xref: /freebsd/share/man/man7/crypto.7 (revision c697fb7f)
1.\" Copyright (c) 2014 The FreeBSD Foundation
2.\" All rights reserved.
3.\"
4.\" This documentation was written by John-Mark Gurney under
5.\" the sponsorship of the FreeBSD Foundation and
6.\" Rubicon Communications, LLC (Netgate).
7.\" Redistribution and use in source and binary forms, with or without
8.\" modification, are permitted provided that the following conditions
9.\" are met:
10.\" 1.  Redistributions of source code must retain the above copyright
11.\"     notice, this list of conditions and the following disclaimer.
12.\" 2.  Redistributions in binary form must reproduce the above copyright
13.\"     notice, this list of conditions and the following disclaimer in the
14.\"     documentation and/or other materials provided with the distribution.
15.\"
16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26.\" SUCH DAMAGE.
27.\"
28.\" $FreeBSD$
29.\"
30.Dd January 2, 2015
31.Dt CRYPTO 7
32.Os
33.Sh NAME
34.Nm crypto
35.Nd OpenCrypto algorithms
36.Sh SYNOPSIS
37In the kernel configuration file:
38.Cd "device crypto"
39.Pp
40Or load the crypto.ko module.
41.Sh DESCRIPTION
42The following cryptographic algorithms that are part of the OpenCrypto
43framework have the following requirements.
44.Pp
45Cipher algorithms:
46.Bl -tag -width ".Dv CRYPTO_AES_CBC"
47.It Dv CRYPTO_AES_CBC
48.Bl -tag -width "Block size :" -compact -offset indent
49.It IV size :
5016
51.It Block size :
5216
53.It Key size :
5416, 24 or 32
55.El
56.Pp
57This algorithm implements Cipher-block chaining.
58.It Dv CRYPTO_AES_NIST_GCM_16
59.Bl -tag -width "Block size :" -compact -offset indent
60.It IV size :
6112
62.It Block size :
631
64.It Key size :
6516, 24 or 32
66.It Digest size :
6716
68.El
69.Pp
70This algorithm implements Galois/Counter Mode.
71This is the cipher part of an AEAD
72.Pq Authenticated Encryption with Associated Data
73mode.
74This requires use of the use of a proper authentication mode, one of
75.Dv CRYPTO_AES_128_NIST_GMAC ,
76.Dv CRYPTO_AES_192_NIST_GMAC
77or
78.Dv CRYPTO_AES_256_NIST_GMAC ,
79that corresponds with the number of bits in the key that you are using.
80.Pp
81The associated data (if any) must be provided by the authentication mode op.
82The authentication tag will be read/written from/to the offset crd_inject
83specified in the descriptor for the authentication mode.
84.Pp
85Note: You must provide an IV on every call.
86.It Dv CRYPTO_AES_ICM
87.Bl -tag -width "Block size :" -compact -offset indent
88.It IV size :
8916
90.It Block size :
911 (aesni), 16 (software)
92.It Key size :
9316, 24 or 32
94.El
95.Pp
96This algorithm implements Integer Counter Mode.
97This is similar to what most people call counter mode, but instead of the
98counter being split into a nonce and a counter part, then entire nonce is
99used as the initial counter.
100This does mean that if a counter is required that rolls over at 32 bits,
101the transaction need to be split into two parts where the counter rolls over.
102The counter incremented as a 128-bit big endian number.
103.Pp
104Note: You must provide an IV on every call.
105.It Dv CRYPTO_AES_XTS
106.Bl -tag -width "Block size :" -compact -offset indent
107.It IV size :
1088
109.It Block size :
11016
111.It Key size :
11232 or 64
113.El
114.Pp
115This algorithm implements XEX Tweakable Block Cipher with Ciphertext Stealing
116as defined in NIST SP 800-38E.
117.Pp
118NOTE: The ciphertext stealing part is not implemented which is why this cipher
119is listed as having a block size of 16 instead of 1.
120.El
121.Pp
122Authentication algorithms:
123.Bl -tag -width ".Dv CRYPTO_AES_256_NIST_GMAC"
124.It CRYPTO_AES_128_NIST_GMAC
125See
126.Dv CRYPTO_AES_NIST_GCM_16
127in the cipher mode section.
128.It CRYPTO_AES_192_NIST_GMAC
129See
130.Dv CRYPTO_AES_NIST_GCM_16
131in the cipher mode section.
132.It CRYPTO_AES_256_NIST_GMAC
133See
134.Dv CRYPTO_AES_NIST_GCM_16
135in the cipher mode section.
136.El
137.Sh SEE ALSO
138.Xr crypto 4 ,
139.Xr crypto 9
140.Sh BUGS
141Not all the implemented algorithms are listed.
142