xref: /freebsd/share/man/man4/aesni.4 (revision 907b59d76938e654f0d040a888e8dfca3de1e222)
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25.\" $FreeBSD$
26.\"
27.Dd December 14, 2015
28.Dt AESNI 4
29.Os
30.Sh NAME
31.Nm aesni
32.Nd "driver for the AES accelerator on Intel CPUs"
33.Sh SYNOPSIS
34To compile this driver into the kernel,
35place the following lines in your
36kernel configuration file:
37.Bd -ragged -offset indent
38.Cd "device crypto"
39.Cd "device cryptodev"
40.Cd "device aesni"
41.Ed
42.Pp
43Alternatively, to load the driver as a
44module at boot time, place the following line in
45.Xr loader.conf 5 :
46.Bd -literal -offset indent
47aesni_load="YES"
48.Ed
49.Sh DESCRIPTION
50Starting with some models of Core i5/i7, Intel processors implement
51a new set of instructions called AESNI.
52The set of six instructions accelerates the calculation of the key
53schedule for key lengths of 128, 192, and 256 of the Advanced
54Encryption Standard (AES) symmetric cipher, and provides a hardware
55implementation of the regular and the last encryption and decryption
56rounds.
57.Pp
58The processor capability is reported as AESNI in the Features2 line at boot.
59The
60.Nm
61driver does not attach on systems that lack the required CPU capability.
62.Pp
63The
64.Nm
65driver registers itself to accelerate AES operations for
66.Xr crypto 4 .
67Besides speed, the advantage of using the
68.Nm
69driver is that the AESNI operation
70is data-independent, thus eliminating some attack vectors based on
71measuring cache use and timings typically present in table-driven
72implementations.
73.Sh SEE ALSO
74.Xr crypt 3 ,
75.Xr crypto 4 ,
76.Xr intro 4 ,
77.Xr ipsec 4 ,
78.Xr padlock 4 ,
79.Xr random 4 ,
80.Xr crypto 9
81.Sh HISTORY
82The
83.Nm
84driver first appeared in
85.Fx 9.0 .
86.Sh AUTHORS
87.An -nosplit
88The
89.Nm
90driver was written by
91.An Konstantin Belousov Aq Mt kib@FreeBSD.org .
92The key schedule calculation code was adopted from the sample provided
93by Intel and used in the analogous
94.Ox
95driver.
96