xref: /dpdk/doc/guides/prog_guide/cryptodev_lib.rst (revision cb0da841649ee317e44faacbc4063caa26008366)
1..  SPDX-License-Identifier: BSD-3-Clause
2    Copyright(c) 2016-2020 Intel Corporation.
3
4Cryptography Device Library
5===========================
6
7The cryptodev library provides a Crypto device framework for management and
8provisioning of hardware and software Crypto poll mode drivers, defining generic
9APIs which support a number of different Crypto operations. The framework
10currently only supports cipher, authentication, chained cipher/authentication
11and AEAD symmetric and asymmetric Crypto operations.
12
13
14Design Principles
15-----------------
16
17The cryptodev library follows the same basic principles as those used in DPDK's
18Ethernet Device framework. The Crypto framework provides a generic Crypto device
19framework which supports both physical (hardware) and virtual (software) Crypto
20devices as well as a generic Crypto API which allows Crypto devices to be
21managed and configured and supports Crypto operations to be provisioned on
22Crypto poll mode driver.
23
24
25Device Management
26-----------------
27
28Device Creation
29~~~~~~~~~~~~~~~
30
31Physical Crypto devices are discovered during the PCI probe/enumeration of the
32EAL function which is executed at DPDK initialization, based on
33their PCI device identifier, each unique PCI BDF (bus/bridge, device,
34function). Specific physical Crypto devices, like other physical devices in DPDK
35can be listed using the EAL command line options.
36
37Virtual devices can be created by two mechanisms, either using the EAL command
38line options or from within the application using an EAL API directly.
39
40From the command line using the --vdev EAL option
41
42.. code-block:: console
43
44   --vdev  'crypto_aesni_mb0,max_nb_queue_pairs=2,socket_id=0'
45
46.. Note::
47
48   * If DPDK application requires multiple software crypto PMD devices then required
49     number of ``--vdev`` with appropriate libraries are to be added.
50
51   * An Application with crypto PMD instances sharing the same library requires unique ID.
52
53   Example: ``--vdev  'crypto_aesni_mb0' --vdev  'crypto_aesni_mb1'``
54
55Or using the rte_vdev_init API within the application code.
56
57.. code-block:: c
58
59   rte_vdev_init("crypto_aesni_mb",
60                     "max_nb_queue_pairs=2,socket_id=0")
61
62All virtual Crypto devices support the following initialization parameters:
63
64* ``max_nb_queue_pairs`` - maximum number of queue pairs supported by the device.
65* ``socket_id`` - socket on which to allocate the device resources on.
66
67
68Device Identification
69~~~~~~~~~~~~~~~~~~~~~
70
71Each device, whether virtual or physical is uniquely designated by two
72identifiers:
73
74- A unique device index used to designate the Crypto device in all functions
75  exported by the cryptodev API.
76
77- A device name used to designate the Crypto device in console messages, for
78  administration or debugging purposes. For ease of use, the port name includes
79  the port index.
80
81
82Device Configuration
83~~~~~~~~~~~~~~~~~~~~
84
85The configuration of each Crypto device includes the following operations:
86
87- Allocation of resources, including hardware resources if a physical device.
88- Resetting the device into a well-known default state.
89- Initialization of statistics counters.
90
91The rte_cryptodev_configure API is used to configure a Crypto device.
92
93.. code-block:: c
94
95   int rte_cryptodev_configure(uint8_t dev_id,
96                               struct rte_cryptodev_config *config)
97
98The ``rte_cryptodev_config`` structure is used to pass the configuration
99parameters for socket selection and number of queue pairs.
100
101.. code-block:: c
102
103    struct rte_cryptodev_config {
104        int socket_id;
105        /**< Socket to allocate resources on */
106        uint16_t nb_queue_pairs;
107        /**< Number of queue pairs to configure on device */
108    };
109
110
111Configuration of Queue Pairs
112~~~~~~~~~~~~~~~~~~~~~~~~~~~~
113
114Each Crypto devices queue pair is individually configured through the
115``rte_cryptodev_queue_pair_setup`` API.
116Each queue pairs resources may be allocated on a specified socket.
117
118.. code-block:: c
119
120    int rte_cryptodev_queue_pair_setup(uint8_t dev_id, uint16_t queue_pair_id,
121                const struct rte_cryptodev_qp_conf *qp_conf,
122                int socket_id)
123
124   struct rte_cryptodev_qp_conf {
125        uint32_t nb_descriptors; /**< Number of descriptors per queue pair */
126        struct rte_mempool *mp_session;
127        /**< The mempool for creating session in sessionless mode */
128    };
129
130
131The field ``mp_session`` is used for creating temporary session to process
132the crypto operations in the session-less mode.
133They can be the same other different mempools. Please note not all Cryptodev
134PMDs supports session-less mode.
135
136
137Logical Cores, Memory and Queues Pair Relationships
138~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
139
140The Crypto device Library as the Poll Mode Driver library support NUMA for when
141a processor’s logical cores and interfaces utilize its local memory. Therefore
142Crypto operations, and in the case of symmetric Crypto operations, the session
143and the mbuf being operated on, should be allocated from memory pools created
144in the local memory. The buffers should, if possible, remain on the local
145processor to obtain the best performance results and buffer descriptors should
146be populated with mbufs allocated from a mempool allocated from local memory.
147
148The run-to-completion model also performs better, especially in the case of
149virtual Crypto devices, if the Crypto operation and session and data buffer is
150in local memory instead of a remote processor's memory. This is also true for
151the pipe-line model provided all logical cores used are located on the same
152processor.
153
154Multiple logical cores should never share the same queue pair for enqueuing
155operations or dequeuing operations on the same Crypto device since this would
156require global locks and hinder performance. It is however possible to use a
157different logical core to dequeue an operation on a queue pair from the logical
158core which it was enqueued on. This means that a crypto burst enqueue/dequeue
159APIs are a logical place to transition from one logical core to another in a
160packet processing pipeline.
161
162
163Device Features and Capabilities
164---------------------------------
165
166Crypto devices define their functionality through two mechanisms, global device
167features and algorithm capabilities. Global devices features identify device
168wide level features which are applicable to the whole device such as
169the device having hardware acceleration or supporting symmetric and/or asymmetric
170Crypto operations.
171
172The capabilities mechanism defines the individual algorithms/functions which
173the device supports, such as a specific symmetric Crypto cipher,
174authentication operation or Authenticated Encryption with Associated Data
175(AEAD) operation.
176
177
178Device Features
179~~~~~~~~~~~~~~~
180
181Currently the following Crypto device features are defined:
182
183* Symmetric Crypto operations
184* Asymmetric Crypto operations
185* Chaining of symmetric Crypto operations
186* SSE accelerated SIMD vector operations
187* AVX accelerated SIMD vector operations
188* AVX2 accelerated SIMD vector operations
189* AESNI accelerated instructions
190* Hardware off-load processing
191
192
193Device Operation Capabilities
194~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
195
196Crypto capabilities which identify particular algorithm which the Crypto PMD
197supports are  defined by the operation type, the operation transform, the
198transform identifier and then the particulars of the transform. For the full
199scope of the Crypto capability see the definition of the structure in the
200*DPDK API Reference*.
201
202.. code-block:: c
203
204   struct rte_cryptodev_capabilities;
205
206Each Crypto poll mode driver defines its own private array of capabilities
207for the operations it supports. Below is an example of the capabilities for a
208PMD which supports the authentication algorithm SHA1_HMAC and the cipher
209algorithm AES_CBC.
210
211.. code-block:: c
212
213    static const struct rte_cryptodev_capabilities pmd_capabilities[] = {
214        {    /* SHA1 HMAC */
215            .op = RTE_CRYPTO_OP_TYPE_SYMMETRIC,
216            .sym = {
217                .xform_type = RTE_CRYPTO_SYM_XFORM_AUTH,
218                .auth = {
219                    .algo = RTE_CRYPTO_AUTH_SHA1_HMAC,
220                    .block_size = 64,
221                    .key_size = {
222                        .min = 64,
223                        .max = 64,
224                        .increment = 0
225                    },
226                    .digest_size = {
227                        .min = 12,
228                        .max = 12,
229                        .increment = 0
230                    },
231                    .aad_size = { 0 },
232                    .iv_size = { 0 }
233                }
234            }
235        },
236        {    /* AES CBC */
237            .op = RTE_CRYPTO_OP_TYPE_SYMMETRIC,
238            .sym = {
239                .xform_type = RTE_CRYPTO_SYM_XFORM_CIPHER,
240                .cipher = {
241                    .algo = RTE_CRYPTO_CIPHER_AES_CBC,
242                    .block_size = 16,
243                    .key_size = {
244                        .min = 16,
245                        .max = 32,
246                        .increment = 8
247                    },
248                    .iv_size = {
249                        .min = 16,
250                        .max = 16,
251                        .increment = 0
252                    }
253                }
254            }
255        }
256    }
257
258
259Capabilities Discovery
260~~~~~~~~~~~~~~~~~~~~~~
261
262Discovering the features and capabilities of a Crypto device poll mode driver
263is achieved through the ``rte_cryptodev_info_get`` function.
264
265.. code-block:: c
266
267   void rte_cryptodev_info_get(uint8_t dev_id,
268                               struct rte_cryptodev_info *dev_info);
269
270This allows the user to query a specific Crypto PMD and get all the device
271features and capabilities. The ``rte_cryptodev_info`` structure contains all the
272relevant information for the device.
273
274.. code-block:: c
275
276    struct rte_cryptodev_info {
277        const char *driver_name;
278        uint8_t driver_id;
279        struct rte_device *device;
280
281        uint64_t feature_flags;
282
283        const struct rte_cryptodev_capabilities *capabilities;
284
285        unsigned max_nb_queue_pairs;
286
287        struct {
288            unsigned max_nb_sessions;
289        } sym;
290    };
291
292
293Operation Processing
294--------------------
295
296Scheduling of Crypto operations on DPDK's application data path is
297performed using a burst oriented asynchronous API set. A queue pair on a Crypto
298device accepts a burst of Crypto operations using enqueue burst API. On physical
299Crypto devices the enqueue burst API will place the operations to be processed
300on the devices hardware input queue, for virtual devices the processing of the
301Crypto operations is usually completed during the enqueue call to the Crypto
302device. The dequeue burst API will retrieve any processed operations available
303from the queue pair on the Crypto device, from physical devices this is usually
304directly from the devices processed queue, and for virtual device's from a
305``rte_ring`` where processed operations are placed after being processed on the
306enqueue call.
307
308
309Private data
310~~~~~~~~~~~~
311For session-based operations, the set and get API provides a mechanism for an
312application to store and retrieve the private user data information stored along
313with the crypto session.
314
315For example, suppose an application is submitting a crypto operation with a session
316associated and wants to indicate private user data information which is required to be
317used after completion of the crypto operation. In this case, the application can use
318the set API to set the user data and retrieve it using get API.
319
320.. code-block:: c
321
322	int rte_cryptodev_sym_session_set_user_data(
323		struct rte_cryptodev_sym_session *sess,	void *data, uint16_t size);
324
325	void * rte_cryptodev_sym_session_get_user_data(
326		struct rte_cryptodev_sym_session *sess);
327
328Please note the ``size`` passed to set API cannot be bigger than the predefined
329``user_data_sz`` when creating the session header mempool, otherwise the
330function will return error. Also when ``user_data_sz`` was defined as ``0`` when
331creating the session header mempool, the get API will always return ``NULL``.
332
333For session-less mode, the private user data information can be placed along with the
334``struct rte_crypto_op``. The ``rte_crypto_op::private_data_offset`` indicates the
335start of private data information. The offset is counted from the start of the
336rte_crypto_op including other crypto information such as the IVs (since there can
337be an IV also for authentication).
338
339User callback APIs
340~~~~~~~~~~~~~~~~~~
341The add APIs configures a user callback function to be called for each burst of crypto
342ops received/sent on a given crypto device queue pair. The return value is a pointer
343that can be used later to remove the callback using remove API. Application is expected
344to register a callback function of type ``rte_cryptodev_callback_fn``. Multiple callback
345functions can be added for a given queue pair. API does not restrict on maximum number of
346callbacks.
347
348Callbacks registered by application would not survive ``rte_cryptodev_configure`` as it
349reinitializes the callback list. It is user responsibility to remove all installed
350callbacks before calling ``rte_cryptodev_configure`` to avoid possible memory leakage.
351
352So, the application is expected to add user callback after ``rte_cryptodev_configure``.
353The callbacks can also be added at the runtime. These callbacks get executed when
354``rte_cryptodev_enqueue_burst``/``rte_cryptodev_dequeue_burst`` is called.
355
356.. code-block:: c
357
358	struct rte_cryptodev_cb *
359		rte_cryptodev_add_enq_callback(uint8_t dev_id, uint16_t qp_id,
360					       rte_cryptodev_callback_fn cb_fn,
361					       void *cb_arg);
362
363	struct rte_cryptodev_cb *
364		rte_cryptodev_add_deq_callback(uint8_t dev_id, uint16_t qp_id,
365					       rte_cryptodev_callback_fn cb_fn,
366					       void *cb_arg);
367
368	uint16_t (* rte_cryptodev_callback_fn)(uint16_t dev_id, uint16_t qp_id,
369					       struct rte_crypto_op **ops,
370					       uint16_t nb_ops, void *user_param);
371
372The remove API removes a callback function added by
373``rte_cryptodev_add_enq_callback``/``rte_cryptodev_add_deq_callback``.
374
375.. code-block:: c
376
377	int rte_cryptodev_remove_enq_callback(uint8_t dev_id, uint16_t qp_id,
378					      struct rte_cryptodev_cb *cb);
379
380	int rte_cryptodev_remove_deq_callback(uint8_t dev_id, uint16_t qp_id,
381					      struct rte_cryptodev_cb *cb);
382
383
384Enqueue / Dequeue Burst APIs
385~~~~~~~~~~~~~~~~~~~~~~~~~~~~
386
387The burst enqueue API uses a Crypto device identifier and a queue pair
388identifier to specify the Crypto device queue pair to schedule the processing on.
389The ``nb_ops`` parameter is the number of operations to process which are
390supplied in the ``ops`` array of ``rte_crypto_op`` structures.
391The enqueue function returns the number of operations it actually enqueued for
392processing, a return value equal to ``nb_ops`` means that all packets have been
393enqueued.
394
395.. code-block:: c
396
397   uint16_t rte_cryptodev_enqueue_burst(uint8_t dev_id, uint16_t qp_id,
398                                        struct rte_crypto_op **ops, uint16_t nb_ops)
399
400The dequeue API uses the same format as the enqueue API of processed but
401the ``nb_ops`` and ``ops`` parameters are now used to specify the max processed
402operations the user wishes to retrieve and the location in which to store them.
403The API call returns the actual number of processed operations returned, this
404can never be larger than ``nb_ops``.
405
406.. code-block:: c
407
408   uint16_t rte_cryptodev_dequeue_burst(uint8_t dev_id, uint16_t qp_id,
409                                        struct rte_crypto_op **ops, uint16_t nb_ops)
410
411
412Operation Representation
413~~~~~~~~~~~~~~~~~~~~~~~~
414
415An Crypto operation is represented by an rte_crypto_op structure, which is a
416generic metadata container for all necessary information required for the
417Crypto operation to be processed on a particular Crypto device poll mode driver.
418
419.. figure:: img/crypto_op.*
420
421The operation structure includes the operation type, the operation status
422and the session type (session-based/less), a reference to the operation
423specific data, which can vary in size and content depending on the operation
424being provisioned. It also contains the source mempool for the operation,
425if it allocated from a mempool.
426
427If Crypto operations are allocated from a Crypto operation mempool, see next
428section, there is also the ability to allocate private memory with the
429operation for applications purposes.
430
431Application software is responsible for specifying all the operation specific
432fields in the ``rte_crypto_op`` structure which are then used by the Crypto PMD
433to process the requested operation.
434
435
436Operation Management and Allocation
437~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
438
439The cryptodev library provides an API set for managing Crypto operations which
440utilize the Mempool Library to allocate operation buffers. Therefore, it ensures
441that the crypto operation is interleaved optimally across the channels and
442ranks for optimal processing.
443A ``rte_crypto_op`` contains a field indicating the pool that it originated from.
444When calling ``rte_crypto_op_free(op)``, the operation returns to its original pool.
445
446.. code-block:: c
447
448   extern struct rte_mempool *
449   rte_crypto_op_pool_create(const char *name, enum rte_crypto_op_type type,
450                             unsigned nb_elts, unsigned cache_size, uint16_t priv_size,
451                             int socket_id);
452
453During pool creation ``rte_crypto_op_init()`` is called as a constructor to
454initialize each Crypto operation which subsequently calls
455``__rte_crypto_op_reset()`` to configure any operation type specific fields based
456on the type parameter.
457
458
459``rte_crypto_op_alloc()`` and ``rte_crypto_op_bulk_alloc()`` are used to allocate
460Crypto operations of a specific type from a given Crypto operation mempool.
461``__rte_crypto_op_reset()`` is called on each operation before being returned to
462allocate to a user so the operation is always in a good known state before use
463by the application.
464
465.. code-block:: c
466
467   struct rte_crypto_op *rte_crypto_op_alloc(struct rte_mempool *mempool,
468                                             enum rte_crypto_op_type type)
469
470   unsigned rte_crypto_op_bulk_alloc(struct rte_mempool *mempool,
471                                     enum rte_crypto_op_type type,
472                                     struct rte_crypto_op **ops, uint16_t nb_ops)
473
474``rte_crypto_op_free()`` is called by the application to return an operation to
475its allocating pool.
476
477.. code-block:: c
478
479   void rte_crypto_op_free(struct rte_crypto_op *op)
480
481
482Symmetric Cryptography Support
483------------------------------
484
485The cryptodev library currently provides support for the following symmetric
486Crypto operations; cipher, authentication, including chaining of these
487operations, as well as also supporting AEAD operations.
488
489
490Session and Session Management
491~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
492
493Sessions are used in symmetric cryptographic processing to store the immutable
494data defined in a cryptographic transform which is used in the operation
495processing of a packet flow. Sessions are used to manage information such as
496expand cipher keys and HMAC IPADs and OPADs, which need to be calculated for a
497particular Crypto operation, but are immutable on a packet to packet basis for
498a flow. Crypto sessions cache this immutable data in a optimal way for the
499underlying PMD and this allows further acceleration of the offload of
500Crypto workloads.
501
502The Crypto device framework provides APIs to create session mempool and allocate
503and initialize sessions for crypto devices, where sessions are mempool objects.
504The application has to use ``rte_cryptodev_sym_session_pool_create()`` to
505create the session mempool header and the private data with the size specified
506by the user through the ``elt_size`` parameter in the function.
507The session private data is for the driver to initialize and access
508during crypto operations, hence the ``elt_size`` should be big enough
509for all drivers that will share this mempool.
510To obtain the proper session private data size of a crypto device,
511the user can call ``rte_cryptodev_sym_get_private_session_size()`` function.
512In case of heterogeneous crypto devices which will share the same session mempool,
513the maximum session private data size of them should be passed.
514
515Once the session mempools have been created, ``rte_cryptodev_sym_session_create()``
516is used to allocate and initialize the session from the given mempool.
517The created session can ONLY be used by the crypto devices sharing the same driver ID
518as the device ID passed into the function as the parameter.
519In addition, a symmetric transform chain is used to specify the operation and its parameters.
520See the section below for details on transforms.
521
522When a session is no longer used, user must call ``rte_cryptodev_sym_session_free()``
523to uninitialize the session data and return the session
524back to the mempool it belongs.
525
526
527Transforms and Transform Chaining
528~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
529
530Symmetric Crypto transforms (``rte_crypto_sym_xform``) are the mechanism used
531to specify the details of the Crypto operation. For chaining of symmetric
532operations such as cipher encrypt and authentication generate, the next pointer
533allows transform to be chained together. Crypto devices which support chaining
534must publish the chaining of symmetric Crypto operations feature flag. Allocation of the
535xform structure is in the application domain. To allow future API extensions in a
536backwardly compatible manner, e.g. addition of a new parameter, the application should
537zero the full xform struct before populating it.
538
539Currently there are three transforms types cipher, authentication and AEAD.
540Also it is important to note that the order in which the
541transforms are passed indicates the order of the chaining.
542
543.. code-block:: c
544
545    struct rte_crypto_sym_xform {
546        struct rte_crypto_sym_xform *next;
547        /**< next xform in chain */
548        enum rte_crypto_sym_xform_type type;
549        /**< xform type */
550        union {
551            struct rte_crypto_auth_xform auth;
552            /**< Authentication / hash xform */
553            struct rte_crypto_cipher_xform cipher;
554            /**< Cipher xform */
555            struct rte_crypto_aead_xform aead;
556            /**< AEAD xform */
557        };
558    };
559
560The API does not place a limit on the number of transforms that can be chained
561together but this will be limited by the underlying Crypto device poll mode
562driver which is processing the operation.
563
564.. figure:: img/crypto_xform_chain.*
565
566
567Symmetric Operations
568~~~~~~~~~~~~~~~~~~~~
569
570The symmetric Crypto operation structure contains all the mutable data relating
571to performing symmetric cryptographic processing on a referenced mbuf data
572buffer. It is used for either cipher, authentication, AEAD and chained
573operations.
574
575As a minimum the symmetric operation must have a source data buffer (``m_src``),
576a valid session (or transform chain if in session-less mode) and the minimum
577authentication/ cipher/ AEAD parameters required depending on the type of operation
578specified in the session or the transform
579chain.
580
581.. code-block:: c
582
583    struct rte_crypto_sym_op {
584        struct rte_mbuf *m_src;
585        struct rte_mbuf *m_dst;
586
587        union {
588            void *session;
589            /**< Handle for the initialised session context */
590            struct rte_crypto_sym_xform *xform;
591            /**< Session-less API Crypto operation parameters */
592        };
593
594        union {
595            struct {
596                struct {
597                    uint32_t offset;
598                    uint32_t length;
599                } data; /**< Data offsets and length for AEAD */
600
601                struct {
602                    uint8_t *data;
603                    rte_iova_t phys_addr;
604                } digest; /**< Digest parameters */
605
606                struct {
607                    uint8_t *data;
608                    rte_iova_t phys_addr;
609                } aad;
610                /**< Additional authentication parameters */
611            } aead;
612
613            struct {
614                struct {
615                    struct {
616                        uint32_t offset;
617                        uint32_t length;
618                    } data; /**< Data offsets and length for ciphering */
619                } cipher;
620
621                struct {
622                    struct {
623                        uint32_t offset;
624                        uint32_t length;
625                    } data;
626                    /**< Data offsets and length for authentication */
627
628                    struct {
629                        uint8_t *data;
630                        rte_iova_t phys_addr;
631                    } digest; /**< Digest parameters */
632                } auth;
633            };
634        };
635    };
636
637Synchronous mode
638----------------
639
640Some cryptodevs support synchronous mode alongside with a standard asynchronous
641mode. In that case operations are performed directly when calling
642``rte_cryptodev_sym_cpu_crypto_process`` method instead of enqueuing and
643dequeuing an operation before. This mode of operation allows cryptodevs which
644utilize CPU cryptographic acceleration to have significant performance boost
645comparing to standard asynchronous approach. Cryptodevs supporting synchronous
646mode have ``RTE_CRYPTODEV_FF_SYM_CPU_CRYPTO`` feature flag set.
647
648To perform a synchronous operation a call to
649``rte_cryptodev_sym_cpu_crypto_process`` has to be made with vectorized
650operation descriptor (``struct rte_crypto_sym_vec``) containing:
651
652- ``num`` - number of operations to perform,
653- pointer to an array of size ``num`` containing a scatter-gather list
654  descriptors of performed operations (``struct rte_crypto_sgl``). Each instance
655  of ``struct rte_crypto_sgl`` consists of a number of segments and a pointer to
656  an array of segment descriptors ``struct rte_crypto_vec``;
657- pointers to arrays of size ``num`` containing IV, AAD and digest information
658  in the ``cpu_crypto`` sub-structure,
659- pointer to an array of size ``num`` where status information will be stored
660  for each operation.
661
662Function returns a number of successfully completed operations and sets
663appropriate status number for each operation in the status array provided as
664a call argument. Status different than zero must be treated as error.
665
666For more details, e.g. how to convert an mbuf to an SGL, please refer to an
667example usage in the IPsec library implementation.
668
669Cryptodev Raw Data-path APIs
670~~~~~~~~~~~~~~~~~~~~~~~~~~~~
671
672The Crypto Raw data-path APIs are a set of APIs designed to enable external
673libraries/applications to leverage the cryptographic processing provided by
674DPDK crypto PMDs through the cryptodev API but in a manner that is not
675dependent on native DPDK data structures (eg. rte_mbuf, rte_crypto_op, ... etc)
676in their data-path implementation.
677
678The raw data-path APIs have the following advantages:
679
680- External data structure friendly design. The new APIs uses the operation
681  descriptor ``struct rte_crypto_sym_vec`` that supports raw data pointer and
682  IOVA addresses as input. Moreover, the APIs does not require the user to
683  allocate the descriptor from mempool, nor requiring mbufs to describe input
684  data's virtual and IOVA addresses. All these features made the translation
685  from user's own data structure into the descriptor easier and more efficient.
686
687- Flexible enqueue and dequeue operation. The raw data-path APIs gives the
688  user more control to the enqueue and dequeue operations, including the
689  capability of precious enqueue/dequeue count, abandoning enqueue or dequeue
690  at any time, and operation status translation and set on the fly.
691
692Cryptodev PMDs which support the raw data-path APIs will have
693``RTE_CRYPTODEV_FF_SYM_RAW_DP`` feature flag presented. To use this feature,
694the user shall create a local ``struct rte_crypto_raw_dp_ctx`` buffer and
695extend to at least the length returned by ``rte_cryptodev_get_raw_dp_ctx_size``
696function call. The created buffer is then initialized using
697``rte_cryptodev_configure_raw_dp_ctx`` function with the ``is_update``
698parameter as 0. The library and the crypto device driver will then set the
699buffer and attach either the cryptodev sym session, the rte_security session,
700or the cryptodev xform for session-less operation into the ctx buffer, and
701set the corresponding enqueue and dequeue function handlers based on the
702algorithm information stored in the session or xform. When the ``is_update``
703parameter passed into ``rte_cryptodev_configure_raw_dp_ctx`` is 1, the driver
704will not initialize the buffer but only update the session or xform and
705the function handlers accordingly.
706
707After the ``struct rte_crypto_raw_dp_ctx`` buffer is initialized, it is now
708ready for enqueue and dequeue operation. There are two different enqueue
709functions: ``rte_cryptodev_raw_enqueue`` to enqueue single raw data
710operation, and ``rte_cryptodev_raw_enqueue_burst`` to enqueue a descriptor
711with multiple operations. In case of the application uses similar approach to
712``struct rte_crypto_sym_vec`` to manage its data burst but with different
713data structure, using the ``rte_cryptodev_raw_enqueue_burst`` function may be
714less efficient as this is a situation where the application has to loop over
715all crypto operations to assemble the ``struct rte_crypto_sym_vec`` descriptor
716from its own data structure, and then the driver will loop over them again to
717translate every operation in the descriptor to the driver's specific queue data.
718The ``rte_cryptodev_raw_enqueue`` should be used to save one loop for each data
719burst instead.
720
721The ``rte_cryptodev_raw_enqueue`` and ``rte_cryptodev_raw_enqueue_burst``
722functions will return or set the enqueue status. ``rte_cryptodev_raw_enqueue``
723will return the status directly, ``rte_cryptodev_raw_enqueue_burst`` will
724return the number of operations enqueued or stored (explained as follows) and
725set the ``enqueue_status`` buffer provided by the user. The possible
726enqueue status values are:
727
728- ``1``: the operation(s) is/are enqueued successfully.
729- ``0``: the operation(s) is/are cached successfully in the crypto device queue
730  but is not actually enqueued. The user shall call
731  ``rte_cryptodev_raw_enqueue_done`` function after the expected operations
732  are stored. The crypto device will then start enqueuing all of them at
733  once.
734- The negative integer: error occurred during enqueue.
735
736Calling ``rte_cryptodev_configure_raw_dp_ctx`` with the parameter ``is_update``
737set as 0 twice without the enqueue function returning or setting enqueue status
738to 1 or ``rte_cryptodev_raw_enqueue_done`` function being called in between will
739invalidate any operation stored in the device queue but not enqueued. This
740feature is useful when the user wants to abandon partially enqueued operations
741for a failed enqueue burst operation and try enqueuing in a whole later.
742
743Similar as enqueue, there are two dequeue functions:
744``rte_cryptodev_raw_dequeue`` for dequeuing single operation, and
745``rte_cryptodev_raw_dequeue_burst`` for dequeuing a burst of operations (e.g.
746all operations in a ``struct rte_crypto_sym_vec`` descriptor). The
747``rte_cryptodev_raw_dequeue_burst`` function allows the user to provide callback
748functions to retrieve dequeue count from the enqueued user data and write the
749expected status value to the user data on the fly. The dequeue functions also
750set the dequeue status:
751
752- ``1``: the operation(s) is/are dequeued successfully.
753- ``0``: the operation(s) is/are completed but is not actually dequeued (hence
754  still kept in the device queue). The user shall call the
755  ``rte_cryptodev_raw_dequeue_done`` function after the expected number of
756  operations (e.g. all operations in a descriptor) are dequeued. The crypto
757  device driver will then free them from the queue at once.
758- The negative integer: error occurred during dequeue.
759
760Calling ``rte_cryptodev_configure_raw_dp_ctx`` with the parameter ``is_update``
761set as 0 twice without the dequeue functions execution changed dequeue_status
762to 1 or ``rte_cryptodev_raw_dequeue_done`` function being called in between will
763revert the crypto device queue's dequeue effort to the moment when the
764``struct rte_crypto_raw_dp_ctx`` buffer is initialized. This feature is useful
765when the user wants to abandon partially dequeued data and try dequeuing again
766later in a whole.
767
768There are a few limitations to the raw data path APIs:
769
770* Only support in-place operations.
771* APIs are NOT thread-safe.
772* CANNOT mix the raw data-path API's enqueue with rte_cryptodev_enqueue_burst,
773  or vice versa.
774
775See *DPDK API Reference* for details on each API definitions.
776
777Sample code
778-----------
779
780There are various sample applications that show how to use the cryptodev library,
781such as the L2fwd with Crypto sample application (L2fwd-crypto) and
782the IPsec Security Gateway application (ipsec-secgw).
783
784While these applications demonstrate how an application can be created to perform
785generic crypto operation, the required complexity hides the basic steps of
786how to use the cryptodev APIs.
787
788The following sample code shows the basic steps to encrypt several buffers
789with AES-CBC (although performing other crypto operations is similar),
790using one of the crypto PMDs available in DPDK.
791
792.. code-block:: c
793
794    /*
795     * Simple example to encrypt several buffers with AES-CBC using
796     * the Cryptodev APIs.
797     */
798
799    #define MAX_SESSIONS         1024
800    #define NUM_MBUFS            1024
801    #define POOL_CACHE_SIZE      128
802    #define BURST_SIZE           32
803    #define BUFFER_SIZE          1024
804    #define AES_CBC_IV_LENGTH    16
805    #define AES_CBC_KEY_LENGTH   16
806    #define IV_OFFSET            (sizeof(struct rte_crypto_op) + \
807                                 sizeof(struct rte_crypto_sym_op))
808
809    struct rte_mempool *mbuf_pool, *crypto_op_pool;
810    struct rte_mempool *session_pool, *session_priv_pool;
811    unsigned int session_size;
812    int ret;
813
814    /* Initialize EAL. */
815    ret = rte_eal_init(argc, argv);
816    if (ret < 0)
817        rte_exit(EXIT_FAILURE, "Invalid EAL arguments\n");
818
819    uint8_t socket_id = rte_socket_id();
820
821    /* Create the mbuf pool. */
822    mbuf_pool = rte_pktmbuf_pool_create("mbuf_pool",
823                                    NUM_MBUFS,
824                                    POOL_CACHE_SIZE,
825                                    0,
826                                    RTE_MBUF_DEFAULT_BUF_SIZE,
827                                    socket_id);
828    if (mbuf_pool == NULL)
829        rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n");
830
831    /*
832     * The IV is always placed after the crypto operation,
833     * so some private data is required to be reserved.
834     */
835    unsigned int crypto_op_private_data = AES_CBC_IV_LENGTH;
836
837    /* Create crypto operation pool. */
838    crypto_op_pool = rte_crypto_op_pool_create("crypto_op_pool",
839                                            RTE_CRYPTO_OP_TYPE_SYMMETRIC,
840                                            NUM_MBUFS,
841                                            POOL_CACHE_SIZE,
842                                            crypto_op_private_data,
843                                            socket_id);
844    if (crypto_op_pool == NULL)
845        rte_exit(EXIT_FAILURE, "Cannot create crypto op pool\n");
846
847    /* Create the virtual crypto device. */
848    char args[128];
849    const char *crypto_name = "crypto_aesni_mb0";
850    snprintf(args, sizeof(args), "socket_id=%d", socket_id);
851    ret = rte_vdev_init(crypto_name, args);
852    if (ret != 0)
853        rte_exit(EXIT_FAILURE, "Cannot create virtual device");
854
855    uint8_t cdev_id = rte_cryptodev_get_dev_id(crypto_name);
856
857    /* Get private session data size. */
858    session_size = rte_cryptodev_sym_get_private_session_size(cdev_id);
859
860    #ifdef USE_TWO_MEMPOOLS
861    /* Create session mempool for the session header. */
862    session_pool = rte_cryptodev_sym_session_pool_create("session_pool",
863                                    MAX_SESSIONS,
864                                    0,
865                                    POOL_CACHE_SIZE,
866                                    0,
867                                    socket_id);
868
869    /*
870     * Create session private data mempool for the
871     * private session data for the crypto device.
872     */
873    session_priv_pool = rte_mempool_create("session_pool",
874                                    MAX_SESSIONS,
875                                    session_size,
876                                    POOL_CACHE_SIZE,
877                                    0, NULL, NULL, NULL,
878                                    NULL, socket_id,
879                                    0);
880
881    #else
882    /* Use of the same mempool for session header and private data */
883	session_pool = rte_cryptodev_sym_session_pool_create("session_pool",
884                                    MAX_SESSIONS * 2,
885                                    session_size,
886                                    POOL_CACHE_SIZE,
887                                    0,
888                                    socket_id);
889
890	session_priv_pool = session_pool;
891
892    #endif
893
894    /* Configure the crypto device. */
895    struct rte_cryptodev_config conf = {
896        .nb_queue_pairs = 1,
897        .socket_id = socket_id
898    };
899
900    struct rte_cryptodev_qp_conf qp_conf = {
901        .nb_descriptors = 2048,
902        .mp_session = session_pool,
903        .mp_session_private = session_priv_pool
904    };
905
906    if (rte_cryptodev_configure(cdev_id, &conf) < 0)
907        rte_exit(EXIT_FAILURE, "Failed to configure cryptodev %u", cdev_id);
908
909    if (rte_cryptodev_queue_pair_setup(cdev_id, 0, &qp_conf, socket_id) < 0)
910        rte_exit(EXIT_FAILURE, "Failed to setup queue pair\n");
911
912    if (rte_cryptodev_start(cdev_id) < 0)
913        rte_exit(EXIT_FAILURE, "Failed to start device\n");
914
915    /* Create the crypto transform. */
916    uint8_t cipher_key[16] = {0};
917    struct rte_crypto_sym_xform cipher_xform = {
918        .next = NULL,
919        .type = RTE_CRYPTO_SYM_XFORM_CIPHER,
920        .cipher = {
921            .op = RTE_CRYPTO_CIPHER_OP_ENCRYPT,
922            .algo = RTE_CRYPTO_CIPHER_AES_CBC,
923            .key = {
924                .data = cipher_key,
925                .length = AES_CBC_KEY_LENGTH
926            },
927            .iv = {
928                .offset = IV_OFFSET,
929                .length = AES_CBC_IV_LENGTH
930            }
931        }
932    };
933
934    /* Create crypto session and initialize it for the crypto device. */
935    struct rte_cryptodev_sym_session *session;
936    session = rte_cryptodev_sym_session_create(cdev_id, &cipher_xform,
937                    session_pool);
938    if (session == NULL)
939        rte_exit(EXIT_FAILURE, "Session could not be created\n");
940
941    /* Get a burst of crypto operations. */
942    struct rte_crypto_op *crypto_ops[BURST_SIZE];
943    if (rte_crypto_op_bulk_alloc(crypto_op_pool,
944                            RTE_CRYPTO_OP_TYPE_SYMMETRIC,
945                            crypto_ops, BURST_SIZE) == 0)
946        rte_exit(EXIT_FAILURE, "Not enough crypto operations available\n");
947
948    /* Get a burst of mbufs. */
949    struct rte_mbuf *mbufs[BURST_SIZE];
950    if (rte_pktmbuf_alloc_bulk(mbuf_pool, mbufs, BURST_SIZE) < 0)
951        rte_exit(EXIT_FAILURE, "Not enough mbufs available");
952
953    /* Initialize the mbufs and append them to the crypto operations. */
954    unsigned int i;
955    for (i = 0; i < BURST_SIZE; i++) {
956        if (rte_pktmbuf_append(mbufs[i], BUFFER_SIZE) == NULL)
957            rte_exit(EXIT_FAILURE, "Not enough room in the mbuf\n");
958        crypto_ops[i]->sym->m_src = mbufs[i];
959    }
960
961    /* Set up the crypto operations. */
962    for (i = 0; i < BURST_SIZE; i++) {
963        struct rte_crypto_op *op = crypto_ops[i];
964        /* Modify bytes of the IV at the end of the crypto operation */
965        uint8_t *iv_ptr = rte_crypto_op_ctod_offset(op, uint8_t *,
966                                                IV_OFFSET);
967
968        generate_random_bytes(iv_ptr, AES_CBC_IV_LENGTH);
969
970        op->sym->cipher.data.offset = 0;
971        op->sym->cipher.data.length = BUFFER_SIZE;
972
973        /* Attach the crypto session to the operation */
974        rte_crypto_op_attach_sym_session(op, session);
975    }
976
977    /* Enqueue the crypto operations in the crypto device. */
978    uint16_t num_enqueued_ops = rte_cryptodev_enqueue_burst(cdev_id, 0,
979                                            crypto_ops, BURST_SIZE);
980
981    /*
982     * Dequeue the crypto operations until all the operations
983     * are processed in the crypto device.
984     */
985    uint16_t num_dequeued_ops, total_num_dequeued_ops = 0;
986    do {
987        struct rte_crypto_op *dequeued_ops[BURST_SIZE];
988        num_dequeued_ops = rte_cryptodev_dequeue_burst(cdev_id, 0,
989                                        dequeued_ops, BURST_SIZE);
990        total_num_dequeued_ops += num_dequeued_ops;
991
992        /* Check if operation was processed successfully */
993        for (i = 0; i < num_dequeued_ops; i++) {
994            if (dequeued_ops[i]->status != RTE_CRYPTO_OP_STATUS_SUCCESS)
995                rte_exit(EXIT_FAILURE,
996                        "Some operations were not processed correctly");
997        }
998
999        rte_mempool_put_bulk(crypto_op_pool, (void **)dequeued_ops,
1000                                            num_dequeued_ops);
1001    } while (total_num_dequeued_ops < num_enqueued_ops);
1002
1003Asymmetric Cryptography
1004-----------------------
1005
1006The cryptodev library currently provides support for the following asymmetric
1007Crypto operations; RSA, Modular exponentiation and inversion, Diffie-Hellman and
1008Elliptic Curve Diffie-Hellman public and/or private key generation and shared
1009secret compute, DSA Signature generation and verification.
1010
1011Session and Session Management
1012~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1013
1014Sessions are used in asymmetric cryptographic processing to store the immutable
1015data defined in asymmetric cryptographic transform which is further used in the
1016operation processing. Sessions typically stores information, such as, public
1017and private key information or domain params or prime modulus data i.e. immutable
1018across data sets. Crypto sessions cache this immutable data in a optimal way for the
1019underlying PMD and this allows further acceleration of the offload of Crypto workloads.
1020
1021Like symmetric, the Crypto device framework provides APIs to allocate and initialize
1022asymmetric sessions for crypto devices, where sessions are mempool objects.
1023It is the application's responsibility to create and manage the session mempools.
1024Application using both symmetric and asymmetric sessions should allocate and maintain
1025different sessions pools for each type.
1026
1027An application can use ``rte_cryptodev_asym_session_pool_create()`` to create a mempool
1028with a specified number of elements. The element size will allow for the session header,
1029and the max private session size.
1030The max private session size is chosen based on available crypto devices,
1031the biggest private session size is used. This means any of those devices can be used,
1032and the mempool element will have available space for its private session data.
1033
1034Once the session mempools have been created, ``rte_cryptodev_asym_session_create()``
1035is used to allocate and initialize an asymmetric session from the given mempool.
1036An asymmetric transform chain is used to specify the operation and its parameters.
1037See the section below for details on transforms.
1038
1039When a session is no longer used, user must call ``rte_cryptodev_asym_session_clear()``
1040for each of the crypto devices that are using the session, to free all driver
1041private asymmetric session data. Once this is done, session should be freed using
1042``rte_cryptodev_asym_session_free()`` which returns them to their mempool.
1043
1044Asymmetric Sessionless Support
1045~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1046
1047Asymmetric crypto framework supports session-less operations as well.
1048
1049Fields that should be set by user are:
1050
1051Member xform of struct rte_crypto_asym_op should point to the user created rte_crypto_asym_xform.
1052Note that rte_crypto_asym_xform should be immutable for the lifetime of associated crypto_op.
1053
1054Member sess_type of rte_crypto_op should also be set to RTE_CRYPTO_OP_SESSIONLESS.
1055
1056Transforms and Transform Chaining
1057~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1058
1059Asymmetric Crypto transforms (``rte_crypto_asym_xform``) are the mechanism used
1060to specify the details of the asymmetric Crypto operation. Next pointer within
1061xform allows transform to be chained together. Also it is important to note that
1062the order in which the transforms are passed indicates the order of the chaining. Allocation
1063of the xform structure is in the application domain. To allow future API extensions in a
1064backwardly compatible manner, e.g. addition of a new parameter, the application should
1065zero the full xform struct before populating it.
1066
1067Not all asymmetric crypto xforms are supported for chaining. Currently supported
1068asymmetric crypto chaining is Diffie-Hellman private key generation followed by
1069public generation. Also, currently API does not support chaining of symmetric and
1070asymmetric crypto xforms.
1071
1072Each xform defines specific asymmetric crypto algo. Currently supported are:
1073* RSA
1074* Modular operations (Exponentiation and Inverse)
1075* Diffie-Hellman
1076* DSA
1077* Elliptic Curve Diffie-Hellman
1078* None - special case where PMD may support a passthrough mode. More for diagnostic purpose
1079
1080See *DPDK API Reference* for details on each rte_crypto_xxx_xform struct
1081
1082Asymmetric Operations
1083~~~~~~~~~~~~~~~~~~~~~
1084
1085The asymmetric Crypto operation structure contains all the mutable data relating
1086to asymmetric cryptographic processing on an input data buffer. It uses either
1087RSA, Modular, Diffie-Hellman or DSA operations depending upon session it is attached
1088to.
1089
1090Every operation must carry a valid session handle which further carries information
1091on xform or xform-chain to be performed on op. Every xform type defines its own set
1092of operational params in their respective rte_crypto_xxx_op_param struct. Depending
1093on xform information within session, PMD picks up and process respective op_param
1094struct.
1095Unlike symmetric, asymmetric operations do not use mbufs for input/output.
1096They operate on data buffer of type ``rte_crypto_param``.
1097
1098See *DPDK API Reference* for details on each rte_crypto_xxx_op_param struct
1099
1100Private user data
1101~~~~~~~~~~~~~~~~~
1102
1103Similar to symmetric above, asymmetric also has a set and get API that provides a
1104mechanism for an application to store and retrieve the private user data information
1105stored along with the crypto session.
1106
1107.. code-block:: c
1108
1109	int rte_cryptodev_asym_session_set_user_data(void *sess,
1110		void *data, uint16_t size);
1111
1112	void * rte_cryptodev_asym_session_get_user_data(void *sess);
1113
1114Please note the ``size`` passed to set API cannot be bigger than the predefined
1115``user_data_sz`` when creating the session mempool, otherwise the function will
1116return an error. Also when ``user_data_sz`` was defined as ``0`` when
1117creating the session mempool, the get API will always return ``NULL``.
1118
1119Asymmetric crypto Sample code
1120-----------------------------
1121
1122There's a unit test application test_cryptodev_asym.c inside unit test framework that
1123show how to setup and process asymmetric operations using cryptodev library.
1124
1125The following code samples are taken from the test application mentioned above,
1126and show basic steps to compute modular exponentiation using an openssl PMD
1127available in DPDK (performing other crypto operations is similar except change
1128to respective op and xform setup).
1129
1130.. note::
1131   The following code snippets are taken from multiple functions, so variable
1132   names may differ slightly between sections.
1133
1134Configure the virtual device, queue pairs, crypto op pool and session mempool.
1135
1136.. literalinclude:: ../../../app/test/test_cryptodev_asym.c
1137   :language: c
1138   :start-after: Device, op pool and session configuration for asymmetric crypto. 8<
1139   :end-before: >8 End of device, op pool and session configuration for asymmetric crypto section.
1140   :dedent: 1
1141
1142Create MODEX data vectors.
1143
1144.. literalinclude:: ../../../app/test/test_cryptodev_mod_test_vectors.h
1145   :language: c
1146   :start-after: MODEX data. 8<
1147   :end-before: >8 End of MODEX data.
1148
1149Setup crypto xform to do modular exponentiation using data vectors.
1150
1151.. literalinclude:: ../../../app/test/test_cryptodev_mod_test_vectors.h
1152   :language: c
1153   :start-after: MODEX vector. 8<
1154   :end-before: >8 End of MODEX vector.
1155
1156Generate crypto op, create and attach a session, then process packets.
1157
1158.. literalinclude:: ../../../app/test/test_cryptodev_asym.c
1159   :language: c
1160   :start-after: Create op, create session, and process packets. 8<
1161   :end-before: >8 End of create op, create session, and process packets section.
1162   :dedent: 1
1163
1164.. note::
1165   The ``rte_cryptodev_asym_session`` struct is hidden from the application.
1166   The ``sess`` pointer used above is a void pointer.
1167
1168
1169Asymmetric Crypto Device API
1170~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1171
1172The cryptodev Library API is described in the
1173`DPDK API Reference <https://doc.dpdk.org/api/>`_
1174
1175
1176Device Statistics
1177-----------------
1178
1179The Cryptodev library has support for displaying Crypto device information
1180through the Telemetry interface. Telemetry commands that can be used
1181are shown below.
1182
1183#. Get the list of available Crypto devices by ID::
1184
1185     --> /cryptodev/list
1186     {"/cryptodev/list": [0, 1, 2, 3]}
1187
1188#. Get general information from a Crypto device::
1189
1190     --> /cryptodev/info,0
1191     {"/cryptodev/info": {"device_name": "0000:1c:01.0_qat_sym",
1192     "max_nb_queue_pairs": 2}}
1193
1194#. Get the statistics for a particular Crypto device::
1195
1196     --> /cryptodev/stats,0
1197     {"/cryptodev/stats": {"enqueued_count": 0, "dequeued_count": 0,
1198     "enqueue_err_count": 0, "dequeue_err_count": 0}}
1199
1200#. Get the capabilities of a particular Crypto device::
1201
1202     --> /cryptodev/caps,0
1203     {"/cryptodev/caps": {"crypto_caps": [<array of serialized bytes of
1204     capabilities>], "crypto_caps_n": <number of capabilities>}}
1205
1206For more information on how to use the Telemetry interface, see
1207the :doc:`../howto/telemetry`.
1208