* EaR: Configurable encryption framework
Description
EaR implementation only supports fixed size on-disk encryption header format.
One drawback of the scheme is, introducing a newer encryption scheme as well
as updating header format in future may incur data migration restrictions.
Major changes proposed in the patch includes:
1. Flexible Encryption header format allowing the following:
1.1. Header flags (metadata) can evolve separately from the encryption algorithm
1.2. Specific encryption algorithm header to allow future extensions.
2. Update the BlobCipher encryption/decryption util classes to work with newer
encryption header format.
3. Continue supporting multiple encryption authentication schemes such as:
HMAC-SHA and AES-CMAC; also, supports no encryption-authentication schemes.
4. Refactor BlobCipher unit test to enable testing of new format.
5. Configuration knobs to control encryption header flags and algorithm
versions.
Note:
The on-disk header storage footprint savings due to the newer scheme is as follows:
1. No encryption authentication: 54% smaller compared to existing implementation.
3. AES-CMAC: 16% smaller compared to existing implementation.
3. HMAC-SHA encryption authentication: almost same size.
Testing
BlobCipherTest
EncryptionOpsTest
Description
FDB native encryption data at-rest supports two type of cipher-keys
in-memory caching:
1. Revocable keys - with a definite expiry (future timestamp)
2. Non-revocable keys - with or without expiry timestamp and/or
refreshAt timestamp.
Patch update BlobCipherKey in-memory cache to respect EKP/KMS
supplied 'refreshAt' and 'expireAt' timestamp. GetLatestCipher
validates `cipher key freshness' as well as GetCipherKey checks
for 'cipher key liveness' before replying details to the caller.
Patch also optimizes the BlobCipher module logging by taking
following measures:
1. BLOB_CIPHER_DEBUG macro to guard spammy log messages needed
mostly for debugging failures.
2. Minimize log volume by logging cipherKey details for any new
key added to the cache, key-refreshes are not logged.
3. Categorize logs into: debug, info and warn on per-usecase basis
Testing
devRunCorrectness - 100K
EncryptOps.toml - 100K
* 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.
Yi Wu