Allow rejection of NaN and Inf float values on encode and decode.

[benluddy]

Description

Implements #512 to allow users to error rather than encode or decode NaN and Inf floating-point values.

PR Was Proposed and Welcomed in Currently Open Issue

• This PR was proposed and welcomed by maintainer(s) in issue #___
• Closes or Updates Issue feature: Options to reject floating-point NaN and Inf values on encode and decode #512

Checklist (for code PR only, ignore for docs PR)

• Include unit tests that cover the new code
• Pass all unit tests
• Pass all lint checks in CI (goimports, gosec, staticcheck, etc.)
• Sign each commit with your real name and email.
  Last line of each commit message should be in this format:
  Signed-off-by: Firstname Lastname [email protected]
• Certify the Developer's Certificate of Origin 1.1
  (see next section).

Certify the Developer's Certificate of Origin 1.1

• By marking this item as completed, I certify
  the Developer Certificate of Origin 1.1.

Developer Certificate of Origin
Version 1.1

Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
660 York Street, Suite 102,
San Francisco, CA 94110 USA

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.

Developer's Certificate of Origin 1.1

By making a contribution to this project, I certify that:

(a) The contribution was created in whole or in part by me and I
    have the right to submit it under the open source license
    indicated in the file; or

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
    license and I have the right under that license to submit that
    work with modifications, whether created in whole or in part
    by me, under the same open source license (unless I am
    permitted to submit under a different license), as indicated
    in the file; or

(c) The contribution was provided directly to me by some other
    person who certified (a), (b) or (c) and I have not modified
    it.

(d) I understand and agree that this project and the contribution
    are public and that a record of the contribution (including all
    personal information I submit with it, including my sign-off) is
    maintained indefinitely and may be redistributed consistent with
    this project or the open source license(s) involved.

[fxamacker]

@benluddy Thanks for opening this PR! It makes sense to add options to reject NaN and infinity for some use cases.

Encoding looks great!

For decoding, we can probably handle decoding options similar to way it is done for TagsMode and IndefLengthMode:

• Handle new decoding options in wellformedl() instead of decoding functions, so codec can reject CBOR data early without allocating decoded objects. It would also simplify decoding function because wellformed() is called before parseToValue().

• Use the same naming convention (e.g. TagsMode has options TagsAllowed and TagsForbidden).

Thoughts?

[benluddy]

Thoughts?

Sounds great. I had been thinking to myself, "what if a user needs to distinguish between ill-formed input and well-formed input that is rejected by the application's protocol." Now I realize that that case can be served just fine by a second call to Wellformed using a permissive decode mode on error cases.

I'll implement your recommendations today.

[benluddy]

I'll implement your recommendations today.

Done. Please take another look when you have a chance.

[fxamacker]

Thanks for updating this PR! I left some comments about checking CBOR type before converting to float.

[benluddy]

D'oh! Thank you. Added test cases to catch that and fixed.

[fxamacker]

Nice! 👍 Thanks for updating this PR!