xref: /dpdk/doc/guides/prog_guide/rte_security.rst (revision 0a23d4b6f4c25f64c663fba768df05b291a527e6)
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30
31Security Library
32================
33
34The security library provides a framework for management and provisioning
35of security protocol operations offloaded to hardware based devices. The
36library defines generic APIs to create and free security sessions which can
37support full protocol offload as well as inline crypto operation with
38NIC or crypto devices. The framework currently only supports the IPSec protocol
39and associated operations, other protocols will be added in future.
40
41Design Principles
42-----------------
43
44The security library provides an additional offload capability to an existing
45crypto device and/or ethernet device.
46
47.. code-block:: console
48
49               +---------------+
50               | rte_security  |
51               +---------------+
52                 \            /
53        +-----------+    +--------------+
54        |  NIC PMD  |    |  CRYPTO PMD  |
55        +-----------+    +--------------+
56
57.. note::
58
59    Currently, the security library does not support the case of multi-process.
60    It will be updated in the future releases.
61
62The supported offload types are explained in the sections below.
63
64Inline Crypto
65~~~~~~~~~~~~~
66
67RTE_SECURITY_ACTION_TYPE_INLINE_CRYPTO:
68The crypto processing for security protocol (e.g. IPSec) is processed
69inline during receive and transmission on NIC port. The flow based
70security action should be configured on the port.
71
72Ingress Data path - The packet is decrypted in RX path and relevant
73crypto status is set in Rx descriptors. After the successful inline
74crypto processing the packet is presented to host as a regular Rx packet
75however all security protocol related headers are still attached to the
76packet. e.g. In case of IPSec, the IPSec tunnel headers (if any),
77ESP/AH headers will remain in the packet but the received packet
78contains the decrypted data where the encrypted data was when the packet
79arrived. The driver Rx path check the descriptors and and based on the
80crypto status sets additional flags in the rte_mbuf.ol_flags field.
81
82.. note::
83
84    The underlying device may not support crypto processing for all ingress packet
85    matching to a particular flow (e.g. fragmented packets), such packets will
86    be passed as encrypted packets. It is the responsibility of application to
87    process such encrypted packets using other crypto driver instance.
88
89Egress Data path - The software prepares the egress packet by adding
90relevant security protocol headers. Only the data will not be
91encrypted by the software. The driver will accordingly configure the
92tx descriptors. The hardware device will encrypt the data before sending the
93the packet out.
94
95.. note::
96
97    The underlying device may support post encryption TSO.
98
99.. code-block:: console
100
101          Egress Data Path
102                 |
103        +--------|--------+
104        |  egress IPsec   |
105        |        |        |
106        | +------V------+ |
107        | | SADB lookup | |
108        | +------|------+ |
109        | +------V------+ |
110        | |   Tunnel    | |   <------ Add tunnel header to packet
111        | +------|------+ |
112        | +------V------+ |
113        | |     ESP     | |   <------ Add ESP header without trailer to packet
114        | |             | |   <------ Mark packet to be offloaded, add trailer
115        | +------|------+ |            meta-data to mbuf
116        +--------V--------+
117                 |
118        +--------V--------+
119        |    L2 Stack     |
120        +--------|--------+
121                 |
122        +--------V--------+
123        |                 |
124        |     NIC PMD     |   <------ Set hw context for inline crypto offload
125        |                 |
126        +--------|--------+
127                 |
128        +--------|--------+
129        |  HW ACCELERATED |   <------ Packet Encryption and
130        |        NIC      |           Authentication happens inline
131        |                 |
132        +-----------------+
133
134
135Inline protocol offload
136~~~~~~~~~~~~~~~~~~~~~~~
137
138RTE_SECURITY_ACTION_TYPE_INLINE_PROTOCOL:
139The crypto and protocol processing for security protocol (e.g. IPSec)
140is processed inline during receive and transmission.  The flow based
141security action should be configured on the port.
142
143Ingress Data path - The packet is decrypted in the RX path and relevant
144crypto status is set in the Rx descriptors. After the successful inline
145crypto processing the packet is presented to the host as a regular Rx packet
146but all security protocol related headers are optionally removed from the
147packet. e.g. in the case of IPSec, the IPSec tunnel headers (if any),
148ESP/AH headers will be removed from the packet and the received packet
149will contains the decrypted packet only. The driver Rx path checks the
150descriptors and based on the crypto status sets additional flags in
151``rte_mbuf.ol_flags`` field.
152
153.. note::
154
155    The underlying device in this case is stateful. It is expected that
156    the device shall support crypto processing for all kind of packets matching
157    to a given flow, this includes fragmented packets (post reassembly).
158    E.g. in case of IPSec the device may internally manage anti-replay etc.
159    It will provide a configuration option for anti-replay behavior i.e. to drop
160    the packets or pass them to driver with error flags set in the descriptor.
161
162Egress Data path - The software will send the plain packet without any
163security protocol headers added to the packet. The driver will configure
164the security index and other requirement in tx descriptors.
165The hardware device will do security processing on the packet that includes
166adding the relevant protocol headers and encrypting the data before sending
167the packet out. The software should make sure that the buffer
168has required head room and tail room for any protocol header addition. The
169software may also do early fragmentation if the resultant packet is expected
170to cross the MTU size.
171
172
173.. note::
174
175    The underlying device will manage state information required for egress
176    processing. E.g. in case of IPSec, the seq number will be added to the
177    packet, however the device shall provide indication when the sequence number
178    is about to overflow. The underlying device may support post encryption TSO.
179
180.. code-block:: console
181
182         Egress Data Path
183                 |
184        +--------|--------+
185        |  egress IPsec   |
186        |        |        |
187        | +------V------+ |
188        | | SADB lookup | |
189        | +------|------+ |
190        | +------V------+ |
191        | |   Desc      | |   <------ Mark packet to be offloaded
192        | +------|------+ |
193        +--------V--------+
194                 |
195        +--------V--------+
196        |    L2 Stack     |
197        +--------|--------+
198                 |
199        +--------V--------+
200        |                 |
201        |     NIC PMD     |   <------ Set hw context for inline crypto offload
202        |                 |
203        +--------|--------+
204                 |
205        +--------|--------+
206        |  HW ACCELERATED |   <------ Add tunnel, ESP header etc header to
207        |        NIC      |           packet. Packet Encryption and
208        |                 |           Authentication happens inline.
209        +-----------------+
210
211
212Lookaside protocol offload
213~~~~~~~~~~~~~~~~~~~~~~~~~~
214
215RTE_SECURITY_ACTION_TYPE_LOOKASIDE_PROTOCOL:
216This extends librte_cryptodev to support the programming of IPsec
217Security Association (SA) as part of a crypto session creation including
218the definition. In addition to standard crypto processing, as defined by
219the cryptodev, the security protocol processing is also offloaded to the
220crypto device.
221
222Decryption: The packet is sent to the crypto device for security
223protocol processing. The device will decrypt the packet and it will also
224optionally remove additional security headers from the packet.
225E.g. in case of IPSec, IPSec tunnel headers (if any), ESP/AH headers
226will be removed from the packet and the decrypted packet may contain
227plain data only.
228
229.. note::
230
231    In case of IPSec the device may internally manage anti-replay etc.
232    It will provide a configuration option for anti-replay behavior i.e. to drop
233    the packets or pass them to driver with error flags set in descriptor.
234
235Encryption: The software will submit the packet to cryptodev as usual
236for encryption, the hardware device in this case will also add the relevant
237security protocol header along with encrypting the packet. The software
238should make sure that the buffer has required head room and tail room
239for any protocol header addition.
240
241.. note::
242
243    In the case of IPSec, the seq number will be added to the packet,
244    It shall provide an indication when the sequence number is about to
245    overflow.
246
247.. code-block:: console
248
249          Egress Data Path
250                 |
251        +--------|--------+
252        |  egress IPsec   |
253        |        |        |
254        | +------V------+ |
255        | | SADB lookup | |   <------ SA maps to cryptodev session
256        | +------|------+ |
257        | +------|------+ |
258        | |      \--------------------\
259        | |    Crypto   | |           |  <- Crypto processing through
260        | |      /----------------\   |     inline crypto PMD
261        | +------|------+ |       |   |
262        +--------V--------+       |   |
263                 |                |   |
264        +--------V--------+       |   |  create   <-- SA is added to hw
265        |    L2 Stack     |       |   |  inline       using existing create
266        +--------|--------+       |   |  session      sym session APIs
267                 |                |   |    |
268        +--------V--------+   +---|---|----V---+
269        |                 |   |   \---/    |   | <--- Add tunnel, ESP header etc
270        |     NIC PMD     |   |   INLINE   |   |      header to packet.Packet
271        |                 |   | CRYPTO PMD |   |      Encryption/Decryption and
272        +--------|--------+   +----------------+      Authentication happens
273                 |                                    inline.
274        +--------|--------+
275        |       NIC       |
276        +--------|--------+
277                 V
278
279Device Features and Capabilities
280---------------------------------
281
282Device Capabilities For Security Operations
283~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
284
285The device (crypto or ethernet) capabilities which support security operations,
286are defined by the security action type, security protocol, protocol
287capabilities and corresponding crypto capabilities for security. For the full
288scope of the Security capability see definition of rte_security_capability
289structure in the *DPDK API Reference*.
290
291.. code-block:: c
292
293   struct rte_security_capability;
294
295Each driver (crypto or ethernet) defines its own private array of capabilities
296for the operations it supports. Below is an example of the capabilities for a
297PMD which supports the IPSec protocol.
298
299.. code-block:: c
300
301    static const struct rte_security_capability pmd_security_capabilities[] = {
302        { /* IPsec Lookaside Protocol offload ESP Tunnel Egress */
303                .action = RTE_SECURITY_ACTION_TYPE_LOOKASIDE_PROTOCOL,
304                .protocol = RTE_SECURITY_PROTOCOL_IPSEC,
305                .ipsec = {
306                        .proto = RTE_SECURITY_IPSEC_SA_PROTO_ESP,
307                        .mode = RTE_SECURITY_IPSEC_SA_MODE_TUNNEL,
308                        .direction = RTE_SECURITY_IPSEC_SA_DIR_EGRESS,
309                        .options = { 0 }
310                },
311                .crypto_capabilities = pmd_capabilities
312        },
313        { /* IPsec Lookaside Protocol offload ESP Tunnel Ingress */
314                .action = RTE_SECURITY_ACTION_TYPE_LOOKASIDE_PROTOCOL,
315                .protocol = RTE_SECURITY_PROTOCOL_IPSEC,
316                .ipsec = {
317                        .proto = RTE_SECURITY_IPSEC_SA_PROTO_ESP,
318                        .mode = RTE_SECURITY_IPSEC_SA_MODE_TUNNEL,
319                        .direction = RTE_SECURITY_IPSEC_SA_DIR_INGRESS,
320                        .options = { 0 }
321                },
322                .crypto_capabilities = pmd_capabilities
323        },
324        {
325                .action = RTE_SECURITY_ACTION_TYPE_NONE
326        }
327    };
328    static const struct rte_cryptodev_capabilities pmd_capabilities[] = {
329        {    /* SHA1 HMAC */
330            .op = RTE_CRYPTO_OP_TYPE_SYMMETRIC,
331            .sym = {
332                .xform_type = RTE_CRYPTO_SYM_XFORM_AUTH,
333                .auth = {
334                    .algo = RTE_CRYPTO_AUTH_SHA1_HMAC,
335                    .block_size = 64,
336                    .key_size = {
337                        .min = 64,
338                        .max = 64,
339                        .increment = 0
340                    },
341                    .digest_size = {
342                        .min = 12,
343                        .max = 12,
344                        .increment = 0
345                    },
346                    .aad_size = { 0 },
347                    .iv_size = { 0 }
348                }
349            }
350        },
351        {    /* AES CBC */
352            .op = RTE_CRYPTO_OP_TYPE_SYMMETRIC,
353            .sym = {
354                .xform_type = RTE_CRYPTO_SYM_XFORM_CIPHER,
355                .cipher = {
356                    .algo = RTE_CRYPTO_CIPHER_AES_CBC,
357                    .block_size = 16,
358                    .key_size = {
359                        .min = 16,
360                        .max = 32,
361                        .increment = 8
362                    },
363                    .iv_size = {
364                        .min = 16,
365                        .max = 16,
366                        .increment = 0
367                    }
368                }
369            }
370        }
371    }
372
373
374Capabilities Discovery
375~~~~~~~~~~~~~~~~~~~~~~
376
377Discovering the features and capabilities of a driver (crypto/ethernet)
378is achieved through the ``rte_security_capabilities_get()`` function.
379
380.. code-block:: c
381
382   const struct rte_security_capability *rte_security_capabilities_get(uint16_t id);
383
384This allows the user to query a specific driver and get all device
385security capabilities. It returns an array of ``rte_security_capability`` structures
386which contains all the capabilities for that device.
387
388Security Session Create/Free
389~~~~~~~~~~~~~~~~~~~~~~~~~~~~
390
391Security Sessions are created to store the immutable fields of a particular Security
392Association for a particular protocol which is defined by a security session
393configuration structure which is used in the operation processing of a packet flow.
394Sessions are used to manage protocol specific information as well as crypto parameters.
395Security sessions cache this immutable data in a optimal way for the underlying PMD
396and this allows further acceleration of the offload of Crypto workloads.
397
398The Security framework provides APIs to create and free sessions for crypto/ethernet
399devices, where sessions are mempool objects. It is the application's responsibility
400to create and manage the session mempools. The mempool object size should be able to
401accommodate the driver's private data of security session.
402
403Once the session mempools have been created, ``rte_security_session_create()``
404is used to allocate and initialize a session for the required crypto/ethernet device.
405
406Session APIs need a parameter ``rte_security_ctx`` to identify the crypto/ethernet
407security ops. This parameter can be retrieved using the APIs
408``rte_cryptodev_get_sec_ctx()`` (for crypto device) or ``rte_eth_dev_get_sec_ctx``
409(for ethernet port).
410
411Sessions already created can be updated with ``rte_security_session_update()``.
412
413When a session is no longer used, the user must call ``rte_security_session_destroy()``
414to free the driver private session data and return the memory back to the mempool.
415
416For look aside protocol offload to hardware crypto device, the ``rte_crypto_op``
417created by the application is attached to the security session by the API
418``rte_security_attach_session()``.
419
420For Inline Crypto and Inline protocol offload, device specific defined metadata is
421updated in the mbuf using ``rte_security_set_pkt_metadata()`` if
422``DEV_TX_OFFLOAD_SEC_NEED_MDATA`` is set.
423
424Security session configuration
425~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
426
427Security Session configuration structure is defined as ``rte_security_session_conf``
428
429.. code-block:: c
430
431    struct rte_security_session_conf {
432        enum rte_security_session_action_type action_type;
433        /**< Type of action to be performed on the session */
434        enum rte_security_session_protocol protocol;
435        /**< Security protocol to be configured */
436        union {
437                struct rte_security_ipsec_xform ipsec;
438                struct rte_security_macsec_xform macsec;
439        };
440        /**< Configuration parameters for security session */
441        struct rte_crypto_sym_xform *crypto_xform;
442        /**< Security Session Crypto Transformations */
443    };
444
445The configuration structure reuses the ``rte_crypto_sym_xform`` struct for crypto related
446configuration. The ``rte_security_session_action_type`` struct is used to specify whether the
447session is configured for Lookaside Protocol offload or Inline Crypto or Inline Protocol
448Offload.
449
450.. code-block:: c
451
452    enum rte_security_session_action_type {
453        RTE_SECURITY_ACTION_TYPE_NONE,
454        /**< No security actions */
455        RTE_SECURITY_ACTION_TYPE_INLINE_CRYPTO,
456        /**< Crypto processing for security protocol is processed inline
457         * during transmission */
458        RTE_SECURITY_ACTION_TYPE_INLINE_PROTOCOL,
459        /**< All security protocol processing is performed inline during
460         * transmission */
461        RTE_SECURITY_ACTION_TYPE_LOOKASIDE_PROTOCOL
462        /**< All security protocol processing including crypto is performed
463         * on a lookaside accelerator */
464    };
465
466The ``rte_security_session_protocol`` is defined as
467
468.. code-block:: c
469
470    enum rte_security_session_protocol {
471        RTE_SECURITY_PROTOCOL_IPSEC,
472        /**< IPsec Protocol */
473        RTE_SECURITY_PROTOCOL_MACSEC,
474        /**< MACSec Protocol */
475    };
476
477Currently the library defines configuration parameters for IPSec only. For other
478protocols like MACSec, structures and enums are defined as place holders which
479will be updated in the future.
480
481IPsec related configuration parameters are defined in ``rte_security_ipsec_xform``
482
483.. code-block:: c
484
485    struct rte_security_ipsec_xform {
486        uint32_t spi;
487        /**< SA security parameter index */
488        uint32_t salt;
489        /**< SA salt */
490        struct rte_security_ipsec_sa_options options;
491        /**< various SA options */
492        enum rte_security_ipsec_sa_direction direction;
493        /**< IPSec SA Direction - Egress/Ingress */
494        enum rte_security_ipsec_sa_protocol proto;
495        /**< IPsec SA Protocol - AH/ESP */
496        enum rte_security_ipsec_sa_mode mode;
497        /**< IPsec SA Mode - transport/tunnel */
498        struct rte_security_ipsec_tunnel_param tunnel;
499        /**< Tunnel parameters, NULL for transport mode */
500    };
501
502
503Security API
504~~~~~~~~~~~~
505
506The rte_security Library API is described in the *DPDK API Reference* document.
507
508Flow based Security Session
509~~~~~~~~~~~~~~~~~~~~~~~~~~~
510
511In the case of NIC based offloads, the security session specified in the
512'rte_flow_action_security' must be created on the same port as the
513flow action that is being specified.
514
515The ingress/egress flow attribute should match that specified in the security
516session if the security session supports the definition of the direction.
517
518Multiple flows can be configured to use the same security session. For
519example if the security session specifies an egress IPsec SA, then multiple
520flows can be specified to that SA. In the case of an ingress IPsec SA then
521it is only valid to have a single flow to map to that security session.
522
523.. code-block:: console
524
525         Configuration Path
526                 |
527        +--------|--------+
528        |    Add/Remove   |
529        |     IPsec SA    |   <------ Build security flow action of
530        |        |        |           ipsec transform
531        |--------|--------|
532                 |
533        +--------V--------+
534        |   Flow API      |
535        +--------|--------+
536                 |
537        +--------V--------+
538        |                 |
539        |     NIC PMD     |   <------ Add/Remove SA to/from hw context
540        |                 |
541        +--------|--------+
542                 |
543        +--------|--------+
544        |  HW ACCELERATED |
545        |        NIC      |
546        |                 |
547        +--------|--------+
548
549* Add/Delete SA flow:
550  To add a new inline SA construct a rte_flow_item for Ethernet + IP + ESP
551  using the SA selectors and the ``rte_crypto_ipsec_xform`` as the ``rte_flow_action``.
552  Note that any rte_flow_items may be empty, which means it is not checked.
553
554.. code-block:: console
555
556    In its most basic form, IPsec flow specification is as follows:
557        +-------+     +----------+    +--------+    +-----+
558        |  Eth  | ->  |   IP4/6  | -> |   ESP  | -> | END |
559        +-------+     +----------+    +--------+    +-----+
560
561    However, the API can represent, IPsec crypto offload with any encapsulation:
562        +-------+            +--------+    +-----+
563        |  Eth  | ->  ... -> |   ESP  | -> | END |
564        +-------+            +--------+    +-----+
565