2c907637bc
This requests that the cipher be performed before rather than after the HMAC when both are specified for a single operation. Reviewed by: cem Sponsored by: Chelsio Communications Differential Revision: https://reviews.freebsd.org/D11757
443 lines
13 KiB
Groff
443 lines
13 KiB
Groff
.\" $NetBSD: crypto.4,v 1.24 2014/01/27 21:23:59 pgoyette Exp $
|
|
.\"
|
|
.\" Copyright (c) 2008 The NetBSD Foundation, Inc.
|
|
.\" Copyright (c) 2014 The FreeBSD Foundation
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Portions of this documentation were written by John-Mark Gurney
|
|
.\" under sponsorship of the FreeBSD Foundation and
|
|
.\" Rubicon Communications, LLC (Netgate).
|
|
.\"
|
|
.\" This code is derived from software contributed to The NetBSD Foundation
|
|
.\" by Coyote Point Systems, Inc.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
|
|
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
.\" POSSIBILITY OF SUCH DAMAGE.
|
|
.\"
|
|
.\"
|
|
.\"
|
|
.\" Copyright (c) 2004
|
|
.\" Jonathan Stone <jonathan@dsg.stanford.edu>. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY Jonathan Stone AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL Jonathan Stone OR THE VOICES IN HIS HEAD
|
|
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
|
|
.\" THE POSSIBILITY OF SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd September 21, 2017
|
|
.Dt CRYPTO 4
|
|
.Os
|
|
.Sh NAME
|
|
.Nm crypto ,
|
|
.Nm cryptodev
|
|
.Nd user-mode access to hardware-accelerated cryptography
|
|
.Sh SYNOPSIS
|
|
.Cd device crypto
|
|
.Cd device cryptodev
|
|
.Pp
|
|
.In sys/ioctl.h
|
|
.In sys/time.h
|
|
.In crypto/cryptodev.h
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
driver gives user-mode applications access to hardware-accelerated
|
|
cryptographic transforms, as implemented by the
|
|
.Xr crypto 9
|
|
in-kernel interface.
|
|
.Pp
|
|
The
|
|
.Pa /dev/crypto
|
|
special device provides an
|
|
.Xr ioctl 2
|
|
based interface.
|
|
User-mode applications should open the special device,
|
|
then issue
|
|
.Xr ioctl 2
|
|
calls on the descriptor.
|
|
User-mode access to
|
|
.Pa /dev/crypto
|
|
is controlled by three
|
|
.Xr sysctl 8
|
|
variables,
|
|
.Ic kern.userasymcrypto
|
|
and
|
|
.Ic kern.cryptodevallowsoft .
|
|
.Pp
|
|
The
|
|
.Nm
|
|
device provides two distinct modes of operation: one mode for
|
|
symmetric-keyed cryptographic requests, and a second mode for
|
|
both asymmetric-key (public-key/private-key) requests, and for
|
|
modular arithmetic (for Diffie-Hellman key exchange and other
|
|
cryptographic protocols).
|
|
The two modes are described separately below.
|
|
.Sh THEORY OF OPERATION
|
|
Regardless of whether symmetric-key or asymmetric-key operations are
|
|
to be performed, use of the device requires a basic series of steps:
|
|
.Bl -enum
|
|
.It
|
|
Open a file descriptor for the device.
|
|
See
|
|
.Xr open 2 .
|
|
.It
|
|
If any symmetric operation will be performed,
|
|
create one session, with
|
|
.Dv CIOCGSESSION .
|
|
Most applications will require at least one symmetric session.
|
|
Since cipher and MAC keys are tied to sessions, many
|
|
applications will require more.
|
|
Asymmetric operations do not use sessions.
|
|
.It
|
|
Submit requests, synchronously with
|
|
.Dv CIOCCRYPT
|
|
(symmetric),
|
|
.Dv CIOCCRYPTAEAD
|
|
(symmetric),
|
|
or
|
|
.Dv CIOCKEY
|
|
(asymmetric).
|
|
.It
|
|
Destroy one session with
|
|
.Dv CIOCFSESSION .
|
|
.It
|
|
Close the device with
|
|
.Xr close 2 .
|
|
.El
|
|
.Sh SYMMETRIC-KEY OPERATION
|
|
The symmetric-key operation mode provides a context-based API
|
|
to traditional symmetric-key encryption (or privacy) algorithms,
|
|
or to keyed and unkeyed one-way hash (HMAC and MAC) algorithms.
|
|
The symmetric-key mode also permits fused operation,
|
|
where the hardware performs both a privacy algorithm and an integrity-check
|
|
algorithm in a single pass over the data: either a fused
|
|
encrypt/HMAC-generate operation, or a fused HMAC-verify/decrypt operation.
|
|
.Pp
|
|
To use symmetric mode, you must first create a session specifying
|
|
the algorithm(s) and key(s) to use; then issue encrypt or decrypt
|
|
requests against the session.
|
|
.Ss Algorithms
|
|
For a list of supported algorithms, see
|
|
.Xr crypto 7
|
|
and
|
|
.Xr crypto 9 .
|
|
.Ss IOCTL Request Descriptions
|
|
.\"
|
|
.Bl -tag -width CIOCGSESSION
|
|
.\"
|
|
.It Dv CRIOGET Fa int *fd
|
|
Clone the fd argument to
|
|
.Xr ioctl 2 ,
|
|
yielding a new file descriptor for the creation of sessions.
|
|
.\"
|
|
.It Dv CIOCFINDDEV Fa struct crypt_find_op *fop
|
|
.Bd -literal
|
|
struct crypt_find_op {
|
|
int crid; /* driver id + flags */
|
|
char name[32]; /* device/driver name */
|
|
};
|
|
|
|
.Ed
|
|
If
|
|
.Fa crid
|
|
is -1, then find the driver named
|
|
.Fa name
|
|
and return the id in
|
|
.Fa crid .
|
|
If
|
|
.Fa crid
|
|
is not -1, return the name of the driver with
|
|
.Fa crid
|
|
in
|
|
.Fa name .
|
|
In either case, if the driver is not found,
|
|
.Dv ENOENT
|
|
is returned.
|
|
.It Dv CIOCGSESSION Fa struct session_op *sessp
|
|
.Bd -literal
|
|
struct session_op {
|
|
u_int32_t cipher; /* e.g. CRYPTO_DES_CBC */
|
|
u_int32_t mac; /* e.g. CRYPTO_MD5_HMAC */
|
|
|
|
u_int32_t keylen; /* cipher key */
|
|
void * key;
|
|
int mackeylen; /* mac key */
|
|
void * mackey;
|
|
|
|
u_int32_t ses; /* returns: ses # */
|
|
};
|
|
|
|
.Ed
|
|
Create a new cryptographic session on a file descriptor for the device;
|
|
that is, a persistent object specific to the chosen
|
|
privacy algorithm, integrity algorithm, and keys specified in
|
|
.Fa sessp .
|
|
The special value 0 for either privacy or integrity
|
|
is reserved to indicate that the indicated operation (privacy or integrity)
|
|
is not desired for this session.
|
|
.Pp
|
|
Multiple sessions may be bound to a single file descriptor.
|
|
The session ID returned in
|
|
.Fa sessp-\*[Gt]ses
|
|
is supplied as a required field in the symmetric-operation structure
|
|
.Fa crypt_op
|
|
for future encryption or hashing requests.
|
|
.\" .Pp
|
|
.\" This implementation will never return a session ID of 0 for a successful
|
|
.\" creation of a session, which is a
|
|
.\" .Nx
|
|
.\" extension.
|
|
.Pp
|
|
For non-zero symmetric-key privacy algorithms, the privacy algorithm
|
|
must be specified in
|
|
.Fa sessp-\*[Gt]cipher ,
|
|
the key length in
|
|
.Fa sessp-\*[Gt]keylen ,
|
|
and the key value in the octets addressed by
|
|
.Fa sessp-\*[Gt]key .
|
|
.Pp
|
|
For keyed one-way hash algorithms, the one-way hash must be specified
|
|
in
|
|
.Fa sessp-\*[Gt]mac ,
|
|
the key length in
|
|
.Fa sessp-\*[Gt]mackey ,
|
|
and the key value in the octets addressed by
|
|
.Fa sessp-\*[Gt]mackeylen .
|
|
.\"
|
|
.Pp
|
|
Support for a specific combination of fused privacy and
|
|
integrity-check algorithms depends on whether the underlying
|
|
hardware supports that combination.
|
|
Not all combinations are supported
|
|
by all hardware, even if the hardware supports each operation as a
|
|
stand-alone non-fused operation.
|
|
.It Dv CIOCCRYPT Fa struct crypt_op *cr_op
|
|
.Bd -literal
|
|
struct crypt_op {
|
|
u_int32_t ses;
|
|
u_int16_t op; /* e.g. COP_ENCRYPT */
|
|
u_int16_t flags;
|
|
u_int len;
|
|
caddr_t src, dst;
|
|
caddr_t mac; /* must be large enough for result */
|
|
caddr_t iv;
|
|
};
|
|
|
|
.Ed
|
|
Request a symmetric-key (or hash) operation.
|
|
The file descriptor argument to
|
|
.Xr ioctl 2
|
|
must have been bound to a valid session.
|
|
To encrypt, set
|
|
.Fa cr_op-\*[Gt]op
|
|
to
|
|
.Dv COP_ENCRYPT .
|
|
To decrypt, set
|
|
.Fa cr_op-\*[Gt]op
|
|
to
|
|
.Dv COP_DECRYPT .
|
|
The field
|
|
.Fa cr_op-\*[Gt]len
|
|
supplies the length of the input buffer; the fields
|
|
.Fa cr_op-\*[Gt]src ,
|
|
.Fa cr_op-\*[Gt]dst ,
|
|
.Fa cr_op-\*[Gt]mac ,
|
|
.Fa cr_op-\*[Gt]iv
|
|
supply the addresses of the input buffer, output buffer,
|
|
one-way hash, and initialization vector, respectively.
|
|
If a session is using both a privacy algorithm and a hash algorithm,
|
|
the request will generate a hash of the input buffer before
|
|
generating the output buffer by default.
|
|
If the
|
|
.Dv COP_F_CIPHER_FIRST
|
|
flag is included in the
|
|
.Fa cr_op-\*[Gt]flags
|
|
field,
|
|
then the request will generate a hash of the output buffer after
|
|
executing the privacy algorithm.
|
|
.It Dv CIOCCRYPTAEAD Fa struct crypt_aead *cr_aead
|
|
.Bd -literal
|
|
struct crypt_aead {
|
|
u_int32_t ses;
|
|
u_int16_t op; /* e.g. COP_ENCRYPT */
|
|
u_int16_t flags;
|
|
u_int len;
|
|
u_int aadlen;
|
|
u_int ivlen;
|
|
caddr_t src, dst;
|
|
caddr_t aad;
|
|
caddr_t tag; /* must be large enough for result */
|
|
caddr_t iv;
|
|
};
|
|
|
|
.Ed
|
|
The
|
|
.Dv CIOCCRYPTAEAD
|
|
is similar to the
|
|
.Dv CIOCCRYPT
|
|
but provides additional data in
|
|
.Fa cr_aead-\*[Gt]aad
|
|
to include in the authentication mode.
|
|
.It Dv CIOCFSESSION Fa u_int32_t ses_id
|
|
Destroys the /dev/crypto session associated with the file-descriptor
|
|
argument.
|
|
.It Dv CIOCNFSESSION Fa struct crypt_sfop *sfop ;
|
|
.Bd -literal
|
|
struct crypt_sfop {
|
|
size_t count;
|
|
u_int32_t *sesid;
|
|
};
|
|
|
|
.Ed
|
|
Destroys the
|
|
.Fa sfop-\*[Gt]count
|
|
sessions specified by the
|
|
.Fa sfop
|
|
array of session identifiers.
|
|
.El
|
|
.\"
|
|
.Sh ASYMMETRIC-KEY OPERATION
|
|
.Ss Asymmetric-key algorithms
|
|
Contingent upon hardware support, the following asymmetric
|
|
(public-key/private-key; or key-exchange subroutine) operations may
|
|
also be available:
|
|
.Pp
|
|
.Bl -column "CRK_DH_COMPUTE_KEY" "Input parameter" "Output parameter" -offset indent -compact
|
|
.It Em "Algorithm" Ta "Input parameter" Ta "Output parameter"
|
|
.It Em " " Ta "Count" Ta "Count"
|
|
.It Dv CRK_MOD_EXP Ta 3 Ta 1
|
|
.It Dv CRK_MOD_EXP_CRT Ta 6 Ta 1
|
|
.It Dv CRK_DSA_SIGN Ta 5 Ta 2
|
|
.It Dv CRK_DSA_VERIFY Ta 7 Ta 0
|
|
.It Dv CRK_DH_COMPUTE_KEY Ta 3 Ta 1
|
|
.El
|
|
.Pp
|
|
See below for discussion of the input and output parameter counts.
|
|
.Ss Asymmetric-key commands
|
|
.Bl -tag -width CIOCKEY
|
|
.It Dv CIOCASYMFEAT Fa int *feature_mask
|
|
Returns a bitmask of supported asymmetric-key operations.
|
|
Each of the above-listed asymmetric operations is present
|
|
if and only if the bit position numbered by the code for that operation
|
|
is set.
|
|
For example,
|
|
.Dv CRK_MOD_EXP
|
|
is available if and only if the bit
|
|
.Pq 1 \*[Lt]\*[Lt] Dv CRK_MOD_EXP
|
|
is set.
|
|
.It Dv CIOCKEY Fa struct crypt_kop *kop
|
|
.Bd -literal
|
|
struct crypt_kop {
|
|
u_int crk_op; /* e.g. CRK_MOD_EXP */
|
|
u_int crk_status; /* return status */
|
|
u_short crk_iparams; /* # of input params */
|
|
u_short crk_oparams; /* # of output params */
|
|
u_int crk_pad1;
|
|
struct crparam crk_param[CRK_MAXPARAM];
|
|
};
|
|
|
|
/* Bignum parameter, in packed bytes. */
|
|
struct crparam {
|
|
void * crp_p;
|
|
u_int crp_nbits;
|
|
};
|
|
|
|
.Ed
|
|
Performs an asymmetric-key operation from the list above.
|
|
The specific operation is supplied in
|
|
.Fa kop-\*[Gt]crk_op ;
|
|
final status for the operation is returned in
|
|
.Fa kop-\*[Gt]crk_status .
|
|
The number of input arguments and the number of output arguments
|
|
is specified in
|
|
.Fa kop-\*[Gt]crk_iparams
|
|
and
|
|
.Fa kop-\*[Gt]crk_iparams ,
|
|
respectively.
|
|
The field
|
|
.Fa crk_param[]
|
|
must be filled in with exactly
|
|
.Fa kop-\*[Gt]crk_iparams + kop-\*[Gt]crk_oparams
|
|
arguments, each encoded as a
|
|
.Fa struct crparam
|
|
(address, bitlength) pair.
|
|
.Pp
|
|
The semantics of these arguments are currently undocumented.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr aesni 4 ,
|
|
.Xr hifn 4 ,
|
|
.Xr ipsec 4 ,
|
|
.Xr padlock 4 ,
|
|
.Xr safe 4 ,
|
|
.Xr ubsec 4 ,
|
|
.Xr crypto 7 ,
|
|
.Xr geli 8 ,
|
|
.Xr crypto 9
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
driver first appeared in
|
|
.Ox 3.0 .
|
|
The
|
|
.Nm
|
|
driver was imported to
|
|
.Fx 5.0 .
|
|
.Sh BUGS
|
|
Error checking and reporting is weak.
|
|
.Pp
|
|
The values specified for symmetric-key key sizes to
|
|
.Dv CIOCGSESSION
|
|
must exactly match the values expected by
|
|
.Xr opencrypto 9 .
|
|
The output buffer and MAC buffers supplied to
|
|
.Dv CIOCCRYPT
|
|
must follow whether privacy or integrity algorithms were specified for
|
|
session: if you request a
|
|
.No non- Ns Dv NULL
|
|
algorithm, you must supply a suitably-sized buffer.
|
|
.Pp
|
|
The scheme for passing arguments for asymmetric requests is baroque.
|
|
.Pp
|
|
The naming inconsistency between
|
|
.Dv CRIOGET
|
|
and the various
|
|
.Dv CIOC Ns \&*
|
|
names is an unfortunate historical artifact.
|