17. SNOW 3G Crypto Poll Mode Driver
The SNOW 3G PMD (librte_pmd_snow3g) provides poll mode crypto driver support for utilizing Intel Libsso library, which implements F8 and F9 functions for SNOW 3G UEA2 cipher and UIA2 hash algorithms.
SNOW 3G PMD has support for:
- Chained mbufs are not supported.
- SNOW 3G (UIA2) supported only if hash offset field is byte-aligned.
- In-place bit-level operations for SNOW 3G (UEA2) are not supported (if length and/or offset of data to be ciphered is not byte-aligned).
To build DPDK with the SNOW3G_PMD the user is required to download
the export controlled
libsso_snow3g library, by registering in
Intel Resource & Design Center.
Once approval has been granted, the user needs to search for
Snow3G F8 F9 3GPP cryptographic algorithms Software Library to download the
library or directly through this link.
After downloading the library, the user needs to unpack and compile it
on their system before building DPDK:
Note: When encrypting with SNOW3G UEA2, by default the library encrypts blocks of 4 bytes, regardless the number of bytes to be encrypted provided (which leads to a possible buffer overflow). To avoid this situation, it is necessary not to pass 3GPP_SAFE_BUFFERS as a compilation flag. For this, in the Makefile of the library, make sure that this flag is commented out.:
#EXTRA_CFLAGS += -D_3GPP_SAFE_BUFFERS
In order to enable this virtual crypto PMD, user must:
- Export the environmental variable LIBSSO_SNOW3G_PATH with the path where the library was extracted (snow3g folder).
- Build the LIBSSO_SNOW3G library (explained in Installation section).
- Set CONFIG_RTE_LIBRTE_PMD_SNOW3G=y in config/common_base.
To use the PMD in an application, user must:
- Call rte_vdev_init(“crypto_snow3g”) within the application.
- Use –vdev=”crypto_snow3g” in the EAL options, which will call rte_vdev_init() internally.
The following parameters (all optional) can be provided in the previous two calls:
- socket_id: Specify the socket where the memory for the device is going to be allocated (by default, socket_id will be the socket where the core that is creating the PMD is running on).
- max_nb_queue_pairs: Specify the maximum number of queue pairs in the device (8 by default).
- max_nb_sessions: Specify the maximum number of sessions that can be created (2048 by default).
./l2fwd-crypto -l 1 -n 4 --vdev="crypto_snow3g,socket_id=0,max_nb_sessions=128" \ -- -p 1 --cdev SW --chain CIPHER_ONLY --cipher_algo "snow3g-uea2"