From 84814d642a4f1f294bd675ab11aae1ca54c6cedb Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Fri, 13 Mar 2009 13:51:59 -0700 Subject: [PATCH] eCryptfs: don't encrypt file key with filename key eCryptfs has file encryption keys (FEK), file encryption key encryption keys (FEKEK), and filename encryption keys (FNEK). The per-file FEK is encrypted with one or more FEKEKs and stored in the header of the encrypted file. I noticed that the FEK is also being encrypted by the FNEK. This is a problem if a user wants to use a different FNEK than their FEKEK, as their file contents will still be accessible with the FNEK. This is a minimalistic patch which prevents the FNEKs signatures from being copied to the inode signatures list. Ultimately, it keeps the FEK from being encrypted with a FNEK. Signed-off-by: Tyler Hicks Cc: Serge Hallyn Acked-by: Dustin Kirkland Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/crypto.c | 2 ++ fs/ecryptfs/ecryptfs_kernel.h | 3 ++- fs/ecryptfs/keystore.c | 3 ++- fs/ecryptfs/main.c | 5 +++-- 4 files changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index f6caeb1d1106..bdca1f4b3a3e 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -946,6 +946,8 @@ static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs( list_for_each_entry(global_auth_tok, &mount_crypt_stat->global_auth_tok_list, mount_crypt_stat_list) { + if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_FNEK) + continue; rc = ecryptfs_add_keysig(crypt_stat, global_auth_tok->sig); if (rc) { printk(KERN_ERR "Error adding keysig; rc = [%d]\n", rc); diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index c11fc95714ab..eb2267eca1fe 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -328,6 +328,7 @@ struct ecryptfs_dentry_info { */ struct ecryptfs_global_auth_tok { #define ECRYPTFS_AUTH_TOK_INVALID 0x00000001 +#define ECRYPTFS_AUTH_TOK_FNEK 0x00000002 u32 flags; struct list_head mount_crypt_stat_list; struct key *global_auth_tok_key; @@ -696,7 +697,7 @@ ecryptfs_write_header_metadata(char *virt, int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig); int ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, - char *sig); + char *sig, u32 global_auth_tok_flags); int ecryptfs_get_global_auth_tok_for_sig( struct ecryptfs_global_auth_tok **global_auth_tok, struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig); diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c index ff539420cc6f..e4a6223c3145 100644 --- a/fs/ecryptfs/keystore.c +++ b/fs/ecryptfs/keystore.c @@ -2375,7 +2375,7 @@ struct kmem_cache *ecryptfs_global_auth_tok_cache; int ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, - char *sig) + char *sig, u32 global_auth_tok_flags) { struct ecryptfs_global_auth_tok *new_auth_tok; int rc = 0; @@ -2389,6 +2389,7 @@ ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, goto out; } memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX); + new_auth_tok->flags = global_auth_tok_flags; new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); list_add(&new_auth_tok->mount_crypt_stat_list, diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index 789cf2e1be1e..aed56c25539b 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -319,7 +319,7 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options) case ecryptfs_opt_ecryptfs_sig: sig_src = args[0].from; rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, - sig_src); + sig_src, 0); if (rc) { printk(KERN_ERR "Error attempting to register " "global sig; rc = [%d]\n", rc); @@ -370,7 +370,8 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options) ECRYPTFS_SIG_SIZE_HEX] = '\0'; rc = ecryptfs_add_global_auth_tok( mount_crypt_stat, - mount_crypt_stat->global_default_fnek_sig); + mount_crypt_stat->global_default_fnek_sig, + ECRYPTFS_AUTH_TOK_FNEK); if (rc) { printk(KERN_ERR "Error attempting to register " "global fnek sig [%s]; rc = [%d]\n",