crypto: arm/nhpoly1305 - add NEON-accelerated NHPoly1305
authorEric Biggers <ebiggers@google.com>
Sat, 17 Nov 2018 01:26:30 +0000 (17:26 -0800)
committerHerbert Xu <herbert@gondor.apana.org.au>
Tue, 20 Nov 2018 06:26:56 +0000 (14:26 +0800)
Add an ARM NEON implementation of NHPoly1305, an ε-almost-∆-universal
hash function used in the Adiantum encryption mode.  For now, only the
NH portion is actually NEON-accelerated; the Poly1305 part is less
performance-critical so is just implemented in C.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
arch/arm/crypto/Kconfig
arch/arm/crypto/Makefile
arch/arm/crypto/nh-neon-core.S [new file with mode: 0644]
arch/arm/crypto/nhpoly1305-neon-glue.c [new file with mode: 0644]

index 59c674c..a95322b 100644 (file)
@@ -131,4 +131,9 @@ config CRYPTO_CHACHA20_NEON
        select CRYPTO_BLKCIPHER
        select CRYPTO_CHACHA20
 
+config CRYPTO_NHPOLY1305_NEON
+       tristate "NEON accelerated NHPoly1305 hash function (for Adiantum)"
+       depends on KERNEL_MODE_NEON
+       select CRYPTO_NHPOLY1305
+
 endif
index 005482f..b65d6bf 100644 (file)
@@ -10,6 +10,7 @@ obj-$(CONFIG_CRYPTO_SHA1_ARM_NEON) += sha1-arm-neon.o
 obj-$(CONFIG_CRYPTO_SHA256_ARM) += sha256-arm.o
 obj-$(CONFIG_CRYPTO_SHA512_ARM) += sha512-arm.o
 obj-$(CONFIG_CRYPTO_CHACHA20_NEON) += chacha-neon.o
+obj-$(CONFIG_CRYPTO_NHPOLY1305_NEON) += nhpoly1305-neon.o
 
 ce-obj-$(CONFIG_CRYPTO_AES_ARM_CE) += aes-arm-ce.o
 ce-obj-$(CONFIG_CRYPTO_SHA1_ARM_CE) += sha1-arm-ce.o
@@ -53,6 +54,7 @@ ghash-arm-ce-y        := ghash-ce-core.o ghash-ce-glue.o
 crct10dif-arm-ce-y     := crct10dif-ce-core.o crct10dif-ce-glue.o
 crc32-arm-ce-y:= crc32-ce-core.o crc32-ce-glue.o
 chacha-neon-y := chacha-neon-core.o chacha-neon-glue.o
+nhpoly1305-neon-y := nh-neon-core.o nhpoly1305-neon-glue.o
 
 ifdef REGENERATE_ARM_CRYPTO
 quiet_cmd_perl = PERL    $@
diff --git a/arch/arm/crypto/nh-neon-core.S b/arch/arm/crypto/nh-neon-core.S
new file mode 100644 (file)
index 0000000..434d80a
--- /dev/null
@@ -0,0 +1,116 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * NH - ε-almost-universal hash function, NEON accelerated version
+ *
+ * Copyright 2018 Google LLC
+ *
+ * Author: Eric Biggers <ebiggers@google.com>
+ */
+
+#include <linux/linkage.h>
+
+       .text
+       .fpu            neon
+
+       KEY             .req    r0
+       MESSAGE         .req    r1
+       MESSAGE_LEN     .req    r2
+       HASH            .req    r3
+
+       PASS0_SUMS      .req    q0
+       PASS0_SUM_A     .req    d0
+       PASS0_SUM_B     .req    d1
+       PASS1_SUMS      .req    q1
+       PASS1_SUM_A     .req    d2
+       PASS1_SUM_B     .req    d3
+       PASS2_SUMS      .req    q2
+       PASS2_SUM_A     .req    d4
+       PASS2_SUM_B     .req    d5
+       PASS3_SUMS      .req    q3
+       PASS3_SUM_A     .req    d6
+       PASS3_SUM_B     .req    d7
+       K0              .req    q4
+       K1              .req    q5
+       K2              .req    q6
+       K3              .req    q7
+       T0              .req    q8
+       T0_L            .req    d16
+       T0_H            .req    d17
+       T1              .req    q9
+       T1_L            .req    d18
+       T1_H            .req    d19
+       T2              .req    q10
+       T2_L            .req    d20
+       T2_H            .req    d21
+       T3              .req    q11
+       T3_L            .req    d22
+       T3_H            .req    d23
+
+.macro _nh_stride      k0, k1, k2, k3
+
+       // Load next message stride
+       vld1.8          {T3}, [MESSAGE]!
+
+       // Load next key stride
+       vld1.32         {\k3}, [KEY]!
+
+       // Add message words to key words
+       vadd.u32        T0, T3, \k0
+       vadd.u32        T1, T3, \k1
+       vadd.u32        T2, T3, \k2
+       vadd.u32        T3, T3, \k3
+
+       // Multiply 32x32 => 64 and accumulate
+       vmlal.u32       PASS0_SUMS, T0_L, T0_H
+       vmlal.u32       PASS1_SUMS, T1_L, T1_H
+       vmlal.u32       PASS2_SUMS, T2_L, T2_H
+       vmlal.u32       PASS3_SUMS, T3_L, T3_H
+.endm
+
+/*
+ * void nh_neon(const u32 *key, const u8 *message, size_t message_len,
+ *             u8 hash[NH_HASH_BYTES])
+ *
+ * It's guaranteed that message_len % 16 == 0.
+ */
+ENTRY(nh_neon)
+
+       vld1.32         {K0,K1}, [KEY]!
+         vmov.u64      PASS0_SUMS, #0
+         vmov.u64      PASS1_SUMS, #0
+       vld1.32         {K2}, [KEY]!
+         vmov.u64      PASS2_SUMS, #0
+         vmov.u64      PASS3_SUMS, #0
+
+       subs            MESSAGE_LEN, MESSAGE_LEN, #64
+       blt             .Lloop4_done
+.Lloop4:
+       _nh_stride      K0, K1, K2, K3
+       _nh_stride      K1, K2, K3, K0
+       _nh_stride      K2, K3, K0, K1
+       _nh_stride      K3, K0, K1, K2
+       subs            MESSAGE_LEN, MESSAGE_LEN, #64
+       bge             .Lloop4
+
+.Lloop4_done:
+       ands            MESSAGE_LEN, MESSAGE_LEN, #63
+       beq             .Ldone
+       _nh_stride      K0, K1, K2, K3
+
+       subs            MESSAGE_LEN, MESSAGE_LEN, #16
+       beq             .Ldone
+       _nh_stride      K1, K2, K3, K0
+
+       subs            MESSAGE_LEN, MESSAGE_LEN, #16
+       beq             .Ldone
+       _nh_stride      K2, K3, K0, K1
+
+.Ldone:
+       // Sum the accumulators for each pass, then store the sums to 'hash'
+       vadd.u64        T0_L, PASS0_SUM_A, PASS0_SUM_B
+       vadd.u64        T0_H, PASS1_SUM_A, PASS1_SUM_B
+       vadd.u64        T1_L, PASS2_SUM_A, PASS2_SUM_B
+       vadd.u64        T1_H, PASS3_SUM_A, PASS3_SUM_B
+       vst1.8          {T0-T1}, [HASH]
+       bx              lr
+ENDPROC(nh_neon)
diff --git a/arch/arm/crypto/nhpoly1305-neon-glue.c b/arch/arm/crypto/nhpoly1305-neon-glue.c
new file mode 100644 (file)
index 0000000..49aae87
--- /dev/null
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NHPoly1305 - ε-almost-∆-universal hash function for Adiantum
+ * (NEON accelerated version)
+ *
+ * Copyright 2018 Google LLC
+ */
+
+#include <asm/neon.h>
+#include <asm/simd.h>
+#include <crypto/internal/hash.h>
+#include <crypto/nhpoly1305.h>
+#include <linux/module.h>
+
+asmlinkage void nh_neon(const u32 *key, const u8 *message, size_t message_len,
+                       u8 hash[NH_HASH_BYTES]);
+
+/* wrapper to avoid indirect call to assembly, which doesn't work with CFI */
+static void _nh_neon(const u32 *key, const u8 *message, size_t message_len,
+                    __le64 hash[NH_NUM_PASSES])
+{
+       nh_neon(key, message, message_len, (u8 *)hash);
+}
+
+static int nhpoly1305_neon_update(struct shash_desc *desc,
+                                 const u8 *src, unsigned int srclen)
+{
+       if (srclen < 64 || !may_use_simd())
+               return crypto_nhpoly1305_update(desc, src, srclen);
+
+       do {
+               unsigned int n = min_t(unsigned int, srclen, PAGE_SIZE);
+
+               kernel_neon_begin();
+               crypto_nhpoly1305_update_helper(desc, src, n, _nh_neon);
+               kernel_neon_end();
+               src += n;
+               srclen -= n;
+       } while (srclen);
+       return 0;
+}
+
+static struct shash_alg nhpoly1305_alg = {
+       .base.cra_name          = "nhpoly1305",
+       .base.cra_driver_name   = "nhpoly1305-neon",
+       .base.cra_priority      = 200,
+       .base.cra_ctxsize       = sizeof(struct nhpoly1305_key),
+       .base.cra_module        = THIS_MODULE,
+       .digestsize             = POLY1305_DIGEST_SIZE,
+       .init                   = crypto_nhpoly1305_init,
+       .update                 = nhpoly1305_neon_update,
+       .final                  = crypto_nhpoly1305_final,
+       .setkey                 = crypto_nhpoly1305_setkey,
+       .descsize               = sizeof(struct nhpoly1305_state),
+};
+
+static int __init nhpoly1305_mod_init(void)
+{
+       if (!(elf_hwcap & HWCAP_NEON))
+               return -ENODEV;
+
+       return crypto_register_shash(&nhpoly1305_alg);
+}
+
+static void __exit nhpoly1305_mod_exit(void)
+{
+       crypto_unregister_shash(&nhpoly1305_alg);
+}
+
+module_init(nhpoly1305_mod_init);
+module_exit(nhpoly1305_mod_exit);
+
+MODULE_DESCRIPTION("NHPoly1305 ε-almost-∆-universal hash function (NEON-accelerated)");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Eric Biggers <ebiggers@google.com>");
+MODULE_ALIAS_CRYPTO("nhpoly1305");
+MODULE_ALIAS_CRYPTO("nhpoly1305-neon");