[PATCH 1/2] ubifs-media: Update to Linux-5.3-rc3

[Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>]

This updates ubifs-media.h to Linux-5.3-rc3 which brings us the bits
and pieces necessary for UBIFS authentication and offline signing.

Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
---
 include/mtd/ubifs-media.h | 75 ++++++++++++++++++++++++++++++++++++---
 1 file changed, 70 insertions(+), 5 deletions(-)

diff --git a/include/mtd/ubifs-media.h b/include/mtd/ubifs-media.h
index 7751ac7..f1e3a14 100644
--- a/include/mtd/ubifs-media.h
+++ b/include/mtd/ubifs-media.h
@@ -288,6 +288,9 @@ enum {
 #define UBIFS_IDX_NODE_SZ  sizeof(struct ubifs_idx_node)
 #define UBIFS_CS_NODE_SZ   sizeof(struct ubifs_cs_node)
 #define UBIFS_ORPH_NODE_SZ sizeof(struct ubifs_orph_node)
+#define UBIFS_AUTH_NODE_SZ sizeof(struct ubifs_auth_node)
+#define UBIFS_SIG_NODE_SZ  sizeof(struct ubifs_sig_node)
+
 /* Extended attribute entry nodes are identical to directory entry nodes */
 #define UBIFS_XENT_NODE_SZ UBIFS_DENT_NODE_SZ
 /* Only this does not have to be multiple of 8 bytes */
@@ -302,12 +305,20 @@ enum {
 /* The largest UBIFS node */
 #define UBIFS_MAX_NODE_SZ UBIFS_MAX_INO_NODE_SZ
 
+/* The maxmimum size of a hash, enough for sha512 */
+#define UBIFS_MAX_HASH_LEN 64
+
+/* The maxmimum size of a hmac, enough for hmac(sha512) */
+#define UBIFS_MAX_HMAC_LEN 64
+
 /*
  * xattr name of UBIFS encryption context, we don't use a prefix
  * nor a long name to not waste space on the flash.
  */
 #define UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT "c"
 
+/* Type field in ubifs_sig_node */
+#define UBIFS_SIGNATURE_TYPE_PKCS7	1
 
 /*
  * On-flash inode flags.
@@ -369,6 +380,8 @@ enum {
  * UBIFS_IDX_NODE: index node
  * UBIFS_CS_NODE: commit start node
  * UBIFS_ORPH_NODE: orphan node
+ * UBIFS_AUTH_NODE: authentication node
+ * UBIFS_SIG_NODE: signature node
  * UBIFS_NODE_TYPES_CNT: count of supported node types
  *
  * Note, we index arrays by these numbers, so keep them low and contiguous.
@@ -388,6 +401,8 @@ enum {
 	UBIFS_IDX_NODE,
 	UBIFS_CS_NODE,
 	UBIFS_ORPH_NODE,
+	UBIFS_AUTH_NODE,
+	UBIFS_SIG_NODE,
 	UBIFS_NODE_TYPES_CNT,
 };
 
@@ -425,15 +440,19 @@ enum {
  * UBIFS_FLG_DOUBLE_HASH: store a 32bit cookie in directory entry nodes to
  *			  support 64bit cookies for lookups by hash
  * UBIFS_FLG_ENCRYPTION: this filesystem contains encrypted files
+ * UBIFS_FLG_AUTHENTICATION: this filesystem contains hashes for authentication
  */
 enum {
 	UBIFS_FLG_BIGLPT = 0x02,
 	UBIFS_FLG_SPACE_FIXUP = 0x04,
 	UBIFS_FLG_DOUBLE_HASH = 0x08,
 	UBIFS_FLG_ENCRYPTION = 0x10,
+	UBIFS_FLG_AUTHENTICATION = 0x20,
 };
 
-#define UBIFS_FLG_MASK (UBIFS_FLG_BIGLPT|UBIFS_FLG_SPACE_FIXUP|UBIFS_FLG_DOUBLE_HASH|UBIFS_FLG_ENCRYPTION)
+#define UBIFS_FLG_MASK (UBIFS_FLG_BIGLPT | UBIFS_FLG_SPACE_FIXUP | \
+		UBIFS_FLG_DOUBLE_HASH | UBIFS_FLG_ENCRYPTION | \
+		UBIFS_FLG_AUTHENTICATION)
 
 /**
  * struct ubifs_ch - common header node.
@@ -568,8 +587,6 @@ struct ubifs_dent_node {
  * @compr_size: compressed data size in bytes, only valid when data is encrypted
  * @data: data
  *
- * Note, do not forget to amend 'zero_data_node_unused()' function when
- * changing the padding fields.
  */
 struct ubifs_data_node {
 	struct ubifs_ch ch;
@@ -639,6 +656,12 @@ struct ubifs_pad_node {
  * @time_gran: time granularity in nanoseconds
  * @uuid: UUID generated when the file system image was created
  * @ro_compat_version: UBIFS R/O compatibility version
+ * @hmac: HMAC to authenticate the superblock node
+ * @hmac_wkm: HMAC of a well known message (the string "UBIFS") as a convenience
+ *            to the user to check if the correct key is passed.
+ * @hash_algo: The hash algo used for this filesystem (one of enum hash_algo)
+ * @hash_mst: hash of the master node, only valid for signed images in which the
+ *            master node does not contain a hmac
  */
 struct ubifs_sb_node {
 	struct ubifs_ch ch;
@@ -665,7 +688,12 @@ struct ubifs_sb_node {
 	__le64 rp_size;
 	__le32 time_gran;
 	__u8 uuid[16];
-	__u8 padding2[3972];
+	__le32 ro_compat_version;
+	__u8 hmac[UBIFS_MAX_HMAC_LEN];
+	__u8 hmac_wkm[UBIFS_MAX_HMAC_LEN];
+	__le16 hash_algo;
+	__u8 hash_mst[UBIFS_MAX_HASH_LEN];
+	__u8 padding2[3774];
 } __attribute__ ((packed));
 
 /**
@@ -700,6 +728,9 @@ struct ubifs_sb_node {
  * @empty_lebs: number of empty logical eraseblocks
  * @idx_lebs: number of indexing logical eraseblocks
  * @leb_cnt: count of LEBs used by file-system
+ * @hash_root_idx: the hash of the root index node
+ * @hash_lpt: the hash of the LPT
+ * @hmac: HMAC to authenticate the master node
  * @padding: reserved for future, zeroes
  */
 struct ubifs_mst_node {
@@ -732,7 +763,10 @@ struct ubifs_mst_node {
 	__le32 empty_lebs;
 	__le32 idx_lebs;
 	__le32 leb_cnt;
-	__u8 padding[344];
+	__u8 hash_root_idx[UBIFS_MAX_HASH_LEN];
+	__u8 hash_lpt[UBIFS_MAX_HASH_LEN];
+	__u8 hmac[UBIFS_MAX_HMAC_LEN];
+	__u8 padding[152];
 } __attribute__ ((packed));
 
 /**
@@ -751,12 +785,43 @@ struct ubifs_ref_node {
 	__u8 padding[28];
 } __attribute__ ((packed));
 
+/**
+ * struct ubifs_auth_node - node for authenticating other nodes
+ * @ch: common header
+ * @hmac: The HMAC
+ */
+struct ubifs_auth_node {
+	struct ubifs_ch ch;
+	__u8 hmac[];
+} __attribute__ ((packed));
+
+/**
+ * struct ubifs_sig_node - node for signing other nodes
+ * @ch: common header
+ * @type: type of the signature, currently only UBIFS_SIGNATURE_TYPE_PKCS7
+ * supported
+ * @len: The length of the signature data
+ * @padding: reserved for future, zeroes
+ * @sig: The signature data
+ */
+struct ubifs_sig_node {
+	struct ubifs_ch ch;
+	__le32 type;
+	__le32 len;
+	__u8 padding[32];
+	__u8 sig[];
+} __attribute__ ((packed));
+
 /**
  * struct ubifs_branch - key/reference/length branch
  * @lnum: LEB number of the target node
  * @offs: offset within @lnum
  * @len: target node length
  * @key: key
+ *
+ * In an authenticated UBIFS we have the hash of the referenced node after @key.
+ * This can't be added to the struct type definition because @key is a
+ * dynamically sized element already.
  */
 struct ubifs_branch {
 	__le32 lnum;
-- 
2.20.1


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