1.\" $OpenBSD: crypto.9,v 1.19 2002/07/16 06:31:57 angelos Exp $
2.\"
3.\" The author of this manual page is Angelos D. Keromytis (angelos@cis.upenn.edu)
4.\"
5.\" Copyright (c) 2000, 2001 Angelos D. Keromytis
6.\"
7.\" Permission to use, copy, and modify this software with or without fee
8.\" is hereby granted, provided that this entire notice is included in
9.\" all source code copies of any software which is or includes a copy or
10.\" modification of this software.
11.\"
12.\" THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
13.\" IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
14.\" REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
15.\" MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
16.\" PURPOSE.
17.\"
| 1.\" $OpenBSD: crypto.9,v 1.19 2002/07/16 06:31:57 angelos Exp $
2.\"
3.\" The author of this manual page is Angelos D. Keromytis (angelos@cis.upenn.edu)
4.\"
5.\" Copyright (c) 2000, 2001 Angelos D. Keromytis
6.\"
7.\" Permission to use, copy, and modify this software with or without fee
8.\" is hereby granted, provided that this entire notice is included in
9.\" all source code copies of any software which is or includes a copy or
10.\" modification of this software.
11.\"
12.\" THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
13.\" IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
14.\" REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
15.\" MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
16.\" PURPOSE.
17.\"
|
18.\" $FreeBSD: head/share/man/man9/crypto.9 158850 2006-05-23 08:43:28Z pjd $
| 18.\" $FreeBSD: head/share/man/man9/crypto.9 159214 2006-06-03 23:39:13Z pjd $
|
19.\"
| 19.\"
|
20.Dd May 17, 2006
| 20.Dd June 4, 2006
|
21.Dt CRYPTO 9
22.Os
23.Sh NAME
24.Nm crypto
25.Nd API for cryptographic services in the kernel
26.Sh SYNOPSIS
27.In opencrypto/cryptodev.h
28.Ft int32_t
29.Fn crypto_get_driverid u_int8_t
30.Ft int
31.Fn crypto_register u_int32_t int u_int16_t u_int32_t "int \*[lp]*\*[rp]\*[lp]void *, u_int32_t *, struct cryptoini *\*[rp]" "int \*[lp]*\*[rp]\*[lp]void *, u_int64_t\*[rp]" "int \*[lp]*\*[rp]\*[lp]void *, struct cryptop *\*[rp]" "void *"
32.Ft int
33.Fn crypto_kregister u_int32_t int u_int32_t "int \*[lp]*\*[rp]\*[lp]void *, struct cryptkop *\*[rp]" "void *"
34.Ft int
35.Fn crypto_unregister u_int32_t int
36.Ft int
37.Fn crypto_unregister_all u_int32_t
38.Ft void
39.Fn crypto_done "struct cryptop *"
40.Ft void
41.Fn crypto_kdone "struct cryptkop *"
42.Ft int
43.Fn crypto_newsession "u_int64_t *" "struct cryptoini *" int
44.Ft int
45.Fn crypto_freesession u_int64_t
46.Ft int
47.Fn crypto_dispatch "struct cryptop *"
48.Ft int
49.Fn crypto_kdispatch "struct cryptkop *"
50.Ft int
51.Fn crypto_unblock u_int32_t int
52.Ft "struct cryptop *"
53.Fn crypto_getreq int
54.Ft void
55.Fn crypto_freereq void
56.Bd -literal
57#define CRYPTO_SYMQ 0x1
58#define CRYPTO_ASYMQ 0x2
59
60#define EALG_MAX_BLOCK_LEN 16
61
62struct cryptoini {
63 int cri_alg;
64 int cri_klen;
65 int cri_mlen;
66 caddr_t cri_key;
67 u_int8_t cri_iv[EALG_MAX_BLOCK_LEN];
68 struct cryptoini *cri_next;
69};
70
71struct cryptodesc {
72 int crd_skip;
73 int crd_len;
74 int crd_inject;
75 int crd_flags;
76 struct cryptoini CRD_INI;
| 21.Dt CRYPTO 9
22.Os
23.Sh NAME
24.Nm crypto
25.Nd API for cryptographic services in the kernel
26.Sh SYNOPSIS
27.In opencrypto/cryptodev.h
28.Ft int32_t
29.Fn crypto_get_driverid u_int8_t
30.Ft int
31.Fn crypto_register u_int32_t int u_int16_t u_int32_t "int \*[lp]*\*[rp]\*[lp]void *, u_int32_t *, struct cryptoini *\*[rp]" "int \*[lp]*\*[rp]\*[lp]void *, u_int64_t\*[rp]" "int \*[lp]*\*[rp]\*[lp]void *, struct cryptop *\*[rp]" "void *"
32.Ft int
33.Fn crypto_kregister u_int32_t int u_int32_t "int \*[lp]*\*[rp]\*[lp]void *, struct cryptkop *\*[rp]" "void *"
34.Ft int
35.Fn crypto_unregister u_int32_t int
36.Ft int
37.Fn crypto_unregister_all u_int32_t
38.Ft void
39.Fn crypto_done "struct cryptop *"
40.Ft void
41.Fn crypto_kdone "struct cryptkop *"
42.Ft int
43.Fn crypto_newsession "u_int64_t *" "struct cryptoini *" int
44.Ft int
45.Fn crypto_freesession u_int64_t
46.Ft int
47.Fn crypto_dispatch "struct cryptop *"
48.Ft int
49.Fn crypto_kdispatch "struct cryptkop *"
50.Ft int
51.Fn crypto_unblock u_int32_t int
52.Ft "struct cryptop *"
53.Fn crypto_getreq int
54.Ft void
55.Fn crypto_freereq void
56.Bd -literal
57#define CRYPTO_SYMQ 0x1
58#define CRYPTO_ASYMQ 0x2
59
60#define EALG_MAX_BLOCK_LEN 16
61
62struct cryptoini {
63 int cri_alg;
64 int cri_klen;
65 int cri_mlen;
66 caddr_t cri_key;
67 u_int8_t cri_iv[EALG_MAX_BLOCK_LEN];
68 struct cryptoini *cri_next;
69};
70
71struct cryptodesc {
72 int crd_skip;
73 int crd_len;
74 int crd_inject;
75 int crd_flags;
76 struct cryptoini CRD_INI;
|
| 77#define crd_iv CRD_INI.cri_iv
78#define crd_key CRD_INI.cri_key
79#define crd_alg CRD_INI.cri_alg
80#define crd_klen CRD_INI.cri_klen
|
77 struct cryptodesc *crd_next;
78};
79
80struct cryptop {
81 TAILQ_ENTRY(cryptop) crp_next;
82 u_int64_t crp_sid;
83 int crp_ilen;
84 int crp_olen;
85 int crp_etype;
86 int crp_flags;
87 caddr_t crp_buf;
88 caddr_t crp_opaque;
89 struct cryptodesc *crp_desc;
90 int (*crp_callback) (struct cryptop *);
91 caddr_t crp_mac;
92};
93
94struct crparam {
95 caddr_t crp_p;
96 u_int crp_nbits;
97};
98
99#define CRK_MAXPARAM 8
100
101struct cryptkop {
102 TAILQ_ENTRY(cryptkop) krp_next;
103 u_int krp_op; /* ie. CRK_MOD_EXP or other */
104 u_int krp_status; /* return status */
105 u_short krp_iparams; /* # of input parameters */
106 u_short krp_oparams; /* # of output parameters */
107 u_int32_t krp_hid;
108 struct crparam krp_param[CRK_MAXPARAM];
109 int (*krp_callback)(struct cryptkop *);
110};
111.Ed
112.Sh DESCRIPTION
113.Nm
114is a framework for drivers of cryptographic hardware to register with
115the kernel so
116.Dq consumers
117(other kernel subsystems, and
118users through the
119.Pa /dev/crypto
120device) are able to make use of it.
121Drivers register with the framework the algorithms they support,
122and provide entry points (functions) the framework may call to
123establish, use, and tear down sessions.
124Sessions are used to cache cryptographic information in a particular driver
125(or associated hardware), so initialization is not needed with every request.
126Consumers of cryptographic services pass a set of
127descriptors that instruct the framework (and the drivers registered
128with it) of the operations that should be applied on the data (more
129than one cryptographic operation can be requested).
130.Pp
131Keying operations are supported as well.
132Unlike the symmetric operators described above,
133these sessionless commands perform mathematical operations using
134input and output parameters.
135.Pp
136Since the consumers may not be associated with a process, drivers may
137not
138.Xr sleep 9 .
139The same holds for the framework.
140Thus, a callback mechanism is used
141to notify a consumer that a request has been completed (the
142callback is specified by the consumer on an per-request basis).
143The callback is invoked by the framework whether the request was
144successfully completed or not.
145An error indication is provided in the latter case.
146A specific error code,
147.Er EAGAIN ,
148is used to indicate that a session number has changed and that the
149request may be re-submitted immediately with the new session number.
150Errors are only returned to the invoking function if not
151enough information to call the callback is available (meaning, there
152was a fatal error in verifying the arguments).
153For session initialization and teardown there is no callback mechanism used.
154.Pp
155The
156.Fn crypto_newsession
157routine is called by consumers of cryptographic services (such as the
158.Xr ipsec 4
159stack) that wish to establish a new session with the framework.
160On success, the first argument will contain the Session Identifier (SID).
161The second argument contains all the necessary information for
162the driver to establish the session.
163The third argument indicates whether a
164hardware driver (1) should be used or not (0).
165The various fields in the
166.Vt cryptoini
167structure are:
168.Bl -tag -width ".Va cri_next"
169.It Va cri_alg
170Contains an algorithm identifier.
171Currently supported algorithms are:
172.Pp
173.Bl -tag -width ".Dv CRYPTO_RIPEMD160_HMAC" -compact
174.It Dv CRYPTO_DES_CBC
175.It Dv CRYPTO_3DES_CBC
176.It Dv CRYPTO_BLF_CBC
177.It Dv CRYPTO_CAST_CBC
178.It Dv CRYPTO_SKIPJACK_CBC
179.It Dv CRYPTO_MD5_HMAC
180.It Dv CRYPTO_SHA1_HMAC
181.It Dv CRYPTO_RIPEMD160_HMAC
182.It Dv CRYPTO_MD5_KPDK
183.It Dv CRYPTO_SHA1_KPDK
184.It Dv CRYPTO_AES_CBC
185.It Dv CRYPTO_ARC4
186.It Dv CRYPTO_MD5
187.It Dv CRYPTO_SHA1
188.It Dv CRYPTO_SHA2_256_HMAC
189.It Dv CRYPTO_SHA2_384_HMAC
190.It Dv CRYPTO_SHA2_512_HMAC
191.It Dv CRYPTO_NULL_HMAC
192.It Dv CRYPTO_NULL_CBC
193.El
194.It Va cri_klen
195Specifies the length of the key in bits, for variable-size key
196algorithms.
197.It Va cri_mlen
198Specifies how many bytes from the calculated hash should be copied back.
1990 means entire hash.
200.It Va cri_key
201Contains the key to be used with the algorithm.
202.It Va cri_iv
203Contains an explicit initialization vector (IV), if it does not prefix
204the data.
205This field is ignored during initialization.
206If no IV is explicitly passed (see below on details), a random IV is used
207by the device driver processing the request.
208.It Va cri_next
209Contains a pointer to another
210.Vt cryptoini
211structure.
212Multiple such structures may be linked to establish multi-algorithm sessions
213.Xr ( ipsec 4
214is an example consumer of such a feature).
215.El
216.Pp
217The
218.Vt cryptoini
219structure and its contents will not be modified by the framework (or
220the drivers used).
221Subsequent requests for processing that use the
222SID returned will avoid the cost of re-initializing the hardware (in
223essence, SID acts as an index in the session cache of the driver).
224.Pp
225.Fn crypto_freesession
226is called with the SID returned by
227.Fn crypto_newsession
228to disestablish the session.
229.Pp
230.Fn crypto_dispatch
231is called to process a request.
232The various fields in the
233.Vt cryptop
234structure are:
235.Bl -tag -width ".Va crp_callback"
236.It Va crp_sid
237Contains the SID.
238.It Va crp_ilen
239Indicates the total length in bytes of the buffer to be processed.
240.It Va crp_olen
241On return, contains the total length of the result.
242For symmetric crypto operations, this will be the same as the input length.
243This will be used if the framework needs to allocate a new
244buffer for the result (or for re-formatting the input).
245.It Va crp_callback
246This routine is invoked upon completion of the request, whether
247successful or not.
248It is invoked through the
249.Fn crypto_done
250routine.
251If the request was not successful, an error code is set in the
252.Va crp_etype
253field.
254It is the responsibility of the callback routine to set the appropriate
255.Xr spl 9
256level.
257.It Va crp_etype
258Contains the error type, if any errors were encountered, or zero if
259the request was successfully processed.
260If the
261.Er EAGAIN
262error code is returned, the SID has changed (and has been recorded in the
263.Va crp_sid
264field).
265The consumer should record the new SID and use it in all subsequent requests.
266In this case, the request may be re-submitted immediately.
267This mechanism is used by the framework to perform
268session migration (move a session from one driver to another, because
269of availability, performance, or other considerations).
270.Pp
271Note that this field only makes sense when examined by
272the callback routine specified in
273.Va crp_callback .
274Errors are returned to the invoker of
275.Fn crypto_process
276only when enough information is not present to call the callback
277routine (i.e., if the pointer passed is
278.Dv NULL
279or if no callback routine was specified).
280.It Va crp_flags
281Is a bitmask of flags associated with this request.
282Currently defined flags are:
283.Bl -tag -width ".Dv CRYPTO_F_CBIFSYNC"
284.It Dv CRYPTO_F_IMBUF
285The buffer pointed to by
286.Va crp_buf
287is an mbuf chain.
288.It Dv CRYPTO_F_IOV
289The buffer pointed to by
290.Va crp_buf
291is an uio structure.
292.It Dv CRYPTO_F_REL
293Must return data in the same place.
294.It Dv CRYPTO_F_BATCH
295Batch operation if possible.
296.It Dv CRYPTO_F_CBIMM
297Do callback immediatelly instead of doing it from a dedicated kernel thread.
298.It Dv CRYPTO_F_DONE
299Operation completed.
300.It Dv CRYPTO_F_CBIFSYNC
301Do callback immediatelly if operation is synchronous.
302.El
303.It Va crp_buf
304Points to the input buffer.
305On return (when the callback is invoked),
306it contains the result of the request.
307The input buffer may be an mbuf
308chain or a contiguous buffer,
309depending on
310.Va crp_flags .
311.It Va crp_opaque
312This is passed through the crypto framework untouched and is
313intended for the invoking application's use.
314.It Va crp_desc
315This is a linked list of descriptors.
316Each descriptor provides
317information about what type of cryptographic operation should be done
318on the input buffer.
319The various fields are:
320.Bl -tag -width ".Va crd_inject"
| 81 struct cryptodesc *crd_next;
82};
83
84struct cryptop {
85 TAILQ_ENTRY(cryptop) crp_next;
86 u_int64_t crp_sid;
87 int crp_ilen;
88 int crp_olen;
89 int crp_etype;
90 int crp_flags;
91 caddr_t crp_buf;
92 caddr_t crp_opaque;
93 struct cryptodesc *crp_desc;
94 int (*crp_callback) (struct cryptop *);
95 caddr_t crp_mac;
96};
97
98struct crparam {
99 caddr_t crp_p;
100 u_int crp_nbits;
101};
102
103#define CRK_MAXPARAM 8
104
105struct cryptkop {
106 TAILQ_ENTRY(cryptkop) krp_next;
107 u_int krp_op; /* ie. CRK_MOD_EXP or other */
108 u_int krp_status; /* return status */
109 u_short krp_iparams; /* # of input parameters */
110 u_short krp_oparams; /* # of output parameters */
111 u_int32_t krp_hid;
112 struct crparam krp_param[CRK_MAXPARAM];
113 int (*krp_callback)(struct cryptkop *);
114};
115.Ed
116.Sh DESCRIPTION
117.Nm
118is a framework for drivers of cryptographic hardware to register with
119the kernel so
120.Dq consumers
121(other kernel subsystems, and
122users through the
123.Pa /dev/crypto
124device) are able to make use of it.
125Drivers register with the framework the algorithms they support,
126and provide entry points (functions) the framework may call to
127establish, use, and tear down sessions.
128Sessions are used to cache cryptographic information in a particular driver
129(or associated hardware), so initialization is not needed with every request.
130Consumers of cryptographic services pass a set of
131descriptors that instruct the framework (and the drivers registered
132with it) of the operations that should be applied on the data (more
133than one cryptographic operation can be requested).
134.Pp
135Keying operations are supported as well.
136Unlike the symmetric operators described above,
137these sessionless commands perform mathematical operations using
138input and output parameters.
139.Pp
140Since the consumers may not be associated with a process, drivers may
141not
142.Xr sleep 9 .
143The same holds for the framework.
144Thus, a callback mechanism is used
145to notify a consumer that a request has been completed (the
146callback is specified by the consumer on an per-request basis).
147The callback is invoked by the framework whether the request was
148successfully completed or not.
149An error indication is provided in the latter case.
150A specific error code,
151.Er EAGAIN ,
152is used to indicate that a session number has changed and that the
153request may be re-submitted immediately with the new session number.
154Errors are only returned to the invoking function if not
155enough information to call the callback is available (meaning, there
156was a fatal error in verifying the arguments).
157For session initialization and teardown there is no callback mechanism used.
158.Pp
159The
160.Fn crypto_newsession
161routine is called by consumers of cryptographic services (such as the
162.Xr ipsec 4
163stack) that wish to establish a new session with the framework.
164On success, the first argument will contain the Session Identifier (SID).
165The second argument contains all the necessary information for
166the driver to establish the session.
167The third argument indicates whether a
168hardware driver (1) should be used or not (0).
169The various fields in the
170.Vt cryptoini
171structure are:
172.Bl -tag -width ".Va cri_next"
173.It Va cri_alg
174Contains an algorithm identifier.
175Currently supported algorithms are:
176.Pp
177.Bl -tag -width ".Dv CRYPTO_RIPEMD160_HMAC" -compact
178.It Dv CRYPTO_DES_CBC
179.It Dv CRYPTO_3DES_CBC
180.It Dv CRYPTO_BLF_CBC
181.It Dv CRYPTO_CAST_CBC
182.It Dv CRYPTO_SKIPJACK_CBC
183.It Dv CRYPTO_MD5_HMAC
184.It Dv CRYPTO_SHA1_HMAC
185.It Dv CRYPTO_RIPEMD160_HMAC
186.It Dv CRYPTO_MD5_KPDK
187.It Dv CRYPTO_SHA1_KPDK
188.It Dv CRYPTO_AES_CBC
189.It Dv CRYPTO_ARC4
190.It Dv CRYPTO_MD5
191.It Dv CRYPTO_SHA1
192.It Dv CRYPTO_SHA2_256_HMAC
193.It Dv CRYPTO_SHA2_384_HMAC
194.It Dv CRYPTO_SHA2_512_HMAC
195.It Dv CRYPTO_NULL_HMAC
196.It Dv CRYPTO_NULL_CBC
197.El
198.It Va cri_klen
199Specifies the length of the key in bits, for variable-size key
200algorithms.
201.It Va cri_mlen
202Specifies how many bytes from the calculated hash should be copied back.
2030 means entire hash.
204.It Va cri_key
205Contains the key to be used with the algorithm.
206.It Va cri_iv
207Contains an explicit initialization vector (IV), if it does not prefix
208the data.
209This field is ignored during initialization.
210If no IV is explicitly passed (see below on details), a random IV is used
211by the device driver processing the request.
212.It Va cri_next
213Contains a pointer to another
214.Vt cryptoini
215structure.
216Multiple such structures may be linked to establish multi-algorithm sessions
217.Xr ( ipsec 4
218is an example consumer of such a feature).
219.El
220.Pp
221The
222.Vt cryptoini
223structure and its contents will not be modified by the framework (or
224the drivers used).
225Subsequent requests for processing that use the
226SID returned will avoid the cost of re-initializing the hardware (in
227essence, SID acts as an index in the session cache of the driver).
228.Pp
229.Fn crypto_freesession
230is called with the SID returned by
231.Fn crypto_newsession
232to disestablish the session.
233.Pp
234.Fn crypto_dispatch
235is called to process a request.
236The various fields in the
237.Vt cryptop
238structure are:
239.Bl -tag -width ".Va crp_callback"
240.It Va crp_sid
241Contains the SID.
242.It Va crp_ilen
243Indicates the total length in bytes of the buffer to be processed.
244.It Va crp_olen
245On return, contains the total length of the result.
246For symmetric crypto operations, this will be the same as the input length.
247This will be used if the framework needs to allocate a new
248buffer for the result (or for re-formatting the input).
249.It Va crp_callback
250This routine is invoked upon completion of the request, whether
251successful or not.
252It is invoked through the
253.Fn crypto_done
254routine.
255If the request was not successful, an error code is set in the
256.Va crp_etype
257field.
258It is the responsibility of the callback routine to set the appropriate
259.Xr spl 9
260level.
261.It Va crp_etype
262Contains the error type, if any errors were encountered, or zero if
263the request was successfully processed.
264If the
265.Er EAGAIN
266error code is returned, the SID has changed (and has been recorded in the
267.Va crp_sid
268field).
269The consumer should record the new SID and use it in all subsequent requests.
270In this case, the request may be re-submitted immediately.
271This mechanism is used by the framework to perform
272session migration (move a session from one driver to another, because
273of availability, performance, or other considerations).
274.Pp
275Note that this field only makes sense when examined by
276the callback routine specified in
277.Va crp_callback .
278Errors are returned to the invoker of
279.Fn crypto_process
280only when enough information is not present to call the callback
281routine (i.e., if the pointer passed is
282.Dv NULL
283or if no callback routine was specified).
284.It Va crp_flags
285Is a bitmask of flags associated with this request.
286Currently defined flags are:
287.Bl -tag -width ".Dv CRYPTO_F_CBIFSYNC"
288.It Dv CRYPTO_F_IMBUF
289The buffer pointed to by
290.Va crp_buf
291is an mbuf chain.
292.It Dv CRYPTO_F_IOV
293The buffer pointed to by
294.Va crp_buf
295is an uio structure.
296.It Dv CRYPTO_F_REL
297Must return data in the same place.
298.It Dv CRYPTO_F_BATCH
299Batch operation if possible.
300.It Dv CRYPTO_F_CBIMM
301Do callback immediatelly instead of doing it from a dedicated kernel thread.
302.It Dv CRYPTO_F_DONE
303Operation completed.
304.It Dv CRYPTO_F_CBIFSYNC
305Do callback immediatelly if operation is synchronous.
306.El
307.It Va crp_buf
308Points to the input buffer.
309On return (when the callback is invoked),
310it contains the result of the request.
311The input buffer may be an mbuf
312chain or a contiguous buffer,
313depending on
314.Va crp_flags .
315.It Va crp_opaque
316This is passed through the crypto framework untouched and is
317intended for the invoking application's use.
318.It Va crp_desc
319This is a linked list of descriptors.
320Each descriptor provides
321information about what type of cryptographic operation should be done
322on the input buffer.
323The various fields are:
324.Bl -tag -width ".Va crd_inject"
|
| 325.It Va crd_iv
326The field where IV should be provided when the
327.Dv CRD_F_IV_EXPLICIT
328flag is given.
329.It Va crd_key
330When the
331.Dv CRD_F_KEY_EXPLICIT
332flag is given, the
333.Va crd_key
334points to a buffer with encryption or authentication key.
335.It Va crd_alg
336An algorithm to use.
337Must be the same as the one given at newsession time.
338.It Va crd_klen
339The
340.Va crd_key
341key length.
|
321.It Va crd_skip
322The offset in the input buffer where processing should start.
323.It Va crd_len
324How many bytes, after
325.Va crd_skip ,
326should be processed.
327.It Va crd_inject
328Offset from the beginning of the buffer to insert any results.
329For encryption algorithms, this is where the initialization vector
330(IV) will be inserted when encrypting or where it can be found when
331decrypting (subject to
332.Va crd_flags ) .
333For MAC algorithms, this is where the result of the keyed hash will be
334inserted.
335.It Va crd_flags
336The following flags are defined:
337.Bl -tag -width ".Dv CRD"
338.It Dv CRD_F_ENCRYPT
339For encryption algorithms, this bit is set when encryption is required
340(when not set, decryption is performed).
341.It Dv CRD_F_IV_PRESENT
342For encryption algorithms, this bit is set when the IV already
343precedes the data, so the
344.Va crd_inject
345value will be ignored and no IV will be written in the buffer.
346Otherwise, the IV used to encrypt the packet will be written
347at the location pointed to by
348.Va crd_inject .
349The IV length is assumed to be equal to the blocksize of the
350encryption algorithm.
351Some applications that do special
352.Dq "IV cooking" ,
353such as the half-IV mode in
354.Xr ipsec 4 ,
355can use this flag to indicate that the IV should not be written on the packet.
356This flag is typically used in conjunction with the
357.Dv CRD_F_IV_EXPLICIT
358flag.
359.It Dv CRD_F_IV_EXPLICIT
360For encryption algorithms, this bit is set when the IV is explicitly
361provided by the consumer in the
| 342.It Va crd_skip
343The offset in the input buffer where processing should start.
344.It Va crd_len
345How many bytes, after
346.Va crd_skip ,
347should be processed.
348.It Va crd_inject
349Offset from the beginning of the buffer to insert any results.
350For encryption algorithms, this is where the initialization vector
351(IV) will be inserted when encrypting or where it can be found when
352decrypting (subject to
353.Va crd_flags ) .
354For MAC algorithms, this is where the result of the keyed hash will be
355inserted.
356.It Va crd_flags
357The following flags are defined:
358.Bl -tag -width ".Dv CRD"
359.It Dv CRD_F_ENCRYPT
360For encryption algorithms, this bit is set when encryption is required
361(when not set, decryption is performed).
362.It Dv CRD_F_IV_PRESENT
363For encryption algorithms, this bit is set when the IV already
364precedes the data, so the
365.Va crd_inject
366value will be ignored and no IV will be written in the buffer.
367Otherwise, the IV used to encrypt the packet will be written
368at the location pointed to by
369.Va crd_inject .
370The IV length is assumed to be equal to the blocksize of the
371encryption algorithm.
372Some applications that do special
373.Dq "IV cooking" ,
374such as the half-IV mode in
375.Xr ipsec 4 ,
376can use this flag to indicate that the IV should not be written on the packet.
377This flag is typically used in conjunction with the
378.Dv CRD_F_IV_EXPLICIT
379flag.
380.It Dv CRD_F_IV_EXPLICIT
381For encryption algorithms, this bit is set when the IV is explicitly
382provided by the consumer in the
|
362.Va cri_iv
| 383.Va crd_iv
|
363field.
364Otherwise, for encryption operations the IV is provided for by
365the driver used to perform the operation, whereas for decryption
366operations it is pointed to by the
367.Va crd_inject
368field.
369This flag is typically used when the IV is calculated
370.Dq "on the fly"
371by the consumer, and does not precede the data (some
372.Xr ipsec 4
373configurations, and the encrypted swap are two such examples).
374.It Dv CRD_F_KEY_EXPLICIT
| 384field.
385Otherwise, for encryption operations the IV is provided for by
386the driver used to perform the operation, whereas for decryption
387operations it is pointed to by the
388.Va crd_inject
389field.
390This flag is typically used when the IV is calculated
391.Dq "on the fly"
392by the consumer, and does not precede the data (some
393.Xr ipsec 4
394configurations, and the encrypted swap are two such examples).
395.It Dv CRD_F_KEY_EXPLICIT
|
375For encryption algorithms, this bit is set when the key is explicitly
376provided by the consumer in the
377.Va cri_key
| 396For encryption and authentication (MAC) algorithms, this bit is set when the key
397is explicitly provided by the consumer in the
398.Va crd_key
|
378field for the given operation.
| 399field for the given operation.
|
379Otherwise, the key is taken at newsession time from the same field.
| 400Otherwise, the key is taken at newsession time from the
401.Va cri_key
402field.
|
380.It Dv CRD_F_COMP
381For compression algorithms, this bit is set when compression is required (when
382not set, decompression is performed).
383.El
384.It Va CRD_INI
385This
386.Vt cryptoini
387structure will not be modified by the framework or the device drivers.
388Since this information accompanies every cryptographic
389operation request, drivers may re-initialize state on-demand
390(typically an expensive operation).
391Furthermore, the cryptographic
392framework may re-route requests as a result of full queues or hardware
393failure, as described above.
394.It Va crd_next
395Point to the next descriptor.
396Linked operations are useful in protocols such as
397.Xr ipsec 4 ,
398where multiple cryptographic transforms may be applied on the same
399block of data.
400.El
401.El
402.Pp
403.Fn crypto_getreq
404allocates a
405.Vt cryptop
406structure with a linked list of as many
407.Vt cryptodesc
408structures as were specified in the argument passed to it.
409.Pp
410.Fn crypto_freereq
411deallocates a structure
412.Vt cryptop
413and any
414.Vt cryptodesc
415structures linked to it.
416Note that it is the responsibility of the
417callback routine to do the necessary cleanups associated with the
418opaque field in the
419.Vt cryptop
420structure.
421.Pp
422.Fn crypto_kdispatch
423is called to perform a keying operation.
424The various fields in the
425.Vt cryptkop
426structure are:
427.Bl -tag -width ".Va krp_callback'
428.It Va krp_op
429Operation code, such as
430.Dv CRK_MOD_EXP .
431.It Va krp_status
432Return code.
433This
434.Va errno Ns -style
435variable indicates whether lower level reasons
436for operation failure.
437.It Va krp_iparams
438Number if input parameters to the specified operation.
439Note that each operation has a (typically hardwired) number of such parameters.
440.It Va krp_oparams
441Number if output parameters from the specified operation.
442Note that each operation has a (typically hardwired) number of such parameters.
443.It Va krp_kvp
444An array of kernel memory blocks containing the parameters.
445.It Va krp_hid
446Identifier specifying which low-level driver is being used.
447.It Va krp_callback
448Callback called on completion of a keying operation.
449.El
450.Sh DRIVER-SIDE API
451The
452.Fn crypto_get_driverid ,
453.Fn crypto_register ,
454.Fn crypto_kregister ,
455.Fn crypto_unregister ,
456.Fn crypto_unblock ,
457and
458.Fn crypto_done
459routines are used by drivers that provide support for cryptographic
460primitives to register and unregister with the kernel crypto services
461framework.
462Drivers must first use the
463.Fn crypto_get_driverid
464function to acquire a driver identifier, specifying the
465.Fa cc_flags
466as an argument (normally 0, but software-only drivers should specify
467.Dv CRYPTOCAP_F_SOFTWARE ) .
468For each algorithm the driver supports, it must then call
469.Fn crypto_register .
470The first two arguments are the driver and algorithm identifiers.
471The next two arguments specify the largest possible operator length (in bits,
472important for public key operations) and flags for this algorithm.
473The last four arguments must be provided in the first call to
474.Fn crypto_register
475and are ignored in all subsequent calls.
476They are pointers to three
477driver-provided functions that the framework may call to establish new
478cryptographic context with the driver, free already established
479context, and ask for a request to be processed (encrypt, decrypt,
480etc.); and an opaque parameter to pass when calling each of these routines.
481.Fn crypto_unregister
482is called by drivers that wish to withdraw support for an algorithm.
483The two arguments are the driver and algorithm identifiers, respectively.
484Typically, drivers for
485PCMCIA
486crypto cards that are being ejected will invoke this routine for all
487algorithms supported by the card.
488.Fn crypto_unregister_all
489will unregister all algorithms registered by a driver
490and the driver will be disabled (no new sessions will be allocated on
491that driver, and any existing sessions will be migrated to other
492drivers).
493The same will be done if all algorithms associated with a driver are
494unregistered one by one.
495.Pp
496The calling convention for the three driver-supplied routines is:
497.Pp
498.Bl -item -compact
499.It
500.Ft int
501.Fn \*[lp]*newsession\*[rp] "void *" "u_int32_t *" "struct cryptoini *" ;
502.It
503.Ft int
504.Fn \*[lp]*freesession\*[rp] "void *" "u_int64_t" ;
505.It
506.Ft int
507.Fn \*[lp]*process\*[rp] "void *" "struct cryptop *" ;
508.It
509.Ft int
510.Fn \*[lp]*kprocess\*[rp] "void *" "struct cryptkop *" ;
511.El
512.Pp
513On invocation, the first argument to
514all routines is an opaque data value supplied when the algorithm
515is registered with
516.Fn crypto_register .
517The second argument to
518.Fn newsession
519contains the driver identifier obtained via
520.Fn crypto_get_driverid .
521On successful return, it should contain a driver-specific session
522identifier.
523The third argument is identical to that of
524.Fn crypto_newsession .
525.Pp
526The
527.Fn freesession
528routine takes as arguments the opaque data value and the SID
529(which is the concatenation of the
530driver identifier and the driver-specific session identifier).
531It should clear any context associated with the session (clear hardware
532registers, memory, etc.).
533.Pp
534The
535.Fn process
536routine is invoked with a request to perform crypto processing.
537This routine must not block, but should queue the request and return
538immediately.
539Upon processing the request, the callback routine should be invoked.
540In case of an unrecoverable error, the error indication must be placed in the
541.Va crp_etype
542field of the
543.Vt cryptop
544structure.
545When the request is completed, or an error is detected, the
546.Fn process
547routine should invoke
548.Fn crypto_done .
549Session migration may be performed, as mentioned previously.
550.Pp
551In case of a temporary resource exhaustion, the
552.Fn process
553routine may return
554.Er ERESTART
555in which case the crypto services will requeue the request, mark the driver
556as
557.Dq blocked ,
558and stop submitting requests for processing.
559The driver is then responsible for notifying the crypto services
560when it is again able to process requests through the
561.Fn crypto_unblock
562routine.
563This simple flow control mechanism should only be used for short-lived
564resource exhaustion as it causes operations to be queued in the crypto
565layer.
566Doing so is preferable to returning an error in such cases as
567it can cause network protocols to degrade performance by treating the
568failure much like a lost packet.
569.Pp
570The
571.Fn kprocess
572routine is invoked with a request to perform crypto key processing.
573This routine must not block, but should queue the request and return
574immediately.
575Upon processing the request, the callback routine should be invoked.
576In case of an unrecoverable error, the error indication must be placed in the
577.Va krp_status
578field of the
579.Vt cryptkop
580structure.
581When the request is completed, or an error is detected, the
582.Fn kprocess
583routine should invoked
584.Fn crypto_kdone .
585.Sh RETURN VALUES
586.Fn crypto_register ,
587.Fn crypto_kregister ,
588.Fn crypto_unregister ,
589.Fn crypto_newsession ,
590.Fn crypto_freesession ,
591and
592.Fn crypto_unblock
593return 0 on success, or an error code on failure.
594.Fn crypto_get_driverid
595returns a non-negative value on error, and \-1 on failure.
596.Fn crypto_getreq
597returns a pointer to a
598.Vt cryptop
599structure and
600.Dv NULL
601on failure.
602.Fn crypto_dispatch
603returns
604.Er EINVAL
605if its argument or the callback function was
606.Dv NULL ,
607and 0 otherwise.
608The callback is provided with an error code in case of failure, in the
609.Va crp_etype
610field.
611.Sh FILES
612.Bl -tag -width ".Pa sys/opencrypto/crypto.c"
613.It Pa sys/opencrypto/crypto.c
614most of the framework code
615.El
616.Sh SEE ALSO
617.Xr ipsec 4 ,
618.Xr malloc 9 ,
619.Xr sleep 9
620.Sh HISTORY
621The cryptographic framework first appeared in
622.Ox 2.7
623and was written by
624.An "Angelos D. Keromytis" Aq angelos@openbsd.org .
625.Sh BUGS
626The framework currently assumes that all the algorithms in a
627.Fn crypto_newsession
628operation must be available by the same driver.
629If that is not the case, session initialization will fail.
630.Pp
631The framework also needs a mechanism for determining which driver is
632best for a specific set of algorithms associated with a session.
633Some type of benchmarking is in order here.
634.Pp
635Multiple instances of the same algorithm in the same session are not
636supported.
637Note that 3DES is considered one algorithm (and not three
638instances of DES).
639Thus, 3DES and DES could be mixed in the same request.
| 403.It Dv CRD_F_COMP
404For compression algorithms, this bit is set when compression is required (when
405not set, decompression is performed).
406.El
407.It Va CRD_INI
408This
409.Vt cryptoini
410structure will not be modified by the framework or the device drivers.
411Since this information accompanies every cryptographic
412operation request, drivers may re-initialize state on-demand
413(typically an expensive operation).
414Furthermore, the cryptographic
415framework may re-route requests as a result of full queues or hardware
416failure, as described above.
417.It Va crd_next
418Point to the next descriptor.
419Linked operations are useful in protocols such as
420.Xr ipsec 4 ,
421where multiple cryptographic transforms may be applied on the same
422block of data.
423.El
424.El
425.Pp
426.Fn crypto_getreq
427allocates a
428.Vt cryptop
429structure with a linked list of as many
430.Vt cryptodesc
431structures as were specified in the argument passed to it.
432.Pp
433.Fn crypto_freereq
434deallocates a structure
435.Vt cryptop
436and any
437.Vt cryptodesc
438structures linked to it.
439Note that it is the responsibility of the
440callback routine to do the necessary cleanups associated with the
441opaque field in the
442.Vt cryptop
443structure.
444.Pp
445.Fn crypto_kdispatch
446is called to perform a keying operation.
447The various fields in the
448.Vt cryptkop
449structure are:
450.Bl -tag -width ".Va krp_callback'
451.It Va krp_op
452Operation code, such as
453.Dv CRK_MOD_EXP .
454.It Va krp_status
455Return code.
456This
457.Va errno Ns -style
458variable indicates whether lower level reasons
459for operation failure.
460.It Va krp_iparams
461Number if input parameters to the specified operation.
462Note that each operation has a (typically hardwired) number of such parameters.
463.It Va krp_oparams
464Number if output parameters from the specified operation.
465Note that each operation has a (typically hardwired) number of such parameters.
466.It Va krp_kvp
467An array of kernel memory blocks containing the parameters.
468.It Va krp_hid
469Identifier specifying which low-level driver is being used.
470.It Va krp_callback
471Callback called on completion of a keying operation.
472.El
473.Sh DRIVER-SIDE API
474The
475.Fn crypto_get_driverid ,
476.Fn crypto_register ,
477.Fn crypto_kregister ,
478.Fn crypto_unregister ,
479.Fn crypto_unblock ,
480and
481.Fn crypto_done
482routines are used by drivers that provide support for cryptographic
483primitives to register and unregister with the kernel crypto services
484framework.
485Drivers must first use the
486.Fn crypto_get_driverid
487function to acquire a driver identifier, specifying the
488.Fa cc_flags
489as an argument (normally 0, but software-only drivers should specify
490.Dv CRYPTOCAP_F_SOFTWARE ) .
491For each algorithm the driver supports, it must then call
492.Fn crypto_register .
493The first two arguments are the driver and algorithm identifiers.
494The next two arguments specify the largest possible operator length (in bits,
495important for public key operations) and flags for this algorithm.
496The last four arguments must be provided in the first call to
497.Fn crypto_register
498and are ignored in all subsequent calls.
499They are pointers to three
500driver-provided functions that the framework may call to establish new
501cryptographic context with the driver, free already established
502context, and ask for a request to be processed (encrypt, decrypt,
503etc.); and an opaque parameter to pass when calling each of these routines.
504.Fn crypto_unregister
505is called by drivers that wish to withdraw support for an algorithm.
506The two arguments are the driver and algorithm identifiers, respectively.
507Typically, drivers for
508PCMCIA
509crypto cards that are being ejected will invoke this routine for all
510algorithms supported by the card.
511.Fn crypto_unregister_all
512will unregister all algorithms registered by a driver
513and the driver will be disabled (no new sessions will be allocated on
514that driver, and any existing sessions will be migrated to other
515drivers).
516The same will be done if all algorithms associated with a driver are
517unregistered one by one.
518.Pp
519The calling convention for the three driver-supplied routines is:
520.Pp
521.Bl -item -compact
522.It
523.Ft int
524.Fn \*[lp]*newsession\*[rp] "void *" "u_int32_t *" "struct cryptoini *" ;
525.It
526.Ft int
527.Fn \*[lp]*freesession\*[rp] "void *" "u_int64_t" ;
528.It
529.Ft int
530.Fn \*[lp]*process\*[rp] "void *" "struct cryptop *" ;
531.It
532.Ft int
533.Fn \*[lp]*kprocess\*[rp] "void *" "struct cryptkop *" ;
534.El
535.Pp
536On invocation, the first argument to
537all routines is an opaque data value supplied when the algorithm
538is registered with
539.Fn crypto_register .
540The second argument to
541.Fn newsession
542contains the driver identifier obtained via
543.Fn crypto_get_driverid .
544On successful return, it should contain a driver-specific session
545identifier.
546The third argument is identical to that of
547.Fn crypto_newsession .
548.Pp
549The
550.Fn freesession
551routine takes as arguments the opaque data value and the SID
552(which is the concatenation of the
553driver identifier and the driver-specific session identifier).
554It should clear any context associated with the session (clear hardware
555registers, memory, etc.).
556.Pp
557The
558.Fn process
559routine is invoked with a request to perform crypto processing.
560This routine must not block, but should queue the request and return
561immediately.
562Upon processing the request, the callback routine should be invoked.
563In case of an unrecoverable error, the error indication must be placed in the
564.Va crp_etype
565field of the
566.Vt cryptop
567structure.
568When the request is completed, or an error is detected, the
569.Fn process
570routine should invoke
571.Fn crypto_done .
572Session migration may be performed, as mentioned previously.
573.Pp
574In case of a temporary resource exhaustion, the
575.Fn process
576routine may return
577.Er ERESTART
578in which case the crypto services will requeue the request, mark the driver
579as
580.Dq blocked ,
581and stop submitting requests for processing.
582The driver is then responsible for notifying the crypto services
583when it is again able to process requests through the
584.Fn crypto_unblock
585routine.
586This simple flow control mechanism should only be used for short-lived
587resource exhaustion as it causes operations to be queued in the crypto
588layer.
589Doing so is preferable to returning an error in such cases as
590it can cause network protocols to degrade performance by treating the
591failure much like a lost packet.
592.Pp
593The
594.Fn kprocess
595routine is invoked with a request to perform crypto key processing.
596This routine must not block, but should queue the request and return
597immediately.
598Upon processing the request, the callback routine should be invoked.
599In case of an unrecoverable error, the error indication must be placed in the
600.Va krp_status
601field of the
602.Vt cryptkop
603structure.
604When the request is completed, or an error is detected, the
605.Fn kprocess
606routine should invoked
607.Fn crypto_kdone .
608.Sh RETURN VALUES
609.Fn crypto_register ,
610.Fn crypto_kregister ,
611.Fn crypto_unregister ,
612.Fn crypto_newsession ,
613.Fn crypto_freesession ,
614and
615.Fn crypto_unblock
616return 0 on success, or an error code on failure.
617.Fn crypto_get_driverid
618returns a non-negative value on error, and \-1 on failure.
619.Fn crypto_getreq
620returns a pointer to a
621.Vt cryptop
622structure and
623.Dv NULL
624on failure.
625.Fn crypto_dispatch
626returns
627.Er EINVAL
628if its argument or the callback function was
629.Dv NULL ,
630and 0 otherwise.
631The callback is provided with an error code in case of failure, in the
632.Va crp_etype
633field.
634.Sh FILES
635.Bl -tag -width ".Pa sys/opencrypto/crypto.c"
636.It Pa sys/opencrypto/crypto.c
637most of the framework code
638.El
639.Sh SEE ALSO
640.Xr ipsec 4 ,
641.Xr malloc 9 ,
642.Xr sleep 9
643.Sh HISTORY
644The cryptographic framework first appeared in
645.Ox 2.7
646and was written by
647.An "Angelos D. Keromytis" Aq angelos@openbsd.org .
648.Sh BUGS
649The framework currently assumes that all the algorithms in a
650.Fn crypto_newsession
651operation must be available by the same driver.
652If that is not the case, session initialization will fail.
653.Pp
654The framework also needs a mechanism for determining which driver is
655best for a specific set of algorithms associated with a session.
656Some type of benchmarking is in order here.
657.Pp
658Multiple instances of the same algorithm in the same session are not
659supported.
660Note that 3DES is considered one algorithm (and not three
661instances of DES).
662Thus, 3DES and DES could be mixed in the same request.
|