On Tue, 25 Jan 2022 at 02:47, Nathan Huckleberry <nhuck@xxxxxxxxxx> wrote: > > Add hardware accelerated version of XCTR for ARM64 CPUs with ARMv8 > Crypto Extension support. This XCTR implementation is based on the CTR > implementation in aes-modes.S. > > More information on XCTR can be found in > the HCTR2 paper: Length-preserving encryption with HCTR2: > https://eprint.iacr.org/2021/1441.pdf > > Signed-off-by: Nathan Huckleberry <nhuck@xxxxxxxxxx> > --- > arch/arm64/crypto/Kconfig | 4 +- > arch/arm64/crypto/aes-glue.c | 70 ++++++++++++++++++- > arch/arm64/crypto/aes-modes.S | 128 ++++++++++++++++++++++++++++++++++ > 3 files changed, 198 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig > index addfa413650b..cab469e279ec 100644 > --- a/arch/arm64/crypto/Kconfig > +++ b/arch/arm64/crypto/Kconfig > @@ -84,13 +84,13 @@ config CRYPTO_AES_ARM64_CE_CCM > select CRYPTO_LIB_AES > > config CRYPTO_AES_ARM64_CE_BLK > - tristate "AES in ECB/CBC/CTR/XTS modes using ARMv8 Crypto Extensions" > + tristate "AES in ECB/CBC/CTR/XTS/XCTR modes using ARMv8 Crypto Extensions" > depends on KERNEL_MODE_NEON > select CRYPTO_SKCIPHER > select CRYPTO_AES_ARM64_CE > > config CRYPTO_AES_ARM64_NEON_BLK > - tristate "AES in ECB/CBC/CTR/XTS modes using NEON instructions" > + tristate "AES in ECB/CBC/CTR/XTS/XCTR modes using NEON instructions" > depends on KERNEL_MODE_NEON > select CRYPTO_SKCIPHER > select CRYPTO_LIB_AES > diff --git a/arch/arm64/crypto/aes-glue.c b/arch/arm64/crypto/aes-glue.c > index 30b7cc6a7079..377f8d8369fb 100644 > --- a/arch/arm64/crypto/aes-glue.c > +++ b/arch/arm64/crypto/aes-glue.c > @@ -35,10 +35,11 @@ > #define aes_essiv_cbc_encrypt ce_aes_essiv_cbc_encrypt > #define aes_essiv_cbc_decrypt ce_aes_essiv_cbc_decrypt > #define aes_ctr_encrypt ce_aes_ctr_encrypt > +#define aes_xctr_encrypt ce_aes_xctr_encrypt > #define aes_xts_encrypt ce_aes_xts_encrypt > #define aes_xts_decrypt ce_aes_xts_decrypt > #define aes_mac_update ce_aes_mac_update > -MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS using ARMv8 Crypto Extensions"); > +MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS/XCTR using ARMv8 Crypto Extensions"); > #else > #define MODE "neon" > #define PRIO 200 > @@ -52,16 +53,18 @@ MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS using ARMv8 Crypto Extensions"); > #define aes_essiv_cbc_encrypt neon_aes_essiv_cbc_encrypt > #define aes_essiv_cbc_decrypt neon_aes_essiv_cbc_decrypt > #define aes_ctr_encrypt neon_aes_ctr_encrypt > +#define aes_xctr_encrypt neon_aes_xctr_encrypt > #define aes_xts_encrypt neon_aes_xts_encrypt > #define aes_xts_decrypt neon_aes_xts_decrypt > #define aes_mac_update neon_aes_mac_update > -MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS using ARMv8 NEON"); > +MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS/XCTR using ARMv8 NEON"); > #endif > #if defined(USE_V8_CRYPTO_EXTENSIONS) || !IS_ENABLED(CONFIG_CRYPTO_AES_ARM64_BS) > MODULE_ALIAS_CRYPTO("ecb(aes)"); > MODULE_ALIAS_CRYPTO("cbc(aes)"); > MODULE_ALIAS_CRYPTO("ctr(aes)"); > MODULE_ALIAS_CRYPTO("xts(aes)"); > +MODULE_ALIAS_CRYPTO("xctr(aes)"); > #endif > MODULE_ALIAS_CRYPTO("cts(cbc(aes))"); > MODULE_ALIAS_CRYPTO("essiv(cbc(aes),sha256)"); > @@ -91,6 +94,10 @@ asmlinkage void aes_cbc_cts_decrypt(u8 out[], u8 const in[], u32 const rk[], > asmlinkage void aes_ctr_encrypt(u8 out[], u8 const in[], u32 const rk[], > int rounds, int bytes, u8 ctr[], u8 finalbuf[]); > > +asmlinkage void aes_xctr_encrypt(u8 out[], u8 const in[], u32 const rk[], > + int rounds, int bytes, u8 ctr[], u8 finalbuf[], > + int byte_ctr); > + > asmlinkage void aes_xts_encrypt(u8 out[], u8 const in[], u32 const rk1[], > int rounds, int bytes, u32 const rk2[], u8 iv[], > int first); > @@ -444,6 +451,49 @@ static int __maybe_unused essiv_cbc_decrypt(struct skcipher_request *req) > return err ?: cbc_decrypt_walk(req, &walk); > } > > +static int __maybe_unused xctr_encrypt(struct skcipher_request *req) > +{ > + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); > + struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm); > + int err, rounds = 6 + ctx->key_length / 4; > + struct skcipher_walk walk; > + unsigned int byte_ctr = 0; > + > + err = skcipher_walk_virt(&walk, req, false); > + > + while (walk.nbytes > 0) { > + const u8 *src = walk.src.virt.addr; > + unsigned int nbytes = walk.nbytes; > + u8 *dst = walk.dst.virt.addr; > + u8 buf[AES_BLOCK_SIZE]; > + unsigned int tail; > + > + if (unlikely(nbytes < AES_BLOCK_SIZE)) > + src = memcpy(buf, src, nbytes); > + else if (nbytes < walk.total) > + nbytes &= ~(AES_BLOCK_SIZE - 1); > + > + kernel_neon_begin(); > + aes_xctr_encrypt(dst, src, ctx->key_enc, rounds, nbytes, > + walk.iv, buf, byte_ctr); > + kernel_neon_end(); > + > + tail = nbytes % (STRIDE * AES_BLOCK_SIZE); > + if (tail > 0 && tail < AES_BLOCK_SIZE) > + /* > + * The final partial block could not be returned using > + * an overlapping store, so it was passed via buf[] > + * instead. > + */ > + memcpy(dst + nbytes - tail, buf, tail); I have a patch [0] that elides this memcpy() for the CTR routine if the input is more than a block. It's independent of this one, of course, but for symmetry, it would make sense to do the same. [0] https://lore.kernel.org/r/20220127095211.3481959-1-ardb@xxxxxxxxxx > > + byte_ctr += nbytes; > + > + err = skcipher_walk_done(&walk, walk.nbytes - nbytes); > + } > + > + return err; > +} > + > static int __maybe_unused ctr_encrypt(struct skcipher_request *req) > { > struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); > @@ -676,6 +726,22 @@ static struct skcipher_alg aes_algs[] = { { > .setkey = skcipher_aes_setkey, > .encrypt = ctr_encrypt, > .decrypt = ctr_encrypt, > +}, { > + .base = { > + .cra_name = "xctr(aes)", > + .cra_driver_name = "xctr-aes-" MODE, > + .cra_priority = PRIO, > + .cra_blocksize = 1, > + .cra_ctxsize = sizeof(struct crypto_aes_ctx), > + .cra_module = THIS_MODULE, > + }, > + .min_keysize = AES_MIN_KEY_SIZE, > + .max_keysize = AES_MAX_KEY_SIZE, > + .ivsize = AES_BLOCK_SIZE, > + .chunksize = AES_BLOCK_SIZE, > + .setkey = skcipher_aes_setkey, > + .encrypt = xctr_encrypt, > + .decrypt = xctr_encrypt, > }, { > .base = { > .cra_name = "xts(aes)", > diff --git a/arch/arm64/crypto/aes-modes.S b/arch/arm64/crypto/aes-modes.S > index ff01f0167ba2..7128907f8190 100644 > --- a/arch/arm64/crypto/aes-modes.S > +++ b/arch/arm64/crypto/aes-modes.S > @@ -471,6 +471,134 @@ ST5( mov v3.16b, v4.16b ) > b .Lctrout > AES_FUNC_END(aes_ctr_encrypt) > > + /* > + * aes_xctr_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds, > + * int bytes, u8 const ctr[], u8 finalbuf[], int byte_ctr) > + */ > + > +AES_FUNC_START(aes_xctr_encrypt) > + stp x29, x30, [sp, #-16]! > + mov x29, sp > + > + enc_prepare w3, x2, x12 > + ld1 {vctr.16b}, [x5] > + > + umov x12, vctr.d[0] /* keep ctr in reg */ > + lsr x7, x7, #4 > + add x11, x7, #1 > + > +.LxctrloopNx: > + add w7, w4, #15 > + sub w4, w4, #MAX_STRIDE << 4 > + lsr w7, w7, #4 > + mov w8, #MAX_STRIDE > + cmp w7, w8 > + csel w7, w7, w8, lt > + add x11, x11, x7 > + > + mov v0.16b, vctr.16b > + mov v1.16b, vctr.16b > + mov v2.16b, vctr.16b > + mov v3.16b, vctr.16b > +ST5( mov v4.16b, vctr.16b ) > + > + sub x7, x11, #MAX_STRIDE > + eor x7, x12, x7 > + ins v0.d[0], x7 > + sub x7, x11, #MAX_STRIDE - 1 > + sub x8, x11, #MAX_STRIDE - 2 > + eor x7, x7, x12 > + sub x9, x11, #MAX_STRIDE - 3 > + mov v1.d[0], x7 > + eor x8, x8, x12 > + eor x9, x9, x12 > +ST5( sub x10, x11, #MAX_STRIDE - 4) > + mov v2.d[0], x8 > + eor x10, x10, x12 > + mov v3.d[0], x9 > +ST5( mov v4.d[0], x10 ) > + tbnz w4, #31, .Lxctrtail > + ld1 {v5.16b-v7.16b}, [x1], #48 > +ST4( bl aes_encrypt_block4x ) > +ST5( bl aes_encrypt_block5x ) > + eor v0.16b, v5.16b, v0.16b > +ST4( ld1 {v5.16b}, [x1], #16 ) > + eor v1.16b, v6.16b, v1.16b > +ST5( ld1 {v5.16b-v6.16b}, [x1], #32 ) > + eor v2.16b, v7.16b, v2.16b > + eor v3.16b, v5.16b, v3.16b > +ST5( eor v4.16b, v6.16b, v4.16b ) > + st1 {v0.16b-v3.16b}, [x0], #64 > +ST5( st1 {v4.16b}, [x0], #16 ) > + cbz w4, .Lxctrout > + b .LxctrloopNx > + > +.Lxctrout: > + ldp x29, x30, [sp], #16 > + ret > + > +.Lxctrtail: > + /* XOR up to MAX_STRIDE * 16 - 1 bytes of in/output with v0 ... v3/v4 */ > + mov x17, #16 > + ands x13, x4, #0xf > + csel x13, x13, x17, ne > + > +ST5( cmp w4, #64 - (MAX_STRIDE << 4)) > +ST5( csel x14, x17, xzr, gt ) > + cmp w4, #48 - (MAX_STRIDE << 4) > + csel x15, x17, xzr, gt > + cmp w4, #32 - (MAX_STRIDE << 4) > + csel x16, x17, xzr, gt > + cmp w4, #16 - (MAX_STRIDE << 4) > + ble .Lxctrtail1x > + > +ST5( mov v4.d[0], x10 ) > + > + adr_l x12, .Lcts_permute_table > + add x12, x12, x13 > + > +ST5( ld1 {v5.16b}, [x1], x14 ) > + ld1 {v6.16b}, [x1], x15 > + ld1 {v7.16b}, [x1], x16 > + > +ST4( bl aes_encrypt_block4x ) > +ST5( bl aes_encrypt_block5x ) > + > + ld1 {v8.16b}, [x1], x13 > + ld1 {v9.16b}, [x1] > + ld1 {v10.16b}, [x12] > + > +ST4( eor v6.16b, v6.16b, v0.16b ) > +ST4( eor v7.16b, v7.16b, v1.16b ) > +ST4( tbl v3.16b, {v3.16b}, v10.16b ) > +ST4( eor v8.16b, v8.16b, v2.16b ) > +ST4( eor v9.16b, v9.16b, v3.16b ) > + > +ST5( eor v5.16b, v5.16b, v0.16b ) > +ST5( eor v6.16b, v6.16b, v1.16b ) > +ST5( tbl v4.16b, {v4.16b}, v10.16b ) > +ST5( eor v7.16b, v7.16b, v2.16b ) > +ST5( eor v8.16b, v8.16b, v3.16b ) > +ST5( eor v9.16b, v9.16b, v4.16b ) > + > +ST5( st1 {v5.16b}, [x0], x14 ) > + st1 {v6.16b}, [x0], x15 > + st1 {v7.16b}, [x0], x16 > + add x13, x13, x0 > + st1 {v9.16b}, [x13] // overlapping stores > + st1 {v8.16b}, [x0] > + b .Lxctrout > + > +.Lxctrtail1x: > + csel x0, x0, x6, eq // use finalbuf if less than a full block > + ld1 {v5.16b}, [x1] > +ST5( mov v3.16b, v4.16b ) > + encrypt_block v3, w3, x2, x8, w7 > + eor v5.16b, v5.16b, v3.16b > + st1 {v5.16b}, [x0] > + b .Lxctrout > +AES_FUNC_END(aes_xctr_encrypt) > + > > /* > * aes_xts_encrypt(u8 out[], u8 const in[], u8 const rk1[], int rounds, > -- > 2.35.0.rc0.227.g00780c9af4-goog > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
