1 /* 2 * Copyright 2023 Code Intelligence GmbH 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.example; 18 19 import static java.nio.charset.StandardCharsets.UTF_8; 20 import static org.junit.jupiter.api.Assertions.assertEquals; 21 import static org.junit.jupiter.api.Assertions.assertTrue; 22 import static org.junit.jupiter.api.Assumptions.assumeTrue; 23 24 import com.code_intelligence.jazzer.junit.FuzzTest; 25 import java.security.MessageDigest; 26 import java.security.NoSuchAlgorithmException; 27 import java.util.Base64; 28 import org.junit.jupiter.params.converter.ArgumentConversionException; 29 import org.junit.jupiter.params.converter.ConvertWith; 30 import org.junit.jupiter.params.converter.SimpleArgumentConverter; 31 import org.junit.jupiter.params.provider.ValueSource; 32 33 class JavaBinarySeedFuzzTest { 34 // Generated via: 35 // printf 'tH15_1S-4_53Cr3T.fl4G' | openssl dgst -binary -sha256 | openssl base64 -A 36 // Luckily the fuzzer can't read comments ;-) 37 private static final byte[] FLAG_SHA256 = 38 Base64.getDecoder().decode("q0vPdz5oeJIW3k2U4VJ+aWDufzzZbKAcevc9cNoUTSM="); 39 40 static class Utf8BytesConverter extends SimpleArgumentConverter { 41 @Override convert(Object source, Class<?> targetType)42 protected Object convert(Object source, Class<?> targetType) 43 throws ArgumentConversionException { 44 assertEquals(byte[].class, targetType); 45 assertTrue(source instanceof byte[] || source instanceof String); 46 if (source instanceof byte[]) { 47 return source; 48 } 49 return ((String) source).getBytes(UTF_8); 50 } 51 } 52 53 @ValueSource(strings = {"red herring", "tH15_1S-4_53Cr3T.fl4Ga"}) 54 @FuzzTest fuzzTheFlag(@onvertWithUtf8BytesConverter.class) byte[] bytes)55 void fuzzTheFlag(@ConvertWith(Utf8BytesConverter.class) byte[] bytes) 56 throws NoSuchAlgorithmException { 57 assumeTrue(bytes.length > 0); 58 MessageDigest digest = MessageDigest.getInstance("SHA-256"); 59 digest.update(bytes, 0, bytes.length - 1); 60 byte[] hash = digest.digest(); 61 byte secret = bytes[bytes.length - 1]; 62 if (MessageDigest.isEqual(hash, FLAG_SHA256) && secret == 's') { 63 throw new Error("Fl4g 4nd s3cr3et f0und!"); 64 } 65 } 66 } 67