Use Cryptography; Don't Learn It

Presentation from Swift and Fika conference.

We talked about securing data, and about mistakes developers make when they are trying to use encryption. And what they actually want from cryptography: they want high level functions, they want easy to use instruments that just works. They want boring crypto. But in a real world we have different levels of paranoia: from Faraday cage to hardware and software solutions. We named three layers of software solutions: boxed, crypto-systems and crypto-libs. And how to select which one to use. And about Edisson lamp as an example of boring, but working system.

Transcript

1. USE CRYPTOGRAPHY, DON’T LEARN IT. @vixentael
2. @vixentael head of customer solutions, security software engineer OSS maintainer: Themis, Acra focused on applied crypto and building e2ee protocols Anastasiia Voitova
3. database searchable encryption eprint.iacr.org/2019/806.pdf e2ee data collaboration cossacklabs.com/files/hermes-theory-paper-rev1.pdf zero knowledge authentication cossacklabs.com/files/secure-comparator-paper-rev12.pdf cossacklabs.com @vixentael Data security solutions based on R&D
5. USABLE
6. “Let’s protect stored data” …imagine simple use case …and calculate potential dev mistakes @vixentael
7. 1. Defining the data scope business-sensitive data regulations, compliance tech data (keys, logs, backups, tokens..) @vixentael
8. 1. Defining the data scope business-sensitive data regulations, compliance tech data (keys, logs, backups, tokens..) @vixentael Mistake 1. wrong scope definition
9. 2. Selecting crypto function @vixentael twofish sha1 des md5
10. 2. Selecting crypto function @vixentael twofish sha1 des md5 Mistake 2. bad algo selection
11. Things to decide on: KEY LENGTH DATA SCOPE CIPHER @vixentael
12. 3. Using cipher @vixentael https://wiki.openssl.org/index.php/EVP_Symmetric_Encryption_and_Decryption
13. 3. Using cipher @vixentael https://wiki.openssl.org/index.php/EVP_Symmetric_Encryption_and_Decryption
14. 3. Using cipher @vixentael https://wiki.openssl.org/index.php/EVP_Symmetric_Encryption_and_Decryption Mistake 3. wrong params
15. Things to decide on: PADDING KEY LENGTH MODE DATA SCOPE CIPHER IV @vixentael
16. 4. Key management @vixentael user password DEK, KEK, master key, transport key, ephemeral key, OTP, token, keypairs … encryption key KDF
17. 4. Key management @vixentael user password DEK, KEK, master key, transport key, ephemeral key, OTP, token, keypairs … encryption key KDF Mistake 4. bad key management https://www.owasp.org/index.php/Key_Management_Cheat_Sheet
18. Things to decide on: PADDING KEY LENGTH KEY ROTATION MODE KEY DERIVATION KEY STORAGE KEY EXCHANGE DATA SCOPE CIPHER IV KEY REVOCATION KMS @vixentael
19. 5. Infrastructure @vixentael
20. Things to decide on: PADDING KEY LENGTH KEY ROTATION MODE KEY DERIVATION KEY STORAGE KEY EXCHANGE DATA SCOPE CIPHER IV KEY REVOCATION BACKUPS PLATFORMS KMS @vixentael
22. https://pdos.csail.mit.edu/papers/cryptobugs:apsys14.pdf 269 CVEs from 2011-2014 17% 83% bugs inside crypto libs misuses of crypto libs by individual apps @vixentael
23. AES DES 3DES CBC CFB SEAL Salsa20 RSA DSA Kuznyechik Blowfish SHARK RC4 DSS ChaCha20 CTR AES-SIV Camelia SEED Rabbit ECDSA @vixentael
24. — crypto that simply works, solidly resists attacks, never needs any upgrades https://cr.yp.to/talks/2015.10.05/slides-djb-20151005-a4.pdf Daniel J. Bernstein Boring crypto @vixentael
25. I want to store data securely I want to send data securely I want to verify data integrity Solve use-cases @vixentael
26. o store data securely o send data securely o verify data integrity KEY DERIVATION KEY EXCHANGE KEY ROTATION SIGN/VERIFY EPHEMERAL KEYS ENCR / DECR Solve use-cases @vixentael
27. Crypto should be: cross-platform easy to install easy to use audited open source time proven well-documented compliant hard to mis-use @vixentael
28. Form factor is important @vixentael
29. encryption integration abstraction level complexity @vixentael
30. encryption integration abstraction level complexity cipher crypto- library crypto- system boxed solution pain @vixentael
31. 1. CRYPTO-LIBS implements single or multiple security functions https://github.com/sobolevn/awesome-cryptography @vixentael RNCryptor Themis OpenSSL/BoringSSL/*SSL CryptoSwift Tink LibSodium/NaCl
32. Matthew Green @vixentael blog.cryptographyengineering.com/2012/12/28/the-anatomy-of-bad-idea/ “OpenSSL is the space shuttle of crypto libraries. It will get you to space, provided you have a team of people to push the ten thousand buttons required to do so. NaCl is more like an elevator — you just press a button and it takes you there. No frills or options. I like elevators.”
33. OpenSSL “high level” API, AES CBC @vixentael
34. CommonCrypto AES @vixentael
35. High lvl API, easy to mis-use @vixentael
36. should be random should use KDF(key) uses AES CBC, not AES GCM padding? salt? High lvl API, easy to mis-use @vixentael
37. github.com/cossacklabs/themis @vixentael Themis: hard to mis-use
38. hides cryptographic details: salt, IV, KDF, padding uses AES-256-GCM github.com/cossacklabs/themis built-in KDF to make keys stronger Themis: hard to mis-use @vixentael
39. 2. CRYPTO-SYSTEMS libsignal hermes SSL/TLS ZeroKit noise combines security functions for solving exact use-case @vixentael
40. ACL based on crypto-keys @vixentael hermes python docs/examples/python/hermes_client.py --id USER1 --config=docs/examples/python/config.json --private_key USER1.priv --doc secretfile --read
41. 3. BOXED SOLUTIONS @vixentael unites crypto-systems and user functions for solving problems truecrypt ssh acra vault Oracle TDE
42. transparent & searchable encryption @vixentael marketplace.digitalocean.com/apps/acra
43. transparent & searchable encryption @vixentael marketplace.digitalocean.com/apps/acra very boring
44. pain curve less boring more boring cipher crypto- library crypto- system boxed solution pain @vixentael
45. Boring crypto tools allow to focus on product, not on crypto code. @vixentael
46. @vixentael
47. VS @vixentael
48. make the light controllable @vixentael
49. make the crypto security controllable and booooring @vixentael
50. @vixentael Anastasiia Voitova github.com/vixentael/ my-talks