JCL-385: Improve PKCE verifier to always produce spec conforming values - #517
Merged
acoburn merged 1 commit intoJun 9, 2023
Merged
acoburn merged 1 commit into
acoburn merged 1 commit into
Conversation
Copy link
Copy Markdown
Contributor
Sorry, something went wrong.
acoburn
force-pushed
the
JCL-385-pkce-verifier-length
branch
from
a86257e to
2f301e0
Compare
June 8, 2023 18:46
NSeydoux
approved these changes
Jun 9, 2023
NSeydoux
reviewed
Jun 9, 2023
Comment thread
openid/src/test/java/com/inrupt/client/openid/PKCETest.java
Comment on lines
-36
to
+32
| assertTrue(PKCE.createChallenge("", "SHA-256").getBytes(UTF_8).length <= 128); | ||
| assertTrue(PKCE.createChallenge("🐶🐶🐶", "SHA-256").length() >= 43); |
Copy link
Copy Markdown
Contributor
There was a problem hiding this comment.
For my own understanding, was the .getBytes(UTF_8) useful in the first place?
Sorry, something went wrong.
Copy link
Copy Markdown
Contributor
Author
There was a problem hiding this comment.
No, the getBytes test was unnecessary. The spec requires checking the character length of the resulting string, not the size of the byte array. Admittedly, for ASCII strings, the two will be equivalent, but it is unnecessary
Sorry, something went wrong.
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
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Occasionally the CI/CD workflows will fail because the PKCE verifier is less than 43 characters (required by the spec). This can happen if the random number selected is too low, resulting in an encoded byte array that has too few characters.
This is fixed here by ensuring a minimum value for the BigInteger.
Effectively it changes the range from [0 - 2^256) to [2^256 - 2^257) so the generated byte array is always sufficiently long.
Imagine that the random number generator selects the number 250 -- this will be packed into a single octet and the entropy of the validator will be too low. This way, there will always be at least 32 octets.