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diff --git a/examples/src/main/java/com/example/ExampleValueProfileFuzzer.java b/examples/src/main/java/com/example/ExampleValueProfileFuzzer.java
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+// Copyright 2021 Code Intelligence GmbH
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.example;
+
+import com.code_intelligence.jazzer.api.FuzzedDataProvider;
+import com.code_intelligence.jazzer.api.FuzzerSecurityIssueLow;
+import java.util.Base64;
+
+public class ExampleValueProfileFuzzer {
+ private static String base64(byte[] input) {
+ return Base64.getEncoder().encodeToString(input);
+ }
+
+ private static long insecureEncrypt(long input) {
+ long key = 0xefe4eb93215cb6b0L;
+ return input ^ key;
+ }
+
+ public static void fuzzerTestOneInput(FuzzedDataProvider data) {
+ // Without -use_value_profile=1, the fuzzer gets stuck here as there is no direct correspondence
+ // between the input bytes and the compared string. With value profile, the fuzzer can guess the
+ // expected input byte by byte, which takes linear rather than exponential time.
+ if (base64(data.consumeBytes(6)).equals("SmF6emVy")) {
+ long[] plaintextBlocks = data.consumeLongs(2);
+ if (plaintextBlocks.length != 2)
+ return;
+ if (insecureEncrypt(plaintextBlocks[0]) == 0x9fc48ee64d3dc090L) {
+ // Without --fake_pcs (enabled by default with -use_value_profile=1), the fuzzer would get
+ // stuck here as the value profile information for long comparisons would not be able to
+ // distinguish between this comparison and the one above.
+ if (insecureEncrypt(plaintextBlocks[1]) == 0x888a82ff483ad9c2L) {
+ mustNeverBeCalled();
+ }
+ }
+ }
+ }
+
+ private static void mustNeverBeCalled() {
+ throw new FuzzerSecurityIssueLow("mustNeverBeCalled has been called");
+ }
+}