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>
---
Only mildly tested, mainly because the internal tcrypt routine only supplies
a single test vector for ghash.
Again, this patch requires the NEON patches to allow kernel mode NEON in
(soft)irq context.
arch/arm64/crypto/Kconfig | 5 ++
arch/arm64/crypto/Makefile | 3 +
arch/arm64/crypto/ghash-ce-core.S | 119 +++++++++++++++++++++++++++++++
arch/arm64/crypto/ghash-ce-glue.c | 143 ++++++++++++++++++++++++++++++++++++++
4 files changed, 270 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 2e869f4b925a..7b5da897a904 100644
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -42,4 +42,9 @@ config CRYPTO_AES_ARM64_NEON_BLK
select CRYPTO_AES
select CRYPTO_ABLK_HELPER
+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 23fbe222cba8..8ad5c8fc8527 100644
--- a/arch/arm64/crypto/Makefile
+++ b/arch/arm64/crypto/Makefile
@@ -33,3 +33,6 @@ CFLAGS_aes-glue-ce.o := -DUSE_V8_CRYPTO_EXTENSIONS
$(obj)/aes-glue-%.o: $(src)/aes-glue.c FORCE
$(call if_changed_dep,cc_o_c)
+
+obj-$(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..a150ad7cae65
--- /dev/null
+++ b/arch/arm64/crypto/ghash-ce-core.S
@@ -0,0 +1,119 @@
+/*
+ * 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
+ T1 .req v2
+ T2 .req v3
+ T3 .req v4
+ T4 .req v5
+ IN1 .req v5
+
+ .text
+ .arch armv8-a+crypto
+ .align 3
+
+ /*
+ * void pmull_ghash_update(char *dst, const char *src, u32 blocks,
+ * const be128 *shash, const char *head);
+ */
+ENTRY(pmull_ghash_update)
+ ld1 {DATA.2d}, [x0]
+ ld1 {SHASH.2d}, [x3]
+
+ /* do the head block first, if supplied */
+ cbz x4, 0f
+ ld1 {IN1.2d}, [x4], #16
+ b 1f
+
+0: sub w2, w2, #1
+ ld1 {IN1.2d}, [x1], #16
+1: rev64 IN1.16b, IN1.16b
+CPU_LE( ext IN1.16b, IN1.16b, IN1.16b, #8 )
+ eor DATA.16b, DATA.16b, IN1.16b
+
+ /* multiply DATA by SHASH in GF(2^128) */
+ eor T4.16b, T4.16b, T4.16b
+ 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, T4.16b, T2.16b, #8
+ ext T2.16b, T2.16b, T4.16b, #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, T4.16b, T3.16b, #8
+ ext T3.16b, T3.16b, T4.16b, #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 w2, 0b
+
+ st1 {DATA.2d}, [x0]
+ ret
+ENDPROC(pmull_ghash_update)
+
+ /*
+ * void pmull_ghash_setkey(be128 *shash, const u8 *key);
+ *
+ * Calculate hash_key << 1 mod poly
+ */
+ENTRY(pmull_ghash_setkey)
+ ldp x2, x3, [x1]
+ movz x4, #0xc200, lsl #48 // BE GF(2^128) multiply mask
+CPU_LE( rev x5, x2 )
+CPU_LE( rev x6, x3 )
+CPU_BE( mov x5, x3 )
+CPU_BE( mov x6, x2 )
+ asr x7, x5, #63
+ lsl x2, x6, #1
+ and x1, x4, x7
+ extr x3, x5, x6, #63
+ and x7, x7, #1
+ eor x3, x3, x1
+ eor x2, x2, x7
+ stp x2, x3, [x0]
+ ret
+ENDPROC(pmull_ghash_setkey)
diff --git a/arch/arm64/crypto/ghash-ce-glue.c b/arch/arm64/crypto/ghash-ce-glue.c
new file mode 100644
index 000000000000..1147646a3155
--- /dev/null
+++ b/arch/arm64/crypto/ghash-ce-glue.c
@@ -0,0 +1,143 @@
+/*
+ * 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 <crypto/gf128mul.h>
+#include <crypto/internal/hash.h>
+#include <linux/cpufeature.h>
+#include <linux/crypto.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.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
+
+asmlinkage void pmull_ghash_update(char *dst, const char *src, unsigned int len,
+ const be128 *shash, const char *head);
+
+asmlinkage void pmull_ghash_setkey(be128 *shash, const u8 *key);
+
+struct ghash_desc_ctx {
+ u8 digest[GHASH_DIGEST_SIZE];
+ u8 buf[GHASH_BLOCK_SIZE];
+ u32 count;
+};
+
+static int ghash_init(struct shash_desc *desc)
+{
+ struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+
+ *dctx = (struct ghash_desc_ctx){};
+ return 0;
+}
+
+static int ghash_update(struct shash_desc *desc, const u8 *src,
+ unsigned int len)
+{
+ struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+ unsigned int partial = dctx->count % GHASH_BLOCK_SIZE;
+
+ dctx->count += len;
+
+ if ((partial + len) >= GHASH_BLOCK_SIZE) {
+ be128 *skey = crypto_shash_ctx(desc->tfm);
+ int blocks;
+
+ if (partial) {
+ int p = GHASH_BLOCK_SIZE - partial;
+
+ memcpy(dctx->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(dctx->digest, src, blocks, skey,
+ partial ? dctx->buf : NULL);
+ kernel_neon_end();
+
+ src += blocks * GHASH_BLOCK_SIZE;
+ partial = 0;
+ }
+ if (len)
+ memcpy(dctx->buf + partial, src, len);
+ return 0;
+}
+
+static int ghash_final(struct shash_desc *desc, u8 *dst)
+{
+ struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
+ int i;
+
+ if (dctx->count % GHASH_BLOCK_SIZE) {
+ be128 *skey = crypto_shash_ctx(desc->tfm);
+
+ kernel_neon_begin_partial(6);
+ pmull_ghash_update(dctx->digest, NULL, 0, skey, dctx->buf);
+ kernel_neon_end();
+ }
+ for (i = 0; i < GHASH_DIGEST_SIZE; i++)
+ dst[i] = dctx->digest[GHASH_DIGEST_SIZE - i - 1];
+
+ return 0;
+}
+
+static int ghash_setkey(struct crypto_shash *tfm,
+ const u8 *key, unsigned int keylen)
+{
+ be128 *skey = crypto_shash_ctx(tfm);
+
+ if (keylen != GHASH_BLOCK_SIZE) {
+ crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+ return -EINVAL;
+ }
+ pmull_ghash_setkey(skey, key);
+ 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(be128),
+ .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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