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CRYPTO(7) FreeBSD Miscellaneous Information Manual CRYPTO(7) NAME crypto - OpenCrypto algorithms DESCRIPTION The in-kernel OpenCrypto framework supports several different encryption and authentication algorithms. This document describes the parameters and requirements of these algorithms. Unless otherwise noted, all sizes listed below are in bytes. Authenticators Authenticators compute a value (also known as a digest, hash, or tag) over an input of bytes. In-kernel requests can either compute the value for a given input, or verify if a given tag matches the computed tag for a given input. The following authentication algorithms are supported: Name Nonce Key Sizes Digest Description CRYPTO_AES_CCM_CBC_MAC 12 16, 24, 32 16 Authentication- only mode of AES-CCM CRYPTO_AES_NIST_GMAC 12 16, 24, 32 16 Galois message authentication code CRYPTO_BLAKE2B 0, 64 64 Blake2b CRYPTO_BLAKE2S 0, 32 32 Blake2s CRYPTO_NULL_HMAC 12 IPsec NULL HMAC CRYPTO_POLY1305 32 16 Poly1305 authenticator CRYPTO_RIPEMD160 20 RIPE Message Digest-160 CRYPTO_RIPEMD160_HMAC 64 20 RIPE Message Digest-160 HMAC CRYPTO_SHA1 20 SHA-1 CRYPTO_SHA1_HMAC 64 20 SHA-1 HMAC CRYPTO_SHA2_224 28 SHA-2 224 CRYPTO_SHA2_224_HMAC 64 28 SHA-2 224 HMAC CRYPTO_SHA2_256 32 SHA-2 256 CRYPTO_SHA2_256_HMAC 64 32 SHA-2 256 HMAC CRYPTO_SHA2_384 48 SHA-2 384 CRYPTO_SHA2_384_HMAC 128 48 SHA-2 384 HMAC CRYPTO_SHA2_512 64 SHA-2 512 CRYPTO_SHA2_512_HMAC 128 64 SHA-2 512 HMAC Block Ciphers Block ciphers in OCF can only operate on messages whose length is an exact multiple of the cipher's block size. OCF supports the following block ciphers: Name IV Size Block Size Key Sizes Description CRYPTO_AES_CBC 16 16 16, 24, 32 AES-CBC CRYPTO_AES_XTS 8 16 32, 64 AES-XTS CRYPTO_CAMELLIA_CBC 16 16 16, 24, 32 Camellia CBC CRYPTO_NULL_CBC 0 4 0-256 IPsec NULL cipher CRYPTO_AES_XTS implements XEX Tweakable Block Cipher with Ciphertext Stealing as defined in NIST SP 800-38E. OCF consumers provide the first Stream Ciphers Stream ciphers can operate on messages with arbitrary lengths. OCF supports the following stream ciphers: Name IV Size Key Sizes Description CRYPTO_AES_ICM 16 16, 24, 32 AES Counter Mode CRYPTO_CHACHA20 16 16, 32 ChaCha20 The IV for each request must be provided in crp_iv via the CRYPTO_F_IV_SEPARATE flag. CRYPTO_AES_ICM uses the entire IV as a 128-bit big endian block counter. The IV sets the initial counter value for a message. If a consumer wishes to use an IV whose value is split into separate nonce and counter fields (e.g., IPsec), the consumer is responsible for splitting requests to handle counter rollover. CRYPTO_CHACHA20 accepts a 16 byte IV. The first 8 bytes are used as a nonce. The last 8 bytes are used as a 64-bit little-endian block counter. Authenticated Encryption with Associated Data Algorithms AEAD algorithms in OCF combine a stream cipher with an authentication algorithm to provide both secrecy and authentication. AEAD algorithms accept additional authentication data (AAD) in addition to the ciphertext or plaintext. AAD is passed to the authentication algorithm as input in a method defined by the specific AEAD algorithm. AEAD algorithms in OCF accept a nonce that is combined with an algorithm- defined counter to construct the IV for the underlying stream cipher. This nonce must be provided in crp_iv via the CRYPTO_F_IV_SEPARATE flag. Some AEAD algorithms support multiple nonce sizes. The first size listed is the default nonce size. The following AEAD algorithms are supported: Name Nonce Key Sizes Tag Description CRYPTO_AES_NIST_GCM_16 12 16, 24, 32 16 AES Galois/Counter Mode CRYPTO_AES_CCM_16 12, 7-13 16, 24, 32 16 AES Counter with CBC-MAC CRYPTO_CHACHA20_POLY1305 12, 8 32 16 ChaCha20-Poly1305 CRYPTO_XCHACHA20_POLY1305 24 32 16 XChaCha20-Poly1305 SEE ALSO crypto(4), crypto(9) HISTORY The crypto manual page first appeared in FreeBSD 10.1. FreeBSD 14.0-RELEASE-p6 January 11, 2022 FreeBSD 14.0-RELEASE-p6