crypto: chtls - Add support for AES256-GCM based ciphers

Added support to set 256 bit key to the hardware from
setsockopt for AES256-GCM based ciphers.
Signed-off-by: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/chelsio/chtls/chtls.h

@@ -179,7 +179,10 @@ struct chtls_hws {
 	u32 copied_seq;
 	u64 tx_seq_no;
 	struct tls_scmd scmd;
-	struct tls12_crypto_info_aes_gcm_128 crypto_info;
+	union {
+		struct tls12_crypto_info_aes_gcm_128 aes_gcm_128;
+		struct tls12_crypto_info_aes_gcm_256 aes_gcm_256;
+	} crypto_info;
 };
 
 struct chtls_sock {
@@ -482,7 +485,7 @@ int send_tx_flowc_wr(struct sock *sk, int compl,
 void chtls_tcp_push(struct sock *sk, int flags);
 int chtls_push_frames(struct chtls_sock *csk, int comp);
 int chtls_set_tcb_tflag(struct sock *sk, unsigned int bit_pos, int val);
-int chtls_setkey(struct chtls_sock *csk, u32 keylen, u32 mode);
+int chtls_setkey(struct chtls_sock *csk, u32 keylen, u32 mode, int cipher_type);
 void skb_entail(struct sock *sk, struct sk_buff *skb, int flags);
 unsigned int keyid_to_addr(int start_addr, int keyid);
 void free_tls_keyid(struct sock *sk);

drivers/crypto/chelsio/chtls/chtls_hw.c

@@ -208,28 +208,53 @@ static void chtls_rxkey_ivauth(struct _key_ctx *kctx)
 
 static int chtls_key_info(struct chtls_sock *csk,
 			  struct _key_ctx *kctx,
-			  u32 keylen, u32 optname)
+			  u32 keylen, u32 optname,
+			  int cipher_type)
 {
-	unsigned char key[AES_KEYSIZE_128];
-	struct tls12_crypto_info_aes_gcm_128 *gcm_ctx;
+	unsigned char key[AES_MAX_KEY_SIZE];
+	unsigned char *key_p, *salt;
 	unsigned char ghash_h[AEAD_H_SIZE];
-	int ck_size, key_ctx_size;
+	int ck_size, key_ctx_size, kctx_mackey_size, salt_size;
 	struct crypto_aes_ctx aes;
 	int ret;
 
-	gcm_ctx = (struct tls12_crypto_info_aes_gcm_128 *)
-		  &csk->tlshws.crypto_info;
-
 	key_ctx_size = sizeof(struct _key_ctx) +
 		       roundup(keylen, 16) + AEAD_H_SIZE;
 
-	if (keylen == AES_KEYSIZE_128) {
-		ck_size = CHCR_KEYCTX_CIPHER_KEY_SIZE_128;
-	} else {
+	/* GCM mode of AES supports 128 and 256 bit encryption, so
+	 * prepare key context base on GCM cipher type
+	 */
+	switch (cipher_type) {
+	case TLS_CIPHER_AES_GCM_128: {
+		struct tls12_crypto_info_aes_gcm_128 *gcm_ctx_128 =
+			(struct tls12_crypto_info_aes_gcm_128 *)
+					&csk->tlshws.crypto_info;
+		memcpy(key, gcm_ctx_128->key, keylen);
+
+		key_p            = gcm_ctx_128->key;
+		salt             = gcm_ctx_128->salt;
+		ck_size          = CHCR_KEYCTX_CIPHER_KEY_SIZE_128;
+		salt_size        = TLS_CIPHER_AES_GCM_128_SALT_SIZE;
+		kctx_mackey_size = CHCR_KEYCTX_MAC_KEY_SIZE_128;
+		break;
+	}
+	case TLS_CIPHER_AES_GCM_256: {
+		struct tls12_crypto_info_aes_gcm_256 *gcm_ctx_256 =
+			(struct tls12_crypto_info_aes_gcm_256 *)
+					&csk->tlshws.crypto_info;
+		memcpy(key, gcm_ctx_256->key, keylen);
+
+		key_p            = gcm_ctx_256->key;
+		salt             = gcm_ctx_256->salt;
+		ck_size          = CHCR_KEYCTX_CIPHER_KEY_SIZE_256;
+		salt_size        = TLS_CIPHER_AES_GCM_256_SALT_SIZE;
+		kctx_mackey_size = CHCR_KEYCTX_MAC_KEY_SIZE_256;
+		break;
+	}
+	default:
 		pr_err("GCM: Invalid key length %d\n", keylen);
 		return -EINVAL;
 	}
-	memcpy(key, gcm_ctx->key, keylen);
 
 	/* Calculate the H = CIPH(K, 0 repeated 16 times).
 	 * It will go in key context
@@ -249,20 +274,20 @@ static int chtls_key_info(struct chtls_sock *csk,
 
 		key_ctx = ((key_ctx_size >> 4) << 3);
 		kctx->ctx_hdr = FILL_KEY_CRX_HDR(ck_size,
-						 CHCR_KEYCTX_MAC_KEY_SIZE_128,
+						 kctx_mackey_size,
 						 0, 0, key_ctx);
 		chtls_rxkey_ivauth(kctx);
 	} else {
 		kctx->ctx_hdr = FILL_KEY_CTX_HDR(ck_size,
-						 CHCR_KEYCTX_MAC_KEY_SIZE_128,
+						 kctx_mackey_size,
 						 0, 0, key_ctx_size >> 4);
 	}
 
-	memcpy(kctx->salt, gcm_ctx->salt, TLS_CIPHER_AES_GCM_128_SALT_SIZE);
-	memcpy(kctx->key, gcm_ctx->key, keylen);
+	memcpy(kctx->salt, salt, salt_size);
+	memcpy(kctx->key, key_p, keylen);
 	memcpy(kctx->key + keylen, ghash_h, AEAD_H_SIZE);
 	/* erase key info from driver */
-	memset(gcm_ctx->key, 0, keylen);
+	memset(key_p, 0, keylen);
 
 	return 0;
 }
@@ -288,7 +313,8 @@ static void chtls_set_scmd(struct chtls_sock *csk)
 		SCMD_TLS_FRAG_ENABLE_V(1);
 }
 
-int chtls_setkey(struct chtls_sock *csk, u32 keylen, u32 optname)
+int chtls_setkey(struct chtls_sock *csk, u32 keylen,
+		 u32 optname, int cipher_type)
 {
 	struct tls_key_req *kwr;
 	struct chtls_dev *cdev;
@@ -352,7 +378,7 @@ int chtls_setkey(struct chtls_sock *csk, u32 keylen, u32 optname)
 
 	/* key info */
 	kctx = (struct _key_ctx *)(kwr + 1);
-	ret = chtls_key_info(csk, kctx, keylen, optname);
+	ret = chtls_key_info(csk, kctx, keylen, optname, cipher_type);
 	if (ret)
 		goto out_notcb;
 

drivers/crypto/chelsio/chtls/chtls_main.c

@@ -486,6 +486,7 @@ static int do_chtls_setsockopt(struct sock *sk, int optname,
 	struct tls_crypto_info *crypto_info, tmp_crypto_info;
 	struct chtls_sock *csk;
 	int keylen;
+	int cipher_type;
 	int rc = 0;
 
 	csk = rcu_dereference_sk_user_data(sk);
@@ -509,6 +510,9 @@ static int do_chtls_setsockopt(struct sock *sk, int optname,
 
 	crypto_info = (struct tls_crypto_info *)&csk->tlshws.crypto_info;
 
+	/* GCM mode of AES supports 128 and 256 bit encryption, so
+	 * copy keys from user based on GCM cipher type.
+	 */
 	switch (tmp_crypto_info.cipher_type) {
 	case TLS_CIPHER_AES_GCM_128: {
 		/* Obtain version and type from previous copy */
@@ -525,13 +529,30 @@ static int do_chtls_setsockopt(struct sock *sk, int optname,
 		}
 
 		keylen = TLS_CIPHER_AES_GCM_128_KEY_SIZE;
-		rc = chtls_setkey(csk, keylen, optname);
+		cipher_type = TLS_CIPHER_AES_GCM_128;
+		break;
+	}
+	case TLS_CIPHER_AES_GCM_256: {
+		crypto_info[0] = tmp_crypto_info;
+		rc = copy_from_user((char *)crypto_info + sizeof(*crypto_info),
+				    optval + sizeof(*crypto_info),
+				sizeof(struct tls12_crypto_info_aes_gcm_256)
+				- sizeof(*crypto_info));
+
+		if (rc) {
+			rc = -EFAULT;
+			goto out;
+		}
+
+		keylen = TLS_CIPHER_AES_GCM_256_KEY_SIZE;
+		cipher_type = TLS_CIPHER_AES_GCM_256;
 		break;
 	}
 	default:
 		rc = -EINVAL;
 		goto out;
 	}
+	rc = chtls_setkey(csk, keylen, optname, cipher_type);
 out:
 	return rc;
 }