xref: /freebsd/share/man/man4/aesni.4 (revision bae28eaa8d26ddd67e9af51979f1a54599e9b3a8)
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25.\" $FreeBSD$
26.\"
27.Dd September 6, 2010
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 aesni"
40.Ed
41.Pp
42Alternatively, to load the driver as a
43module at boot time, place the following line in
44.Xr loader.conf 5 :
45.Bd -literal -offset indent
46aesni_load="YES"
47.Ed
48.Sh DESCRIPTION
49Starting with some models of Core i5/i7, Intel processors implement
50a new set of instructions called AESNI.
51The set of six instructions accelerates the calculation of the key
52schedule for key lengths of 128, 192, and 256 of the Advanced
53Encryption Standard (AES) symmetric cipher, and provides a hardware
54implementation of the regular and the last encryption and decryption
55rounds.
56.Pp
57The processor capability is reported as AESNI in the Features2 line at boot.
58The
59.Nm
60driver does not attach on systems that lack the required CPU capability.
61.Pp
62The
63.Nm
64driver registers itself to accelerate AES operations for
65.Xr crypto 4 .
66Besides speed, the advantage of using the
67.Nm
68driver is that the AESNI operation
69is data-independent, thus eliminating some attack vectors based on
70measuring cache use and timings typically present in table-driven
71implementations.
72.Sh SEE ALSO
73.Xr crypt 3 ,
74.Xr crypto 4 ,
75.Xr intro 4 ,
76.Xr ipsec 4 ,
77.Xr padlock 4 ,
78.Xr random 4 ,
79.Xr crypto 9
80.Sh HISTORY
81The
82.Nm
83driver first appeared in
84.Fx 9.0 .
85.Sh AUTHORS
86.An -nosplit
87The
88.Nm
89driver was written by
90.An Konstantin Belousov Aq Mt kib@FreeBSD.org .
91The key schedule calculation code was adopted from the sample provided
92by Intel and used in the analogous
93.Ox
94driver.
95