This is a port to ARMv8 (Crypto Extensions) of the Intel implementation of the
GHASH Secure Hash (used in the Galois/Counter chaining mode). It relies on the
optional PMULL/PMULL2 instruction (polynomial multiply long, what Intel call
carry-less multiply).
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/arm64/crypto/Kconfig | 6 ++
arch/arm64/crypto/Makefile | 3 +
arch/arm64/crypto/ghash-ce-core.S | 95 +++++++++++++++++++++++
arch/arm64/crypto/ghash-ce-glue.c | 155 ++++++++++++++++++++++++++++++++++++++
4 files changed, 259 insertions(+)
create mode 100644 arch/arm64/crypto/ghash-ce-core.S
create mode 100644 arch/arm64/crypto/ghash-ce-glue.c
diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig
index eb1e99770c21..0c50859ee7b9 100644
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -18,4 +18,10 @@ config CRYPTO_SHA2_ARM64_CE
depends on ARM64 && KERNEL_MODE_NEON
select CRYPTO_HASH
+
+config CRYPTO_GHASH_ARM64_CE
+ tristate "GHASH (for GCM chaining mode) using ARMv8 Crypto Extensions"
+ depends on ARM64 && KERNEL_MODE_NEON
+ select CRYPTO_HASH
+
endif
diff --git a/arch/arm64/crypto/Makefile b/arch/arm64/crypto/Makefile
index 0b3885a60d43..e8c81a068868 100644
--- a/arch/arm64/crypto/Makefile
+++ b/arch/arm64/crypto/Makefile
@@ -13,3 +13,6 @@ sha1-ce-y := sha1-ce-glue.o sha1-ce-core.o
obj-$(CONFIG_CRYPTO_SHA2_ARM64_CE) += sha2-ce.o
sha2-ce-y := sha2-ce-glue.o sha2-ce-core.o
+
+obj-$(CONFIG_CRYPTO_GHASH_ARM64_CE) += ghash-ce.o
+ghash-ce-y := ghash-ce-glue.o ghash-ce-core.o
diff --git a/arch/arm64/crypto/ghash-ce-core.S b/arch/arm64/crypto/ghash-ce-core.S
new file mode 100644
index 000000000000..b9e6eaf41c9b
--- /dev/null
+++ b/arch/arm64/crypto/ghash-ce-core.S
@@ -0,0 +1,95 @@
+/*
+ * Accelerated GHASH implementation with ARMv8 PMULL instructions.
+ *
+ * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@xxxxxxxxxx>
+ *
+ * Based on arch/x86/crypto/ghash-pmullni-intel_asm.S
+ *
+ * Copyright (c) 2009 Intel Corp.
+ * Author: Huang Ying <ying.huang@xxxxxxxxx>
+ * Vinodh Gopal
+ * Erdinc Ozturk
+ * Deniz Karakoyunlu
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+ DATA .req v0
+ SHASH .req v1
+ IN1 .req v2
+ T1 .req v2
+ T2 .req v3
+ T3 .req v4
+ VZR .req v5
+
+ .text
+ .arch armv8-a+crypto
+
+ /*
+ * void pmull_ghash_update(int blocks, u64 dg[], const char *src,
+ * struct ghash_key const *k, const char *head)
+ */
+ENTRY(pmull_ghash_update)
+ ld1 {DATA.16b}, [x1]
+ ld1 {SHASH.16b}, [x3]
+ eor VZR.16b, VZR.16b, VZR.16b
+
+ /* do the head block first, if supplied */
+ cbz x4, 0f
+ ld1 {IN1.2d}, [x4]
+ b 1f
+
+0: ld1 {IN1.2d}, [x2], #16
+ sub w0, w0, #1
+1: ext IN1.16b, IN1.16b, IN1.16b, #8
+CPU_LE( rev64 IN1.16b, IN1.16b )
+ eor DATA.16b, DATA.16b, IN1.16b
+
+ /* multiply DATA by SHASH in GF(2^128) */
+ ext T2.16b, DATA.16b, DATA.16b, #8
+ ext T3.16b, SHASH.16b, SHASH.16b, #8
+ eor T2.16b, T2.16b, DATA.16b
+ eor T3.16b, T3.16b, SHASH.16b
+
+ pmull2 T1.1q, SHASH.2d, DATA.2d // a1 * b1
+ pmull DATA.1q, SHASH.1d, DATA.1d // a0 * b0
+ pmull T2.1q, T2.1d, T3.1d // (a1 + a0)(b1 + b0)
+ eor T2.16b, T2.16b, T1.16b // (a0 * b1) + (a1 * b0)
+ eor T2.16b, T2.16b, DATA.16b
+
+ ext T3.16b, VZR.16b, T2.16b, #8
+ ext T2.16b, T2.16b, VZR.16b, #8
+ eor DATA.16b, DATA.16b, T3.16b
+ eor T1.16b, T1.16b, T2.16b // <T1:DATA> is result of
+ // carry-less multiplication
+
+ /* first phase of the reduction */
+ shl T3.2d, DATA.2d, #1
+ eor T3.16b, T3.16b, DATA.16b
+ shl T3.2d, T3.2d, #5
+ eor T3.16b, T3.16b, DATA.16b
+ shl T3.2d, T3.2d, #57
+ ext T2.16b, VZR.16b, T3.16b, #8
+ ext T3.16b, T3.16b, VZR.16b, #8
+ eor DATA.16b, DATA.16b, T2.16b
+ eor T1.16b, T1.16b, T3.16b
+
+ /* second phase of the reduction */
+ ushr T2.2d, DATA.2d, #5
+ eor T2.16b, T2.16b, DATA.16b
+ ushr T2.2d, T2.2d, #1
+ eor T2.16b, T2.16b, DATA.16b
+ ushr T2.2d, T2.2d, #1
+ eor T1.16b, T1.16b, T2.16b
+ eor DATA.16b, DATA.16b, T1.16b
+
+ cbnz w0, 0b
+
+ st1 {DATA.16b}, [x1]
+ ret
+ENDPROC(pmull_ghash_update)
diff --git a/arch/arm64/crypto/ghash-ce-glue.c b/arch/arm64/crypto/ghash-ce-glue.c
new file mode 100644
index 000000000000..b92baf3f68c7
--- /dev/null
+++ b/arch/arm64/crypto/ghash-ce-glue.c
@@ -0,0 +1,155 @@
+/*
+ * Accelerated GHASH implementation with ARMv8 PMULL instructions.
+ *
+ * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <asm/neon.h>
+#include <asm/unaligned.h>
+#include <crypto/internal/hash.h>
+#include <linux/cpufeature.h>
+#include <linux/crypto.h>
+#include <linux/module.h>
+
+MODULE_DESCRIPTION("GHASH secure hash using ARMv8 Crypto Extensions");
+MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
+
+#define GHASH_BLOCK_SIZE 16
+#define GHASH_DIGEST_SIZE 16
+
+struct ghash_key {
+ u64 a;
+ u64 b;
+};
+
+struct ghash_desc_ctx {
+ u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
+ u8 buf[GHASH_BLOCK_SIZE];
+ u32 count;
+};
+
+asmlinkage void pmull_ghash_update(int blocks, u64 dg[], const char *src,
+ struct ghash_key const *k, const char *head);
+
+static int ghash_init(struct shash_desc *desc)
+{
+ struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
+
+ *ctx = (struct ghash_desc_ctx){};
+ return 0;
+}
+
+static int ghash_update(struct shash_desc *desc, const u8 *src,
+ unsigned int len)
+{
+ struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
+ unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
+
+ ctx->count += len;
+
+ if ((partial + len) >= GHASH_BLOCK_SIZE) {
+ struct ghash_key *key = crypto_shash_ctx(desc->tfm);
+ int blocks;
+
+ if (partial) {
+ int p = GHASH_BLOCK_SIZE - partial;
+
+ memcpy(ctx->buf + partial, src, p);
+ src += p;
+ len -= p;
+ }
+
+ blocks = len / GHASH_BLOCK_SIZE;
+ len %= GHASH_BLOCK_SIZE;
+
+ kernel_neon_begin_partial(6);
+ pmull_ghash_update(blocks, ctx->digest, src, key,
+ partial ? ctx->buf : NULL);
+ kernel_neon_end();
+ src += blocks * GHASH_BLOCK_SIZE;
+ }
+ if (len)
+ memcpy(ctx->buf + partial, src, len);
+ return 0;
+}
+
+static int ghash_final(struct shash_desc *desc, u8 *dst)
+{
+ struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
+ unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
+
+ if (partial) {
+ struct ghash_key *key = crypto_shash_ctx(desc->tfm);
+
+ memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
+
+ kernel_neon_begin_partial(6);
+ pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL);
+ kernel_neon_end();
+ }
+ put_unaligned_be64(ctx->digest[1], dst);
+ put_unaligned_be64(ctx->digest[0], dst + 8);
+
+ *ctx = (struct ghash_desc_ctx){};
+ return 0;
+}
+
+static int ghash_setkey(struct crypto_shash *tfm,
+ const u8 *inkey, unsigned int keylen)
+{
+ struct ghash_key *key = crypto_shash_ctx(tfm);
+ u64 a, b;
+
+ if (keylen != GHASH_BLOCK_SIZE) {
+ crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+ return -EINVAL;
+ }
+
+ /* perform multiplication by 'x' in GF(2^128) */
+ b = get_unaligned_be64(inkey);
+ a = get_unaligned_be64(inkey + 8);
+
+ key->a = (a << 1) | (b >> 63);
+ key->b = (b << 1) | (a >> 63);
+
+ if (b >> 63)
+ key->b ^= 0xc200000000000000UL;
+
+ return 0;
+}
+
+static struct shash_alg ghash_alg = {
+ .digestsize = GHASH_DIGEST_SIZE,
+ .init = ghash_init,
+ .update = ghash_update,
+ .final = ghash_final,
+ .setkey = ghash_setkey,
+ .descsize = sizeof(struct ghash_desc_ctx),
+ .base = {
+ .cra_name = "ghash",
+ .cra_driver_name = "ghash-ce",
+ .cra_priority = 200,
+ .cra_flags = CRYPTO_ALG_TYPE_SHASH,
+ .cra_blocksize = GHASH_BLOCK_SIZE,
+ .cra_ctxsize = sizeof(struct ghash_key),
+ .cra_module = THIS_MODULE,
+ },
+};
+
+static int __init ghash_ce_mod_init(void)
+{
+ return crypto_register_shash(&ghash_alg);
+}
+
+static void __exit ghash_ce_mod_exit(void)
+{
+ crypto_unregister_shash(&ghash_alg);
+}
+
+module_cpu_feature_match(PMULL, ghash_ce_mod_init);
+module_exit(ghash_ce_mod_exit);
--
1.8.3.2
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