smb: client: Make generate_key() return void

Since the crypto library API is now being used instead of crypto_shash,
generate_key() can no longer fail.  Make it return void and simplify the
callers accordingly.

Reviewed-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Eric Biggers <[email protected]>
Signed-off-by: Steve French <[email protected]>

Author: Eric Biggers

fs/smb/client/smb2transport.c

@@ -251,8 +251,8 @@ smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
 	return rc;
 }
 
-static int generate_key(struct cifs_ses *ses, struct kvec label,
-			struct kvec context, __u8 *key, unsigned int key_size)
+static void generate_key(struct cifs_ses *ses, struct kvec label,
+			 struct kvec context, __u8 *key, unsigned int key_size)
 {
 	unsigned char zero = 0x0;
 	__u8 i[4] = {0, 0, 0, 1};
@@ -281,7 +281,6 @@ static int generate_key(struct cifs_ses *ses, struct kvec label,
 	hmac_sha256_final(&hmac_ctx, prfhash);
 
 	memcpy(key, prfhash, key_size);
-	return 0;
 }
 
 struct derivation {
@@ -300,7 +299,6 @@ generate_smb3signingkey(struct cifs_ses *ses,
 			struct TCP_Server_Info *server,
 			const struct derivation_triplet *ptriplet)
 {
-	int rc;
 	bool is_binding = false;
 	int chan_index = 0;
 
@@ -331,38 +329,27 @@ generate_smb3signingkey(struct cifs_ses *ses,
 	 */
 
 	if (is_binding) {
-		rc = generate_key(ses, ptriplet->signing.label,
-				  ptriplet->signing.context,
-				  ses->chans[chan_index].signkey,
-				  SMB3_SIGN_KEY_SIZE);
-		if (rc)
-			return rc;
+		generate_key(ses, ptriplet->signing.label,
+			     ptriplet->signing.context,
+			     ses->chans[chan_index].signkey,
+			     SMB3_SIGN_KEY_SIZE);
 	} else {
-		rc = generate_key(ses, ptriplet->signing.label,
-				  ptriplet->signing.context,
-				  ses->smb3signingkey,
-				  SMB3_SIGN_KEY_SIZE);
-		if (rc)
-			return rc;
+		generate_key(ses, ptriplet->signing.label,
+			     ptriplet->signing.context,
+			     ses->smb3signingkey, SMB3_SIGN_KEY_SIZE);
 
 		/* safe to access primary channel, since it will never go away */
 		spin_lock(&ses->chan_lock);
 		memcpy(ses->chans[chan_index].signkey, ses->smb3signingkey,
 		       SMB3_SIGN_KEY_SIZE);
 		spin_unlock(&ses->chan_lock);
 
-		rc = generate_key(ses, ptriplet->encryption.label,
-				  ptriplet->encryption.context,
-				  ses->smb3encryptionkey,
-				  SMB3_ENC_DEC_KEY_SIZE);
-		if (rc)
-			return rc;
-		rc = generate_key(ses, ptriplet->decryption.label,
-				  ptriplet->decryption.context,
-				  ses->smb3decryptionkey,
-				  SMB3_ENC_DEC_KEY_SIZE);
-		if (rc)
-			return rc;
+		generate_key(ses, ptriplet->encryption.label,
+			     ptriplet->encryption.context,
+			     ses->smb3encryptionkey, SMB3_ENC_DEC_KEY_SIZE);
+		generate_key(ses, ptriplet->decryption.label,
+			     ptriplet->decryption.context,
+			     ses->smb3decryptionkey, SMB3_ENC_DEC_KEY_SIZE);
 	}
 
 #ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
@@ -391,7 +378,7 @@ generate_smb3signingkey(struct cifs_ses *ses,
 				SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3decryptionkey);
 	}
 #endif
-	return rc;
+	return 0;
 }
 
 int