Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
ProGuard
Search
Edward Dale
August 31, 2017
Technology
1
500
ProGuard
An introduction to how ProGuard works.
Edward Dale
August 31, 2017
Tweet
Share
More Decks by Edward Dale
See All by Edward Dale
Write your own ProGuard
scompt
1
200
Screenshot your Entire App with Screengrab and Firebase
scompt
0
460
Screenshot your Entire App
scompt
1
2k
Reactive In-App Billing on Android
scompt
2
290
Fitness Motion Recognition with Android Wear
scompt
1
440
Android Apps with Mortar and Flow
scompt
7
1.6k
Functional Reactive Programming in the Mobile World
scompt
2
330
Other Decks in Technology
See All in Technology
Amazon S3標準/ S3 Tables/S3 Express One Zoneを使ったログ分析
shigeruoda
4
480
Welcome to the LLM Club
koic
0
170
Witchcraft for Memory
pocke
1
310
セキュリティの民主化は何故必要なのか_AWS WAF 運用の 10 の苦悩から学ぶ
yoh
1
140
CI/CD/IaC 久々に0から環境を作ったらこうなりました
kaz29
1
170
製造業からパッケージ製品まで、あらゆる領域をカバー!生成AIを利用したテストシナリオ生成 / 20250627 Suguru Ishii
shift_evolve
PRO
1
140
Snowflake Summit 2025 データエンジニアリング関連新機能紹介 / Snowflake Summit 2025 What's New about Data Engineering
tiltmax3
0
310
変化する開発、進化する体系時代に適応するソフトウェアエンジニアの知識と考え方(JaSST'25 Kansai)
mizunori
1
210
【TiDB GAME DAY 2025】Shadowverse: Worlds Beyond にみる TiDB 活用術
cygames
0
1.1k
2年でここまで成長!AWSで育てたAI Slack botの軌跡
iwamot
PRO
4
700
A2Aのクライアントを自作する
rynsuke
1
170
BigQuery Remote FunctionでLooker Studioをインタラクティブ化
cuebic9bic
3
280
Featured
See All Featured
The Cult of Friendly URLs
andyhume
79
6.5k
Designing Dashboards & Data Visualisations in Web Apps
destraynor
231
53k
Gamification - CAS2011
davidbonilla
81
5.3k
JavaScript: Past, Present, and Future - NDC Porto 2020
reverentgeek
48
5.4k
Docker and Python
trallard
44
3.4k
StorybookのUI Testing Handbookを読んだ
zakiyama
30
5.8k
Agile that works and the tools we love
rasmusluckow
329
21k
Refactoring Trust on Your Teams (GOTO; Chicago 2020)
rmw
34
3k
Rails Girls Zürich Keynote
gr2m
94
14k
"I'm Feeling Lucky" - Building Great Search Experiences for Today's Users (#IAC19)
danielanewman
229
22k
Producing Creativity
orderedlist
PRO
346
40k
Evolution of real-time – Irina Nazarova, EuRuKo, 2024
irinanazarova
8
790
Transcript
ProGuard Edward Dale @scompt Freeletics https://www.freeletics.com August 31, 2017 ©
Edward Dale, 2017 1
Agenda • Overview • Steps • Problems • Future ©
Edward Dale, 2017 2
Purpose ProGuard is the most popular optimizer for Java bytecode.
It makes your Java and Android applications up to 90% smaller and up to 20% faster. ProGuard also provides minimal protection against reverse engineering by obfuscating the names of classes, fields and methods. — https://www.guardsquare.com/en/proguard © Edward Dale, 2017 3
Purpose ProGuard is the most popular optimizer for Java bytecode.
It makes your Java and Android applications up to 90% smaller and up to 20% faster. ProGuard also provides minimal protection against reverse engineering by obfuscating the names of classes, fields and methods. — https://www.guardsquare.com/en/proguard © Edward Dale, 2017 4
Highlights 1 • ProGuard is a command-line tool with an
optional graphical user interface. • ProGuard is easy to configure. A few intuitive command line options or a simple configuration file is all it takes. All available options are detailed in the user manual. 1 https://www.guardsquare.com/en/proguard © Edward Dale, 2017 5
Highlights 1 (continued) • ProGuard is fast. It processes small
Android applications and entire run-time libraries in seconds. • ProGuard is the default tool in development environments like Oracle’s Wireless Toolkit, NetBeans, EclipseME, Intel’s TXE SDK and Google’s Android SDK. 1 https://www.guardsquare.com/en/proguard © Edward Dale, 2017 6
Highlights (annotated) • ProGuard is easy to configure. A few
intuitive command line options or a simple configuration file is all it takes. All available options are detailed in the user manual. • ProGuard is fast. It processes small Android applications and entire run- time libraries in seconds. © Edward Dale, 2017 7
Steps start shrink end optimize obfuscate preverify © Edward Dale,
2017 8
Shrink Step • Enabled by default • Disabled with -dontshrink
• Removes all classes, methods, resources not reachable from from an entry point (seeds) • Dynamically referenced classes/methods need to be "kept" using -keep or -keepclasseswithmembers © Edward Dale, 2017 9
Example Class Diagram LoginActivity UserManager UserApi FeedActivity FeedApi OldUserManager OldUserApi
© Edward Dale, 2017 10
After Shrinking • No seeds LoginActivity UserManager UserApi FeedActivity FeedApi
OldUserManager OldUserApi © Edward Dale, 2017 11
After Shrinking • -keep MainActivity • -keep SecondActivity LoginActivity UserManager
UserApi FeedActivity FeedApi OldUserManager OldUserApi © Edward Dale, 2017 12
After Shrinking • -keep public class * extends android.app.Activity LoginActivity
UserManager UserApi FeedActivity FeedApi OldUserManager OldUserApi © Edward Dale, 2017 13
Keep Options -keep Specifies classes and class members (fields and
methods) to be preserved as entry points to your code. -keepclassmembers Specifies class members to be preserved, if their classes are preserved as well. -keepclasseswithmembers Specifies classes and class members to be preserved, on the condition that all of the specified class members are present. © Edward Dale, 2017 14
Optimize Step • Enabled by default • Disabled with -dontoptimize
• Performs lots of different bytecode-level optimizations to the code © Edward Dale, 2017 15
Optimize Step • -optimizationpasses declares how many times to optimize/shrink
• Freeletics does 5 passes © Edward Dale, 2017 16
Optimize Step • -optimizations can be used to disable specific
optimizations • Freeletics disables optimizations that cause problems on Android • More information in $ANDROID_HOME/tools/proguard/ proguard-android-optimize.txt © Edward Dale, 2017 17
Example Optimizations 2 • Marks methods as final, whenever possible.
• Removes unused method parameters. • Propagates the values of method parameters from method invocations to the invoked methods. • Propagates the values of method return values from methods to their invocations. • Inlines short methods. • Inlines methods that are only called once. 2 https://www.guardsquare.com/en/proguard/manual/optimizations © Edward Dale, 2017 18
Obfuscate Step • Enabled by default • Disabled with -dontobfuscate
• Classes and class members receive new short random names, except for the ones listed by the various -keep options • Internal attributes that are useful for debugging are removed © Edward Dale, 2017 19
After Obfuscation LoginActivity A B FeedActivity C OldUserManager OldUserApi ©
Edward Dale, 2017 20
Preverification Step • Enabled by default • Disabled with -dontpreverify
• When loading class files, the class loader performs some sophisticated verification of the byte code. • Unnecessary on Android © Edward Dale, 2017 21
Problems © Edward Dale, 2017 22
Problem 1 Class is unintentionally removed/obfuscated Symptom: Runtime crash java.lang.NoClassDefFoundError:
Failed resolution of: Lcom/freeletics/LoginActivity; © Edward Dale, 2017 23
Problem 1 Class is unintentionally removed/obfuscated Symptom: Runtime crash java.lang.NoClassDefFoundError:
Failed resolution of: Lcom/freeletics/LoginActivity; Solution: Ensure class is kept -keep com.freeletics.LoginActivity © Edward Dale, 2017 24
Problem 2 Code references a class not available Symptom:: Build
failure Warning: rx.internal.util.unsafe.ConcurrentCircularArrayQueue: can't find referenced class sun.misc.Unsafe ... Warning: there were 47 unresolved references to classes or interfaces. © Edward Dale, 2017 25
Problem 2 Code references a class not available Symptom:: Build
failure Warning: rx.internal.util.unsafe.ConcurrentCircularArrayQueue: can't find referenced class sun.misc.Unsafe ... Warning: there were 47 unresolved references to classes or interfaces. Solution: Don't warn about classes unavailable on Android -dontwarn sun.misc.Unsafe © Edward Dale, 2017 26
Problem 3 Adding a new library breaks build Symptom: Build
failure © Edward Dale, 2017 27
Problem 3 Adding a new library breaks build Symptom: Build
failure Solution: Google Should only happen with non-Android-specific libraries. Android-specific Libraries can add a ProGuard configuration that should be used. © Edward Dale, 2017 28
The Future we are also working on R8, which is
a Proguard replacement for whole program minification and optimization3 — James Lau, Product Manager 3 https://android-developers.googleblog.com/2017/08/next-generation-dex-compiler-now-in.html © Edward Dale, 2017 29
The Future • D8 is a dexer that converts java
byte code to dex code. • R8 is a java program shrinking and minification tool that converts java byte code to optimized dex code. • R8 is a Proguard replacement for whole-program optimization, shrinking and minification. R8 uses the Proguard keep rule format for specifying the entry points for an application. © Edward Dale, 2017 30
Questions? Edward Dale @scompt Freeletics https://www.freeletics.com © Edward Dale, 2017
31
Citations • http://knowyourmeme.com/memes/yao-ming-face-bitch- please © Edward Dale, 2017 32