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Commit 23a251cc authored by Nathan Huckleberry's avatar Nathan Huckleberry Committed by Herbert Xu
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crypto: arm64/aes-xctr - Add accelerated implementation of XCTR 

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.pdfSigned-off-by: default avatarNathan Huckleberry <nhuck@google.com>
Reviewed-by: default avatarArd Biesheuvel <ardb@kernel.org>
Reviewed-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent fd94fcf0
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Inline Side-by-side
Showing with 168 additions and 66 deletions
arch/arm64/crypto/Kconfig
View file @ 23a251cc
......@@ -96,13 +96,13 @@ 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
......
arch/arm64/crypto/aes-glue.c
View file @ 23a251cc
......@@ -34,10 +34,11 @@
#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
......@@ -50,16 +51,18 @@ 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)");
......@@ -89,6 +92,9 @@ 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[]);
asmlinkage void aes_xctr_encrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int bytes, u8 ctr[], 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);
......@@ -442,6 +448,44 @@ 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];
if (unlikely(nbytes < AES_BLOCK_SIZE))
src = dst = memcpy(buf + sizeof(buf) - nbytes,
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, byte_ctr);
kernel_neon_end();
if (unlikely(nbytes < AES_BLOCK_SIZE))
memcpy(walk.dst.virt.addr,
buf + sizeof(buf) - nbytes, nbytes);
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);
......@@ -669,6 +713,22 @@ 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)",
......
arch/arm64/crypto/aes-modes.S
View file @ 23a251cc
......@@ -318,38 +318,60 @@ AES_FUNC_END(aes_cbc_cts_decrypt)
.byte 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
.previous
/*
* aes_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int bytes, u8 ctr[])
* This macro generates the code for CTR and XCTR mode.
*/
AES_FUNC_START(aes_ctr_encrypt)
.macro ctr_encrypt xctr
stp x29, x30, [sp, #-16]!
mov x29, sp
enc_prepare w3, x2, x12
ld1 {vctr.16b}, [x5]
.if \xctr
umov x12, vctr.d[0]
lsr w11, w6, #4
.else
umov x12, vctr.d[1] /* keep swabbed ctr in reg */
rev x12, x12
.endif
.LctrloopNx:
.LctrloopNx\xctr:
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
adds x12, x12, x7
.if \xctr
add x11, x11, x7
.else
adds x12, x12, x7
.endif
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 )
.if \xctr
sub x6, x11, #MAX_STRIDE - 1
sub x7, x11, #MAX_STRIDE - 2
sub x8, x11, #MAX_STRIDE - 3
sub x9, x11, #MAX_STRIDE - 4
ST5( sub x10, x11, #MAX_STRIDE - 5 )
eor x6, x6, x12
eor x7, x7, x12
eor x8, x8, x12
eor x9, x9, x12
ST5( eor x10, x10, x12 )
mov v0.d[0], x6
mov v1.d[0], x7
mov v2.d[0], x8
mov v3.d[0], x9
ST5( mov v4.d[0], x10 )
.else
bcs 0f
.subsection 1
/* apply carry to outgoing counter */
0: umov x8, vctr.d[0]
......@@ -390,7 +412,8 @@ ST5( sub x10, x12, #MAX_STRIDE - 4 )
ST5( rev x10, x10 )
mov v3.d[1], x9
ST5( mov v4.d[1], x10 )
tbnz w4, #31, .Lctrtail
.endif
tbnz w4, #31, .Lctrtail\xctr
ld1 {v5.16b-v7.16b}, [x1], #48
ST4( bl aes_encrypt_block4x )
ST5( bl aes_encrypt_block5x )
......@@ -403,16 +426,17 @@ ST5( ld1 {v5.16b-v6.16b}, [x1], #32 )
ST5( eor v4.16b, v6.16b, v4.16b )
st1 {v0.16b-v3.16b}, [x0], #64
ST5( st1 {v4.16b}, [x0], #16 )
cbz w4, .Lctrout
b .LctrloopNx
cbz w4, .Lctrout\xctr
b .LctrloopNx\xctr
.Lctrout:
.Lctrout\xctr:
.if !\xctr
st1 {vctr.16b}, [x5] /* return next CTR value */
.endif
ldp x29, x30, [sp], #16
ret
.Lctrtail:
/* XOR up to MAX_STRIDE * 16 - 1 bytes of in/output with v0 ... v3/v4 */
.Lctrtail\xctr:
mov x16, #16
ands x6, x4, #0xf
csel x13, x6, x16, ne
......@@ -427,7 +451,7 @@ ST5( csel x14, x16, xzr, gt )
adr_l x12, .Lcts_permute_table
add x12, x12, x13
ble .Lctrtail1x
ble .Lctrtail1x\xctr
ST5( ld1 {v5.16b}, [x1], x14 )
ld1 {v6.16b}, [x1], x15
......@@ -459,9 +483,9 @@ ST5( st1 {v5.16b}, [x0], x14 )
add x13, x13, x0
st1 {v9.16b}, [x13] // overlapping stores
st1 {v8.16b}, [x0]
b .Lctrout
b .Lctrout\xctr
.Lctrtail1x:
.Lctrtail1x\xctr:
sub x7, x6, #16
csel x6, x6, x7, eq
add x1, x1, x6
......@@ -476,9 +500,27 @@ ST5( mov v3.16b, v4.16b )
eor v5.16b, v5.16b, v3.16b
bif v5.16b, v6.16b, v11.16b
st1 {v5.16b}, [x0]
b .Lctrout
b .Lctrout\xctr
.endm
/*
* aes_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int bytes, u8 ctr[])
*/
AES_FUNC_START(aes_ctr_encrypt)
ctr_encrypt 0
AES_FUNC_END(aes_ctr_encrypt)
/*
* aes_xctr_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int bytes, u8 const iv[], int byte_ctr)
*/
AES_FUNC_START(aes_xctr_encrypt)
ctr_encrypt 1
AES_FUNC_END(aes_xctr_encrypt)
/*
* aes_xts_encrypt(u8 out[], u8 const in[], u8 const rk1[], int rounds,
......
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