* Upgrade AES 128 GCM -> AES 256, StreamCipher code refactor
Major changes proposed are:
1. Refactor StreamCipher code to enable instantiation of
multiple encryption keys. However, code still retains
a globalEncryption key semantics used in Backup file
encryption usecase.
2. Enhance StreamCipher to provide HMAC signature digest
generation. Further, the class implements HMAC encryption
key derivation function.
3. Upgrade StreamCipher to use AES 256 GCM mode from currently
supported AES 128 GCM mode.
Note: The code changes the encryption key size, however, the
feature is NOT currently in use, hence, should be OK.
3. Add EncryptionOps validation and benchmark toml supported
workload, it does the following:
a. Allow user to configure encrypt-decrypt of a fixed size
buffer or variable size buffer [100, 512K]
b. Allow user to configure number of interactions of the runs,
in each iteration: generate random data, derive an encryption
key using HMAC SHA256 method, encrypt data and
then decrypt data. It collects following metrics:
i) time taken to derive encryption key.
ii) time taken to encrypt the buffer.
iii) time taken to decrypt the buffer.
iv) total bytes encrypted and/or decrypted
c. Along with stats it basic basic validations on the encrypted
and decrypted buffer
d. On completion for test, records the above mentioned metrics
in trace files.