1 files changed, 303 insertions, 0 deletions
diff --git a/arch/arm64/crypto/sm4-ce-ccm-glue.c b/arch/arm64/crypto/sm4-ce-ccm-glue.c
new file mode 100644
index 000000000000..f2cec7b52efc
--- /dev/null
+++ b/arch/arm64/crypto/sm4-ce-ccm-glue.c
@@ -0,0 +1,303 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * SM4-CCM AEAD Algorithm using ARMv8 Crypto Extensions
+ * as specified in rfc8998
+ * https://datatracker.ietf.org/doc/html/rfc8998
+ *
+ * Copyright (C) 2022 Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
+ */
+
+#include <linux/module.h>
+#include <linux/crypto.h>
+#include <linux/kernel.h>
+#include <linux/cpufeature.h>
+#include <asm/neon.h>
+#include <crypto/scatterwalk.h>
+#include <crypto/internal/aead.h>
+#include <crypto/internal/skcipher.h>
+#include <crypto/sm4.h>
+#include "sm4-ce.h"
+
+asmlinkage void sm4_ce_cbcmac_update(const u32 *rkey_enc, u8 *mac,
+				     const u8 *src, unsigned int nblocks);
+asmlinkage void sm4_ce_ccm_enc(const u32 *rkey_enc, u8 *dst, const u8 *src,
+			       u8 *iv, unsigned int nbytes, u8 *mac);
+asmlinkage void sm4_ce_ccm_dec(const u32 *rkey_enc, u8 *dst, const u8 *src,
+			       u8 *iv, unsigned int nbytes, u8 *mac);
+asmlinkage void sm4_ce_ccm_final(const u32 *rkey_enc, u8 *iv, u8 *mac);
+
+
+static int ccm_setkey(struct crypto_aead *tfm, const u8 *key,
+		      unsigned int key_len)
+{
+	struct sm4_ctx *ctx = crypto_aead_ctx(tfm);
+
+	if (key_len != SM4_KEY_SIZE)
+		return -EINVAL;
+
+	kernel_neon_begin();
+	sm4_ce_expand_key(key, ctx->rkey_enc, ctx->rkey_dec,
+			  crypto_sm4_fk, crypto_sm4_ck);
+	kernel_neon_end();
+
+	return 0;
+}
+
+static int ccm_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
+{
+	if ((authsize & 1) || authsize < 4)
+		return -EINVAL;
+	return 0;
+}
+
+static int ccm_format_input(u8 info[], struct aead_request *req,
+			    unsigned int msglen)
+{
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	unsigned int l = req->iv[0] + 1;
+	unsigned int m;
+	__be32 len;
+
+	/* verify that CCM dimension 'L': 2 <= L <= 8 */
+	if (l < 2 || l > 8)
+		return -EINVAL;
+	if (l < 4 && msglen >> (8 * l))
+		return -EOVERFLOW;
+
+	memset(&req->iv[SM4_BLOCK_SIZE - l], 0, l);
+
+	memcpy(info, req->iv, SM4_BLOCK_SIZE);
+
+	m = crypto_aead_authsize(aead);
+
+	/* format flags field per RFC 3610/NIST 800-38C */
+	*info |= ((m - 2) / 2) << 3;
+	if (req->assoclen)
+		*info |= (1 << 6);
+
+	/*
+	 * format message length field,
+	 * Linux uses a u32 type to represent msglen
+	 */
+	if (l >= 4)
+		l = 4;
+
+	len = cpu_to_be32(msglen);
+	memcpy(&info[SM4_BLOCK_SIZE - l], (u8 *)&len + 4 - l, l);
+
+	return 0;
+}
+
+static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[])
+{
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	struct sm4_ctx *ctx = crypto_aead_ctx(aead);
+	struct __packed { __be16 l; __be32 h; } aadlen;
+	u32 assoclen = req->assoclen;
+	struct scatter_walk walk;
+	unsigned int len;
+
+	if (assoclen < 0xff00) {
+		aadlen.l = cpu_to_be16(assoclen);
+		len = 2;
+	} else {
+		aadlen.l = cpu_to_be16(0xfffe);
+		put_unaligned_be32(assoclen, &aadlen.h);
+		len = 6;
+	}
+
+	sm4_ce_crypt_block(ctx->rkey_enc, mac, mac);
+	crypto_xor(mac, (const u8 *)&aadlen, len);
+
+	scatterwalk_start(&walk, req->src);
+
+	do {
+		u32 n = scatterwalk_clamp(&walk, assoclen);
+		u8 *p, *ptr;
+
+		if (!n) {
+			scatterwalk_start(&walk, sg_next(walk.sg));
+			n = scatterwalk_clamp(&walk, assoclen);
+		}
+
+		p = ptr = scatterwalk_map(&walk);
+		assoclen -= n;
+		scatterwalk_advance(&walk, n);
+
+		while (n > 0) {
+			unsigned int l, nblocks;
+
+			if (len == SM4_BLOCK_SIZE) {
+				if (n < SM4_BLOCK_SIZE) {
+					sm4_ce_crypt_block(ctx->rkey_enc,
+							   mac, mac);
+
+					len = 0;
+				} else {
+					nblocks = n / SM4_BLOCK_SIZE;
+					sm4_ce_cbcmac_update(ctx->rkey_enc,
+							     mac, ptr, nblocks);
+
+					ptr += nblocks * SM4_BLOCK_SIZE;
+					n %= SM4_BLOCK_SIZE;
+
+					continue;
+				}
+			}
+
+			l = min(n, SM4_BLOCK_SIZE - len);
+			if (l) {
+				crypto_xor(mac + len, ptr, l);
+				len += l;
+				ptr += l;
+				n -= l;
+			}
+		}
+
+		scatterwalk_unmap(p);
+		scatterwalk_done(&walk, 0, assoclen);
+	} while (assoclen);
+}
+
+static int ccm_crypt(struct aead_request *req, struct skcipher_walk *walk,
+		     u32 *rkey_enc, u8 mac[],
+		     void (*sm4_ce_ccm_crypt)(const u32 *rkey_enc, u8 *dst,
+					const u8 *src, u8 *iv,
+					unsigned int nbytes, u8 *mac))
+{
+	u8 __aligned(8) ctr0[SM4_BLOCK_SIZE];
+	int err;
+
+	/* preserve the initial ctr0 for the TAG */
+	memcpy(ctr0, walk->iv, SM4_BLOCK_SIZE);
+	crypto_inc(walk->iv, SM4_BLOCK_SIZE);
+
+	kernel_neon_begin();
+
+	if (req->assoclen)
+		ccm_calculate_auth_mac(req, mac);
+
+	do {
+		unsigned int tail = walk->nbytes % SM4_BLOCK_SIZE;
+		const u8 *src = walk->src.virt.addr;
+		u8 *dst = walk->dst.virt.addr;
+
+		if (walk->nbytes == walk->total)
+			tail = 0;
+
+		if (walk->nbytes - tail)
+			sm4_ce_ccm_crypt(rkey_enc, dst, src, walk->iv,
+					 walk->nbytes - tail, mac);
+
+		if (walk->nbytes == walk->total)
+			sm4_ce_ccm_final(rkey_enc, ctr0, mac);
+
+		kernel_neon_end();
+
+		if (walk->nbytes) {
+			err = skcipher_walk_done(walk, tail);
+			if (err)
+				return err;
+			if (walk->nbytes)
+				kernel_neon_begin();
+		}
+	} while (walk->nbytes > 0);
+
+	return 0;
+}
+
+static int ccm_encrypt(struct aead_request *req)
+{
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	struct sm4_ctx *ctx = crypto_aead_ctx(aead);
+	u8 __aligned(8) mac[SM4_BLOCK_SIZE];
+	struct skcipher_walk walk;
+	int err;
+
+	err = ccm_format_input(mac, req, req->cryptlen);
+	if (err)
+		return err;
+
+	err = skcipher_walk_aead_encrypt(&walk, req, false);
+	if (err)
+		return err;
+
+	err = ccm_crypt(req, &walk, ctx->rkey_enc, mac, sm4_ce_ccm_enc);
+	if (err)
+		return err;
+
+	/* copy authtag to end of dst */
+	scatterwalk_map_and_copy(mac, req->dst, req->assoclen + req->cryptlen,
+				 crypto_aead_authsize(aead), 1);
+
+	return 0;
+}
+
+static int ccm_decrypt(struct aead_request *req)
+{
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	unsigned int authsize = crypto_aead_authsize(aead);
+	struct sm4_ctx *ctx = crypto_aead_ctx(aead);
+	u8 __aligned(8) mac[SM4_BLOCK_SIZE];
+	u8 authtag[SM4_BLOCK_SIZE];
+	struct skcipher_walk walk;
+	int err;
+
+	err = ccm_format_input(mac, req, req->cryptlen - authsize);
+	if (err)
+		return err;
+
+	err = skcipher_walk_aead_decrypt(&walk, req, false);
+	if (err)
+		return err;
+
+	err = ccm_crypt(req, &walk, ctx->rkey_enc, mac, sm4_ce_ccm_dec);
+	if (err)
+		return err;
+
+	/* compare calculated auth tag with the stored one */
+	scatterwalk_map_and_copy(authtag, req->src,
+				 req->assoclen + req->cryptlen - authsize,
+				 authsize, 0);
+
+	if (crypto_memneq(authtag, mac, authsize))
+		return -EBADMSG;
+
+	return 0;
+}
+
+static struct aead_alg sm4_ccm_alg = {
+	.base = {
+		.cra_name		= "ccm(sm4)",
+		.cra_driver_name	= "ccm-sm4-ce",
+		.cra_priority		= 400,
+		.cra_blocksize		= 1,
+		.cra_ctxsize		= sizeof(struct sm4_ctx),
+		.cra_module		= THIS_MODULE,
+	},
+	.ivsize		= SM4_BLOCK_SIZE,
+	.chunksize	= SM4_BLOCK_SIZE,
+	.maxauthsize	= SM4_BLOCK_SIZE,
+	.setkey		= ccm_setkey,
+	.setauthsize	= ccm_setauthsize,
+	.encrypt	= ccm_encrypt,
+	.decrypt	= ccm_decrypt,
+};
+
+static int __init sm4_ce_ccm_init(void)
+{
+	return crypto_register_aead(&sm4_ccm_alg);
+}
+
+static void __exit sm4_ce_ccm_exit(void)
+{
+	crypto_unregister_aead(&sm4_ccm_alg);
+}
+
+module_cpu_feature_match(SM4, sm4_ce_ccm_init);
+module_exit(sm4_ce_ccm_exit);
+
+MODULE_DESCRIPTION("Synchronous SM4 in CCM mode using ARMv8 Crypto Extensions");
+MODULE_ALIAS_CRYPTO("ccm(sm4)");
+MODULE_AUTHOR("Tianjia Zhang <tianjia.zhang@linux.alibaba.com>");
+MODULE_LICENSE("GPL v2");