Secrets: Add encryption at rest Generates a master key file if it doesn't exist and encrypts secrets using the master key contained in the file. Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

UTIL: Add HMAC-SHA-1 function

UTIL: Provide base64 encoding and decoding functions

Password obfuscation utility functions Adds two utility functions to obfuscate a password and inverse to extract the cleartext password back. So far, only NSS-based implementation is provided.

Move crypto functions into its own subdir A refactoring patch that creates a common util/crypto subdir with per-implementation subdirectories for each underlying crypto library supported by SSSD.