xref: /freebsd/share/man/man7/crypto.7 (revision 77a1348b3c1cfe8547be49a121b56299a1e18b69)
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30.Dd March 27, 2020
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 cipher uses AEAD
72.Pq Authenticated Encryption with Associated Data
73mode.
74.Pp
75The authentication tag will be read/written from/to the offset
76.Va crp_digest_start
77specified in the request.
78.Pp
79Note: You must provide an IV on every call.
80.It Dv CRYPTO_AES_ICM
81.Bl -tag -width "Block size :" -compact -offset indent
82.It IV size :
8316
84.It Block size :
851 (aesni), 16 (software)
86.It Key size :
8716, 24 or 32
88.El
89.Pp
90This algorithm implements Integer Counter Mode.
91This is similar to what most people call counter mode, but instead of the
92counter being split into a nonce and a counter part, then entire nonce is
93used as the initial counter.
94This does mean that if a counter is required that rolls over at 32 bits,
95the transaction need to be split into two parts where the counter rolls over.
96The counter incremented as a 128-bit big endian number.
97.Pp
98Note: You must provide an IV on every call.
99.It Dv CRYPTO_AES_XTS
100.Bl -tag -width "Block size :" -compact -offset indent
101.It IV size :
1028
103.It Block size :
10416
105.It Key size :
10632 or 64
107.El
108.Pp
109This algorithm implements XEX Tweakable Block Cipher with Ciphertext Stealing
110as defined in NIST SP 800-38E.
111.Pp
112NOTE: The ciphertext stealing part is not implemented which is why this cipher
113is listed as having a block size of 16 instead of 1.
114.El
115.Sh SEE ALSO
116.Xr crypto 4 ,
117.Xr crypto 9
118.Sh BUGS
119Not all the implemented algorithms are listed.
120