Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

CanonicalName case folding of non-US-ASCII letters #1434

Closed
zeroizerz opened this issue Mar 12, 2023 · 0 comments · Fixed by #1470
Closed

CanonicalName case folding of non-US-ASCII letters #1434

zeroizerz opened this issue Mar 12, 2023 · 0 comments · Fixed by #1470

Comments

@zeroizerz
Copy link

https://www.rfc-editor.org/rfc/rfc4034#section-6.2:

all uppercase US-ASCII letters in the owner name of the RR are replaced by the corresponding lowercase US-ASCII letters

Currently the CanonicalName function is implemented using strings.ToLower, which lowercases both US-ASCII and non-US-ASCII letters. But only US-ASCII letters should be lowercased according to the RFC.

This is further corroborated by https://www.rfc-editor.org/rfc/rfc4343#section-3:

Note that the DNS case insensitivity does NOT correspond to the case folding specified in [ISO-8859-1] or [ISO-8859-2]. For example, the octets 0xDD (\221) and 0xFD (\253) do NOT match, although in other contexts, where they are interpreted as the upper- and lower-case version of "Y" with an acute accent, they might.

Accordingly, dns.CanonicalName("ÉxamplE.com") should output Éxample.com., but currently outputs éxample.com..
retornam added a commit to retornam/dns that referenced this issue Jul 2, 2023
@retornam
CanonicalName should casefold non-US-ASCII chars
d722ee8 
According to Section 6.2 [1] of RFC 4034,
all uppercase US-ASCII letters in the owner name
of the RR are replaced by the corresponding lowercase
US-ASCII letters.

I updated the CanonicalName function to conform to
the RFC and updated its tests too.

[1] https://www.rfc-editor.org/rfc/rfc4034#section-6.2

Fixes miekg#1434
retornam added a commit to retornam/dns that referenced this issue Jul 2, 2023
@retornam
CanonicalName should casefold non-US-ASCII chars
0ce86e3 
According to Section 6.2 [1] of RFC 4034,all uppercase US-ASCII letters in the
owner name of the RR are replaced by the corresponding lowercase US-ASCII
letters.

This updates CanonicalName to conform to the RFC.

[1] https://www.rfc-editor.org/rfc/rfc4034#section-6.2

Fixes miekg#1434
@retornam retornam mentioned this issue Jul 2, 2023
Merged
miekg pushed a commit that referenced this issue Sep 12, 2023
@retornam
CanonicalName should casefold non-US-ASCII chars (#1470)
a9ed73a 
According to Section 6.2 [1] of RFC 4034,all uppercase US-ASCII letters in the
owner name of the RR are replaced by the corresponding lowercase US-ASCII
letters.

This updates CanonicalName to conform to the RFC.

[1] https://www.rfc-editor.org/rfc/rfc4034#section-6.2

Fixes #1434
@tmthrgd tmthrgd mentioned this issue Oct 31, 2023
Merged
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
None yet
Projects
None yet
Milestone
No milestone
Development

Successfully merging a pull request may close this issue.

CanonicalName should casefold non-US-ASCII chars retornam/dns
1 participant
@zeroizerz