Crypto wallets security: for developers

Transcript

1. Crypto Wallets Security
   
   
   for developers
   Julia Potapenko
   

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2. Security Software Engineer
   Julia Potapenko
   
   
   @julepka
   We help companies to
   protect their sensitive
   and valuable data.
   OWASP Zhytomyr Leader.
   Contributor to OWASP security
   standards and guides.
   Women Who Code Kyiv Director
   

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3. OWASP
   
   
   Open Web Application
   Security Project
   A nonpro
   f
   it foundation that works to
   improve the security of software
   OWASP Top 10
   
   
   OWASP ASVS
   
   
   OWASP WSTG
   
   
   OWASP MASVS/MSTG
   https://owasp.org/www-project-mobile-security-testing-guide/
   https://owasp.org/www-project-application-security-veri
   f
   ication-standard/
   https://owasp.org/www-project-web-security-testing-guide/
   https://owasp.org/www-project-top-ten/
   

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4. Today we will talks about
   
   
   #cryptocurrency_wallets #sensitive_assets
   
   
   #authentication #local_storage #platform #cryptography
   
   
   #dependencies_management
   

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5. How does it work?
   Your account = your seed / private key
   
   
   Loosing seed / private key = loosing the account
   
   
   Wallet gives access to several accounts
   
   
   The main challenge is to secure seed / private keys
   

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6. Cryptocurrency wallet types
   Custodial
   
   
   third-party storage
   Non-custodial
   
   
   user-controled
   

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7. Cryptocurrency wallet types
   Custodial
   
   
   third-party storage
   Non-custodial
   
   
   user-controled
   Hot
   
   
   online
   Cold
   
   
   of
   f
   line
   

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8. https://www.wired.com/story/hack-binance-cryptocurrency-exchange/
   Why should devs care?
   

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9. https://www.wired.com/story/hack-binance-cryptocurrency-exchange/
   https://www.bbc.com/news/technology-59549606
   Why should devs care?
   

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10. https://www.theverge.com/2022/1/24/22898712/crypto-
    hardware-wallet-hacking-lost-bitcoin-ethereum-nft
    https://www.wired.com/story/hack-binance-cryptocurrency-exchange/
    https://www.bbc.com/news/technology-59549606
    Why should devs care?
    

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11. https://www.theverge.com/2022/1/24/22898712/crypto-
    hardware-wallet-hacking-lost-bitcoin-ethereum-nft
    https://www.wired.com/story/hack-binance-cryptocurrency-exchange/
    https://www.bbc.com/news/technology-59549606 https://www.theverge.com/2021/11/4/22763015/cryptocurrency-
    fake-wallet-phishing-scam-google-ads-phantom-metamask
    Why should devs care?
    

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12. https://www.theverge.com/2022/1/24/22898712/crypto-
    hardware-wallet-hacking-lost-bitcoin-ethereum-nft
    https://www.wired.com/story/hack-binance-cryptocurrency-exchange/
    https://www.bbc.com/news/technology-59549606 https://www.theverge.com/2021/11/4/22763015/cryptocurrency-
    fake-wallet-phishing-scam-google-ads-phantom-metamask
    Why should devs care?
    It is not about blockchain security.
    
    
    It is about application security and user education
    

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13. Cryptocurrency wallet types
    Custodial
    
    
    third-party storage
    Non-custodial
    
    
    user-controled
    Hot
    
    
    online
    Cold
    
    
    of
    f
    line
    

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14. Coinbase wallet example
    

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15. Similar to banking apps,
    cryptocurrency wallets
    operate user funds,
    meaning security baseline
    should be nearly the same.
    

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16. Similar to banking apps,
    cryptocurrency wallets
    operate user funds,
    meaning security baseline
    should be nearly the same.
    Threat vectors considerations
    
    
    • Authentication
    
    
    • Local storage
    
    
    • Platform trust
    
    
    • Cryptography
    
    
    • Communication
    
    
    • User education
    
    
    • Supply chain
    

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17. User Authentication
    LOCAL VS REMOTE
    If the app provides users access to a remote service, some form of authentication,
    such as username/password authentication, is performed at the remote endpoint.
    
    
    No sensitive data should be stored locally on the mobile device. Instead, data should
    be retrieved from a remote endpoint when needed and only be kept in memory.
    
    
    If sensitive data is still required to be stored locally, it should be encrypted using a
    key derived from hardware backed storage which requires authentication.
    
    
    – OWASP MASVS 4.1, 2.11, 2.12
    

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18. User Authentication
    LOCAL VS REMOTE
    If the app provides users access to a remote service, some form of authentication,
    such as username/password authentication, is performed at the remote endpoint.
    
    
    No sensitive data should be stored locally on the mobile device. Instead, data should
    be retrieved from a remote endpoint when needed and only be kept in memory.
    
    
    If sensitive data is still required to be stored locally, it should be encrypted using a
    key derived from hardware backed storage which requires authentication.
    
    
    – OWASP MASVS 4.1, 2.11, 2.12
    But what about deanonymisation?
    Non-custodial wallets are usually fat clients
    

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19. Password policy
    
    
    Password rotation when leaked
    
    
    Defences against brute-force attacks
    
    
    Step-up authentication
    
    
    Biometry veri
    f
    ication
    User Authentication
    

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20. Know your platform
    What kind of storage should be used to deliver the best security guarantees?
    

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21. Know your platform
    What kind of storage should be used to deliver the best security guarantees?
    Is it a
    f
    ile? Can you steal it?
    
    
    Can other apps access it?
    
    
    What about integrity?
    
    
    And Encryption?
    

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22. Know your platform
    What kind of storage should be used to deliver the best security guarantees?
    Is it a
    f
    ile? Can you steal it?
    
    
    Can other apps access it?
    
    
    What about integrity?
    
    
    And Encryption?
    It is a developer’s responsibility to
    know how the storage works on the
    platform you use.
    

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23. 000003.log is a storage
    f
    ile of web-extension. You can copy it from
    one browser and paste into another.
    Know your platform
    

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24. Objection tool that allows to access Keychain of the device, no jailbreak required
    Know your platform
    

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25. Cryptography
    How to encrypt the data with a password?
    
    
    

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26. Cryptography
    How to encrypt the data with a password?
    
    
    You decided to pick AES. You need a key length of 256 bits but the
    password is shorter.
    
    
    You use a hash function SHA256.
    
    
    

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27. Cryptography
    How to encrypt the data with a password?
    
    
    You decided to pick AES. You need a key length of 256 bits but the
    password is shorter.
    
    
    You use a hash function SHA256. KDF (Key Derivation Function)
    
    
    

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28. Cryptography
    How to encrypt the data with a password?
    
    
    You decided to pick AES. You need a key length of 256 bits but the
    password is shorter.
    
    
    You use a hash function SHA256. KDF (Key Derivation Function)
    
    
    Your pick PBKDF2. You need to specify number of rounds for it.
    
    
    Similar to some example in the Internet you pick 2 000.
    
    
    

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29. Cryptography
    How to encrypt the data with a password?
    
    
    You decided to pick AES. You need a key length of 256 bits but the
    password is shorter.
    
    
    You use a hash function SHA256. KDF (Key Derivation Function)
    
    
    Your pick PBKDF2. You need to specify number of rounds for it.
    
    
    Similar to some example in the Internet you pick 2 000. 310 000
    
    
    

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30. Cryptography
    How to encrypt the data with a password?
    
    
    You decided to pick AES. You need a key length of 256 bits but the
    password is shorter.
    
    
    You use a hash function SHA256. KDF (Key Derivation Function)
    
    
    Your pick PBKDF2. You need to specify number of rounds for it.
    
    
    Similar to some example in the Internet you pick 2 000. 310 000
    
    
    CBC or GCM mode? Random IV? … ? ? ?
    

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31. Cryptography
    How to encrypt the data with a password?
    
    
    You decided to pick AES. You need a key length of 256 bits but the
    password is shorter.
    
    
    You use a hash function SHA256. KDF (Key Derivation Function)
    
    
    Your pick PBKDF2. You need to specify number of rounds for it.
    
    
    Similar to some example in the Internet you pick 2 000. 310 000
    
    
    CBC or GCM mode? Random IV? … ? ? ?
    Don’t roll your own crypto
    Use Themis https://github.com/cossacklabs/themis
    Use libsodium
    

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32. Cryptography
    Comes from mvayngrib/react-native-crypto library…
    
    
    that uses react-native-randombytes library…
    
    
    that uses Stanford Javascript Crypto Library (SJCL) for synchronous random
    values generation.
    
    
    React Native mobile
    app example
    

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33. Cryptography
    Comes from mvayngrib/react-native-crypto library…
    
    
    that uses react-native-randombytes library…
    
    
    that uses Stanford Javascript Crypto Library (SJCL) for synchronous random
    values generation.
    
    
    SJCL random values generator relies on mouse movements and keyboard listeners.
    React Native mobile
    app example
    

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34. Supply chain
    

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35. Supply chain
    

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36. Supply chain
    

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37. Supply chain
    

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38. Supply chain
    

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39. How to identify a good library
    Looks alive
    
    
    Built for required platform
    
    
    Easy to use, hard to misuse
    
    
    Covered with tests
    
    
    Documentation
    
    
    Secure
    
    
    Performance
    
    
    Licence
    

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40. https://snyk.io/advisor/npm-package/
    react-native-sensitive-info
    How to identify a good library
    

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41. Useful tools
    Automate and add to PRs
    
    
    SonarQube
    
    
    Snyk
    
    
    Dependabot
    

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42. Useful tools
    Automate and add to PRs
    
    
    SonarQube
    
    
    Snyk
    
    
    Dependabot
    SAST (Static Application Security Testing):
    
    
    https://owasp.org/www-community/
    Source_Code_Analysis_Tools
    
    
    DAST (Dynamic Application Security Testing):
    
    
    https://owasp.org/www-community/
    Vulnerability_Scanning_Tools
    

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43. User is a single point of
    failure
    Non-custodial wallets security is the
    user responsibility.
    

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44. Useful links
    [Article] Crypto wallets security as seen by security engineers:
    
    
    https://www.cossacklabs.com/blog/crypto-wallets-security/
    
    
    [Article] Security of React Native libraries: the bad, the worse and the ugly:
    
    
    https://www.cossacklabs.com/blog/react-native-libraries-security/
    
    
    [Article] React Native security: things to keep in mind:
    
    
    https://www.cossacklabs.com/blog/react-native-app-security/
    
    
    [Slides] Why can’t developers make it secure:
    
    
    https://speakerdeck.com/julep/why-cant-developers-make-it-secure
    

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45. Thank you!
    Follow me on Twitter
    
    
    @julepka
    

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