chore: added deterministic tests

[gilcu3]

Closes #107

• This removes the usage of non-determinism from the code-base, except from the integration tests. I believe using OsRng in these files is preferred, as currently they are the closest we have to usage examples.
• It checks that the results of the main functions in the crate are deterministic, which covers all functions (albeit indirectly). I think this is good enough atm.
• This PR is meant to be merged after the test_utils refactor Simon/test utils folder #217. It should not have any conflict with the snapshots Simon/snapshots #218
• This PR had no choice but slightly breaking the API of test_utils, as some functions were using OsRng internally, and now expect the RNG as a parameter.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 93.70861% with 38 lines in your changes missing coverage. Please review.
✅ Project coverage is 88.33%. Comparing base (24238cd) to head (8bee803).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/test_utils/test_generators.rs	0.00%	24 Missing ⚠️
src/ecdsa/robust_ecdsa/test.rs	87.03%	0 Missing and 7 partials ⚠️
src/ecdsa/ot_based_ecdsa/test.rs	92.85%	0 Missing and 3 partials ⚠️
src/test_utils/mockrng.rs	25.00%	3 Missing ⚠️
src/crypto/polynomials.rs	98.21%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #225      +/-   ##
==========================================
+ Coverage   88.07%   88.33%   +0.25%     
==========================================
  Files          48       48              
  Lines        9201     9488     +287     
  Branches     9201     9488     +287     
==========================================
+ Hits         8104     8381     +277     
- Misses        652      662      +10     
  Partials      445      445              

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[DSharifi]

Thanks a lot for these changes! :)

[gilcu3]

we might want to address this ugliness (and lack of efficiency, as afaik we send this over the wire) here. The bad part is that this would be a breaking change :| (incompatible with nodes running other version type)

[SimonRastikian]

Why would this exist?
I am unsure whether I really enjoy it.

[gilcu3]

the file was proposed by @netrome as a better way to make snapshot tests on determinism.

My comment here refers to the serialization of the CKD types, which is defined by the underlying lib

[Copilot]

Pull Request Overview

This PR removes non-deterministic RNG usage from the codebase by replacing OsRng with a seeded MockCryptoRng in tests. It adds deterministic test coverage using snapshot testing (via the insta crate) to verify that key cryptographic operations produce consistent outputs. The changes also update the test_utils API to accept RNG parameters instead of using OsRng internally, which is a minor breaking change to the test utilities API.

Key changes:

• Modified MockCryptoRng to implement SeedableRng trait for better RNG control
• Updated test utility functions (run_keygen, run_refresh, run_reshare, etc.) to accept RNG parameters
• Added deterministic snapshot tests for keygen, refresh, and reshare operations across multiple signature schemes
• Added insta dependency for snapshot testing

Reviewed Changes

Copilot reviewed 49 out of 50 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/test_utils.rs	Added SeedableRng implementation to MockCryptoRng and updated helper functions to accept RNG parameters
src/dkg.rs	Refactored test functions to return results and accept RNG parameters for deterministic testing
src/eddsa/test.rs	Added deterministic tests with snapshot assertions and updated existing tests to use seeded RNG
src/ecdsa/mod.rs	Added deterministic snapshot tests for ECDSA keygen/refresh/reshare operations
src/ecdsa/robust_ecdsa/*.rs	Updated all tests to use deterministic RNG instead of OsRng
src/ecdsa/ot_based_ecdsa/*.rs	Updated OT-based ECDSA tests to use seeded RNG for determinism
src/confidential_key_derivation/*.rs	Added deterministic tests and updated existing tests to use seeded RNG
src/crypto/*.rs	Updated cryptographic proof tests to use MockCryptoRng instead of OsRng
benches/*.rs	Updated benchmarks to use MockCryptoRng for consistency
Cargo.toml/Cargo.lock	Added insta dependency for snapshot testing
snapshots/*.snap	Added snapshot files capturing deterministic outputs of key operations

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[barakeinav1]

I did a brief review (loved your use of 42) . but I don't feel I have any useful feedback here.
I can approve as a rubber stamp, or you can wait for another reviewer.
let me know.

[gilcu3]

I did a brief review (loved your use of 42) . but I don't feel I have any useful feedback here. I can approve as a rubber stamp, or you can wait for another reviewer. let me know.

I think is fine to approve even without feedback, as this was a second review after quite a few review changes yesterday. Anyway it will change a little bit after another PR is merged and I rebase this one, so I will ask for the rubber stamp then.

[SimonRastikian]

Should be good overall,
Couple of comments about rng traits. Also I am not a big fan of the added files...

[SimonRastikian]

Why would this exist?
I am unsure whether I really enjoy it.