Merge "Use encoder id as insecure DP encoder random seed"

4 files changed, 12 insertions, 13 deletions

diff --git a/core/java/android/privacy/internal/rappor/RapporEncoder.java b/core/java/android/privacy/internal/rappor/RapporEncoder.java
index 2eca4c98d235..9ac2b3e1136e 100644
--- a/core/java/android/privacy/internal/rappor/RapporEncoder.java
+++ b/core/java/android/privacy/internal/rappor/RapporEncoder.java
@@ -33,7 +33,6 @@ import java.util.Random;
 public class RapporEncoder implements DifferentialPrivacyEncoder {
 
     // Hard-coded seed and secret for insecure encoder
-    private static final long INSECURE_RANDOM_SEED = 0x12345678L;
     private static final byte[] INSECURE_SECRET = new byte[]{
             (byte) 0xD7, (byte) 0x68, (byte) 0x99, (byte) 0x93,
             (byte) 0x94, (byte) 0x13, (byte) 0x53, (byte) 0x54,
@@ -66,8 +65,8 @@ public class RapporEncoder implements DifferentialPrivacyEncoder {
             // Use SecureRandom as random generator.
             random = sSecureRandom;
         } else {
-            // Hard-coded random generator, to have deterministic result.
-            random = new Random(INSECURE_RANDOM_SEED);
+            // To have deterministic result by hard coding encoder id as seed.
+            random = new Random((long) config.mEncoderId.hashCode());
             userSecret = INSECURE_SECRET;
         }
         mEncoder = new Encoder(random, null, null,
diff --git a/core/tests/privacytests/src/android/privacy/LongitudinalReportingEncoderTest.java b/core/tests/privacytests/src/android/privacy/LongitudinalReportingEncoderTest.java
index 91664381efe0..6fe19a263e8b 100644
--- a/core/tests/privacytests/src/android/privacy/LongitudinalReportingEncoderTest.java
+++ b/core/tests/privacytests/src/android/privacy/LongitudinalReportingEncoderTest.java
@@ -72,13 +72,13 @@ public class LongitudinalReportingEncoderTest {
         final LongitudinalReportingEncoder encoder =
                 LongitudinalReportingEncoder.createInsecureEncoderForTest(
                         config);
-        assertEquals(1, encoder.encodeBoolean(true)[0]);
+        assertEquals(0, encoder.encodeBoolean(true)[0]);
         assertEquals(0, encoder.encodeBoolean(true)[0]);
         assertEquals(1, encoder.encodeBoolean(true)[0]);
+        assertEquals(0, encoder.encodeBoolean(true)[0]);
         assertEquals(1, encoder.encodeBoolean(true)[0]);
         assertEquals(1, encoder.encodeBoolean(true)[0]);
         assertEquals(1, encoder.encodeBoolean(true)[0]);
-        assertEquals(0, encoder.encodeBoolean(true)[0]);
         assertEquals(1, encoder.encodeBoolean(true)[0]);
         assertEquals(1, encoder.encodeBoolean(true)[0]);
         assertEquals(1, encoder.encodeBoolean(true)[0]);
@@ -86,12 +86,12 @@ public class LongitudinalReportingEncoderTest {
         assertEquals(0, encoder.encodeBoolean(false)[0]);
         assertEquals(1, encoder.encodeBoolean(false)[0]);
         assertEquals(1, encoder.encodeBoolean(false)[0]);
-        assertEquals(0, encoder.encodeBoolean(false)[0]);
+        assertEquals(1, encoder.encodeBoolean(false)[0]);
         assertEquals(0, encoder.encodeBoolean(false)[0]);
         assertEquals(0, encoder.encodeBoolean(false)[0]);
         assertEquals(1, encoder.encodeBoolean(false)[0]);
         assertEquals(0, encoder.encodeBoolean(false)[0]);
-        assertEquals(0, encoder.encodeBoolean(false)[0]);
+        assertEquals(1, encoder.encodeBoolean(false)[0]);
         assertEquals(1, encoder.encodeBoolean(false)[0]);
 
         // Test if IRR returns original result when f = 0
diff --git a/core/tests/privacytests/src/android/privacy/RapporEncoderTest.java b/core/tests/privacytests/src/android/privacy/RapporEncoderTest.java
index dad98b8e4a35..fa0343df88b4 100644
--- a/core/tests/privacytests/src/android/privacy/RapporEncoderTest.java
+++ b/core/tests/privacytests/src/android/privacy/RapporEncoderTest.java
@@ -80,7 +80,7 @@ public class RapporEncoderTest {
         int numBits = 8;
         final long inputValue = 254L;
         final long prrValue = 250L;
-        final long prrAndIrrValue = 184L;
+        final long prrAndIrrValue = 244L;
 
         final RapporConfig config1 = new RapporConfig(
                 "Foo", // encoderId
diff --git a/services/tests/servicestests/src/com/android/server/net/watchlist/PrivacyUtilsTests.java b/services/tests/servicestests/src/com/android/server/net/watchlist/PrivacyUtilsTests.java
index a31b46ce5534..999dce51bd9c 100644
--- a/services/tests/servicestests/src/com/android/server/net/watchlist/PrivacyUtilsTests.java
+++ b/services/tests/servicestests/src/com/android/server/net/watchlist/PrivacyUtilsTests.java
@@ -77,9 +77,9 @@ public class PrivacyUtilsTests {
         assertEquals(6, result.size());
         assertTrue(result.get("C86F9D37425340B635F43D6BC2506630761ADA71F5E6BBDBCA4651C479F9FB48"));
         assertTrue(result.get("C86F9D37425340B635F43D6BC2506630761ADA71F5E6BBDBCA4651C479F9FB49"));
-        assertFalse(result.get("C86F9D37425340B635F43D6BC2506630761ADA71F5E6BBDBCA4651C479F9FB47"));
-        assertTrue(result.get("E86F9D37425340B635F43D6BC2506630761ADA71F5E6BBDBCA4651C479F9FB45"));
-        assertFalse(result.get("C86F9D37425340B635F43D6BC2506630761ADA71F5E6BBDBCA4651C479F9FB44"));
+        assertTrue(result.get("C86F9D37425340B635F43D6BC2506630761ADA71F5E6BBDBCA4651C479F9FB47"));
+        assertFalse(result.get("E86F9D37425340B635F43D6BC2506630761ADA71F5E6BBDBCA4651C479F9FB45"));
+        assertTrue(result.get("C86F9D37425340B635F43D6BC2506630761ADA71F5E6BBDBCA4651C479F9FB44"));
         assertTrue(result.get("B86F9D37425340B635F43D6BC2506630761ADA71F5E6BBDBCA4651C479F9FB43"));
     }
 
@@ -87,7 +87,7 @@ public class PrivacyUtilsTests {
     public void testPrivacyUtils_createInsecureDPEncoderForTest() throws Exception {
         DifferentialPrivacyEncoder encoder = PrivacyUtils.createInsecureDPEncoderForTest("foo");
         assertEquals(
-                "EncoderId: watchlist_encoder:foo, ProbabilityF: 0.400, ProbabilityP: 0.250, "
+                "EncoderId: watchlist_encoder:foo, ProbabilityF: 0.469, ProbabilityP: 0.280, "
                         + "ProbabilityQ: 1.000",
                 encoder.getConfig().toString());
         assertTrue(encoder.isInsecureEncoderForTest());
@@ -97,7 +97,7 @@ public class PrivacyUtilsTests {
     public void testPrivacyUtils_createSecureDPEncoderTest() throws Exception {
         DifferentialPrivacyEncoder encoder = PrivacyUtils.createSecureDPEncoder(TEST_SECRET, "foo");
         assertEquals(
-                "EncoderId: watchlist_encoder:foo, ProbabilityF: 0.400, ProbabilityP: 0.250, "
+                "EncoderId: watchlist_encoder:foo, ProbabilityF: 0.469, ProbabilityP: 0.280, "
                         + "ProbabilityQ: 1.000",
                 encoder.getConfig().toString());
         assertFalse(encoder.isInsecureEncoderForTest());