21. SNOW 3G Crypto Poll Mode Driver

The SNOW3G PMD (librte_crypto_snow3g) provides poll mode crypto driver support for utilizing Intel IPSec Multi-buffer library which implements F8 and F8 functions for SNOW 3G UEA2 cipher and UIA2 hash algorithms.

21.1. Features

SNOW 3G PMD has support for:

Cipher algorithm:

  • RTE_CRYPTO_CIPHER_SNOW3G_UEA2

Authentication algorithm:

  • RTE_CRYPTO_AUTH_SNOW3G_UIA2

21.2. Limitations

  • 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).

21.3. Installation

To build DPDK with the SNOW3G_PMD the user is required to download the multi-buffer library from here and compile it on their user system before building DPDK. The latest version of the library supported by this PMD is v1.1, which can be downloaded from https://github.com/01org/intel-ipsec-mb/archive/v1.1.zip.

After downloading the library, the user needs to unpack and compile it on their system before building DPDK:

make
make install

The library requires NASM to be built. Depending on the library version, it might require a minimum NASM version (e.g. v0.54 requires at least NASM 2.14).

NASM is packaged for different OS. However, on some OS the version is too old, so a manual installation is required. In that case, NASM can be downloaded from NASM website. Once it is downloaded, extract it and follow these steps:

./configure
make
make install

Note

Compilation of the Multi-Buffer library is broken when GCC < 5.0, if library <= v0.53. If a lower GCC version than 5.0, the workaround proposed by the following link should be used: https://github.com/intel/intel-ipsec-mb/issues/40.

As a reference, the following table shows a mapping between the past DPDK versions and the external crypto libraries supported by them:

Table 21.1 DPDK and external crypto library version compatibility
DPDK version Crypto library version
16.04 - 19.11 LibSSO SNOW3G
20.02 - 21.08 Multi-buffer library 0.53 - 1.1*
21.11+ Multi-buffer library 1.0 - 1.1*

* Multi-buffer library 1.0 or newer only works for Meson but not Make build system.

21.4. Initialization

In order to enable this virtual crypto PMD, user must:

  • Build the multi buffer library (explained in Installation section).

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).

Example:

./dpdk-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"