crypto: arm64/chacha20 - refactor to allow varying number of rounds (95a34b77) · Commits · jan.koester / Linux

arch/arm64/crypto/Makefile

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -50,8 +50,8 @@ sha256-arm64-y := sha256-glue.o sha256-core.o
	obj-$(CONFIG_CRYPTO_SHA512_ARM64) += sha512-arm64.o		obj-$(CONFIG_CRYPTO_SHA512_ARM64) += sha512-arm64.o
	sha512-arm64-y := sha512-glue.o sha512-core.o		sha512-arm64-y := sha512-glue.o sha512-core.o

	obj-$(CONFIG_CRYPTO_CHACHA20_NEON) += chacha20-neon.o		obj-$(CONFIG_CRYPTO_CHACHA20_NEON) += chacha-neon.o
	chacha20-neon-y := chacha20-neon-core.o chacha20-neon-glue.o		chacha-neon-y := chacha-neon-core.o chacha-neon-glue.o

	obj-$(CONFIG_CRYPTO_NHPOLY1305_NEON) += nhpoly1305-neon.o		obj-$(CONFIG_CRYPTO_NHPOLY1305_NEON) += nhpoly1305-neon.o
	nhpoly1305-neon-y := nh-neon-core.o nhpoly1305-neon-glue.o		nhpoly1305-neon-y := nh-neon-core.o nhpoly1305-neon-glue.o

arch/arm64/crypto/chacha20-neon-core.S→arch/arm64/crypto/chacha-neon-core.S

+24 −21

Original line number	Original line	Diff line number	Diff line
	/*		/*
	* ChaCha20 256-bit cipher algorithm, RFC7539, arm64 NEON functions		* ChaCha/XChaCha NEON helper functions
	*		*
	* Copyright (C) 2016 Linaro, Ltd. <ard.biesheuvel@linaro.org>		* Copyright (C) 2016 Linaro, Ltd. <ard.biesheuvel@linaro.org>
	*		*
	@@ -24,17 +24,18 @@
	.align 6		.align 6

	/*		/*
	* chacha20_permute - permute one block		* chacha_permute - permute one block
	*		*
	* Permute one 64-byte block where the state matrix is stored in the four NEON		* Permute one 64-byte block where the state matrix is stored in the four NEON
	* registers v0-v3. It performs matrix operations on four words in parallel,		* registers v0-v3. It performs matrix operations on four words in parallel,
	* but requires shuffling to rearrange the words after each round.		* but requires shuffling to rearrange the words after each round.
	*		*
	* Clobbers: x3, x10, v4, v12		* The round count is given in w3.
			*
			* Clobbers: w3, x10, v4, v12
	*/		*/
	chacha20_permute:		chacha_permute:

	mov x3, #10
	adr x10, ROT8		adr x10, ROT8
	ld1 {v12.4s}, [x10]		ld1 {v12.4s}, [x10]

	@@ -97,16 +98,17 @@ chacha20_permute:
	// x3 = shuffle32(x3, MASK(0, 3, 2, 1))		// x3 = shuffle32(x3, MASK(0, 3, 2, 1))
	ext v3.16b, v3.16b, v3.16b, #4		ext v3.16b, v3.16b, v3.16b, #4

	subs x3, x3, #1		subs w3, w3, #2
	b.ne .Ldoubleround		b.ne .Ldoubleround

	ret		ret
	ENDPROC(chacha20_permute)		ENDPROC(chacha_permute)

	ENTRY(chacha20_block_xor_neon)		ENTRY(chacha_block_xor_neon)
	// x0: Input state matrix, s		// x0: Input state matrix, s
	// x1: 1 data block output, o		// x1: 1 data block output, o
	// x2: 1 data block input, i		// x2: 1 data block input, i
			// w3: nrounds

	stp x29, x30, [sp, #-16]!		stp x29, x30, [sp, #-16]!
	mov x29, sp		mov x29, sp
	@@ -115,7 +117,7 @@ ENTRY(chacha20_block_xor_neon)
	ld1 {v0.4s-v3.4s}, [x0]		ld1 {v0.4s-v3.4s}, [x0]
	ld1 {v8.4s-v11.4s}, [x0]		ld1 {v8.4s-v11.4s}, [x0]

	bl chacha20_permute		bl chacha_permute

	ld1 {v4.16b-v7.16b}, [x2]		ld1 {v4.16b-v7.16b}, [x2]

	@@ -139,42 +141,45 @@ ENTRY(chacha20_block_xor_neon)

	ldp x29, x30, [sp], #16		ldp x29, x30, [sp], #16
	ret		ret
	ENDPROC(chacha20_block_xor_neon)		ENDPROC(chacha_block_xor_neon)

	ENTRY(hchacha20_block_neon)		ENTRY(hchacha_block_neon)
	// x0: Input state matrix, s		// x0: Input state matrix, s
	// x1: output (8 32-bit words)		// x1: output (8 32-bit words)
			// w2: nrounds

	stp x29, x30, [sp, #-16]!		stp x29, x30, [sp, #-16]!
	mov x29, sp		mov x29, sp

	ld1 {v0.4s-v3.4s}, [x0]		ld1 {v0.4s-v3.4s}, [x0]

	bl chacha20_permute		mov w3, w2
			bl chacha_permute

	st1 {v0.16b}, [x1], #16		st1 {v0.16b}, [x1], #16
	st1 {v3.16b}, [x1]		st1 {v3.16b}, [x1]

	ldp x29, x30, [sp], #16		ldp x29, x30, [sp], #16
	ret		ret
	ENDPROC(hchacha20_block_neon)		ENDPROC(hchacha_block_neon)

	.align 6		.align 6
	ENTRY(chacha20_4block_xor_neon)		ENTRY(chacha_4block_xor_neon)
	// x0: Input state matrix, s		// x0: Input state matrix, s
	// x1: 4 data blocks output, o		// x1: 4 data blocks output, o
	// x2: 4 data blocks input, i		// x2: 4 data blocks input, i
			// w3: nrounds

	//		//
	// This function encrypts four consecutive ChaCha20 blocks by loading		// This function encrypts four consecutive ChaCha blocks by loading
	// the state matrix in NEON registers four times. The algorithm performs		// the state matrix in NEON registers four times. The algorithm performs
	// each operation on the corresponding word of each state matrix, hence		// each operation on the corresponding word of each state matrix, hence
	// requires no word shuffling. For final XORing step we transpose the		// requires no word shuffling. For final XORing step we transpose the
	// matrix by interleaving 32- and then 64-bit words, which allows us to		// matrix by interleaving 32- and then 64-bit words, which allows us to
	// do XOR in NEON registers.		// do XOR in NEON registers.
	//		//
	adr x3, CTRINC // ... and ROT8		adr x9, CTRINC // ... and ROT8
	ld1 {v30.4s-v31.4s}, [x3]		ld1 {v30.4s-v31.4s}, [x9]

	// x0..15[0-3] = s0..3[0..3]		// x0..15[0-3] = s0..3[0..3]
	mov x4, x0		mov x4, x0
	@@ -186,8 +191,6 @@ ENTRY(chacha20_4block_xor_neon)
	// x12 += counter values 0-3		// x12 += counter values 0-3
	add v12.4s, v12.4s, v30.4s		add v12.4s, v12.4s, v30.4s

	mov x3, #10

	.Ldoubleround4:		.Ldoubleround4:
	// x0 += x4, x12 = rotl32(x12 ^ x0, 16)		// x0 += x4, x12 = rotl32(x12 ^ x0, 16)
	// x1 += x5, x13 = rotl32(x13 ^ x1, 16)		// x1 += x5, x13 = rotl32(x13 ^ x1, 16)
	@@ -361,7 +364,7 @@ ENTRY(chacha20_4block_xor_neon)
	sri v7.4s, v18.4s, #25		sri v7.4s, v18.4s, #25
	sri v4.4s, v19.4s, #25		sri v4.4s, v19.4s, #25

	subs x3, x3, #1		subs w3, w3, #2
	b.ne .Ldoubleround4		b.ne .Ldoubleround4

	ld4r {v16.4s-v19.4s}, [x0], #16		ld4r {v16.4s-v19.4s}, [x0], #16
	@@ -475,7 +478,7 @@ ENTRY(chacha20_4block_xor_neon)
	st1 {v28.16b-v31.16b}, [x1]		st1 {v28.16b-v31.16b}, [x1]

	ret		ret
	ENDPROC(chacha20_4block_xor_neon)		ENDPROC(chacha_4block_xor_neon)

	CTRINC: .word 0, 1, 2, 3		CTRINC: .word 0, 1, 2, 3
	ROT8: .word 0x02010003, 0x06050407, 0x0a09080b, 0x0e0d0c0f		ROT8: .word 0x02010003, 0x06050407, 0x0a09080b, 0x0e0d0c0f

arch/arm64/crypto/chacha20-neon-glue.c→arch/arm64/crypto/chacha-neon-glue.c

+30 −25

Original line number	Original line	Diff line number	Diff line
	/*		/*
	* ChaCha20 256-bit cipher algorithm, RFC7539, arm64 NEON functions		* ARM NEON accelerated ChaCha and XChaCha stream ciphers,
			* including ChaCha20 (RFC7539)
	*		*
	* Copyright (C) 2016 - 2017 Linaro, Ltd. <ard.biesheuvel@linaro.org>		* Copyright (C) 2016 - 2017 Linaro, Ltd. <ard.biesheuvel@linaro.org>
	*		*
	@@ -28,18 +29,20 @@
	#include <asm/neon.h>		#include <asm/neon.h>
	#include <asm/simd.h>		#include <asm/simd.h>

	asmlinkage void chacha20_block_xor_neon(u32 state, u8 dst, const u8 *src);		asmlinkage void chacha_block_xor_neon(u32 state, u8 dst, const u8 *src,
	asmlinkage void chacha20_4block_xor_neon(u32 state, u8 dst, const u8 *src);		int nrounds);
	asmlinkage void hchacha20_block_neon(const u32 state, u32 out);		asmlinkage void chacha_4block_xor_neon(u32 state, u8 dst, const u8 *src,
			int nrounds);
			asmlinkage void hchacha_block_neon(const u32 state, u32 out, int nrounds);

	static void chacha20_doneon(u32 state, u8 dst, const u8 *src,		static void chacha_doneon(u32 state, u8 dst, const u8 *src,
	unsigned int bytes)		unsigned int bytes, int nrounds)
	{		{
	u8 buf[CHACHA_BLOCK_SIZE];		u8 buf[CHACHA_BLOCK_SIZE];

	while (bytes >= CHACHA_BLOCK_SIZE * 4) {		while (bytes >= CHACHA_BLOCK_SIZE * 4) {
	kernel_neon_begin();		kernel_neon_begin();
	chacha20_4block_xor_neon(state, dst, src);		chacha_4block_xor_neon(state, dst, src, nrounds);
	kernel_neon_end();		kernel_neon_end();
	bytes -= CHACHA_BLOCK_SIZE * 4;		bytes -= CHACHA_BLOCK_SIZE * 4;
	src += CHACHA_BLOCK_SIZE * 4;		src += CHACHA_BLOCK_SIZE * 4;
	@@ -52,7 +55,7 @@ static void chacha20_doneon(u32 state, u8 dst, const u8 *src,

	kernel_neon_begin();		kernel_neon_begin();
	while (bytes >= CHACHA_BLOCK_SIZE) {		while (bytes >= CHACHA_BLOCK_SIZE) {
	chacha20_block_xor_neon(state, dst, src);		chacha_block_xor_neon(state, dst, src, nrounds);
	bytes -= CHACHA_BLOCK_SIZE;		bytes -= CHACHA_BLOCK_SIZE;
	src += CHACHA_BLOCK_SIZE;		src += CHACHA_BLOCK_SIZE;
	dst += CHACHA_BLOCK_SIZE;		dst += CHACHA_BLOCK_SIZE;
	@@ -60,13 +63,13 @@ static void chacha20_doneon(u32 state, u8 dst, const u8 *src,
	}		}
	if (bytes) {		if (bytes) {
	memcpy(buf, src, bytes);		memcpy(buf, src, bytes);
	chacha20_block_xor_neon(state, buf, buf);		chacha_block_xor_neon(state, buf, buf, nrounds);
	memcpy(dst, buf, bytes);		memcpy(dst, buf, bytes);
	}		}
	kernel_neon_end();		kernel_neon_end();
	}		}

	static int chacha20_neon_stream_xor(struct skcipher_request *req,		static int chacha_neon_stream_xor(struct skcipher_request *req,
	struct chacha_ctx ctx, u8 iv)		struct chacha_ctx ctx, u8 iv)
	{		{
	struct skcipher_walk walk;		struct skcipher_walk walk;
	@@ -83,15 +86,15 @@ static int chacha20_neon_stream_xor(struct skcipher_request *req,
	if (nbytes < walk.total)		if (nbytes < walk.total)
	nbytes = round_down(nbytes, walk.stride);		nbytes = round_down(nbytes, walk.stride);

	chacha20_doneon(state, walk.dst.virt.addr, walk.src.virt.addr,		chacha_doneon(state, walk.dst.virt.addr, walk.src.virt.addr,
	nbytes);		nbytes, ctx->nrounds);
	err = skcipher_walk_done(&walk, walk.nbytes - nbytes);		err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
	}		}

	return err;		return err;
	}		}

	static int chacha20_neon(struct skcipher_request *req)		static int chacha_neon(struct skcipher_request *req)
	{		{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);		struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);		struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
	@@ -99,10 +102,10 @@ static int chacha20_neon(struct skcipher_request *req)
	if (req->cryptlen <= CHACHA_BLOCK_SIZE \|\| !may_use_simd())		if (req->cryptlen <= CHACHA_BLOCK_SIZE \|\| !may_use_simd())
	return crypto_chacha_crypt(req);		return crypto_chacha_crypt(req);

	return chacha20_neon_stream_xor(req, ctx, req->iv);		return chacha_neon_stream_xor(req, ctx, req->iv);
	}		}

	static int xchacha20_neon(struct skcipher_request *req)		static int xchacha_neon(struct skcipher_request *req)
	{		{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);		struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);		struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
	@@ -116,12 +119,13 @@ static int xchacha20_neon(struct skcipher_request *req)
	crypto_chacha_init(state, ctx, req->iv);		crypto_chacha_init(state, ctx, req->iv);

	kernel_neon_begin();		kernel_neon_begin();
	hchacha20_block_neon(state, subctx.key);		hchacha_block_neon(state, subctx.key, ctx->nrounds);
	kernel_neon_end();		kernel_neon_end();
			subctx.nrounds = ctx->nrounds;

	memcpy(&real_iv[0], req->iv + 24, 8);		memcpy(&real_iv[0], req->iv + 24, 8);
	memcpy(&real_iv[8], req->iv + 16, 8);		memcpy(&real_iv[8], req->iv + 16, 8);
	return chacha20_neon_stream_xor(req, &subctx, real_iv);		return chacha_neon_stream_xor(req, &subctx, real_iv);
	}		}

	static struct skcipher_alg algs[] = {		static struct skcipher_alg algs[] = {
	@@ -139,8 +143,8 @@ static struct skcipher_alg algs[] = {
	.chunksize = CHACHA_BLOCK_SIZE,		.chunksize = CHACHA_BLOCK_SIZE,
	.walksize = 4 * CHACHA_BLOCK_SIZE,		.walksize = 4 * CHACHA_BLOCK_SIZE,
	.setkey = crypto_chacha20_setkey,		.setkey = crypto_chacha20_setkey,
	.encrypt = chacha20_neon,		.encrypt = chacha_neon,
	.decrypt = chacha20_neon,		.decrypt = chacha_neon,
	}, {		}, {
	.base.cra_name = "xchacha20",		.base.cra_name = "xchacha20",
	.base.cra_driver_name = "xchacha20-neon",		.base.cra_driver_name = "xchacha20-neon",
	@@ -155,12 +159,12 @@ static struct skcipher_alg algs[] = {
	.chunksize = CHACHA_BLOCK_SIZE,		.chunksize = CHACHA_BLOCK_SIZE,
	.walksize = 4 * CHACHA_BLOCK_SIZE,		.walksize = 4 * CHACHA_BLOCK_SIZE,
	.setkey = crypto_chacha20_setkey,		.setkey = crypto_chacha20_setkey,
	.encrypt = xchacha20_neon,		.encrypt = xchacha_neon,
	.decrypt = xchacha20_neon,		.decrypt = xchacha_neon,
	}		}
	};		};

	static int __init chacha20_simd_mod_init(void)		static int __init chacha_simd_mod_init(void)
	{		{
	if (!(elf_hwcap & HWCAP_ASIMD))		if (!(elf_hwcap & HWCAP_ASIMD))
	return -ENODEV;		return -ENODEV;
	@@ -168,14 +172,15 @@ static int __init chacha20_simd_mod_init(void)
	return crypto_register_skciphers(algs, ARRAY_SIZE(algs));		return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
	}		}

	static void __exit chacha20_simd_mod_fini(void)		static void __exit chacha_simd_mod_fini(void)
	{		{
	crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));		crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
	}		}

	module_init(chacha20_simd_mod_init);		module_init(chacha_simd_mod_init);
	module_exit(chacha20_simd_mod_fini);		module_exit(chacha_simd_mod_fini);

			MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (NEON accelerated)");
	MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");		MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
	MODULE_LICENSE("GPL v2");		MODULE_LICENSE("GPL v2");
	MODULE_ALIAS_CRYPTO("chacha20");		MODULE_ALIAS_CRYPTO("chacha20");