curl / Development / Deprecate

Items to be removed from future curl releases

If any of these deprecated features is a cause for concern for you, please email the curl-library mailing list as soon as possible and explain to us why this is a problem for you and how your use case cannot be satisfied properly using a workaround.

NTLM_WB auth

This NTLM authentication method is powered by a separate tool, ntlm_auth. Barely anyone uses this method. It was always a quirky implementation (including fork + exec), it has limited portability and we do not test it in the test suite and CI.

We keep the native NTLM implementation.

Due to a mistake, the NTLM_WB functionality is missing in builds since 8.4.0 (October 2023). It needs to be manually patched to work. See PR 12479.

curl removes the support for NTLM_WB auth in April 2024.

space-separated NOPROXY patterns

When specifying patterns/domain names for curl that should not go through a proxy, the curl tool features the --noproxy command line option and the library supports the NO_PROXY environment variable and the CURLOPT_NOPROXY libcurl option.

They all set the same list of patterns. This list is documented to be a set of comma-separated names, but can also be provided separated with just space. The ability to just use spaces for this has never been documented but some users may still have come to rely on this.

Several other tools and utilities also parse the NO_PROXY environment variable but do not consider a space to be a valid separator. Using spaces for separator is probably less portable and might cause more friction than commas do. Users should use commas for this for greater portability.

curl removes the support for space-separated names in July 2024.

past removals