crypto: inside-secure - Add support for the ecb(sm4) skcipher

This patch adds support for SM4 in ECB mode, i.e. skcipher ecb(sm4).

changes since v1:
- make SAFEXCEL_SM4 case entry explit, using the proper SM4_BLOCK_SIZE
  instead of "borrowing" the AES code which "coincidentally" works
Signed-off-by: Pascal van Leeuwen <pvanleeuwen@verimatrix.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/inside-secure/safexcel.c

@@ -1178,6 +1178,7 @@ static struct safexcel_alg_template *safexcel_algs[] = {
 	&safexcel_alg_chachapoly_esp,
 	&safexcel_alg_sm3,
 	&safexcel_alg_hmac_sm3,
+	&safexcel_alg_ecb_sm4,
 };
 
 static int safexcel_register_algorithms(struct safexcel_crypto_priv *priv)

drivers/crypto/inside-secure/safexcel.h

@@ -359,6 +359,7 @@ struct safexcel_context_record {
 #define CONTEXT_CONTROL_CRYPTO_ALG_AES192	(0x6 << 17)
 #define CONTEXT_CONTROL_CRYPTO_ALG_AES256	(0x7 << 17)
 #define CONTEXT_CONTROL_CRYPTO_ALG_CHACHA20	(0x8 << 17)
+#define CONTEXT_CONTROL_CRYPTO_ALG_SM4		(0xd << 17)
 #define CONTEXT_CONTROL_DIGEST_PRECOMPUTED	(0x1 << 21)
 #define CONTEXT_CONTROL_DIGEST_XCM		(0x2 << 21)
 #define CONTEXT_CONTROL_DIGEST_HMAC		(0x3 << 21)
@@ -878,5 +879,6 @@ extern struct safexcel_alg_template safexcel_alg_chachapoly;
 extern struct safexcel_alg_template safexcel_alg_chachapoly_esp;
 extern struct safexcel_alg_template safexcel_alg_sm3;
 extern struct safexcel_alg_template safexcel_alg_hmac_sm3;
+extern struct safexcel_alg_template safexcel_alg_ecb_sm4;
 
 #endif

drivers/crypto/inside-secure/safexcel_cipher.c

@@ -19,6 +19,7 @@
 #include <crypto/ghash.h>
 #include <crypto/poly1305.h>
 #include <crypto/sha.h>
+#include <crypto/sm4.h>
 #include <crypto/xts.h>
 #include <crypto/skcipher.h>
 #include <crypto/internal/aead.h>
@@ -36,6 +37,7 @@ enum safexcel_cipher_alg {
 	SAFEXCEL_3DES,
 	SAFEXCEL_AES,
 	SAFEXCEL_CHACHA20,
+	SAFEXCEL_SM4,
 };
 
 struct safexcel_cipher_ctx {
@@ -139,6 +141,10 @@ static void safexcel_cipher_token(struct safexcel_cipher_ctx *ctx, u8 *iv,
 			block_sz = DES3_EDE_BLOCK_SIZE;
 			cdesc->control_data.options |= EIP197_OPTION_2_TOKEN_IV_CMD;
 			break;
+		case SAFEXCEL_SM4:
+			block_sz = SM4_BLOCK_SIZE;
+			cdesc->control_data.options |= EIP197_OPTION_4_TOKEN_IV_CMD;
+			break;
 		case SAFEXCEL_AES:
 			block_sz = AES_BLOCK_SIZE;
 			cdesc->control_data.options |= EIP197_OPTION_4_TOKEN_IV_CMD;
@@ -526,6 +532,9 @@ static int safexcel_context_control(struct safexcel_cipher_ctx *ctx,
 	} else if (ctx->alg == SAFEXCEL_CHACHA20) {
 		cdesc->control_data.control0 |=
 			CONTEXT_CONTROL_CRYPTO_ALG_CHACHA20;
+	} else if (ctx->alg == SAFEXCEL_SM4) {
+		cdesc->control_data.control0 |=
+			CONTEXT_CONTROL_CRYPTO_ALG_SM4;
 	}
 
 	return 0;
@@ -2613,3 +2622,88 @@ struct safexcel_alg_template safexcel_alg_chachapoly_esp = {
 		},
 	},
 };
+
+static int safexcel_skcipher_sm4_setkey(struct crypto_skcipher *ctfm,
+					const u8 *key, unsigned int len)
+{
+	struct crypto_tfm *tfm = crypto_skcipher_tfm(ctfm);
+	struct safexcel_cipher_ctx *ctx = crypto_tfm_ctx(tfm);
+	struct safexcel_crypto_priv *priv = ctx->priv;
+	int i;
+
+	if (len != SM4_KEY_SIZE) {
+		crypto_skcipher_set_flags(ctfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+
+	if (priv->flags & EIP197_TRC_CACHE && ctx->base.ctxr_dma) {
+		for (i = 0; i < SM4_KEY_SIZE / sizeof(u32); i++) {
+			if (ctx->key[i] !=
+			    get_unaligned_le32(key + i * sizeof(u32))) {
+				ctx->base.needs_inv = true;
+				break;
+			}
+		}
+	}
+
+	for (i = 0; i < SM4_KEY_SIZE / sizeof(u32); i++)
+		ctx->key[i] = get_unaligned_le32(key + i * sizeof(u32));
+	ctx->key_len = SM4_KEY_SIZE;
+
+	return 0;
+}
+
+static int safexcel_sm4_blk_encrypt(struct skcipher_request *req)
+{
+	/* Workaround for HW bug: EIP96 4.3 does not report blocksize error */
+	if (req->cryptlen & (SM4_BLOCK_SIZE - 1))
+		return -EINVAL;
+	else
+		return safexcel_queue_req(&req->base, skcipher_request_ctx(req),
+					  SAFEXCEL_ENCRYPT);
+}
+
+static int safexcel_sm4_blk_decrypt(struct skcipher_request *req)
+{
+	/* Workaround for HW bug: EIP96 4.3 does not report blocksize error */
+	if (req->cryptlen & (SM4_BLOCK_SIZE - 1))
+		return -EINVAL;
+	else
+		return safexcel_queue_req(&req->base, skcipher_request_ctx(req),
+					  SAFEXCEL_DECRYPT);
+}
+
+static int safexcel_skcipher_sm4_ecb_cra_init(struct crypto_tfm *tfm)
+{
+	struct safexcel_cipher_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	safexcel_skcipher_cra_init(tfm);
+	ctx->alg  = SAFEXCEL_SM4;
+	ctx->mode = CONTEXT_CONTROL_CRYPTO_MODE_ECB;
+	return 0;
+}
+
+struct safexcel_alg_template safexcel_alg_ecb_sm4 = {
+	.type = SAFEXCEL_ALG_TYPE_SKCIPHER,
+	.algo_mask = SAFEXCEL_ALG_SM4,
+	.alg.skcipher = {
+		.setkey = safexcel_skcipher_sm4_setkey,
+		.encrypt = safexcel_sm4_blk_encrypt,
+		.decrypt = safexcel_sm4_blk_decrypt,
+		.min_keysize = SM4_KEY_SIZE,
+		.max_keysize = SM4_KEY_SIZE,
+		.base = {
+			.cra_name = "ecb(sm4)",
+			.cra_driver_name = "safexcel-ecb-sm4",
+			.cra_priority = SAFEXCEL_CRA_PRIORITY,
+			.cra_flags = CRYPTO_ALG_ASYNC |
+				     CRYPTO_ALG_KERN_DRIVER_ONLY,
+			.cra_blocksize = SM4_BLOCK_SIZE,
+			.cra_ctxsize = sizeof(struct safexcel_cipher_ctx),
+			.cra_alignmask = 0,
+			.cra_init = safexcel_skcipher_sm4_ecb_cra_init,
+			.cra_exit = safexcel_skcipher_cra_exit,
+			.cra_module = THIS_MODULE,
+		},
+	},
+};