1 files changed, 517 insertions, 0 deletions

diff --git a/arch/arm64/crypto/ghash-ce-glue.c b/arch/arm64/crypto/ghash-ce-glue.c
new file mode 100644
index 000000000..15794fe21
--- /dev/null
+++ b/arch/arm64/crypto/ghash-ce-glue.c
@@ -0,0 +1,517 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Accelerated GHASH implementation with ARMv8 PMULL instructions.
+ *
+ * Copyright (C) 2014 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org>
+ */
+
+#include <asm/neon.h>
+#include <asm/simd.h>
+#include <asm/unaligned.h>
+#include <crypto/aes.h>
+#include <crypto/algapi.h>
+#include <crypto/b128ops.h>
+#include <crypto/gf128mul.h>
+#include <crypto/internal/aead.h>
+#include <crypto/internal/hash.h>
+#include <crypto/internal/simd.h>
+#include <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.h>
+#include <linux/cpufeature.h>
+#include <linux/crypto.h>
+#include <linux/module.h>
+
+MODULE_DESCRIPTION("GHASH and AES-GCM using ARMv8 Crypto Extensions");
+MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_CRYPTO("ghash");
+
+#define GHASH_BLOCK_SIZE	16
+#define GHASH_DIGEST_SIZE	16
+#define GCM_IV_SIZE		12
+
+struct ghash_key {
+	be128			k;
+	u64			h[][2];
+};
+
+struct ghash_desc_ctx {
+	u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
+	u8 buf[GHASH_BLOCK_SIZE];
+	u32 count;
+};
+
+struct gcm_aes_ctx {
+	struct crypto_aes_ctx	aes_key;
+	struct ghash_key	ghash_key;
+};
+
+asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src,
+				       u64 const h[][2], const char *head);
+
+asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src,
+				      u64 const h[][2], const char *head);
+
+asmlinkage void pmull_gcm_encrypt(int bytes, u8 dst[], const u8 src[],
+				  u64 const h[][2], u64 dg[], u8 ctr[],
+				  u32 const rk[], int rounds, u8 tag[]);
+asmlinkage int pmull_gcm_decrypt(int bytes, u8 dst[], const u8 src[],
+				 u64 const h[][2], u64 dg[], u8 ctr[],
+				 u32 const rk[], int rounds, const u8 l[],
+				 const u8 tag[], u64 authsize);
+
+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 void ghash_do_update(int blocks, u64 dg[], const char *src,
+			    struct ghash_key *key, const char *head)
+{
+	be128 dst = { cpu_to_be64(dg[1]), cpu_to_be64(dg[0]) };
+
+	do {
+		const u8 *in = src;
+
+		if (head) {
+			in = head;
+			blocks++;
+			head = NULL;
+		} else {
+			src += GHASH_BLOCK_SIZE;
+		}
+
+		crypto_xor((u8 *)&dst, in, GHASH_BLOCK_SIZE);
+		gf128mul_lle(&dst, &key->k);
+	} while (--blocks);
+
+	dg[0] = be64_to_cpu(dst.b);
+	dg[1] = be64_to_cpu(dst.a);
+}
+
+static __always_inline
+void ghash_do_simd_update(int blocks, u64 dg[], const char *src,
+			  struct ghash_key *key, const char *head,
+			  void (*simd_update)(int blocks, u64 dg[],
+					      const char *src,
+					      u64 const h[][2],
+					      const char *head))
+{
+	if (likely(crypto_simd_usable())) {
+		kernel_neon_begin();
+		simd_update(blocks, dg, src, key->h, head);
+		kernel_neon_end();
+	} else {
+		ghash_do_update(blocks, dg, src, key, head);
+	}
+}
+
+/* avoid hogging the CPU for too long */
+#define MAX_BLOCKS	(SZ_64K / GHASH_BLOCK_SIZE)
+
+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;
+
+		do {
+			int chunk = min(blocks, MAX_BLOCKS);
+
+			ghash_do_simd_update(chunk, ctx->digest, src, key,
+					     partial ? ctx->buf : NULL,
+					     pmull_ghash_update_p8);
+
+			blocks -= chunk;
+			src += chunk * GHASH_BLOCK_SIZE;
+			partial = 0;
+		} while (unlikely(blocks > 0));
+	}
+	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);
+
+		ghash_do_simd_update(1, ctx->digest, ctx->buf, key, NULL,
+				     pmull_ghash_update_p8);
+	}
+	put_unaligned_be64(ctx->digest[1], dst);
+	put_unaligned_be64(ctx->digest[0], dst + 8);
+
+	memzero_explicit(ctx, sizeof(*ctx));
+	return 0;
+}
+
+static void ghash_reflect(u64 h[], const be128 *k)
+{
+	u64 carry = be64_to_cpu(k->a) & BIT(63) ? 1 : 0;
+
+	h[0] = (be64_to_cpu(k->b) << 1) | carry;
+	h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63);
+
+	if (carry)
+		h[1] ^= 0xc200000000000000UL;
+}
+
+static int ghash_setkey(struct crypto_shash *tfm,
+			const u8 *inkey, unsigned int keylen)
+{
+	struct ghash_key *key = crypto_shash_ctx(tfm);
+
+	if (keylen != GHASH_BLOCK_SIZE)
+		return -EINVAL;
+
+	/* needed for the fallback */
+	memcpy(&key->k, inkey, GHASH_BLOCK_SIZE);
+
+	ghash_reflect(key->h[0], &key->k);
+	return 0;
+}
+
+static struct shash_alg ghash_alg = {
+	.base.cra_name		= "ghash",
+	.base.cra_driver_name	= "ghash-neon",
+	.base.cra_priority	= 150,
+	.base.cra_blocksize	= GHASH_BLOCK_SIZE,
+	.base.cra_ctxsize	= sizeof(struct ghash_key) + sizeof(u64[2]),
+	.base.cra_module	= THIS_MODULE,
+
+	.digestsize		= GHASH_DIGEST_SIZE,
+	.init			= ghash_init,
+	.update			= ghash_update,
+	.final			= ghash_final,
+	.setkey			= ghash_setkey,
+	.descsize		= sizeof(struct ghash_desc_ctx),
+};
+
+static int num_rounds(struct crypto_aes_ctx *ctx)
+{
+	/*
+	 * # of rounds specified by AES:
+	 * 128 bit key		10 rounds
+	 * 192 bit key		12 rounds
+	 * 256 bit key		14 rounds
+	 * => n byte key	=> 6 + (n/4) rounds
+	 */
+	return 6 + ctx->key_length / 4;
+}
+
+static int gcm_setkey(struct crypto_aead *tfm, const u8 *inkey,
+		      unsigned int keylen)
+{
+	struct gcm_aes_ctx *ctx = crypto_aead_ctx(tfm);
+	u8 key[GHASH_BLOCK_SIZE];
+	be128 h;
+	int ret;
+
+	ret = aes_expandkey(&ctx->aes_key, inkey, keylen);
+	if (ret)
+		return -EINVAL;
+
+	aes_encrypt(&ctx->aes_key, key, (u8[AES_BLOCK_SIZE]){});
+
+	/* needed for the fallback */
+	memcpy(&ctx->ghash_key.k, key, GHASH_BLOCK_SIZE);
+
+	ghash_reflect(ctx->ghash_key.h[0], &ctx->ghash_key.k);
+
+	h = ctx->ghash_key.k;
+	gf128mul_lle(&h, &ctx->ghash_key.k);
+	ghash_reflect(ctx->ghash_key.h[1], &h);
+
+	gf128mul_lle(&h, &ctx->ghash_key.k);
+	ghash_reflect(ctx->ghash_key.h[2], &h);
+
+	gf128mul_lle(&h, &ctx->ghash_key.k);
+	ghash_reflect(ctx->ghash_key.h[3], &h);
+
+	return 0;
+}
+
+static int gcm_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
+{
+	switch (authsize) {
+	case 4:
+	case 8:
+	case 12 ... 16:
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void gcm_update_mac(u64 dg[], const u8 *src, int count, u8 buf[],
+			   int *buf_count, struct gcm_aes_ctx *ctx)
+{
+	if (*buf_count > 0) {
+		int buf_added = min(count, GHASH_BLOCK_SIZE - *buf_count);
+
+		memcpy(&buf[*buf_count], src, buf_added);
+
+		*buf_count += buf_added;
+		src += buf_added;
+		count -= buf_added;
+	}
+
+	if (count >= GHASH_BLOCK_SIZE || *buf_count == GHASH_BLOCK_SIZE) {
+		int blocks = count / GHASH_BLOCK_SIZE;
+
+		ghash_do_simd_update(blocks, dg, src, &ctx->ghash_key,
+				     *buf_count ? buf : NULL,
+				     pmull_ghash_update_p64);
+
+		src += blocks * GHASH_BLOCK_SIZE;
+		count %= GHASH_BLOCK_SIZE;
+		*buf_count = 0;
+	}
+
+	if (count > 0) {
+		memcpy(buf, src, count);
+		*buf_count = count;
+	}
+}
+
+static void gcm_calculate_auth_mac(struct aead_request *req, u64 dg[])
+{
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead);
+	u8 buf[GHASH_BLOCK_SIZE];
+	struct scatter_walk walk;
+	u32 len = req->assoclen;
+	int buf_count = 0;
+
+	scatterwalk_start(&walk, req->src);
+
+	do {
+		u32 n = scatterwalk_clamp(&walk, len);
+		u8 *p;
+
+		if (!n) {
+			scatterwalk_start(&walk, sg_next(walk.sg));
+			n = scatterwalk_clamp(&walk, len);
+		}
+		p = scatterwalk_map(&walk);
+
+		gcm_update_mac(dg, p, n, buf, &buf_count, ctx);
+		len -= n;
+
+		scatterwalk_unmap(p);
+		scatterwalk_advance(&walk, n);
+		scatterwalk_done(&walk, 0, len);
+	} while (len);
+
+	if (buf_count) {
+		memset(&buf[buf_count], 0, GHASH_BLOCK_SIZE - buf_count);
+		ghash_do_simd_update(1, dg, buf, &ctx->ghash_key, NULL,
+				     pmull_ghash_update_p64);
+	}
+}
+
+static int gcm_encrypt(struct aead_request *req)
+{
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead);
+	int nrounds = num_rounds(&ctx->aes_key);
+	struct skcipher_walk walk;
+	u8 buf[AES_BLOCK_SIZE];
+	u8 iv[AES_BLOCK_SIZE];
+	u64 dg[2] = {};
+	be128 lengths;
+	u8 *tag;
+	int err;
+
+	lengths.a = cpu_to_be64(req->assoclen * 8);
+	lengths.b = cpu_to_be64(req->cryptlen * 8);
+
+	if (req->assoclen)
+		gcm_calculate_auth_mac(req, dg);
+
+	memcpy(iv, req->iv, GCM_IV_SIZE);
+	put_unaligned_be32(2, iv + GCM_IV_SIZE);
+
+	err = skcipher_walk_aead_encrypt(&walk, req, false);
+
+	do {
+		const u8 *src = walk.src.virt.addr;
+		u8 *dst = walk.dst.virt.addr;
+		int nbytes = walk.nbytes;
+
+		tag = (u8 *)&lengths;
+
+		if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) {
+			src = dst = memcpy(buf + sizeof(buf) - nbytes,
+					   src, nbytes);
+		} else if (nbytes < walk.total) {
+			nbytes &= ~(AES_BLOCK_SIZE - 1);
+			tag = NULL;
+		}
+
+		kernel_neon_begin();
+		pmull_gcm_encrypt(nbytes, dst, src, ctx->ghash_key.h,
+				  dg, iv, ctx->aes_key.key_enc, nrounds,
+				  tag);
+		kernel_neon_end();
+
+		if (unlikely(!nbytes))
+			break;
+
+		if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE))
+			memcpy(walk.dst.virt.addr,
+			       buf + sizeof(buf) - nbytes, nbytes);
+
+		err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
+	} while (walk.nbytes);
+
+	if (err)
+		return err;
+
+	/* copy authtag to end of dst */
+	scatterwalk_map_and_copy(tag, req->dst, req->assoclen + req->cryptlen,
+				 crypto_aead_authsize(aead), 1);
+
+	return 0;
+}
+
+static int gcm_decrypt(struct aead_request *req)
+{
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead);
+	unsigned int authsize = crypto_aead_authsize(aead);
+	int nrounds = num_rounds(&ctx->aes_key);
+	struct skcipher_walk walk;
+	u8 otag[AES_BLOCK_SIZE];
+	u8 buf[AES_BLOCK_SIZE];
+	u8 iv[AES_BLOCK_SIZE];
+	u64 dg[2] = {};
+	be128 lengths;
+	u8 *tag;
+	int ret;
+	int err;
+
+	lengths.a = cpu_to_be64(req->assoclen * 8);
+	lengths.b = cpu_to_be64((req->cryptlen - authsize) * 8);
+
+	if (req->assoclen)
+		gcm_calculate_auth_mac(req, dg);
+
+	memcpy(iv, req->iv, GCM_IV_SIZE);
+	put_unaligned_be32(2, iv + GCM_IV_SIZE);
+
+	scatterwalk_map_and_copy(otag, req->src,
+				 req->assoclen + req->cryptlen - authsize,
+				 authsize, 0);
+
+	err = skcipher_walk_aead_decrypt(&walk, req, false);
+
+	do {
+		const u8 *src = walk.src.virt.addr;
+		u8 *dst = walk.dst.virt.addr;
+		int nbytes = walk.nbytes;
+
+		tag = (u8 *)&lengths;
+
+		if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) {
+			src = dst = memcpy(buf + sizeof(buf) - nbytes,
+					   src, nbytes);
+		} else if (nbytes < walk.total) {
+			nbytes &= ~(AES_BLOCK_SIZE - 1);
+			tag = NULL;
+		}
+
+		kernel_neon_begin();
+		ret = pmull_gcm_decrypt(nbytes, dst, src, ctx->ghash_key.h,
+					dg, iv, ctx->aes_key.key_enc,
+					nrounds, tag, otag, authsize);
+		kernel_neon_end();
+
+		if (unlikely(!nbytes))
+			break;
+
+		if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE))
+			memcpy(walk.dst.virt.addr,
+			       buf + sizeof(buf) - nbytes, nbytes);
+
+		err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
+	} while (walk.nbytes);
+
+	if (err)
+		return err;
+
+	return ret ? -EBADMSG : 0;
+}
+
+static struct aead_alg gcm_aes_alg = {
+	.ivsize			= GCM_IV_SIZE,
+	.chunksize		= AES_BLOCK_SIZE,
+	.maxauthsize		= AES_BLOCK_SIZE,
+	.setkey			= gcm_setkey,
+	.setauthsize		= gcm_setauthsize,
+	.encrypt		= gcm_encrypt,
+	.decrypt		= gcm_decrypt,
+
+	.base.cra_name		= "gcm(aes)",
+	.base.cra_driver_name	= "gcm-aes-ce",
+	.base.cra_priority	= 300,
+	.base.cra_blocksize	= 1,
+	.base.cra_ctxsize	= sizeof(struct gcm_aes_ctx) +
+				  4 * sizeof(u64[2]),
+	.base.cra_module	= THIS_MODULE,
+};
+
+static int __init ghash_ce_mod_init(void)
+{
+	if (!cpu_have_named_feature(ASIMD))
+		return -ENODEV;
+
+	if (cpu_have_named_feature(PMULL))
+		return crypto_register_aead(&gcm_aes_alg);
+
+	return crypto_register_shash(&ghash_alg);
+}
+
+static void __exit ghash_ce_mod_exit(void)
+{
+	if (cpu_have_named_feature(PMULL))
+		crypto_unregister_aead(&gcm_aes_alg);
+	else
+		crypto_unregister_shash(&ghash_alg);
+}
+
+static const struct cpu_feature ghash_cpu_feature[] = {
+	{ cpu_feature(PMULL) }, { }
+};
+MODULE_DEVICE_TABLE(cpu, ghash_cpu_feature);
+
+module_init(ghash_ce_mod_init);
+module_exit(ghash_ce_mod_exit);