5. 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.

5.1. Features

SNOW 3G PMD has support for:

Cipher algorithm:

  • RTE_CRYPTO_SYM_CIPHER_SNOW3G_UEA2

Authentication algorithm:

  • RTE_CRYPTO_SYM_AUTH_SNOW3G_UIA2

5.2. Limitations

  • Chained mbufs are not supported.
  • Snow3g(UEA2) supported only if cipher length, cipher offset fields are byte-aligned.
  • Snow3g(UIA2) supported only if hash length, hash offset fields are byte-aligned.

5.3. Installation

To build DPDK with the SNOW3G_PMD the user is required to download the export controlled libsso library, by requesting it from https://networkbuilders.intel.com/network-technologies/dpdk, and compiling it on their system before building DPDK:

make -f Makefile_snow3g

Note: If using a gcc version higher than 5.0, and compilation fails, apply the following patch:

/libsso/src/snow3g/sso_snow3g.c

static inline void ClockFSM_4(sso_snow3gKeyState4_t *pCtx, __m128i *data)
{
    __m128i F, R;
-    uint32_t K, L;
+    uint32_t K;
+    /* Declare unused if SNOW3G_WSM/SNB are defined */
+    uint32_t L __attribute__ ((unused)) = 0;

     F = _mm_add_epi32(pCtx->LFSR_X[15], pCtx->FSM_X[0]);
     R = _mm_xor_si128(pCtx->LFSR_X[5], pCtx->FSM_X[2]);

/libsso/include/sso_snow3g_internal.h

-inline void ClockFSM_1(sso_snow3gKeyState1_t *pCtx, uint32_t *data);
-inline void ClockLFSR_1(sso_snow3gKeyState1_t *pCtx);
-inline void sso_snow3gStateInitialize_1(sso_snow3gKeyState1_t * pCtx, sso_snow3g_key_schedule_t *pKeySched, uint8_t *pIV);
+void ClockFSM_1(sso_snow3gKeyState1_t *pCtx, uint32_t *data);
+void ClockLFSR_1(sso_snow3gKeyState1_t *pCtx);
+void sso_snow3gStateInitialize_1(sso_snow3gKeyState1_t * pCtx, sso_snow3g_key_schedule_t *pKeySched, uint8_t *pIV);

5.4. Initialization

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

  • Export the environmental variable LIBSSO_PATH with the path where the library was extracted.
  • Build the LIBSSO 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_eal_vdev_init(“cryptodev_snow3g_pmd”) within the application.
  • Use –vdev=”cryptodev_snow3g_pmd” in the EAL options, which will call rte_eal_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:

./l2fwd-crypto -c 40 -n 4 --vdev="cryptodev_snow3g_pmd,socket_id=1,max_nb_sessions=128"