[PATCH 21/25] ubifs: Add hashes and HMACs to default filesystem

[Sascha Hauer]

This patch calculates the necessary hashes and HMACs for the default
filesystem so that the dynamically created default fs can be
authenticated.

Signed-off-by: Sascha Hauer <s.ha...@pengutronix.de>
---
 fs/ubifs/sb.c | 32 +++++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
index 2e814b5fb5d1..99f857224255 100644
--- a/fs/ubifs/sb.c
+++ b/fs/ubifs/sb.c
@@ -87,6 +87,7 @@ static int create_default_filesystem(struct ubifs_info *c)
        __le64 tmp_le64;
        __le32 tmp_le32;
        struct timespec ts;
+       u8 hash[UBIFS_MAX_HASH_LEN];
        u8 hash_lpt[UBIFS_MAX_HASH_LEN];
 
        /* Some functions called from here depend on the @c->key_len filed */
@@ -177,6 +178,14 @@ static int create_default_filesystem(struct ubifs_info *c)
                sup_flags |= UBIFS_FLG_BIGLPT;
        sup_flags |= UBIFS_FLG_DOUBLE_HASH;
 
+       if (ubifs_authenticated(c)) {
+               sup_flags |= UBIFS_FLG_AUTHENTICATION;
+               sup->hash_algo = cpu_to_le16(c->auth_hash_algo);
+               ubifs_hmac_wkm(c, sup->hmac_wkm);
+       } else {
+               sup->hash_algo = 0xffff;
+       }
+
        sup->ch.node_type  = UBIFS_SB_NODE;
        sup->key_hash      = UBIFS_KEY_HASH_R5;
        sup->flags         = cpu_to_le32(sup_flags);
@@ -235,6 +244,7 @@ static int create_default_filesystem(struct ubifs_info *c)
        mst->empty_lebs   = cpu_to_le32(main_lebs - 2);
        mst->idx_lebs     = cpu_to_le32(1);
        mst->leb_cnt      = cpu_to_le32(c->leb_cnt);
+       ubifs_copy_hash(c, hash_lpt, mst->hash_lpt);
 
        /* Calculate lprops statistics */
        tmp64 = main_bytes;
@@ -307,25 +317,33 @@ static int create_default_filesystem(struct ubifs_info *c)
 
        cs->ch.node_type = UBIFS_CS_NODE;
 
-       err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0);
+       err = ubifs_write_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 0, 0,
+                                   offsetof(struct ubifs_sb_node, hmac));
        if (err)
                goto out;
 
-       err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0);
+       err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
+                              main_first + DEFAULT_DATA_LEB, 0);
        if (err)
                goto out;
 
-       err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1,
-                              0);
+       ubifs_node_calc_hash(c, ino, hash);
+       ubifs_copy_hash(c, hash, ubifs_branch_hash(c, br));
+
+       err = ubifs_write_node(c, idx, idx_node_size, main_first + 
DEFAULT_IDX_LEB, 0);
        if (err)
                goto out;
 
-       err = ubifs_write_node(c, idx, idx_node_size, main_first + 
DEFAULT_IDX_LEB, 0);
+       ubifs_node_calc_hash(c, idx, hash);
+       ubifs_copy_hash(c, hash, mst->hash_root_idx);
+
+       err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 
0,
+               offsetof(struct ubifs_mst_node, hmac));
        if (err)
                goto out;
 
-       err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
-                              main_first + DEFAULT_DATA_LEB, 0);
+       err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 
1,
+                              0, offsetof(struct ubifs_mst_node, hmac));
        if (err)
                goto out;
 
-- 
2.18.0