neon

neon is an HTTP/1.1 and WebDAV client library, with a C interface.

Features:

 - High-level wrappers for common HTTP and WebDAV operations (GET, MOVE, DELETE, etc) Low-level interface to the HTTP request/response engine, allowing the use of arbitrary HTTP methods, headers, etc.
 - Authentication support including Basic and Digest support, along with GSSAPI-based Negotiate on Unix, and SSPI-based Negotiate/NTLM on Win32
 - SSL/TLS support using OpenSSL or GnuTLS; exposing an abstraction layer for verifying server certificates, handling client certificates, and examining certificate properties.
 - Smartcard-based client certificates are also supported via a PKCS#11 wrapper interface
 - Abstract interface to parsing XML using libxml2 or expat, and wrappers for simplifying handling XML HTTP response bodies
 - WebDAV metadata support; wrappers for PROPFIND and PROPPATCH to simplify property manipulation