From ede9622162fac42eacde231d64e94c926f4be45d Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Wed, 14 Feb 2018 10:42:21 -0800 Subject: crypto: arm/speck - add NEON-accelerated implementation of Speck-XTS Add an ARM NEON-accelerated implementation of Speck-XTS. It operates on 128-byte chunks at a time, i.e. 8 blocks for Speck128 or 16 blocks for Speck64. Each 128-byte chunk goes through XTS preprocessing, then is encrypted/decrypted (doing one cipher round for all the blocks, then the next round, etc.), then goes through XTS postprocessing. The performance depends on the processor but can be about 3 times faster than the generic code. For example, on an ARMv7 processor we observe the following performance with Speck128/256-XTS: xts-speck128-neon: Encryption 107.9 MB/s, Decryption 108.1 MB/s xts(speck128-generic): Encryption 32.1 MB/s, Decryption 36.6 MB/s In comparison to AES-256-XTS without the Cryptography Extensions: xts-aes-neonbs: Encryption 41.2 MB/s, Decryption 36.7 MB/s xts(aes-asm): Encryption 31.7 MB/s, Decryption 30.8 MB/s xts(aes-generic): Encryption 21.2 MB/s, Decryption 20.9 MB/s Speck64/128-XTS is even faster: xts-speck64-neon: Encryption 138.6 MB/s, Decryption 139.1 MB/s Note that as with the generic code, only the Speck128 and Speck64 variants are supported. Also, for now only the XTS mode of operation is supported, to target the disk and file encryption use cases. The NEON code also only handles the portion of the data that is evenly divisible into 128-byte chunks, with any remainder handled by a C fallback. Of course, other modes of operation could be added later if needed, and/or the NEON code could be updated to handle other buffer sizes. The XTS specification is only defined for AES which has a 128-bit block size, so for the GF(2^64) math needed for Speck64-XTS we use the reducing polynomial 'x^64 + x^4 + x^3 + x + 1' given by the original XEX paper. Of course, when possible users should use Speck128-XTS, but even that may be too slow on some processors; Speck64-XTS can be faster. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu --- arch/arm/crypto/Kconfig | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/arm/crypto/Kconfig') diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig index b8e69fe282b8..925d1364727a 100644 --- a/arch/arm/crypto/Kconfig +++ b/arch/arm/crypto/Kconfig @@ -121,4 +121,10 @@ config CRYPTO_CHACHA20_NEON select CRYPTO_BLKCIPHER select CRYPTO_CHACHA20 +config CRYPTO_SPECK_NEON + tristate "NEON accelerated Speck cipher algorithms" + depends on KERNEL_MODE_NEON + select CRYPTO_BLKCIPHER + select CRYPTO_SPECK + endif -- cgit v1.2.3