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Re: encoding expectations

From: Daniel Stenberg <>
Date: Thu, 26 Apr 2018 20:30:47 +0200 (CEST)

On Wed, 25 Apr 2018, Michael Kilburn wrote:

> In any case, it would be really helpful to mention all this on CURLOPT_URL
> help page.

Feel free and welcome to suggest improvements to the documentation. Even a PR
if you're up for it! What exactly do you think it should say that would've
helped you?

> But there could a problem -- SSL certificates validation. If certificate is
> produces for IDN (and not it's punycode version) -- this workaround will
> fail.

It's not a work-around, it's how it works. With the words from RFC 5280:

  To accommodate internationalized domain names in the current structure,
  conforming implementations MUST convert internationalized domain names to
  the ASCII Compatible Encoding (ACE) format as specified in Section 4 of RFC
  3490 before storage in the dNSName field.

>> EBCDIC systems do a whole lot of converting back and forth to/from ascii
>> for the various protocols.
> This can't be done at socket's send/receive level

I prefer to let the people actually working on the non-ASCII systems to handle
these issues. Of course the conversions have to be done in the proper places.

Received on 2018-04-26