/ curl Public
schannel: Fix ALPN buffer for HTTP/2 #7138
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 Outdated suggestions cannot be applied.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.
After upgrading to version 7.77, I noticed that requests using HTTP/2 with SChannel were failing with an error from the InitializeSecurityContext function.
In a3268ec the schannel code was changed to use the ALPN_H2 constant instead of the NGHTTP2_PROTO_ALPN constant. However, these constants are not the same. The nghttp2 constant included the length of the string, like this: "\x2h2". The ALPN_H2 constant is just "h2". Therefore we need to re-add the length of the string to the ALPN buffer.
This now matches the way that the "http/1.1" string and it's associated length are added to the ALPN buffer.