libnss3-dev 2:3.49.1-1ubuntu1.1 (amd64 binary) in ubuntu focal

 This is a set of libraries designed to support cross-platform development
 of security-enabled client and server applications. It can support SSLv2
 and v4, TLS, PKCS #5, #7, #11, #12, S/MIME, X.509 v3 certificates and
 other security standards.
 .
 Install this package if you wish to develop your own programs using the
 Network Security Service Libraries.