xref: /freebsd/share/man/man7/crypto.7 (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
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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