// SPDX-License-Identifier: GPL-2.0 /* * ARM64 NEON-accelerated implementation of Speck128-XTS and Speck64-XTS * * Copyright (c) 2018 Google, Inc * * Author: Eric Biggers */ #include .text // arguments ROUND_KEYS .req x0 // const {u64,u32} *round_keys NROUNDS .req w1 // int nrounds NROUNDS_X .req x1 DST .req x2 // void *dst SRC .req x3 // const void *src NBYTES .req w4 // unsigned int nbytes TWEAK .req x5 // void *tweak // registers which hold the data being encrypted/decrypted // (underscores avoid a naming collision with ARM64 registers x0-x3) X_0 .req v0 Y_0 .req v1 X_1 .req v2 Y_1 .req v3 X_2 .req v4 Y_2 .req v5 X_3 .req v6 Y_3 .req v7 // the round key, duplicated in all lanes ROUND_KEY .req v8 // index vector for tbl-based 8-bit rotates ROTATE_TABLE .req v9 ROTATE_TABLE_Q .req q9 // temporary registers TMP0 .req v10 TMP1 .req v11 TMP2 .req v12 TMP3 .req v13 // multiplication table for updating XTS tweaks GFMUL_TABLE .req v14 GFMUL_TABLE_Q .req q14 // next XTS tweak value(s) TWEAKV_NEXT .req v15 // XTS tweaks for the blocks currently being encrypted/decrypted TWEAKV0 .req v16 TWEAKV1 .req v17 TWEAKV2 .req v18 TWEAKV3 .req v19 TWEAKV4 .req v20 TWEAKV5 .req v21 TWEAKV6 .req v22 TWEAKV7 .req v23 .align 4 .Lror64_8_table: .octa 0x080f0e0d0c0b0a090007060504030201 .Lror32_8_table: .octa 0x0c0f0e0d080b0a090407060500030201 .Lrol64_8_table: .octa 0x0e0d0c0b0a09080f0605040302010007 .Lrol32_8_table: .octa 0x0e0d0c0f0a09080b0605040702010003 .Lgf128mul_table: .octa 0x00000000000000870000000000000001 .Lgf64mul_table: .octa 0x0000000000000000000000002d361b00 /* * _speck_round_128bytes() - Speck encryption round on 128 bytes at a time * * Do one Speck encryption round on the 128 bytes (8 blocks for Speck128, 16 for * Speck64) stored in X0-X3 and Y0-Y3, using the round key stored in all lanes * of ROUND_KEY. 'n' is the lane size: 64 for Speck128, or 32 for Speck64. * 'lanes' is the lane specifier: "2d" for Speck128 or "4s" for Speck64. */ .macro _speck_round_128bytes n, lanes // x = ror(x, 8) tbl X_0.16b, {X_0.16b}, ROTATE_TABLE.16b tbl X_1.16b, {X_1.16b}, ROTATE_TABLE.16b tbl X_2.16b, {X_2.16b}, ROTATE_TABLE.16b tbl X_3.16b, {X_3.16b}, ROTATE_TABLE.16b // x += y add X_0.\lanes, X_0.\lanes, Y_0.\lanes add X_1.\lanes, X_1.\lanes, Y_1.\lanes add X_2.\lanes, X_2.\lanes, Y_2.\lanes add X_3.\lanes, X_3.\lanes, Y_3.\lanes // x ^= k eor X_0.16b, X_0.16b, ROUND_KEY.16b eor X_1.16b, X_1.16b, ROUND_KEY.16b eor X_2.16b, X_2.16b, ROUND_KEY.16b eor X_3.16b, X_3.16b, ROUND_KEY.16b // y = rol(y, 3) shl TMP0.\lanes, Y_0.\lanes, #3 shl TMP1.\lanes, Y_1.\lanes, #3 shl TMP2.\lanes, Y_2.\lanes, #3 shl TMP3.\lanes, Y_3.\lanes, #3 sri TMP0.\lanes, Y_0.\lanes, #(\n - 3) sri TMP1.\lanes, Y_1.\lanes, #(\n - 3) sri TMP2.\lanes, Y_2.\lanes, #(\n - 3) sri TMP3.\lanes, Y_3.\lanes, #(\n - 3) // y ^= x eor Y_0.16b, TMP0.16b, X_0.16b eor Y_1.16b, TMP1.16b, X_1.16b eor Y_2.16b, TMP2.16b, X_2.16b eor Y_3.16b, TMP3.16b, X_3.16b .endm /* * _speck_unround_128bytes() - Speck decryption round on 128 bytes at a time * * This is the inverse of _speck_round_128bytes(). */ .macro _speck_unround_128bytes n, lanes // y ^= x eor TMP0.16b, Y_0.16b, X_0.16b eor TMP1.16b, Y_1.16b, X_1.16b eor TMP2.16b, Y_2.16b, X_2.16b eor TMP3.16b, Y_3.16b, X_3.16b // y = ror(y, 3) ushr Y_0.\lanes, TMP0.\lanes, #3 ushr Y_1.\lanes, TMP1.\lanes, #3 ushr Y_2.\lanes, TMP2.\lanes, #3 ushr Y_3.\lanes, TMP3.\lanes, #3 sli Y_0.\lanes, TMP0.\lanes, #(\n - 3) sli Y_1.\lanes, TMP1.\lanes, #(\n - 3) sli Y_2.\lanes, TMP2.\lanes, #(\n - 3) sli Y_3.\lanes, TMP3.\lanes, #(\n - 3) // x ^= k eor X_0.16b, X_0.16b, ROUND_KEY.16b eor X_1.16b, X_1.16b, ROUND_KEY.16b eor X_2.16b, X_2.16b, ROUND_KEY.16b eor X_3.16b, X_3.16b, ROUND_KEY.16b // x -= y sub X_0.\lanes, X_0.\lanes, Y_0.\lanes sub X_1.\lanes, X_1.\lanes, Y_1.\lanes sub X_2.\lanes, X_2.\lanes, Y_2.\lanes sub X_3.\lanes, X_3.\lanes, Y_3.\lanes // x = rol(x, 8) tbl X_0.16b, {X_0.16b}, ROTATE_TABLE.16b tbl X_1.16b, {X_1.16b}, ROTATE_TABLE.16b tbl X_2.16b, {X_2.16b}, ROTATE_TABLE.16b tbl X_3.16b, {X_3.16b}, ROTATE_TABLE.16b .endm .macro _next_xts_tweak next, cur, tmp, n .if \n == 64 /* * Calculate the next tweak by multiplying the current one by x, * modulo p(x) = x^128 + x^7 + x^2 + x + 1. */ sshr \tmp\().2d, \cur\().2d, #63 and \tmp\().16b, \tmp\().16b, GFMUL_TABLE.16b shl \next\().2d, \cur\().2d, #1 ext \tmp\().16b, \tmp\().16b, \tmp\().16b, #8 eor \next\().16b, \next\().16b, \tmp\().16b .else /* * Calculate the next two tweaks by multiplying the current ones by x^2, * modulo p(x) = x^64 + x^4 + x^3 + x + 1. */ ushr \tmp\().2d, \cur\().2d, #62 shl \next\().2d, \cur\().2d, #2 tbl \tmp\().16b, {GFMUL_TABLE.16b}, \tmp\().16b eor \next\().16b, \next\().16b, \tmp\().16b .endif .endm /* * _speck_xts_crypt() - Speck-XTS encryption/decryption * * Encrypt or decrypt NBYTES bytes of data from the SRC buffer to the DST buffer * using Speck-XTS, specifically the variant with a block size of '2n' and round * count given by NROUNDS. The expanded round keys are given in ROUND_KEYS, and * the current XTS tweak value is given in TWEAK. It's assumed that NBYTES is a * nonzero multiple of 128. */ .macro _speck_xts_crypt n, lanes, decrypting /* * If decrypting, modify the ROUND_KEYS parameter to point to the last * round key rather than the first, since for decryption the round keys * are used in reverse order. */ .if \decrypting mov NROUNDS, NROUNDS /* zero the high 32 bits */ .if \n == 64 add ROUND_KEYS, ROUND_KEYS, NROUNDS_X, lsl #3 sub ROUND_KEYS, ROUND_KEYS, #8 .else add ROUND_KEYS, ROUND_KEYS, NROUNDS_X, lsl #2 sub ROUND_KEYS, ROUND_KEYS, #4 .endif .endif // Load the index vector for tbl-based 8-bit rotates .if \decrypting ldr ROTATE_TABLE_Q, .Lrol\n\()_8_table .else ldr ROTATE_TABLE_Q, .Lror\n\()_8_table .endif // One-time XTS preparation .if \n == 64 // Load first tweak ld1 {TWEAKV0.16b}, [TWEAK] // Load GF(2^128) multiplication table ldr GFMUL_TABLE_Q, .Lgf128mul_table .else // Load first tweak ld1 {TWEAKV0.8b}, [TWEAK] // Load GF(2^64) multiplication table ldr GFMUL_TABLE_Q, .Lgf64mul_table // Calculate second tweak, packing it together with the first ushr TMP0.2d, TWEAKV0.2d, #63 shl TMP1.2d, TWEAKV0.2d, #1 tbl TMP0.8b, {GFMUL_TABLE.16b}, TMP0.8b eor TMP0.8b, TMP0.8b, TMP1.8b mov TWEAKV0.d[1], TMP0.d[0] .endif .Lnext_128bytes_\@: // Calculate XTS tweaks for next 128 bytes _next_xts_tweak TWEAKV1, TWEAKV0, TMP0, \n _next_xts_tweak TWEAKV2, TWEAKV1, TMP0, \n _next_xts_tweak TWEAKV3, TWEAKV2, TMP0, \n _next_xts_tweak TWEAKV4, TWEAKV3, TMP0, \n _next_xts_tweak TWEAKV5, TWEAKV4, TMP0, \n _next_xts_tweak TWEAKV6, TWEAKV5, TMP0, \n _next_xts_tweak TWEAKV7, TWEAKV6, TMP0, \n _next_xts_tweak TWEAKV_NEXT, TWEAKV7, TMP0, \n // Load the next source blocks into {X,Y}[0-3] ld1 {X_0.16b-Y_1.16b}, [SRC], #64 ld1 {X_2.16b-Y_3.16b}, [SRC], #64 // XOR the source blocks with their XTS tweaks eor TMP0.16b, X_0.16b, TWEAKV0.16b eor Y_0.16b, Y_0.16b, TWEAKV1.16b eor TMP1.16b, X_1.16b, TWEAKV2.16b eor Y_1.16b, Y_1.16b, TWEAKV3.16b eor TMP2.16b, X_2.16b, TWEAKV4.16b eor Y_2.16b, Y_2.16b, TWEAKV5.16b eor TMP3.16b, X_3.16b, TWEAKV6.16b eor Y_3.16b, Y_3.16b, TWEAKV7.16b /* * De-interleave the 'x' and 'y' elements of each block, i.e. make it so * that the X[0-3] registers contain only the second halves of blocks, * and the Y[0-3] registers contain only the first halves of blocks. * (Speck uses the order (y, x) rather than the more intuitive (x, y).) */ uzp2 X_0.\lanes, TMP0.\lanes, Y_0.\lanes uzp1 Y_0.\lanes, TMP0.\lanes, Y_0.\lanes uzp2 X_1.\lanes, TMP1.\lanes, Y_1.\lanes uzp1 Y_1.\lanes, TMP1.\lanes, Y_1.\lanes uzp2 X_2.\lanes, TMP2.\lanes, Y_2.\lanes uzp1 Y_2.\lanes, TMP2.\lanes, Y_2.\lanes uzp2 X_3.\lanes, TMP3.\lanes, Y_3.\lanes uzp1 Y_3.\lanes, TMP3.\lanes, Y_3.\lanes // Do the cipher rounds mov x6, ROUND_KEYS mov w7, NROUNDS .Lnext_round_\@: .if \decrypting ld1r {ROUND_KEY.\lanes}, [x6] sub x6, x6, #( \n / 8 ) _speck_unround_128bytes \n, \lanes .else ld1r {ROUND_KEY.\lanes}, [x6], #( \n / 8 ) _speck_round_128bytes \n, \lanes .endif subs w7, w7, #1 bne .Lnext_round_\@ // Re-interleave the 'x' and 'y' elements of each block zip1 TMP0.\lanes, Y_0.\lanes, X_0.\lanes zip2 Y_0.\lanes, Y_0.\lanes, X_0.\lanes zip1 TMP1.\lanes, Y_1.\lanes, X_1.\lanes zip2 Y_1.\lanes, Y_1.\lanes, X_1.\lanes zip1 TMP2.\lanes, Y_2.\lanes, X_2.\lanes zip2 Y_2.\lanes, Y_2.\lanes, X_2.\lanes zip1 TMP3.\lanes, Y_3.\lanes, X_3.\lanes zip2 Y_3.\lanes, Y_3.\lanes, X_3.\lanes // XOR the encrypted/decrypted blocks with the tweaks calculated earlier eor X_0.16b, TMP0.16b, TWEAKV0.16b eor Y_0.16b, Y_0.16b, TWEAKV1.16b eor X_1.16b, TMP1.16b, TWEAKV2.16b eor Y_1.16b, Y_1.16b, TWEAKV3.16b eor X_2.16b, TMP2.16b, TWEAKV4.16b eor Y_2.16b, Y_2.16b, TWEAKV5.16b eor X_3.16b, TMP3.16b, TWEAKV6.16b eor Y_3.16b, Y_3.16b, TWEAKV7.16b mov TWEAKV0.16b, TWEAKV_NEXT.16b // Store the ciphertext in the destination buffer st1 {X_0.16b-Y_1.16b}, [DST], #64 st1 {X_2.16b-Y_3.16b}, [DST], #64 // Continue if there are more 128-byte chunks remaining subs NBYTES, NBYTES, #128 bne .Lnext_128bytes_\@ // Store the next tweak and return .if \n == 64 st1 {TWEAKV_NEXT.16b}, [TWEAK] .else st1 {TWEAKV_NEXT.8b}, [TWEAK] .endif ret .endm ENTRY(speck128_xts_encrypt_neon) _speck_xts_crypt n=64, lanes=2d, decrypting=0 ENDPROC(speck128_xts_encrypt_neon) ENTRY(speck128_xts_decrypt_neon) _speck_xts_crypt n=64, lanes=2d, decrypting=1 ENDPROC(speck128_xts_decrypt_neon) ENTRY(speck64_xts_encrypt_neon) _speck_xts_crypt n=32, lanes=4s, decrypting=0 ENDPROC(speck64_xts_encrypt_neon) ENTRY(speck64_xts_decrypt_neon) _speck_xts_crypt n=32, lanes=4s, decrypting=1 ENDPROC(speck64_xts_decrypt_neon)