[PATCH v3 15/15] crypto: x86/aes-kl - Support XTS mode

["Chang S. Bae" <chang.seok.bae@intel.com>]

Implement XTS mode using AES-KL. Export the methods with a lower priority
than AES-NI to avoid from selected by default.

The assembly code clobbers more than eight 128-bit registers to make use of
performant wide instructions that process eight 128-bit blocks at once.
But that many 128-bit registers are not available in 32-bit mode, so
support 64-bit mode only.

Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: x86@kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
Changes from RFC v2:
* Separate out the code as a new patch.
---
 arch/x86/crypto/aeskl-intel_asm.S  | 447 +++++++++++++++++++++++++++++
 arch/x86/crypto/aeskl-intel_glue.c |  74 +++++
 2 files changed, 521 insertions(+)

diff --git a/arch/x86/crypto/aeskl-intel_asm.S b/arch/x86/crypto/aeskl-intel_asm.S
index ffde0cd3dd42..d542324071d4 100644
--- a/arch/x86/crypto/aeskl-intel_asm.S
+++ b/arch/x86/crypto/aeskl-intel_asm.S
@@ -737,3 +737,450 @@ SYM_FUNC_START(_aeskl_ctr_enc)
 	ret
 SYM_FUNC_END(_aeskl_ctr_enc)
 
+/*
+ * XTS implementation
+ */
+
+/*
+ * _aeskl_gf128mul_x_ble: 	internal ABI
+ *	Multiply in GF(2^128) for XTS IVs
+ * input:
+ *	IV:	current IV
+ *	GF128MUL_MASK == mask with 0x87 and 0x01
+ * output:
+ *	IV:	next IV
+ * changed:
+ *	CTR:	== temporary value
+ */
+#define _aeskl_gf128mul_x_ble() \
+	pshufd $0x13, IV, KEY; \
+	paddq IV, IV; \
+	psrad $31, KEY; \
+	pand GF128MUL_MASK, KEY; \
+	pxor KEY, IV;
+
+/*
+ * int _aeskl_xts_encrypt(const struct crypto_aes_ctx *ctx, u8 *dst,
+ *			  const u8 *src, unsigned int len, le128 *iv)
+ */
+SYM_FUNC_START(_aeskl_xts_encrypt)
+	FRAME_BEGIN
+	movdqa .Lgf128mul_x_ble_mask(%rip), GF128MUL_MASK
+	movups (IVP), IV
+
+	mov 480(HANDLEP), KLEN
+
+.Lxts_enc8:
+	sub $128, LEN
+	jl .Lxts_enc1_pre
+
+	movdqa IV, STATE1
+	movdqu (INP), INC
+	pxor INC, STATE1
+	movdqu IV, (OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE2
+	movdqu 0x10(INP), INC
+	pxor INC, STATE2
+	movdqu IV, 0x10(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE3
+	movdqu 0x20(INP), INC
+	pxor INC, STATE3
+	movdqu IV, 0x20(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE4
+	movdqu 0x30(INP), INC
+	pxor INC, STATE4
+	movdqu IV, 0x30(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE5
+	movdqu 0x40(INP), INC
+	pxor INC, STATE5
+	movdqu IV, 0x40(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE6
+	movdqu 0x50(INP), INC
+	pxor INC, STATE6
+	movdqu IV, 0x50(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE7
+	movdqu 0x60(INP), INC
+	pxor INC, STATE7
+	movdqu IV, 0x60(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE8
+	movdqu 0x70(INP), INC
+	pxor INC, STATE8
+	movdqu IV, 0x70(OUTP)
+
+	cmp $16, KLEN
+	je .Lxts_enc8_128
+	aesencwide256kl (%rdi)
+	jz .Lxts_enc_ret_err
+	jmp .Lxts_enc8_end
+.Lxts_enc8_128:
+	aesencwide128kl (%rdi)
+	jz .Lxts_enc_ret_err
+
+.Lxts_enc8_end:
+	movdqu 0x00(OUTP), INC
+	pxor INC, STATE1
+	movdqu STATE1, 0x00(OUTP)
+
+	movdqu 0x10(OUTP), INC
+	pxor INC, STATE2
+	movdqu STATE2, 0x10(OUTP)
+
+	movdqu 0x20(OUTP), INC
+	pxor INC, STATE3
+	movdqu STATE3, 0x20(OUTP)
+
+	movdqu 0x30(OUTP), INC
+	pxor INC, STATE4
+	movdqu STATE4, 0x30(OUTP)
+
+	movdqu 0x40(OUTP), INC
+	pxor INC, STATE5
+	movdqu STATE5, 0x40(OUTP)
+
+	movdqu 0x50(OUTP), INC
+	pxor INC, STATE6
+	movdqu STATE6, 0x50(OUTP)
+
+	movdqu 0x60(OUTP), INC
+	pxor INC, STATE7
+	movdqu STATE7, 0x60(OUTP)
+
+	movdqu 0x70(OUTP), INC
+	pxor INC, STATE8
+	movdqu STATE8, 0x70(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+
+	add $128, INP
+	add $128, OUTP
+	test LEN, LEN
+	jnz .Lxts_enc8
+
+.Lxts_enc_ret_iv:
+	movups IV, (IVP)
+.Lxts_enc_ret_noerr:
+	xor AREG, AREG
+	jmp .Lxts_enc_ret
+.Lxts_enc_ret_err:
+	mov $1, AREG
+.Lxts_enc_ret:
+	FRAME_END
+	ret
+
+.Lxts_enc1_pre:
+	add $128, LEN
+	jz .Lxts_enc_ret_iv
+	sub $16, LEN
+	jl .Lxts_enc_cts4
+
+.Lxts_enc1:
+	movdqu (INP), STATE1
+	pxor IV, STATE1
+
+	cmp $16, KLEN
+	je .Lxts_enc1_128
+	aesenc256kl (HANDLEP), STATE1
+	jz .Lxts_enc_ret_err
+	jmp .Lxts_enc1_end
+.Lxts_enc1_128:
+	aesenc128kl (HANDLEP), STATE1
+	jz .Lxts_enc_ret_err
+
+.Lxts_enc1_end:
+	pxor IV, STATE1
+	_aeskl_gf128mul_x_ble()
+
+	test LEN, LEN
+	jz .Lxts_enc1_out
+
+	add $16, INP
+	sub $16, LEN
+	jl .Lxts_enc_cts1
+
+	movdqu STATE1, (OUTP)
+	add $16, OUTP
+	jmp .Lxts_enc1
+
+.Lxts_enc1_out:
+	movdqu STATE1, (OUTP)
+	jmp .Lxts_enc_ret_iv
+
+.Lxts_enc_cts4:
+	movdqu STATE8, STATE1
+	sub $16, OUTP
+
+.Lxts_enc_cts1:
+	lea .Lcts_permute_table(%rip), T1
+	add LEN, INP		/* rewind input pointer */
+	add $16, LEN		/* # bytes in final block */
+	movups (INP), IN1
+
+	mov T1, IVP
+	add $32, IVP
+	add LEN, T1
+	sub LEN, IVP
+	add OUTP, LEN
+
+	movups (T1), STATE2
+	movaps STATE1, STATE3
+	pshufb STATE2, STATE1
+	movups STATE1, (LEN)
+
+	movups (IVP), STATE1
+	pshufb STATE1, IN1
+	pblendvb STATE3, IN1
+	movaps IN1, STATE1
+
+	pxor IV, STATE1
+
+	cmp $16, KLEN
+	je .Lxts_enc1_cts_128
+	aesenc256kl (HANDLEP), STATE1
+	jz .Lxts_enc_ret_err
+	jmp .Lxts_enc1_cts_end
+.Lxts_enc1_cts_128:
+	aesenc128kl (HANDLEP), STATE1
+	jz .Lxts_enc_ret_err
+
+.Lxts_enc1_cts_end:
+	pxor IV, STATE1
+	movups STATE1, (OUTP)
+	jmp .Lxts_enc_ret_noerr
+SYM_FUNC_END(_aeskl_xts_encrypt)
+
+/*
+ * int _aeskl_xts_decrypt(const struct crypto_aes_ctx *ctx, u8 *dst,
+ *			  const u8 *src, unsigned int len, le128 *iv)
+ */
+SYM_FUNC_START(_aeskl_xts_decrypt)
+	FRAME_BEGIN
+	movdqa .Lgf128mul_x_ble_mask(%rip), GF128MUL_MASK
+	movups (IVP), IV
+
+	mov 480(HANDLEP), KLEN
+
+	test $15, LEN
+	jz .Lxts_dec8
+	sub $16, LEN
+
+.Lxts_dec8:
+	sub $128, LEN
+	jl .Lxts_dec1_pre
+
+	movdqa IV, STATE1
+	movdqu (INP), INC
+	pxor INC, STATE1
+	movdqu IV, (OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE2
+	movdqu 0x10(INP), INC
+	pxor INC, STATE2
+	movdqu IV, 0x10(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE3
+	movdqu 0x20(INP), INC
+	pxor INC, STATE3
+	movdqu IV, 0x20(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE4
+	movdqu 0x30(INP), INC
+	pxor INC, STATE4
+	movdqu IV, 0x30(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE5
+	movdqu 0x40(INP), INC
+	pxor INC, STATE5
+	movdqu IV, 0x40(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE6
+	movdqu 0x50(INP), INC
+	pxor INC, STATE6
+	movdqu IV, 0x50(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE7
+	movdqu 0x60(INP), INC
+	pxor INC, STATE7
+	movdqu IV, 0x60(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+	movdqa IV, STATE8
+	movdqu 0x70(INP), INC
+	pxor INC, STATE8
+	movdqu IV, 0x70(OUTP)
+
+	cmp $16, KLEN
+	je .Lxts_dec8_128
+	aesdecwide256kl (%rdi)
+	jz .Lxts_dec_ret_err
+	jmp .Lxts_dec8_end
+.Lxts_dec8_128:
+	aesdecwide128kl (%rdi)
+	jz .Lxts_dec_ret_err
+
+.Lxts_dec8_end:
+	movdqu 0x00(OUTP), INC
+	pxor INC, STATE1
+	movdqu STATE1, 0x00(OUTP)
+
+	movdqu 0x10(OUTP), INC
+	pxor INC, STATE2
+	movdqu STATE2, 0x10(OUTP)
+
+	movdqu 0x20(OUTP), INC
+	pxor INC, STATE3
+	movdqu STATE3, 0x20(OUTP)
+
+	movdqu 0x30(OUTP), INC
+	pxor INC, STATE4
+	movdqu STATE4, 0x30(OUTP)
+
+	movdqu 0x40(OUTP), INC
+	pxor INC, STATE5
+	movdqu STATE5, 0x40(OUTP)
+
+	movdqu 0x50(OUTP), INC
+	pxor INC, STATE6
+	movdqu STATE6, 0x50(OUTP)
+
+	movdqu 0x60(OUTP), INC
+	pxor INC, STATE7
+	movdqu STATE7, 0x60(OUTP)
+
+	movdqu 0x70(OUTP), INC
+	pxor INC, STATE8
+	movdqu STATE8, 0x70(OUTP)
+
+	_aeskl_gf128mul_x_ble()
+
+	add $128, INP
+	add $128, OUTP
+	test LEN, LEN
+	jnz .Lxts_dec8
+
+.Lxts_dec_ret_iv:
+	movups IV, (IVP)
+.Lxts_dec_ret_noerr:
+	xor AREG, AREG
+	jmp .Lxts_dec_ret
+.Lxts_dec_ret_err:
+	mov $1, AREG
+.Lxts_dec_ret:
+	FRAME_END
+	ret
+
+.Lxts_dec1_pre:
+	add $128, LEN
+	jz .Lxts_dec_ret_iv
+
+.Lxts_dec1:
+	movdqu (INP), STATE1
+
+	add $16, INP
+	sub $16, LEN
+	jl .Lxts_dec_cts1
+
+	pxor IV, STATE1
+
+	cmp $16, KLEN
+	je .Lxts_dec1_128
+	aesdec256kl (HANDLEP), STATE1
+	jz .Lxts_dec_ret_err
+	jmp .Lxts_dec1_end
+.Lxts_dec1_128:
+	aesdec128kl (HANDLEP), STATE1
+	jz .Lxts_dec_ret_err
+
+.Lxts_dec1_end:
+	pxor IV, STATE1
+	_aeskl_gf128mul_x_ble()
+
+	test LEN, LEN
+	jz .Lxts_dec1_out
+
+	movdqu STATE1, (OUTP)
+	add $16, OUTP
+	jmp .Lxts_dec1
+
+.Lxts_dec1_out:
+	movdqu STATE1, (OUTP)
+	jmp .Lxts_dec_ret_iv
+
+.Lxts_dec_cts1:
+	movdqa IV, STATE5
+	_aeskl_gf128mul_x_ble()
+
+	pxor IV, STATE1
+
+	cmp $16, KLEN
+	je .Lxts_dec1_cts_pre_128
+	aesdec256kl (HANDLEP), STATE1
+	jz .Lxts_dec_ret_err
+	jmp .Lxts_dec1_cts_pre_end
+.Lxts_dec1_cts_pre_128:
+	aesdec128kl (HANDLEP), STATE1
+	jz .Lxts_dec_ret_err
+
+.Lxts_dec1_cts_pre_end:
+	pxor IV, STATE1
+
+	lea .Lcts_permute_table(%rip), T1
+	add LEN, INP		/* rewind input pointer */
+	add $16, LEN		/* # bytes in final block */
+	movups (INP), IN1
+
+	mov T1, IVP
+	add $32, IVP
+	add LEN, T1
+	sub LEN, IVP
+	add OUTP, LEN
+
+	movups (T1), STATE2
+	movaps STATE1, STATE3
+	pshufb STATE2, STATE1
+	movups STATE1, (LEN)
+
+	movups (IVP), STATE1
+	pshufb STATE1, IN1
+	pblendvb STATE3, IN1
+	movaps IN1, STATE1
+
+	pxor STATE5, STATE1
+
+	cmp $16, KLEN
+	je .Lxts_dec1_cts_128
+	aesdec256kl (HANDLEP), STATE1
+	jz .Lxts_dec_ret_err
+	jmp .Lxts_dec1_cts_end
+.Lxts_dec1_cts_128:
+	aesdec128kl (HANDLEP), STATE1
+	jz .Lxts_dec_ret_err
+
+.Lxts_dec1_cts_end:
+	pxor STATE5, STATE1
+
+	movups STATE1, (OUTP)
+	jmp .Lxts_dec_ret_noerr
+
+SYM_FUNC_END(_aeskl_xts_decrypt)
+
+#endif
diff --git a/arch/x86/crypto/aeskl-intel_glue.c b/arch/x86/crypto/aeskl-intel_glue.c
index f99dfa4a052f..bfac7452709d 100644
--- a/arch/x86/crypto/aeskl-intel_glue.c
+++ b/arch/x86/crypto/aeskl-intel_glue.c
@@ -38,6 +38,11 @@ asmlinkage int _aeskl_cbc_dec(struct crypto_aes_ctx *ctx, u8 *out, const u8 *in,
 #ifdef CONFIG_X86_64
 asmlinkage int _aeskl_ctr_enc(struct crypto_aes_ctx *ctx, u8 *out, const u8 *in, unsigned int len,
 			      u8 *iv);
+
+asmlinkage int _aeskl_xts_encrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in,
+				  unsigned int len, u8 *iv);
+asmlinkage int _aeskl_xts_decrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in,
+				  unsigned int len, u8 *iv);
 #endif
 
 static int aeskl_setkey_common(struct crypto_tfm *tfm, void *raw_ctx, const u8 *in_key,
@@ -164,6 +169,32 @@ static int aeskl_ctr_enc(struct crypto_aes_ctx *ctx, u8 *out, const u8 *in, unsi
 		return 0;
 }
 
+static inline int aeskl_xts_encrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in,
+				    unsigned int len, u8 *iv)
+{
+	if (unlikely(ctx->key_length == AES_KEYSIZE_192))
+		return -EINVAL;
+	else if (!valid_keylocker())
+		return -ENODEV;
+	else if (_aeskl_xts_encrypt(ctx, out, in, len, iv))
+		return -EINVAL;
+	else
+		return 0;
+}
+
+static inline int aeskl_xts_decrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in,
+				    unsigned int len, u8 *iv)
+{
+	if (unlikely(ctx->key_length == AES_KEYSIZE_192))
+		return -EINVAL;
+	else if (!valid_keylocker())
+		return -ENODEV;
+	else if (_aeskl_xts_decrypt(ctx, out, in, len, iv))
+		return -EINVAL;
+	else
+		return 0;
+}
+
 #endif /* CONFIG_X86_64 */
 
 static int aeskl_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
@@ -227,6 +258,32 @@ static int ctr_crypt(struct skcipher_request *req)
 		return ctr_crypt_common(req, aesni_ctr_enc, aesni_enc);
 }
 
+static int aeskl_xts_setkey(struct crypto_skcipher *tfm, const u8 *key,
+			    unsigned int keylen)
+{
+	return xts_setkey_common(tfm, key, keylen, aeskl_setkey_common);
+}
+
+static int xts_encrypt(struct skcipher_request *req)
+{
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+
+	if (likely(keylength(crypto_skcipher_ctx(tfm)) != AES_KEYSIZE_192))
+		return xts_crypt_common(req, aeskl_xts_encrypt, aeskl_enc);
+	else
+		return xts_crypt_common(req, aesni_xts_encrypt, aesni_enc);
+}
+
+static int xts_decrypt(struct skcipher_request *req)
+{
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+
+	if (likely(keylength(crypto_skcipher_ctx(tfm)) != AES_KEYSIZE_192))
+		return xts_crypt_common(req, aeskl_xts_decrypt, aeskl_enc);
+	else
+		return xts_crypt_common(req, aesni_xts_decrypt, aesni_enc);
+}
+
 #endif /* CONFIG_X86_64 */
 
 static struct skcipher_alg aeskl_skciphers[] = {
@@ -279,6 +336,23 @@ static struct skcipher_alg aeskl_skciphers[] = {
 		.setkey		= aeskl_skcipher_setkey,
 		.encrypt	= ctr_crypt,
 		.decrypt	= ctr_crypt,
+	}, {
+		.base = {
+			.cra_name		= "__xts(aes)",
+			.cra_driver_name	= "__xts-aes-aeskl",
+			.cra_priority		= 200,
+			.cra_flags		= CRYPTO_ALG_INTERNAL,
+			.cra_blocksize		= AES_BLOCK_SIZE,
+			.cra_ctxsize		= XTS_AES_CTX_SIZE,
+			.cra_module		= THIS_MODULE,
+		},
+		.min_keysize	= 2 * AES_MIN_KEY_SIZE,
+		.max_keysize	= 2 * AES_MAX_KEY_SIZE,
+		.ivsize		= AES_BLOCK_SIZE,
+		.walksize	= 2 * AES_BLOCK_SIZE,
+		.setkey		= aeskl_xts_setkey,
+		.encrypt	= xts_encrypt,
+		.decrypt	= xts_decrypt,
 #endif
 	}
 };
-- 
2.17.1