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Glancing at your crypto implementation[1], it seems to contain newbie mistakes - eg no public key crypto involved in your public keys, usage of low level raw cr

Glancing at your crypto implementation[1], it seems to contain newbie mistakes - eg no public key crypto involved in your public keys, usage of low level raw crypto algorithm primitives from libsodium without session, replay etc related security concerns, no signs of design requiremnts re what security guarantees it's trying to provide, no PK key management, etc. You're also hand rolling wire protocol code in C++, manipulating raw bytes and lengths, which is a receipe for memory safety vulnerabilities. Use an pre vetted implementation of a good security protocol for this, or if this is a hobby project, spend some time reading up on crypto protocol design. [1] https://github.com/LANDrop/LANDrop/blob/master/LANDrop/crypto.cpp https://github.com/LANDrop/LANDrop/blob/master/LANDrop/crypt...

_1tan 5y ago
Any pointers to good sources on crypto protocol design?
- fulafel 5y ago
  https://blog.cryptographyengineering.com/useful-cryptography-resources/ https://blog.cryptographyengineering.com/useful-cryptography... this link page is from 2012, but still pretty good.
  - _1tan 5y ago
    Thank you
- api 5y ago
  A great starting point to learn about crypto is to first study current best practices until you understand exactly why they are best practices. Then go through a list of vulnerabilities that have been found in flawed algorithms or constructions and try to understand how each of these vulnerabilities works. Keep digging into these rabbit holes until you feel like you have a grasp on what a good construction looks like and common pitfalls.
eps 5y ago
If you feel like throwing "newbie" accusations around, it'd be prudent to back your list of grievances up with more than a single link to crypto.cpp. Chances are you misread the code, didn't grok what the op was doing, etc. As it stands your comment reads like a common variety abrasive and dismissive gatekeeping... rant, basically, which is unfortunately so popular in crypto circles. Edit - the project does dearly need a crypto spec. "Uses state-of-the-art cryptography algorithm" claim begs to be described to be valid.
- rvz 5y ago
  > Edit - the project does dearly need a crypto spec. "Uses state-of-the-art cryptography algorithm" claim begs to be described to be valid. It does not need a spec. It just needs to put a small print on "algorithm" and mention that it is using a cryptography library called libsodium. That's it. As for the armchair field marshal cryptographers ranting around and nitpicking "useful projects", they are the same ones who praised Signal for their actual "state-of-the-art cryptography algorithm" for end-to-end encryption until they added a cryptocurrency coin in the messenger. Same with Keybase. At least this project does not have such frivolous features and is only using libsodium like everyone else. It is very easy to give "expert" criticism (constructive or not) on an open source project (since the project is transparent) but it is much harder for the critics to dive in and fix the aforementioned issues themselves. I would have much more respect for those who do both.
  - 4684499 5y ago
    > on an open source project (since the project is transparent) Not as transparent since the mobile apps are closed source at the moment.
- fulafel 5y ago
  Well, it's about 2 screefuls of very simple code. Eg for the PK part, if you ctrl-f for publicKey and remotePublicKey, you see there are no usages that could plausibly be doing public key crypto or PK key generation based on crypto 101 from school. Not sure how to respond about gatekeeping. What do you think would be a good way to write a comment pointing out these kinds of security problems? Or do you think it's unfair to do it at all?
deleted 5y ago
[deleted]
api 5y ago
Your comment about manipulating raw bytes in C++ is a language criticism, not a criticism of this project.

_1tan 5y ago

Any pointers to good sources on crypto protocol design?

fulafel 5y ago
https://blog.cryptographyengineering.com/useful-cryptography-resources/ https://blog.cryptographyengineering.com/useful-cryptography... this link page is from 2012, but still pretty good.
- _1tan 5y ago
  Thank you
api 5y ago
A great starting point to learn about crypto is to first study current best practices until you understand exactly why they are best practices. Then go through a list of vulnerabilities that have been found in flawed algorithms or constructions and try to understand how each of these vulnerabilities works. Keep digging into these rabbit holes until you feel like you have a grasp on what a good construction looks like and common pitfalls.

eps 5y ago

If you feel like throwing "newbie" accusations around, it'd be prudent to back your list of grievances up with more than a single link to crypto.cpp. Chances are you misread the code, didn't grok what the op was doing, etc. As it stands your comment reads like a common variety abrasive and dismissive gatekeeping... rant, basically, which is unfortunately so popular in crypto circles. Edit - the project does dearly need a crypto spec. "Uses state-of-the-art cryptography algorithm" claim begs to be described to be valid.

rvz 5y ago
> Edit - the project does dearly need a crypto spec. "Uses state-of-the-art cryptography algorithm" claim begs to be described to be valid. It does not need a spec. It just needs to put a small print on "algorithm" and mention that it is using a cryptography library called libsodium. That's it. As for the armchair field marshal cryptographers ranting around and nitpicking "useful projects", they are the same ones who praised Signal for their actual "state-of-the-art cryptography algorithm" for end-to-end encryption until they added a cryptocurrency coin in the messenger. Same with Keybase. At least this project does not have such frivolous features and is only using libsodium like everyone else. It is very easy to give "expert" criticism (constructive or not) on an open source project (since the project is transparent) but it is much harder for the critics to dive in and fix the aforementioned issues themselves. I would have much more respect for those who do both.
- 4684499 5y ago
  > on an open source project (since the project is transparent) Not as transparent since the mobile apps are closed source at the moment.
fulafel 5y ago
Well, it's about 2 screefuls of very simple code. Eg for the PK part, if you ctrl-f for publicKey and remotePublicKey, you see there are no usages that could plausibly be doing public key crypto or PK key generation based on crypto 101 from school. Not sure how to respond about gatekeeping. What do you think would be a good way to write a comment pointing out these kinds of security problems? Or do you think it's unfair to do it at all?

deleted 5y ago

[deleted]

api 5y ago

Your comment about manipulating raw bytes in C++ is a language criticism, not a criticism of this project.