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diff --git a/static/openbsd/man9/crypto.9 b/static/openbsd/man9/crypto.9 new file mode 100644 index 00000000..11f289c8 --- /dev/null +++ b/static/openbsd/man9/crypto.9 @@ -0,0 +1,518 @@ +.\" $OpenBSD: crypto.9,v 1.43 2020/03/28 13:16:09 krw Exp $ +.\" +.\" The author of this man page is Angelos D. Keromytis (angelos@cis.upenn.edu) +.\" +.\" Copyright (c) 2000, 2001 Angelos D. Keromytis +.\" +.\" Permission to use, copy, and modify this software with or without fee +.\" is hereby granted, provided that this entire notice is included in +.\" all source code copies of any software which is or includes a copy or +.\" modification of this software. +.\" +.\" THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR +.\" IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY +.\" REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE +.\" MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR +.\" PURPOSE. +.\" +.Dd $Mdocdate: March 28 2020 $ +.Dt CRYPTO_GET_DRIVERID 9 +.Os +.Sh NAME +.Nm crypto_get_driverid , +.Nm crypto_register , +.Nm crypto_unregister , +.Nm crypto_done , +.Nm crypto_newsession , +.Nm crypto_freesession , +.Nm crypto_dispatch , +.Nm crypto_getreq , +.Nm crypto_freereq +.Nd API for cryptographic services in the kernel +.Sh SYNOPSIS +.In crypto/cryptodev.h +.Ft int32_t +.Fn crypto_get_driverid "u_int8_t" +.Ft int +.Fn crypto_register "u_int32_t" "int *" "int (*)(u_int32_t *, struct cryptoini *)" "int (*)(u_int64_t)" "int (*)(struct cryptop *)" +.Ft int +.Fn crypto_unregister "u_int32_t" "int" +.Ft void +.Fn crypto_done "struct cryptop *" +.Ft int +.Fn crypto_newsession "u_int64_t *" "struct cryptoini *" "int" +.Ft int +.Fn crypto_freesession "u_int64_t" +.Ft int +.Fn crypto_dispatch "struct cryptop *" +.Ft struct cryptop * +.Fn crypto_getreq "int" +.Ft void +.Fn crypto_freereq "struct cryptop *" +.Bd -literal + +#define EALG_MAX_BLOCK_LEN 16 + +struct cryptoini { + int cri_alg; + int cri_klen; + int cri_rnd; + caddr_t cri_key; + u_int8_t cri_iv[EALG_MAX_BLOCK_LEN]; + struct cryptoini *cri_next; +}; + +struct cryptodesc { + int crd_skip; + int crd_len; + int crd_inject; + int crd_flags; + struct cryptoini CRD_INI; + struct cryptodesc *crd_next; +}; + +struct cryptop { + u_int64_t crp_sid; + int crp_ilen; + int crp_olen; + int crp_alloctype; + int crp_etype; + int crp_flags; + void *crp_buf; + void *crp_opaque; + struct cryptodesc *crp_desc; + int (*crp_callback)(struct cryptop *); + struct cryptop *crp_next; + caddr_t crp_mac; +}; +.Ed +.Sh DESCRIPTION +.Nm +is a framework for drivers of cryptographic hardware to register with +the kernel so +.Dq consumers +(other kernel subsystems, and eventually +users through an appropriate device) are able to make use of it. +Drivers register with the framework the algorithms they support, +and provide entry points (functions) the framework may call to +establish, use, and tear down sessions. +Sessions are used to cache cryptographic information in a particular driver +(or associated hardware), so initialization is not needed with every request. +Consumers of cryptographic services pass a set of +descriptors that instruct the framework (and the drivers registered +with it) of the operations that should be applied on the data (more +than one cryptographic operation can be requested). +.Pp +Since the consumers may not be associated with a process, drivers may +not use +.Xr tsleep 9 . +The same holds for the framework. +Thus, a callback mechanism is used +to notify a consumer that a request has been completed (the +callback is specified by the consumer on a per-request basis). +The callback is invoked by the framework whether the request was +successfully completed or not. +An error indication is provided in the latter case. +A specific error code, +.Er EAGAIN , +is used to indicate that a session number has changed and that the +request may be re-submitted immediately with the new session number. +Errors are only returned to the invoking function if not +enough information to call the callback is available (meaning, there +was a fatal error in verifying the arguments). +For session initialization and teardown there is no callback mechanism used. +.Pp +The +.Fn crypto_newsession +routine is called by consumers of cryptographic services (such as the +.Xr ipsec 4 +stack) that wish to establish a new session with the framework. +On success, the first argument will contain the Session Identifier (SID). +The second argument contains all the necessary information for +the driver to establish the session. +The third argument indicates whether a +hardware driver should be used (1) or not (0). +The various fields in the +.Fa cryptoini +structure are: +.Bl -tag -width foobarmoocow +.It Fa cri_alg +Contains an algorithm identifier. +Currently supported encryption algorithms are: +.Bd -literal +CRYPTO_3DES_CBC +CRYPTO_BLF_CBC +CRYPTO_CAST_CBC +CRYPTO_AES_CBC +CRYPTO_AES_CTR +CRYPTO_AES_XTS +.Ed +.Pp +Authentication algorithms are: +.Bd -literal +CRYPTO_MD5_HMAC +CRYPTO_SHA1_HMAC +CRYPTO_RIPEMD160_HMAC +CRYPTO_SHA2_256_HMAC +CRYPTO_SHA2_384_HMAC +CRYPTO_SHA2_512_HMAC +.Ed +.Pp +Algorithms performing authenticated encryption are: +.Bd -literal +CRYPTO_AES_GCM_16 +CRYPTO_AES_GMAC +CRYPTO_CHACHA20_POLY1305 +.Ed +.It Fa cri_klen +Specifies the length of the key in bits, for variable-size key +algorithms. +.It Fa cri_rnd +Specifies the number of rounds to be used with the algorithm, for +variable-round algorithms. +.It Fa cri_key +Contains the key to be used with the algorithm. +.It Fa cri_iv +Contains an explicit initialization vector (IV), if it does not prefix +the data. +This field is ignored during initialization. +If no IV is explicitly passed (see below on details), a random IV is used +by the device driver processing the request. +.Pp +In the case of the CRYPTO_AES_XTS transform, the IV should be provided +as a 64-bit block number in host byte order. +.It Fa cri_next +Contains a pointer to another +.Fa cryptoini +structure. +Multiple such structures may be linked to establish multi-algorithm sessions +.Pf ( Xr ipsec 4 +is an example consumer of such a feature). +.El +.Pp +The +.Fa cryptoini +structure and its contents will not be modified by the framework (or +the drivers used). +Subsequent requests for processing that use the +SID returned will avoid the cost of re-initializing the hardware (in +essence, SID acts as an index in the session cache of the driver). +.Pp +.Fn crypto_freesession +is called with the SID returned by +.Fn crypto_newsession +to disestablish the session. +.Pp +.Fn crypto_dispatch +is called to process a request. +The various fields in the +.Fa cryptop +structure are: +.Bl -tag -width crp_alloctype +.It Fa crp_sid +Contains the SID. +.It Fa crp_ilen +Indicates the total length in bytes of the buffer to be processed. +.It Fa crp_olen +On return, contains the length of the result, not including +.Fa crd_skip . +For symmetric crypto operations, this will be the same as the input length. +.It Fa crp_alloctype +Indicates the type of buffer, as used in the kernel +.Xr malloc 9 +routine. +This will be used if the framework needs to allocate a new +buffer for the result (or for re-formatting the input). +.It Fa crp_callback +This routine is invoked upon completion of the request, whether +successful or not. +It is invoked through the +.Fn crypto_done +routine. +If the request was not successful, an error code is set in the +.Fa crp_etype +field. +It is the responsibility of the callback routine to set the appropriate +.Xr spl 9 +level. +.It Fa crp_etype +Contains the error type, if any errors were encountered, or zero if +the request was successfully processed. +If the +.Er EAGAIN +error code is returned, the SID has changed (and has been recorded in the +.Fa crp_sid +field). +The consumer should record the new SID and use it in all subsequent requests. +In this case, the request may be re-submitted immediately. +This mechanism is used by the framework to perform +session migration (move a session from one driver to another, because +of availability, performance, or other considerations). +.Pp +Note that this field only makes sense when examined by +the callback routine specified in +.Fa crp_callback . +Errors are returned to the invoker of +.Fn crypto_process +only when enough information is not present to call the callback +routine (i.e., if the pointer passed is +.Dv NULL +or if no callback routine was specified). +.It Fa crp_flags +Is a bitmask of flags associated with this request. +Currently defined flags are: +.Bl -tag -width CRYPTO_F_IMBUF +.It Dv CRYPTO_F_IMBUF +The buffer pointed to by +.Fa crp_buf +is an mbuf chain. +.El +.It Fa crp_buf +Points to the input buffer. +On return (when the callback is invoked), +it contains the result of the request. +The input buffer may be an mbuf +chain or a struct uio depending on +.Fa crp_flags . +.It Fa crp_opaque +This is passed through the crypto framework untouched and is +intended for the invoking application's use. +.It Fa crp_desc +This is a linked list of descriptors. +Each descriptor provides +information about what type of cryptographic operation should be done +on the input buffer. +The various fields are: +.Bl -tag -width "crd_inject" +.It Fa crd_skip +The offset in the input buffer where processing should start. +.It Fa crd_len +How many bytes, after +.Fa crd_skip , +should be processed. +.It Fa crd_inject +Offset from the beginning of the buffer to insert any results. +For encryption algorithms, this is where the initialization vector +(IV) will be inserted when encrypting or where it can be found when +decrypting (subject to +.Fa crd_flags ) . +For MAC algorithms, this is where the result of the keyed hash will be +inserted. +.It Fa crd_flags +The following flags are defined: +.Bl -tag -width CRD_F_IV_EXPLICIT +.It Dv CRD_F_ENCRYPT +For encryption algorithms, this bit is set when encryption is required +(when not set, decryption is performed). +.It Dv CRD_F_IV_PRESENT +For encryption algorithms, this bit is set when the IV already +precedes the data, so the +.Fa crd_inject +value will be ignored and no IV will be written in the buffer. +Otherwise, the IV used to encrypt the packet will be written +at the location pointed to by +.Fa crd_inject . +The IV length is assumed to be equal to the blocksize of the +encryption algorithm. +Some applications that do special +.Dq IV cooking , +such as the half-IV mode in +.Xr ipsec 4 , +can use this flag to indicate that the IV should not be written on the packet. +This flag is typically used in conjunction with the +.Dv CRD_F_IV_EXPLICIT +flag. +.It Dv CRD_F_IV_EXPLICIT +For encryption algorithms, this bit is set when the IV is explicitly +provided by the consumer in the +.Fa crd_iv +fields. +Otherwise, for encryption operations the IV is provided for by +the driver used to perform the operation, whereas for decryption +operations it is pointed to by the +.Fa crd_inject +field. +This flag is typically used when the IV is calculated +.Dq on the fly +by the consumer, and does not precede the data (some +.Xr ipsec 4 +configurations, and the encrypted swap are two such examples). +.It Dv CRD_F_COMP +For compression algorithms, this bit is set when compression is required (when +not set, decompression is performed). +.El +.It Fa CRD_INI +This +.Fa cryptoini +structure will not be modified by the framework or the device drivers. +Since this information accompanies every cryptographic +operation request, drivers may re-initialize state on-demand +(typically an expensive operation). +Furthermore, the cryptographic +framework may re-route requests as a result of full queues or hardware +failure, as described above. +.It Fa crd_next +Point to the next descriptor. +Linked operations are useful in protocols such as +.Xr ipsec 4 , +where multiple cryptographic transforms may be applied on the same +block of data. +.El +.El +.Pp +.Fn crypto_getreq +allocates a +.Fa cryptop +structure with a linked list of as many +.Fa cryptodesc +structures as were specified in the argument passed to it. +.Pp +.Fn crypto_freereq +deallocates a structure +.Fa cryptop +and any +.Fa cryptodesc +structures linked to it. +Note that it is the responsibility of the +callback routine to do the necessary cleanups associated with the +opaque field in the +.Fa cryptop +structure. +.Sh DRIVER-SIDE API +The +.Fn crypto_get_driverid , +.Fn crypto_register , +.Fn crypto_unregister , +and +.Fn crypto_done +routines are used by drivers that provide support for cryptographic +primitives to register and unregister with the kernel crypto services +framework. +Drivers must first use the +.Fn crypto_get_driverid +function to acquire a driver identifier, specifying the +.Fa cc_flags +as an argument (normally 0, but software-only drivers should specify +.Dv CRYPTOCAP_F_SOFTWARE ) . +For each algorithm the driver supports, it must then call +.Fn crypto_register . +The first argument is the driver identifier. +The second argument is an array of +.Dv CRYPTO_ALGORITHM_MAX + 1 +elements, indicating which algorithms are supported. +The last three arguments are pointers to three +driver-provided functions that the framework may call to establish new +cryptographic context with the driver, free already established +context, and ask for a request to be processed (encrypt, decrypt, etc.\&) +.Fn crypto_unregister +is called by drivers that wish to withdraw support for an algorithm. +The two arguments are the driver and algorithm identifiers, respectively. +Typically, drivers for +.Xr pcmcia 4 +crypto cards that are being ejected will invoke this routine for all +algorithms supported by the card. +If called with +.Dv CRYPTO_ALGORITHM_MAX + 1 , +all algorithms registered for a driver will be unregistered in one go +and the driver will be disabled (no new sessions will be allocated on +that driver, and any existing sessions will be migrated to other +drivers). +The same will be done if all algorithms associated with a driver are +unregistered one by one. +.Pp +The calling convention for the three driver-supplied routines is: +.Bd -literal +int (*newsession) (u_int32_t *, struct cryptoini *); +int (*freesession) (u_int64_t); +int (*process) (struct cryptop *); +.Ed +.Pp +On invocation, the first argument to +.Fn newsession +contains the driver identifier obtained via +.Fn crypto_get_driverid . +On successfully returning, it should contain a driver-specific session +identifier. +The second argument is identical to that of +.Fn crypto_newsession . +.Pp +The +.Fn freesession +routine takes as argument the SID (which is the concatenation of the +driver identifier and the driver-specific session identifier). +It should clear any context associated with the session (clear hardware +registers, memory, etc.). +.Pp +The +.Fn process +routine is invoked with a request to perform crypto processing. +This routine must not block, but should queue the request and return +immediately. +Upon processing the request, the callback routine should be invoked. +In case of error, the error indication must be placed in the +.Fa crp_etype +field of the +.Fa cryptop +structure. +When the request is completed, or an error is detected, the +.Fn process +routine should invoke +.Fn crypto_done . +Session migration may be performed, as mentioned previously. +.Sh RETURN VALUES +.Fn crypto_register , +.Fn crypto_unregister , +.Fn crypto_newsession , +and +.Fn crypto_freesession +return 0 on success, or an error code on failure. +.Fn crypto_get_driverid +returns a non-negative value on error, and \-1 on failure. +.Fn crypto_getreq +returns a pointer to a +.Fa cryptop +structure and +.Dv NULL +on failure. +.Fn crypto_dispatch +returns +.Er EINVAL +if its argument or the callback function was +.Dv NULL , +and 0 otherwise. +The callback is provided with an error code in case of failure, in the +.Fa crp_etype +field. +.Sh FILES +.Bl -tag -width sys/crypto/crypto.c +.It Pa sys/crypto/crypto.c +most of the framework code +.El +.Sh SEE ALSO +.Xr ipsec 4 , +.Xr pcmcia 4 , +.Xr malloc 9 , +.Xr tsleep 9 +.Sh HISTORY +The cryptographic framework first appeared in +.Ox 2.7 +and was written by +.An Angelos D. Keromytis Aq Mt angelos@openbsd.org . +.Sh BUGS +The framework currently assumes that all the algorithms in a +.Fn crypto_newsession +operation must be available by the same driver. +If that's not the case, session initialization will fail. +.Pp +The framework also needs a mechanism for determining which driver is +best for a specific set of algorithms associated with a session. +Some type of benchmarking is in order here. +.Pp +Multiple instances of the same algorithm in the same session are not +supported. +.Pp +A queue for completed operations should be implemented and processed +at some software +.Xr spl 9 +level, to avoid overall system latency issues, and potential kernel +stack exhaustion while processing a callback. |