Implements an x86_64 assembler driver for the ChaCha20 stream cipher. This
single block variant works on a single state matrix using SSE instructions.
It requires SSSE3 due the use of pshufb for efficient 8/16-bit rotate
operations.
For large messages, throughput increases by ~65% compared to
chacha20-generic:
testing speed of chacha20 (chacha20-generic) encryption
test 0 (256 bit key, 16 byte blocks): 4015926 operations in 1 seconds (64254816 bytes)
test 1 (256 bit key, 64 byte blocks): 4161758 operations in 1 seconds (266352512 bytes)
test 2 (256 bit key, 256 byte blocks): 1223686 operations in 1 seconds (313263616 bytes)
test 3 (256 bit key, 1024 byte blocks): 325200 operations in 1 seconds (333004800 bytes)
test 4 (256 bit key, 8192 byte blocks): 40725 operations in 1 seconds (333619200 bytes)
testing speed of chacha20 (chacha20-simd) encryption
test 0 (256 bit key, 16 byte blocks): 4154698 operations in 1 seconds (66475168 bytes)
test 1 (256 bit key, 64 byte blocks): 4593368 operations in 1 seconds (293975552 bytes)
test 2 (256 bit key, 256 byte blocks): 1796194 operations in 1 seconds (459825664 bytes)
test 3 (256 bit key, 1024 byte blocks): 519725 operations in 1 seconds (532198400 bytes)
test 4 (256 bit key, 8192 byte blocks): 67132 operations in 1 seconds (549945344 bytes)
Benchmark results from a Core i5-4670T.
Signed-off-by: Martin Willi <martin@xxxxxxxxxxxxxx>
---
arch/x86/crypto/Makefile | 2 +
arch/x86/crypto/chacha20-ssse3-x86_64.S | 142 ++++++++++++++++++++++++++++++++
arch/x86/crypto/chacha20_glue.c | 123 +++++++++++++++++++++++++++
crypto/Kconfig | 15 ++++
4 files changed, 282 insertions(+)
create mode 100644 arch/x86/crypto/chacha20-ssse3-x86_64.S
create mode 100644 arch/x86/crypto/chacha20_glue.c
diff --git a/arch/x86/crypto/Makefile b/arch/x86/crypto/Makefile
index 5a4a089..b09e9a4 100644
--- a/arch/x86/crypto/Makefile
+++ b/arch/x86/crypto/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_CRYPTO_BLOWFISH_X86_64) += blowfish-x86_64.o
obj-$(CONFIG_CRYPTO_TWOFISH_X86_64) += twofish-x86_64.o
obj-$(CONFIG_CRYPTO_TWOFISH_X86_64_3WAY) += twofish-x86_64-3way.o
obj-$(CONFIG_CRYPTO_SALSA20_X86_64) += salsa20-x86_64.o
+obj-$(CONFIG_CRYPTO_CHACHA20_X86_64) += chacha20-x86_64.o
obj-$(CONFIG_CRYPTO_SERPENT_SSE2_X86_64) += serpent-sse2-x86_64.o
obj-$(CONFIG_CRYPTO_AES_NI_INTEL) += aesni-intel.o
obj-$(CONFIG_CRYPTO_GHASH_CLMUL_NI_INTEL) += ghash-clmulni-intel.o
@@ -60,6 +61,7 @@ blowfish-x86_64-y := blowfish-x86_64-asm_64.o blowfish_glue.o
twofish-x86_64-y := twofish-x86_64-asm_64.o twofish_glue.o
twofish-x86_64-3way-y := twofish-x86_64-asm_64-3way.o twofish_glue_3way.o
salsa20-x86_64-y := salsa20-x86_64-asm_64.o salsa20_glue.o
+chacha20-x86_64-y := chacha20-ssse3-x86_64.o chacha20_glue.o
serpent-sse2-x86_64-y := serpent-sse2-x86_64-asm_64.o serpent_sse2_glue.o
ifeq ($(avx_supported),yes)
diff --git a/arch/x86/crypto/chacha20-ssse3-x86_64.S b/arch/x86/crypto/chacha20-ssse3-x86_64.S
new file mode 100644
index 0000000..1b97ad0
--- /dev/null
+++ b/arch/x86/crypto/chacha20-ssse3-x86_64.S
@@ -0,0 +1,142 @@
+/*
+ * ChaCha20 256-bit cipher algorithm, RFC7539, x64 SSSE3 functions
+ *
+ * Copyright (C) 2015 Martin Willi
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/linkage.h>
+
+.data
+.align 16
+
+ROT8: .octa 0x0e0d0c0f0a09080b0605040702010003
+ROT16: .octa 0x0d0c0f0e09080b0a0504070601000302
+
+.text
+
+ENTRY(chacha20_block_xor_ssse3)
+ # %rdi: Input state matrix, s
+ # %rsi: 1 data block output, o
+ # %rdx: 1 data block input, i
+
+ # This function encrypts one ChaCha20 block by loading the state matrix
+ # in four SSE registers. It performs matrix operation on four words in
+ # parallel, but requireds shuffling to rearrange the words after each
+ # round. 8/16-bit word rotation is done with the slightly better
+ # performing SSSE3 byte shuffling, 7/12-bit word rotation uses
+ # traditional shift+OR.
+
+ # x0..3 = s0..3
+ movdqa 0x00(%rdi),%xmm0
+ movdqa 0x10(%rdi),%xmm1
+ movdqa 0x20(%rdi),%xmm2
+ movdqa 0x30(%rdi),%xmm3
+ movdqa %xmm0,%xmm8
+ movdqa %xmm1,%xmm9
+ movdqa %xmm2,%xmm10
+ movdqa %xmm3,%xmm11
+
+ movdqa ROT8(%rip),%xmm4
+ movdqa ROT16(%rip),%xmm5
+
+ mov $10,%ecx
+
+.Ldoubleround:
+
+ # x0 += x1, x3 = rotl32(x3 ^ x0, 16)
+ paddd %xmm1,%xmm0
+ pxor %xmm0,%xmm3
+ pshufb %xmm5,%xmm3
+
+ # x2 += x3, x1 = rotl32(x1 ^ x2, 12)
+ paddd %xmm3,%xmm2
+ pxor %xmm2,%xmm1
+ movdqa %xmm1,%xmm6
+ pslld $12,%xmm6
+ psrld $20,%xmm1
+ por %xmm6,%xmm1
+
+ # x0 += x1, x3 = rotl32(x3 ^ x0, 8)
+ paddd %xmm1,%xmm0
+ pxor %xmm0,%xmm3
+ pshufb %xmm4,%xmm3
+
+ # x2 += x3, x1 = rotl32(x1 ^ x2, 7)
+ paddd %xmm3,%xmm2
+ pxor %xmm2,%xmm1
+ movdqa %xmm1,%xmm7
+ pslld $7,%xmm7
+ psrld $25,%xmm1
+ por %xmm7,%xmm1
+
+ # x1 = shuffle32(x1, MASK(0, 3, 2, 1))
+ pshufd $0x39,%xmm1,%xmm1
+ # x2 = shuffle32(x2, MASK(1, 0, 3, 2))
+ pshufd $0x4e,%xmm2,%xmm2
+ # x3 = shuffle32(x3, MASK(2, 1, 0, 3))
+ pshufd $0x93,%xmm3,%xmm3
+
+ # x0 += x1, x3 = rotl32(x3 ^ x0, 16)
+ paddd %xmm1,%xmm0
+ pxor %xmm0,%xmm3
+ pshufb %xmm5,%xmm3
+
+ # x2 += x3, x1 = rotl32(x1 ^ x2, 12)
+ paddd %xmm3,%xmm2
+ pxor %xmm2,%xmm1
+ movdqa %xmm1,%xmm6
+ pslld $12,%xmm6
+ psrld $20,%xmm1
+ por %xmm6,%xmm1
+
+ # x0 += x1, x3 = rotl32(x3 ^ x0, 8)
+ paddd %xmm1,%xmm0
+ pxor %xmm0,%xmm3
+ pshufb %xmm4,%xmm3
+
+ # x2 += x3, x1 = rotl32(x1 ^ x2, 7)
+ paddd %xmm3,%xmm2
+ pxor %xmm2,%xmm1
+ movdqa %xmm1,%xmm7
+ pslld $7,%xmm7
+ psrld $25,%xmm1
+ por %xmm7,%xmm1
+
+ # x1 = shuffle32(x1, MASK(2, 1, 0, 3))
+ pshufd $0x93,%xmm1,%xmm1
+ # x2 = shuffle32(x2, MASK(1, 0, 3, 2))
+ pshufd $0x4e,%xmm2,%xmm2
+ # x3 = shuffle32(x3, MASK(0, 3, 2, 1))
+ pshufd $0x39,%xmm3,%xmm3
+
+ dec %ecx
+ jnz .Ldoubleround
+
+ # o0 = i0 ^ (x0 + s0)
+ movdqu 0x00(%rdx),%xmm4
+ paddd %xmm8,%xmm0
+ pxor %xmm4,%xmm0
+ movdqu %xmm0,0x00(%rsi)
+ # o1 = i1 ^ (x1 + s1)
+ movdqu 0x10(%rdx),%xmm5
+ paddd %xmm9,%xmm1
+ pxor %xmm5,%xmm1
+ movdqu %xmm1,0x10(%rsi)
+ # o2 = i2 ^ (x2 + s2)
+ movdqu 0x20(%rdx),%xmm6
+ paddd %xmm10,%xmm2
+ pxor %xmm6,%xmm2
+ movdqu %xmm2,0x20(%rsi)
+ # o3 = i3 ^ (x3 + s3)
+ movdqu 0x30(%rdx),%xmm7
+ paddd %xmm11,%xmm3
+ pxor %xmm7,%xmm3
+ movdqu %xmm3,0x30(%rsi)
+
+ ret
+ENDPROC(chacha20_block_xor_ssse3)
diff --git a/arch/x86/crypto/chacha20_glue.c b/arch/x86/crypto/chacha20_glue.c
new file mode 100644
index 0000000..250de40
--- /dev/null
+++ b/arch/x86/crypto/chacha20_glue.c
@@ -0,0 +1,123 @@
+/*
+ * ChaCha20 256-bit cipher algorithm, RFC7539, SIMD glue code
+ *
+ * Copyright (C) 2015 Martin Willi
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <crypto/algapi.h>
+#include <crypto/chacha20.h>
+#include <linux/crypto.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/fpu/api.h>
+#include <asm/simd.h>
+
+#define CHACHA20_STATE_ALIGN 16
+
+asmlinkage void chacha20_block_xor_ssse3(u32 *state, u8 *dst, const u8 *src);
+
+static void chacha20_dosimd(u32 *state, u8 *dst, const u8 *src,
+ unsigned int bytes)
+{
+ u8 buf[CHACHA20_BLOCK_SIZE];
+
+ while (bytes >= CHACHA20_BLOCK_SIZE) {
+ chacha20_block_xor_ssse3(state, dst, src);
+ bytes -= CHACHA20_BLOCK_SIZE;
+ src += CHACHA20_BLOCK_SIZE;
+ dst += CHACHA20_BLOCK_SIZE;
+ state[12]++;
+ }
+ if (bytes) {
+ memcpy(buf, src, bytes);
+ chacha20_block_xor_ssse3(state, buf, buf);
+ memcpy(dst, buf, bytes);
+ }
+}
+
+static int chacha20_simd(struct blkcipher_desc *desc, struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ u32 *state, state_buf[16 + (CHACHA20_STATE_ALIGN / sizeof(u32)) - 1];
+ struct blkcipher_walk walk;
+ int err;
+
+ if (!may_use_simd())
+ return crypto_chacha20_crypt(desc, dst, src, nbytes);
+
+ state = (u32 *)roundup((uintptr_t)state_buf, CHACHA20_STATE_ALIGN);
+
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+ err = blkcipher_walk_virt_block(desc, &walk, CHACHA20_BLOCK_SIZE);
+
+ crypto_chacha20_init(state, crypto_blkcipher_ctx(desc->tfm), walk.iv);
+
+ kernel_fpu_begin();
+
+ while (walk.nbytes >= CHACHA20_BLOCK_SIZE) {
+ chacha20_dosimd(state, walk.dst.virt.addr, walk.src.virt.addr,
+ rounddown(walk.nbytes, CHACHA20_BLOCK_SIZE));
+ err = blkcipher_walk_done(desc, &walk,
+ walk.nbytes % CHACHA20_BLOCK_SIZE);
+ }
+
+ if (walk.nbytes) {
+ chacha20_dosimd(state, walk.dst.virt.addr, walk.src.virt.addr,
+ walk.nbytes);
+ err = blkcipher_walk_done(desc, &walk, 0);
+ }
+
+ kernel_fpu_end();
+
+ return err;
+}
+
+static struct crypto_alg alg = {
+ .cra_name = "chacha20",
+ .cra_driver_name = "chacha20-simd",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
+ .cra_blocksize = 1,
+ .cra_type = &crypto_blkcipher_type,
+ .cra_ctxsize = sizeof(struct chacha20_ctx),
+ .cra_alignmask = sizeof(u32) - 1,
+ .cra_module = THIS_MODULE,
+ .cra_u = {
+ .blkcipher = {
+ .min_keysize = CHACHA20_KEY_SIZE,
+ .max_keysize = CHACHA20_KEY_SIZE,
+ .ivsize = CHACHA20_IV_SIZE,
+ .geniv = "seqiv",
+ .setkey = crypto_chacha20_setkey,
+ .encrypt = chacha20_simd,
+ .decrypt = chacha20_simd,
+ },
+ },
+};
+
+static int __init chacha20_simd_mod_init(void)
+{
+ if (!cpu_has_ssse3)
+ return -ENODEV;
+
+ return crypto_register_alg(&alg);
+}
+
+static void __exit chacha20_simd_mod_fini(void)
+{
+ crypto_unregister_alg(&alg);
+}
+
+module_init(chacha20_simd_mod_init);
+module_exit(chacha20_simd_mod_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Martin Willi <martin@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("chacha20 cipher algorithm, SIMD accelerated");
+MODULE_ALIAS_CRYPTO("chacha20");
+MODULE_ALIAS_CRYPTO("chacha20-simd");
diff --git a/crypto/Kconfig b/crypto/Kconfig
index b4cfc57..8f24185 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1213,6 +1213,21 @@ config CRYPTO_CHACHA20
See also:
<http://cr.yp.to/chacha/chacha-20080128.pdf>
+config CRYPTO_CHACHA20_X86_64
+ tristate "ChaCha20 cipher algorithm (x86_64/SSSE3)"
+ depends on X86 && 64BIT
+ select CRYPTO_BLKCIPHER
+ select CRYPTO_CHACHA20
+ help
+ ChaCha20 cipher algorithm, RFC7539.
+
+ ChaCha20 is a 256-bit high-speed stream cipher designed by Daniel J.
+ Bernstein and further specified in RFC7539 for use in IETF protocols.
+ This is the x86_64 assembler implementation using SIMD instructions.
+
+ See also:
+ <http://cr.yp.to/chacha/chacha-20080128.pdf>
+
config CRYPTO_SEED
tristate "SEED cipher algorithm"
select CRYPTO_ALGAPI
--
1.9.1
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