- For HMAC requests, construct a special input buffer to request an empty
hash result.
- For plain cipher requests and requests that chain an AES cipher with an
HMAC, fail with EINVAL if there is no cipher payload. If needed in
the future, chained requests that only contain AAD could be serviced as
HMAC-only requests.
- For GCM requests, the hardware does not support generating the tag for
an AAD-only request. Instead, complete these requests synchronously
in software on the assumption that such requests are rare.
Sponsored by: Chelsio Communications
The adapter firmware in general does not accept PDUs larger than 64k - 1
bytes in size. Sending crypto requests larger than this size result in
hangs or incorrect output, so reject them with EFBIG. For requests
chaining an AES cipher with an HMAC, the firmware appears to require
slightly smaller requests (around 512 bytes).
Sponsored by: Chelsio Communications
The ccr(4) driver supports use of the crypto accelerator engine on
Chelsio T6 NICs in "lookaside" mode via the opencrypto framework.
Currently, the driver supports AES-CBC, AES-CTR, AES-GCM, and AES-XTS
cipher algorithms as well as the SHA1-HMAC, SHA2-256-HMAC, SHA2-384-HMAC,
and SHA2-512-HMAC authentication algorithms. The driver also supports
chaining one of AES-CBC, AES-CTR, or AES-XTS with an authentication
algorithm for encrypt-then-authenticate operations.
Note that this driver is still under active development and testing and
may not yet be ready for production use. It does pass the tests in
tests/sys/opencrypto with the exception that the AES-GCM implementation
in the driver does not yet support requests with a zero byte payload.
To use this driver currently, the "uwire" configuration must be used
along with explicitly enabling support for lookaside crypto capabilities
in the cxgbe(4) driver. These can be done by setting the following
tunables before loading the cxgbe(4) driver:
hw.cxgbe.config_file=uwire
hw.cxgbe.cryptocaps_allowed=-1
MFC after: 1 month
Relnotes: yes
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D10763
