1 files changed, 109 insertions, 0 deletions
diff --git a/fs/ext4/ext4_ice.c b/fs/ext4/ext4_ice.c
new file mode 100644
index 000000000000..d85bcb8ea1ba
--- /dev/null
+++ b/fs/ext4/ext4_ice.c
@@ -0,0 +1,109 @@
+/* Copyright (c) 2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "ext4_ice.h"
+#include "ext4_crypto.h"
+
+
+/*
+ * Retrieves encryption key from the inode
+ */
+char *ext4_get_ice_encryption_key(const struct inode *inode)
+{
+	struct ext4_crypt_info *ci = NULL;
+
+	if (!inode)
+		return NULL;
+
+	ci = ext4_encryption_info((struct inode *)inode);
+	if (!ci)
+		return NULL;
+
+	return &(ci->ci_raw_key[0]);
+}
+
+/*
+ * Retrieves encryption salt from the inode
+ */
+char *ext4_get_ice_encryption_salt(const struct inode *inode)
+{
+	struct ext4_crypt_info *ci = NULL;
+
+	if (!inode)
+		return NULL;
+
+	ci = ext4_encryption_info((struct inode *)inode);
+	if (!ci)
+		return NULL;
+
+	return &(ci->ci_raw_key[ext4_get_ice_encryption_key_size(inode)]);
+}
+
+/*
+ * returns true if the cipher mode in inode is AES XTS
+ */
+int ext4_is_aes_xts_cipher(const struct inode *inode)
+{
+	struct ext4_crypt_info *ci = NULL;
+
+	ci = ext4_encryption_info((struct inode *)inode);
+	if (!ci)
+		return 0;
+
+	return (ci->ci_data_mode == EXT4_ENCRYPTION_MODE_PRIVATE);
+}
+
+/*
+ * returns true if encryption info in both inodes is equal
+ */
+int ext4_is_ice_encryption_info_equal(const struct inode *inode1,
+	const struct inode *inode2)
+{
+	char *key1 = NULL;
+	char *key2 = NULL;
+	char *salt1 = NULL;
+	char *salt2 = NULL;
+
+	if (!inode1 || !inode2)
+		return 0;
+
+	if (inode1 == inode2)
+		return 1;
+
+	/* both do not belong to ice, so we don't care, they are equal for us */
+	if (!ext4_should_be_processed_by_ice(inode1) &&
+		!ext4_should_be_processed_by_ice(inode2))
+		return 1;
+
+	/* one belongs to ice, the other does not -> not equal */
+	if (ext4_should_be_processed_by_ice(inode1) ^
+		ext4_should_be_processed_by_ice(inode2))
+		return 0;
+
+	key1 = ext4_get_ice_encryption_key(inode1);
+	key2 = ext4_get_ice_encryption_key(inode2);
+	salt1 = ext4_get_ice_encryption_salt(inode1);
+	salt2 = ext4_get_ice_encryption_salt(inode2);
+
+	/* key and salt should not be null by this point */
+	if (!key1 || !key2 || !salt1 || !salt2 ||
+		(ext4_get_ice_encryption_key_size(inode1) !=
+		 ext4_get_ice_encryption_key_size(inode2)) ||
+		(ext4_get_ice_encryption_salt_size(inode1) !=
+		 ext4_get_ice_encryption_salt_size(inode2)))
+		return 0;
+
+	return ((memcmp(key1, key2,
+			ext4_get_ice_encryption_key_size(inode1)) == 0) &&
+		(memcmp(salt1, salt2,
+			ext4_get_ice_encryption_salt_size(inode1)) == 0));
+}