Compress encrypted data #231
Open
Conversation
This file contains hidden or 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
This is part of a push to support larger files. The focus is the switch
to using Uint8Array to store binary data. But also includes:
- When running on Node, use Buffer.from() for hex string conversions.
- To avoid large buffer copy, signedMsg as been replaced by an object
containing iv, encrypted, and hmac.
- hmac calculation has changed so it avoids copying (possibly very
large) encrypted data. See signDigest() in lib/codec.js.
- Minor cleanup
Handling hex encode/decode at the input/output boundaries and using
Uint8Array internally for representing binary data has these benefits:
- More memory efficient, allows processing of 2x larger files.
- Aligns with cryptographic best practices: hashing is now performed
on raw binary data (Uint8Array) instead of hex strings.
- Behavior is (mostly) unchanged
- scripts/index_template.html textContent is not implemented and
needs to be redesigned.
makes unnamed function more self documenting
Also removed use of recursion to improve readability (and debugability). As a bonus, function is actually shorter (LoC AND lines of text)
cuts size by 1/3 and noticeably improves performance
Refactored encrypted buffer handling to reduce memory usage Minor cleanup
Author
|
Committed a396bf0 to fix line of code that got messed up between testing and commit/push. |
Author
|
Committed a396bf0 to remove to variable definitions for vars that are no longer used. This was discovered while writing a previous pull request comment. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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Outdated suggestions cannot be applied.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.
Summary
Compress data before encryption because it reduces size by about 30%, at a minimal additional compute cost compared to encryption and signing. This can produce in an encrypted file that's smaller than the original.
Resolves
Resolves #230
Details
Testing
I manually tested node encrypt, node decrypt, and HTML wrapper decrypt.
Notes for Reviewers
In an attempt to avoid, or at least limit, having 3 representations of data simultaneously in memory (file data buffer, decrypted data buffer, decompressed data buffer), we sometimes pass a reader instead of a buffer. Reader here means a callable that can read the data. See 'msgReader' in codec.js, which provides this comment: