Manual Pages  — CRYPTO

crypto – OpenCrypto algorithms

SYNOPSIS DESCRIPTION SEE ALSO HISTORY BUGS

In the kernel configuration file: device crypto

Or load the crypto.ko module.

The following cryptographic algorithms that are part of the OpenCrypto framework have the following requirements.

Cipher algorithms:

CRYPTO_AES_CBC

IV size:	16
Block size:	16
Key size:	16, 24 or 32

This algorithm implements Cipher-block chaining.

CRYPTO_AES_NIST_GCM_16
IV size:	12
Block size:	1
Key size:	16, 24 or 32
Digest size:
	16

This algorithm implements Galois/Counter Mode. This is the cipher part of an AEAD (Authenticated Encryption with Associated Data) mode. This requires use of the use of a proper authentication mode, one of CRYPTO_AES_128_NIST_GMAC, CRYPTO_AES_192_NIST_GMAC or CRYPTO_AES_256_NIST_GMAC, that corresponds with the number of bits in the key that you are using.

The associated data (if any) must be provided by the authentication mode op. The authentication tag will be read/written from/to the offset crd_inject specified in the descriptor for the authentication mode.

Note: You must provide an IV on every call.

CRYPTO_AES_ICM
IV size:	16
Block size:	1 (aesni), 16 (software)
Key size:	16, 24 or 32

This algorithm implements Integer Counter Mode. This is similar to what most people call counter mode, but instead of the counter being split into a nonce and a counter part, then entire nonce is used as the initial counter. This does mean that if a counter is required that rolls over at 32 bits, the transaction need to be split into two parts where the counter rolls over. The counter incremented as a 128-bit big endian number.

Note: You must provide an IV on every call.

CRYPTO_AES_XTS
IV size:	8
Block size:	16
Key size:	32 or 64

This algorithm implements XEX Tweakable Block Cipher with Ciphertext Stealing as defined in NIST SP 800-38E.

NOTE: The ciphertext stealing part is not implemented which is why this cipher is listed as having a block size of 16 instead of 1.

Authentication algorithms:

CRYPTO_AES_128_NIST_GMAC
	See CRYPTO_AES_NIST_GCM_16 in the cipher mode section.
CRYPTO_AES_192_NIST_GMAC
	See CRYPTO_AES_NIST_GCM_16 in the cipher mode section.
CRYPTO_AES_256_NIST_GMAC
	See CRYPTO_AES_NIST_GCM_16 in the cipher mode section.

The crypto manpage first appeared in FreeBSD 10.1 .

Not all the implemented algorithms are listed.