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

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

changes since v1:
- nothing
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

@@ -1180,6 +1180,7 @@ static struct safexcel_alg_template *safexcel_algs[] = {
 	&safexcel_alg_hmac_sm3,
 	&safexcel_alg_ecb_sm4,
 	&safexcel_alg_cbc_sm4,
+	&safexcel_alg_ofb_sm4,
 };
 
 static int safexcel_register_algorithms(struct safexcel_crypto_priv *priv)

drivers/crypto/inside-secure/safexcel.h

@@ -881,5 +881,6 @@ 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;
 extern struct safexcel_alg_template safexcel_alg_cbc_sm4;
+extern struct safexcel_alg_template safexcel_alg_ofb_sm4;
 
 #endif

drivers/crypto/inside-secure/safexcel_cipher.c

@@ -2743,3 +2743,39 @@ struct safexcel_alg_template safexcel_alg_cbc_sm4 = {
 		},
 	},
 };
+
+static int safexcel_skcipher_sm4_ofb_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_OFB;
+	return 0;
+}
+
+struct safexcel_alg_template safexcel_alg_ofb_sm4 = {
+	.type = SAFEXCEL_ALG_TYPE_SKCIPHER,
+	.algo_mask = SAFEXCEL_ALG_SM4 | SAFEXCEL_ALG_AES_XFB,
+	.alg.skcipher = {
+		.setkey = safexcel_skcipher_sm4_setkey,
+		.encrypt = safexcel_encrypt,
+		.decrypt = safexcel_decrypt,
+		.min_keysize = SM4_KEY_SIZE,
+		.max_keysize = SM4_KEY_SIZE,
+		.ivsize = SM4_BLOCK_SIZE,
+		.base = {
+			.cra_name = "ofb(sm4)",
+			.cra_driver_name = "safexcel-ofb-sm4",
+			.cra_priority = SAFEXCEL_CRA_PRIORITY,
+			.cra_flags = CRYPTO_ALG_ASYNC |
+				     CRYPTO_ALG_KERN_DRIVER_ONLY,
+			.cra_blocksize = 1,
+			.cra_ctxsize = sizeof(struct safexcel_cipher_ctx),
+			.cra_alignmask = 0,
+			.cra_init = safexcel_skcipher_sm4_ofb_cra_init,
+			.cra_exit = safexcel_skcipher_cra_exit,
+			.cra_module = THIS_MODULE,
+		},
+	},
+};