feat: normalize native token decimals #100
Open
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…mber of decimals used by native token
…cts into decimals-audit
Post audit fixes for native token decimals feature
![github-advanced-security[bot]](https://avatars.githubusercontent.com/in/57789?s=60&v=4){kind=small}
Comment on lines
+319
to
+333
| function _scaleDownToNativeDecimals(uint256 amount, uint8 decimals) | ||
| internal | ||
| pure | ||
| returns (uint256) | ||
| { | ||
| uint256 scaledAmount = amount; | ||
| if (decimals < 18) { | ||
| scaledAmount = amount / (10**(18 - decimals)); | ||
| // round up if necessary | ||
| if (scaledAmount * (10**(18 - decimals)) < amount) { | ||
| scaledAmount++; | ||
| } | ||
| } | ||
| return scaledAmount; | ||
| } |
Check warning
Code scanning / Slither
Divide before multiply Medium
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Was #65 but have decimal stored in bridge instead of inbox & outbox, also rebased the PR on main for fast-track release.
There is a scenario where custom fee token has number of decimals different than 18. That's not ideal because a lot of tooling assumes that native currency (on child chain) is using 18 decimals. For that reason we do a normalization, and de-normalization, when depositing and withdrawing native asset through native bridge.
Ie. let's say deposit amount is 752.
When withdrawing, opposite process is done. There can be loss of precision, due to the fact that we have to round down amount to the nearest supported value.
We also add 2 requirements on the custom fee token in order to avoid overflow:
type(uint256).max / 10**18which is ~1.1*10^59 tokens