+    Collection<TemporaryExposureKey> submittedKeys = buildPayloadWithMultipleKeys();
     ArgumentCaptor<Collection<DiagnosisKey>> argument = ArgumentCaptor.forClass(Collection.class);
 
-    executor.executePost(keys, buildOkHeaders());
+    executor.executePost(submittedKeys, buildOkHeaders());
 
     verify(diagnosisKeyService, atLeastOnce()).saveDiagnosisKeys(argument.capture());
     verify(fakeDelayManager, times(1)).updateFakeRequestDelay(anyLong());
-    assertElementsCorrespondToEachOther(keys, argument.getValue());
+    assertElementsCorrespondToEachOther(submittedKeys, argument.getValue());
   }
 
   @ParameterizedTest
@@ -186,7 +186,7 @@ private static Stream<Arguments> createDeniedHttpMethods() {
     return Arrays.stream(HttpMethod.values())
         .filter(method -> method != HttpMethod.POST)
         .filter(method -> method != HttpMethod.PATCH) /* not supported by Rest Template */
-        .map(elem -> Arguments.of(elem));
+        .map(Arguments::of);
   }
 
   @Test
@@ -252,18 +252,36 @@ private static Collection<TemporaryExposureKey> buildPayloadWithInvalidKey() {
         .collect(Collectors.toCollection(ArrayList::new));
   }
 
-  private void assertElementsCorrespondToEachOther
-      (Collection<TemporaryExposureKey> submittedKeys, Collection<DiagnosisKey> keyEntities) {
-    Set<DiagnosisKey> expKeys = submittedKeys.stream()
-        .map(aSubmittedKey -> DiagnosisKey.builder().fromProtoBuf(aSubmittedKey).build())
+  private void assertElementsCorrespondToEachOther(Collection<TemporaryExposureKey> submittedTemporaryExposureKeys,
+      Collection<DiagnosisKey> savedDiagnosisKeys) {
+
+    Set<DiagnosisKey> submittedDiagnosisKeys = submittedTemporaryExposureKeys.stream()
+        .map(submittedDiagnosisKey -> DiagnosisKey.builder().fromProtoBuf(submittedDiagnosisKey).build())
         .collect(Collectors.toSet());
 
-    assertThat(keyEntities)
-        .withFailMessage("Number of submitted keys and generated key entities don't match.")
-        .hasSameSizeAs(expKeys);
-    keyEntities.forEach(anActKey -> assertThat(expKeys)
-        .withFailMessage("Key entity does not correspond to a submitted key.")
-        .contains(anActKey)
-    );
+    assertThat(savedDiagnosisKeys).hasSize(submittedDiagnosisKeys.size() * 10);
+    assertThat(savedDiagnosisKeys).containsAll(submittedDiagnosisKeys);
+
+    submittedDiagnosisKeys.forEach(submittedDiagnosisKey -> {
+      List<DiagnosisKey> savedKeysForSingleSubmittedKey = savedDiagnosisKeys.stream()
+          .filter(savedDiagnosisKey -> savedDiagnosisKey.getRollingPeriod() ==
+              submittedDiagnosisKey.getRollingPeriod())
+          .filter(savedDiagnosisKey -> savedDiagnosisKey.getTransmissionRiskLevel() ==
+              submittedDiagnosisKey.getTransmissionRiskLevel())
+          .filter(savedDiagnosisKey -> savedDiagnosisKey.getRollingStartIntervalNumber() ==
+              submittedDiagnosisKey.getRollingStartIntervalNumber())
+          .collect(Collectors.toList());
+
+      assertThat(savedKeysForSingleSubmittedKey).hasSize(10);
+      assertThat(savedKeysForSingleSubmittedKey.stream().filter(savedKey ->
+          Arrays.equals(savedKey.getKeyData(), submittedDiagnosisKey.getKeyData()))).hasSize(1);
+      assertThat(savedKeysForSingleSubmittedKey).allMatch(
+          savedKey -> savedKey.getRollingPeriod() == submittedDiagnosisKey.getRollingPeriod());
+      assertThat(savedKeysForSingleSubmittedKey).allMatch(
+          savedKey -> savedKey.getRollingStartIntervalNumber() == submittedDiagnosisKey
+              .getRollingStartIntervalNumber());
+      assertThat(savedKeysForSingleSubmittedKey).allMatch(
+          savedKey -> savedKey.getTransmissionRiskLevel() == submittedDiagnosisKey.getTransmissionRiskLevel());
+    });
   }
 }
diff --git a/services/submission/src/test/resources/application.yaml b/services/submission/src/test/resources/application.yaml
@@ -25,6 +25,7 @@ services:
     initial-fake-delay-milliseconds: 1
     fake-delay-moving-average-samples: 1
     retention-days: 14
+    random-key-padding-multiplier: 10
     connection-pool-size: 200
     payload:
       max-number-of-keys: 14