I need to secure my UDP traffic. As far as I understand DTLS protocol is the best way to do it. There is another one - IPsec - but it looks not applicable for me because it\'s
I've found the following facts about the libraries and DTLS.
There is another lib with DTLS support - CyaSSL, but it supports DTLS only in test mode for now.
Although RFC 4347 dates from Apr, 2006, the OpenSSL supports DTLS since 2005 (v0.9.8). Many Linux distribs include this version. OpenSSL API looks ugly a little, but it seems like DTLS implementation is stable.
GnuTls supports DTLS since 2011 (v3.0.0). Looks like no Linux includes this version yet. (For example, Ubuntu 11.04 uses v2.8.6, Ubuntu 11.10 is going to use v2.10.5, not v3.0.0.) There is no information about when v3.0 will be used. It can be built manually, however it depends on too many additional libraries which may have no native support in some distribs.
It looks like all of these libraries can be used on other platforms (e.g. Windows).
Known OpenSSL issue: OpenSSL has compression enabled by default for DTLS, but it shouldn't be. OpenSSL v0.9.8 API doesn't provide any method to disable compression. The method should be implemented manually.
SUMMARY:
Speaking about usability, personally I would prefer GnuTls API, but at the time OpenSSL looks more preferable to use.