HTTPSの基本から NetworkSecurityConfigまで

Transcript

1. %SPJE,BJHJ
   )5514ͷجຊ͔Β

   /FUXPSL4FDVSJUZ$POpH·Ͱ
   ೋ֊ಊ ว (Amane Nikaido)
   @a2kaido
   

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2. ࣗݾ঺հ
   • ௨৴͕޷͖Ͱ͢
   
   • conbu͞Μͷ͓ख఻͍Λ

   ͠·ͨ͠
   

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3. ຊηογϣϯͷத਎
   • HTTPS௨৴ͷ໾ׂͱ࢓૊Έ
   
   • NetworkSecurityConfigʹ͍ͭͯ
   
   • NΑΓલͷPinning Certificates
   
   • Pinning Certificatesͷӡ༻
   

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4. എܠ
   • ެऺແઢLANʹ઀ଓ͢Δػձͷ૿Ճ
   
   • ௨৴಺༰ͷ౪ௌ΍վ᜵ͷՄೳੑ͕͋Δ
   

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5. 2014೥ SSLূ໌ॻݕূͷ஫ҙשى
   

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6. 2016೥ HTTPSͷεεϝ
   • Protecting against unintentional
   regressions to cleartext traffic in your
   Android apps

   https://android-developers.googleblog.com/2016/04/protecting-against-unintentional.html
   
   
   • Mythbusting HTTPS: Squashing
   security’s urban legends - Google I/O
   2016

   https://www.youtube.com/watch?v=YMfW1bfyGSY
   

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7. 2017೥ Android Developers Blog
   • 2018/11·ͰʹTarget API levelΛ26Ҏ্ʹ

   ͠·͠ΐ͏
   
   • Android N͔ΒϢʔβʔ͕Πϯετʔϧ

   ͨ͠ϧʔτূ໌ॻΛ৴པ͠ͳ͍Α͏ʹ
   https://android-developers.googleblog.com/2017/12/improving-app-security-and-
   performance.html
   

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8. https://goo.gl/n4Aahh
   

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9. Androidͷ

   Ξοϓσʔτ
   

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10. Android M
    • usesCleartextTraffic
    
    • ฏจͰͷ௨৴Λېࢭ͢Δઃఆ
    …

    android:usesCleartextTraffic=“false”>

    …

    
    

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11. Android N
    • Ϣʔβ͕Πϯετʔϧͨ͠ϧʔτূ໌ॻ

    Λ৴པ͠ͳ͍
    
    • NetworkSecurityConfig
    
    • ฏจͰͷ௨৴ͷ཈ࢭ
    
    • CAͷΞϯΧʔ
    
    • Pinning Certificates(ϐϯཹΊ)
    

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12. ͦ΋ͦ΋HTTPSͱ͸
    

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13. ҉߸Խ௨৴ͷࡾཁૉ
    • ػີੑ
    
    • ϝοηʔδ׬શੑ
    
    • ΤϯυϙΠϯτਅਖ਼ੑ
    

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14. ҉߸Խ௨৴ͷࡾཁૉ
    • ػີੑ
    
    • ϝοηʔδ׬શੑ
    
    • ΤϯυϙΠϯτਅਖ਼ੑ
    ҉߸Խ͞Ε͍ͯͯ

    ౪ௌ͞Εͳ͍͜ͱ
    

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15. ҉߸Խ௨৴ͷࡾཁૉ
    • ػີੑ
    
    • ϝοηʔδ׬શੑ
    
    • ΤϯυϙΠϯτਅਖ਼ੑ
    վ͟Μ͕ͳ͘

    ׬શͰ͋Δ͜ͱ
    

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16. ҉߸Խ௨৴ͷࡾཁૉ
    • ػີੑ
    
    • ϝοηʔδ׬શੑ
    
    • ΤϯυϙΠϯτਅਖ਼ੑ
    ਖ਼͍͠௨৴ઌͱ

    ௨৴͍ͯ͠Δ͜ͱ
    

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17. ҉߸Խ௨৴ͷࡾཁૉ
    • ػີੑ
    
    • ϝοηʔδ׬શੑ
    
    • ΤϯυϙΠϯτਅਖ਼ੑ
    HTTPSͰ҆શੑ͕୲อ͞Ε͍ͯΔ͸ͣͰ͸ʁ
    

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18. HTTPS௨৴Λ͢ΔͨΊͷ

    ূ໌ॻͷ࿩
    

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19. Client Server
    

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20. Client Server
    ΄Μͱʹਖ਼͍͠௨৴૬खͳͷ͔ͳʁ
    

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21. Client Server
    ΄Μͱʹਖ਼͍͠௨৴૬खͳͷ͔ͳʁ
    Certification Authority(ೝূہ)
    

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22. Client Server
    Certification Authority(ೝূہ)
    ϧʔτূ໌ॻ
    

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23. Client Server
    Certification Authority(ೝূہ)
    ϧʔτূ໌ॻ
    ॺ໊෇͖

    SSLূ໌ॻൃߦ
    

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24. Client Server
    Certification Authority(ೝূہ)
    ϧʔτূ໌ॻ
    ॺ໊෇͖

    SSLূ໌ॻൃߦ
    SSLূ໌ॻ
    

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25. Client Server
    Certification Authority(ೝূہ)
    ϧʔτূ໌ॻ
    ॺ໊෇͖

    SSLূ໌ॻൃߦ
    SSLূ໌ॻ
    CAͷॺ໊͕͋Δ͔Β

    ؒҧ͍ͳ͍
    

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26. HTTPS௨৴ͷ

    ϋϯυγΣΠΫ
    

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27. HTTPS௨৴ͷྲྀΕ 1/4
    ClientHello
    Client Server
    

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28. HTTPS௨৴ͷྲྀΕ 2/4
    ClientHello
    Client Server
    ServerHello
    Certificate
    

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29. HTTPS௨৴ͷྲྀΕ 2/4
    ClientHello
    Client Server
    ServerHello
    Certificate
    ূ໌ॻΛνΣοΫ

    ৴པ͢ΔCAͷॺ໊͕͋Δ͔
    

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30. HTTPS௨৴ͷྲྀΕ 3/4
    ClientHello
    Client Server
    ServerHello
    Certificate
    Finish
    Finish
    

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31. HTTPS௨৴ͷྲྀΕ 4/4
    ClientHello
    Client Server
    ServerHello
    Certificate
    Finish
    Finish
    HTTPS
    

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32. தؒऀ߈ܸ
    Client Server
    

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33. தؒऀ߈ܸ
    ClientHello
    Client Server
    ClientHello
    ਖ਼͍͠ূ໌ॻ
    

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34. தؒऀ߈ܸ
    ClientHello
    Client Server
    ClientHello
    ਖ਼͍͠ূ໌ॻ
    ূ໌ॻΛࠩ͠ସ͑
    

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35. தؒऀ߈ܸ
    ClientHello
    Client Server
    ClientHello
    ਖ਼͍͠ূ໌ॻ
    ِ෺ͷূ໌ॻ
    

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36. தؒऀ߈ܸ
    ClientHello
    Client Server
    ClientHello
    ਖ਼͍͠ূ໌ॻ
    ِ෺ͷূ໌ॻ
    Finish Finish
    Finish
    Finish
    HTTPS HTTPS
    

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37. தؒऀ߈ܸ
    ClientHello
    Client Server
    ClientHello
    ਖ਼͍͠ূ໌ॻ
    ِ෺ͷূ໌ॻ
    Finish Finish
    Finish
    Finish
    HTTPS HTTPS
    ͜͜Ͱূ໌ॻͷݕূΛ

    ͍ͯ͠ΔͷͰ͸ʁ
    

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38. ِ෺ͷূ໌ॻΛ৴པʁ
    • ߈ܸऀΛCAͱͯ͠৴པ͍ͯ͠Δ

    (ϧʔτূ໌ॻΛΠϯετʔϧ͍ͯ͠Δ)
    Մೳੑ
    
    • ߈ܸऀ͕CA͔Βॺ໊෇͖ূ໌ॻΛ

    औಘͨ͠Մೳੑ
    

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39. ِ෺ͷূ໌ॻΛ৴པʁ
    • ߈ܸऀΛCAͱͯ͠৴པ͍ͯ͠Δ

    (ϧʔτূ໌ॻΛΠϯετʔϧ͍ͯ͠Δ)
    Մೳੑ
    
    • ߈ܸऀ͕CA͔Βॺ໊෇͖ূ໌ॻΛ

    औಘͨ͠Մೳੑ
    ৴པ͢ΔCAΛ੍ݶ͢Ε͹๷͛Δ
    

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40. ِ෺ͷূ໌ॻΛ৴པʁ
    • ߈ܸऀΛCAͱͯ͠৴པ͍ͯ͠Δ

    (ϧʔτূ໌ॻΛΠϯετʔϧ͍ͯ͠Δ)
    Մೳੑ
    
    • ߈ܸऀ͕CA͔Βॺ໊෇͖ূ໌ॻΛ

    औಘͨ͠Մೳੑ
    αʔό͕ฦ٫͢Δਖ਼͍͠ূ໌ॻΛ

    ͋Β͔͡Ί஌͍ͬͯΕ͹๷͛Δ
    

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41. Android N
    • Ϣʔβ͕Πϯετʔϧͨ͠ϧʔτূ໌ॻ

    Λ৴པ͠ͳ͍
    
    • NetworkSecurityConfig
    
    • ฏจͰͷ௨৴ͷ཈ࢭ
    
    • CAͷΞϯΧʔ
    
    • Pinning Certificates(ϐϯཹΊ)
    

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42. NetworkSecurityConfig

    (Android NҎ߱)
    

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43. NetworkSecurityConfig
    • ฏจͰͷ௨৴ͷ཈ࢭ
    
    • CAͷΞϯΧʔ
    
    • Pinning Certificates(ϐϯཹΊ)
    

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44. ઃఆํ๏
    • res/xml/network_security_config.xml
    
    • ઃఆ಺༰Λهड़
    
    • AndroidManifest.xml
    …

    android:networkSecurityConfig="@xml/network_security_config">

    …

    
    

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45. ฏจͰͷ௨৴ͷ཈ࢭ
    
    
    secure.example.com
    
    
    

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46. CAͷΞϯΧʔ
    
    
    secure.example.com
    cdn.example.com
    
    
    
    
    
    

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47. Pinning Certificates (ϐϯཹΊ)
    
    
    example.com
    
    { hash value }
    
    { hash value }
    
    
    
    

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48. Pinning Certificates
    
    
    example.com
    
    { hash value }
    
    { hash value }
    
    
    
    PinningͷظݶΛઃఆՄೳ

    ୺຤ͷγεςϜ࣌ؒͱͷൺֱ
    

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49. Pinning Certificates
    
    
    example.com
    
    { hash value }
    
    { hash value }
    
    
    
    αʔόʔͷSSLূ໌ॻͷϋογϡ஋Λઃఆ
    

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50. Pinning Certificates
    
    
    example.com
    
    { hash value }
    
    { hash value }
    
    
    
    base64 encoded digest of

    X.509 SubjectPublicKeyInfo (SPKI)
    

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51. digestͷ࡞Γํ (खݩͷূ໌ॻͰ)
    ιʔε:
    https://github.com/datatheorem/TrustKit/blob/master/
    get_pin_from_certificate.py
    $ python get_pin_from_certificate.py ca.pem
    

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52. digestͷ࡞Γํ (αʔόʔ͔Β)
    $ openssl s_client \
    -connect : \
    | openssl x509 -pubkey -noout \
    | openssl rsa -pubin -outform der \
    | openssl dgst -sha256 -binary \
    | openssl enc -base64
    

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53. NetworkSecurityConfig
    ͷιʔείʔυ΁ͷ༠͍
    

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54. ؾ࣋ͪ
    • ͳʹ͔͋ͬͨ࣌ʹௐࠪ͠΍͍͢
    
    • ؾʹͳΔڍಈΛ֬ೝͰ͖ΔΑ͏ʹͳΔ
    

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55. ؔ࿈Ϋϥε
    • ManifestConfigSourceΫϥε
    
    • ઃఆͷಡΈࠐΈ
    
    • XmlConfigSourceΫϥε
    
    • network_security_config.xmlΛύʔε
    

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56. ؔ࿈Ϋϥε
    • NetworkSecurityConfigΫϥε
    
    • XmlConfigSourceͰΠϯελϯεԽ͞ΕΔ
    
    • NetworkSecurityTrustManagerΫϥε
    
    • ূ໌ॻνΣοΫͱPinningνΣοΫΛ࣮ࢪ
    
    • ূ໌ॻνΣοΫ࣮ॲཧ͸delegateͷ
    TrustManagerImplʹ೚ͤΔ
    

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57. ؔ࿈Ϋϥε
    • TrustManagerImplΫϥε
    
    • ূ໌ॻνΣοΫͷ࣮૷
    
    • https://github.com/google/conscrypt/blob/master/platform/
    src/main/java/org/conscrypt/TrustManagerImpl.java
    
    • ߹ΘͤͯಡΉͱྑ͍

    https://developer.android.com/training/
    articles/security-ssl.html
    

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58. Pinning Certificates
    
    
    example.com
    
    { hash value }
    
    { hash value }
    
    
    
    PinningͷظݶΛઃఆՄೳ

    ୺຤ͷγεςϜ࣌ؒͱͷൺֱ
    

    ࠶
    ׃
    

    

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59. NetworkSecurityTrustManager
    private void checkPins(List chain) throws CertificateException
    {
    PinSet pinSet = mNetworkSecurityConfig.getPins();
    if (pinSet.pins.isEmpty()
    || System.currentTimeMillis() > pinSet.expirationTime
    || !isPinningEnforced(chain)) {
    return;
    }
    …
    }
    PinningͷظݶΛઃఆՄೳ

    ୺຤ͷγεςϜ࣌ؒͱͷൺֱ
    

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60. ஫ҙ
    • ʮશͯཧղͨ͠ʯͱ͍ͬͯࣗ෼Ͱ

    ࣮૷͠ͳ͍͜ͱ
    

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61. Android NΑΓલͰ΋

    Pinning Certificates͢Δ
    

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62. Pinning Certificates (ϐϯཹΊ)
    ɹ TrustKit-AndroidΛར༻
    
    ɹ OkHttpClientͷcertificatePinnerΛར༻
    

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63. Pinning Certificates (ϐϯཹΊ)
    → TrustKit-AndroidΛར༻
    
    ɹ OkHttpClientͷcertificatePinnerΛར༻
    

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64. TrustKit-AndroidΛར༻
    • API 15+
    
    • MIT License
    
    • NetworkSecurityConfigͷઃఆΛ

    ಡΈࠐΜͰূ໌ॻͷݕূΛ͢Δ
    

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65. TrustKit-AndroidΛར༻
    TrustKit.initializeWithNetworkSecurityConfiguration(this);
    URL url = new URL("https://www.datatheorem.com");
    String serverHostname = url.getHost();
    // HttpsUrlConnection
    HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
    connection.setSSLSocketFactory(
    TrustKit.getInstance().getSSLSocketFactory(serverHostname)
    );
    // OkHttp 3.3.x and higher
    OkHttpClient client =
    new OkHttpClient().newBuilder()
    .sslSocketFactory(
    TrustKit.getInstance().getSSLSocketFactory(serverHostname),
    TrustKit.getInstance().getTrustManager(serverHostname)
    )
    .build();
    }
    

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66. TrustKit-AndroidΛར༻
    TrustKit.initializeWithNetworkSecurityConfiguration(this);
    URL url = new URL("https://www.datatheorem.com");
    String serverHostname = url.getHost();
    // HttpsUrlConnection
    HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
    connection.setSSLSocketFactory(
    TrustKit.getInstance().getSSLSocketFactory(serverHostname)
    );
    // OkHttp 3.3.x and higher
    OkHttpClient client =
    new OkHttpClient().newBuilder()
    .sslSocketFactory(
    TrustKit.getInstance().getSSLSocketFactory(serverHostname),
    TrustKit.getInstance().getTrustManager(serverHostname)
    )
    .build();
    }
    

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67. TrustKit-AndroidΛར༻
    TrustKit.initializeWithNetworkSecurityConfiguration(this);
    URL url = new URL("https://www.datatheorem.com");
    String serverHostname = url.getHost();
    // HttpsUrlConnection
    HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
    connection.setSSLSocketFactory(
    TrustKit.getInstance().getSSLSocketFactory(serverHostname)
    );
    // OkHttp 3.3.x and higher
    OkHttpClient client =
    new OkHttpClient().newBuilder()
    .sslSocketFactory(
    TrustKit.getInstance().getSSLSocketFactory(serverHostname),
    TrustKit.getInstance().getTrustManager(serverHostname)
    )
    .build();
    }
    

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68. Pinning Certificates
    ɹ TrustKit-AndroidΛར༻
    
    → OkHttpClientͷcertificatePinnerΛར༻
    

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69. OkHttpClientͷcertificatePinnerΛར༻
    public void run() throws Exception {
    OkHttpClient client = new OkHttpClient.Builder()
    .certificatePinner(new CertificatePinner.Builder()
    .add("publicobject.com", “sha256/{ hash value }”)
    .build())
    .build();
    Request request = new Request.Builder()
    .url("https://publicobject.com/robots.txt")
    .build();
    Response response = client.newCall(request).execute();
    }
    

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70. OkHttpClientͷcertificatePinnerΛར༻
    public void run() throws Exception {
    OkHttpClient client = new OkHttpClient.Builder()
    .certificatePinner(new CertificatePinner.Builder()
    .add("publicobject.com", “sha256/{ hash value }”)
    .build())
    .build();
    Request request = new Request.Builder()
    .url("https://publicobject.com/robots.txt")
    .build();
    Response response = client.newCall(request).execute();
    }
    PinningͷظݶΛઃఆ͸ෆՄ
    

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71. Pinning Certificatesͷ

    ӡ༻
    

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72. ӡ༻࣌ͷϙΠϯτ
    • αʔόʔαΠυͱͷௐ੔
    
    • SSLূ໌ॻΛม͑ΒΕΔͱ௨৴Ͱ͖ͳ͘ͳΔ
    
    • SSLূ໌ॻߋ৽࣌ͷϧʔϧ੍ఆ
    
    • Pinning CerficatesͷexpireઃఆͳͲ
    

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73. ཧ૝తͳӡ༻
    Server
    ূ໌ॻAظݶ
    ূ໌ॻAϐϯཹΊ + expireઃఆͳ͠
    Client
    

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74. ཧ૝తͳӡ༻
    Server
    ূ໌ॻAظݶ
    Client
    ূ໌ॻBൃߦ
    ূ໌ॻAϐϯཹΊ + expireઃఆͳ͠
    

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75. ཧ૝తͳӡ༻
    Server
    ূ໌ॻAظݶ
    Client
    ূ໌ॻBൃߦ
    ূ໌ॻA + BϐϯཹΊͷΞϓϦϦϦʔε

    ڧ੍Ξοϓσʔτ
    ূ໌ॻAϐϯཹΊ + expireઃఆͳ͠
    

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76. ཧ૝తͳӡ༻
    Server
    ূ໌ॻAظݶ
    Client
    ূ໌ॻBൃߦ ূ໌ॻBʹ੾Γସ͑
    ূ໌ॻA + BϐϯཹΊͷΞϓϦϦϦʔε

    ڧ੍Ξοϓσʔτ
    ূ໌ॻAϐϯཹΊ + expireઃఆͳ͠
    

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77. ཧ૝తͳӡ༻ͷؾ࣋ͪ
    • ৗʹPinning Certificates͕༗ޮ
    
    • ূ໌ॻͷೖΕସ͑ͷλΠϛϯάͰ΋༗ޮ
    
    • expireͷઃఆΛ͍Ε͍ͯͳ͍ͷͰ

    γεςϜ͕࣌ؒͣΕ͍ͯͯ΋༗ޮ
    

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78. ཧ૝తͳӡ༻ͷؾ࣋ͪ
    • ৗʹPinning Certificates͕༗ޮ
    
    • ূ໌ॻͷೖΕସ͑ͷλΠϛϯάͰ΋༗ޮ
    
    • expireͷઃఆΛ͍Ε͍ͯͳ͍ͷͰ

    γεςϜ͕࣌ؒͣΕ͍ͯͯ΋༗ޮ
    ⚠ ΞϓϦͷߋ৽Λ๨ΕΔͱ௨৴Ͱ͖ͳ͘ͳΔ

    ⚠ ڧ੍Ξοϓσʔτ͕ඞཁ
    

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79. expireઃఆʹΑΔଥڠҊ
    Server
    ূ໌ॻAظݶ
    Client
    ূ໌ॻAϐϯཹΊظݶ
    

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80. expireઃఆʹΑΔଥڠҊ
    Server
    ূ໌ॻAظݶ
    Client
    ূ໌ॻAϐϯཹΊظݶ
    ূ໌ॻBൃߦ
    

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81. expireઃఆʹΑΔଥڠҊ
    Server
    ূ໌ॻAظݶ
    Client
    ূ໌ॻAϐϯཹΊظݶ
    ূ໌ॻBൃߦ ূ໌ॻBʹ੾Γସ͑
    

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82. expireઃఆʹΑΔଥڠҊ
    Server
    ূ໌ॻAظݶ
    Client
    ূ໌ॻAϐϯཹΊظݶ
    ূ໌ॻBൃߦ ূ໌ॻBʹ੾Γସ͑
    ূ໌ॻBϐϯཹΊ൛ϦϦʔε
    

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83. ଥڠҊͷؾ࣋ͪ
    • ΞϓϦͷߋ৽Λ๨Εͯ΋௨৴Ͱ͖Δ
    
    • ڧ੍Ξοϓσʔτ͕ඞཁͳ͍
    
    • ূ໌ॻ੾Γସ͑࣌ʹPinning͕ޮ͔ͳ͍
    ࣌ظ͕͋Δ
    

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84. ·ͱΊ
    

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85. ·ͱΊ
    • HTTP͸΍Ί·͠ΐ͏
    
    • NetworkSecurityConfigʹΑͬͯɺѱҙ
    ͷ͋Δ߈ܸऀ͔ΒϢʔβʔΛकΔઃఆ͕
    ؆୯ʹͰ͖ΔΑ͏ʹͳΓ·ͨ͠
    
    • ӡ༻࣌͸ؾΛ͚ͭ·͠ΐ͏
    

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86. ͝੩ௌ͋Γ͕ͱ͏

    ͍͟͝·ͨ͠
    

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87. Appendix
    • GMailͷϝοηʔδݟΒΕͨ࿩

    https://www.computerworld.com/article/2510951/cybercrime-hacking/
    hackers-spied-on-300-000-iranians-using-fake-google-certificate.html
    
    • ෆਖ਼ͳূ໌ॻ͕ൃߦ͞Εͨ࿩

    http://www.atmarkit.co.jp/news/201109/08/diginotar.html
    

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