2. AES-NI Multi Buffer Crypto Poll Mode Driver

The AESNI MB PMD (librte_crypto_aesni_mb) provides poll mode crypto driver support for utilizing Intel multi buffer library, see the white paper Fast Multi-buffer IPsec Implementations on Intel® Architecture Processors.

The AES-NI MB PMD supports synchronous mode of operation with rte_cryptodev_sym_cpu_crypto_process function call.

2.1. Features

AESNI MB PMD has support for:

Cipher algorithms:

  • RTE_CRYPTO_CIPHER_AES128_CBC
  • RTE_CRYPTO_CIPHER_AES192_CBC
  • RTE_CRYPTO_CIPHER_AES256_CBC
  • RTE_CRYPTO_CIPHER_AES128_CTR
  • RTE_CRYPTO_CIPHER_AES192_CTR
  • RTE_CRYPTO_CIPHER_AES256_CTR
  • RTE_CRYPTO_CIPHER_AES_DOCSISBPI
  • RTE_CRYPTO_CIPHER_DES_CBC
  • RTE_CRYPTO_CIPHER_3DES_CBC
  • RTE_CRYPTO_CIPHER_DES_DOCSISBPI
  • RTE_CRYPTO_CIPHER_AES128_ECB
  • RTE_CRYPTO_CIPHER_AES192_ECB
  • RTE_CRYPTO_CIPHER_AES256_ECB
  • RTE_CRYPTO_CIPHER_ZUC_EEA3
  • RTE_CRYPTO_CIPHER_SNOW3G_UEA2
  • RTE_CRYPTO_CIPHER_KASUMI_F8

Hash algorithms:

  • RTE_CRYPTO_AUTH_MD5_HMAC
  • RTE_CRYPTO_AUTH_SHA1_HMAC
  • RTE_CRYPTO_AUTH_SHA224_HMAC
  • RTE_CRYPTO_AUTH_SHA256_HMAC
  • RTE_CRYPTO_AUTH_SHA384_HMAC
  • RTE_CRYPTO_AUTH_SHA512_HMAC
  • RTE_CRYPTO_AUTH_AES_XCBC_HMAC
  • RTE_CRYPTO_AUTH_AES_CMAC
  • RTE_CRYPTO_AUTH_AES_GMAC
  • RTE_CRYPTO_AUTH_SHA1
  • RTE_CRYPTO_AUTH_SHA224
  • RTE_CRYPTO_AUTH_SHA256
  • RTE_CRYPTO_AUTH_SHA384
  • RTE_CRYPTO_AUTH_SHA512
  • RTE_CRYPTO_AUTH_ZUC_EIA3
  • RTE_CRYPTO_AUTH_SNOW3G_UIA2
  • RTE_CRYPTO_AUTH_KASUMI_F9

AEAD algorithms:

  • RTE_CRYPTO_AEAD_AES_CCM
  • RTE_CRYPTO_AEAD_AES_GCM
  • RTE_CRYPTO_AEAD_CHACHA20_POLY1305

Protocol offloads:

  • RTE_SECURITY_PROTOCOL_DOCSIS

2.2. Limitations

  • Out-of-place is not supported for combined Crypto-CRC DOCSIS security protocol.
  • RTE_CRYPTO_CIPHER_DES_DOCSISBPI is not supported for combined Crypto-CRC DOCSIS security protocol.

2.3. AESNI MB PMD selection over SNOW3G/ZUC/KASUMI PMDs

This PMD supports wireless cipher suite (SNOW3G, ZUC and KASUMI). On Intel processors, it is recommended to use this PMD instead of SNOW3G, ZUC and KASUMI PMDs, as it enables algorithm mixing (e.g. cipher algorithm SNOW3G-UEA2 with authentication algorithm AES-CMAC-128) and performance over IMIX (packet size mix) traffic is significantly higher.

2.4. AESNI MB PMD selection over CHACHA20-POLY1305 PMD

This PMD supports Chacha20-Poly1305 algorithm. On Intel processors, it is recommended to use this PMD instead of CHACHA20-POLY1305 PMD, as it delivers better performance on single segment buffers. For multi-segment buffers, it is still recommended to use CHACHA20-POLY1305 PMD, until the new SGL API is introduced in the AESNI MB PMD.

2.5. Installation

To build DPDK with the AESNI_MB_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 v1.5, which can be downloaded from https://github.com/01org/intel-ipsec-mb/archive/v1.5.zip.

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 Multi-Buffer library version supported by them:

Table 2.1 DPDK and Multi-Buffer library version compatibility
DPDK version Multi-buffer library version
2.2 - 16.11 0.43 - 0.44
17.02 0.44
17.05 - 17.08 0.45 - 0.48
17.11 0.47 - 0.48
18.02 0.48
18.05 - 19.02 0.49 - 0.52
19.05 - 19.08 0.52
19.11 - 20.08 0.52 - 0.55
20.11 - 21.08 0.53 - 1.3*
21.11+ 1.0 - 1.5*

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

2.6. 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_aesni_mb”) within the application.
  • Use –vdev=”crypto_aesni_mb” 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_aesni_mb,socket_id=0,max_nb_sessions=128" \
-- -p 1 --cdev SW --chain CIPHER_HASH --cipher_algo "aes-cbc" --auth_algo "sha1-hmac"

2.7. Extra notes

For AES Counter mode (AES-CTR), the library supports two different sizes for Initialization Vector (IV):

  • 12 bytes: used mainly for IPsec, as it requires 12 bytes from the user, which internally are appended the counter block (4 bytes), which is set to 1 for the first block (no padding required from the user)
  • 16 bytes: when passing 16 bytes, the library will take them and use the last 4 bytes as the initial counter block for the first block.