Re: [PATCH 3/3] ecryptfs: added ecryptfs_mount_auth_tok_only mount parameter

[Roberto Sassu]

Sorry, i noted this patch is incomplete since the function ecryptfs_show_options()
does not display the string relative to the added mount option.
I will send the new patch after receiving comments and suggestions.
Thanks.

Roberto


On Wednesday, October 06, 2010 06:31:32 pm Roberto Sassu wrote:
> This patch adds a new mount parameter 'ecryptfs_mount_auth_tok_only' to force 
> ecryptfs to use only authentication tokens which signature has been 
> specified at mount time with parameters 'ecryptfs_sig' and 'ecryptfs_fnek_sig'. 
> In this way, after disabling the passthrough and the encrypted view modes,
> it's possible to make available to users only files encrypted with the specified
> authentication token.
> 
> 
> Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxx>
> ---
>  fs/ecryptfs/ecryptfs_kernel.h |    1 +
>  fs/ecryptfs/keystore.c        |    7 +++++++
>  fs/ecryptfs/main.c            |    8 +++++++-
>  3 files changed, 15 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
> index 0032a9f..59ab793 100644
> --- a/fs/ecryptfs/ecryptfs_kernel.h
> +++ b/fs/ecryptfs/ecryptfs_kernel.h
> @@ -377,6 +377,7 @@ struct ecryptfs_mount_crypt_stat {
>  #define ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES      0x00000010
>  #define ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK   0x00000020
>  #define ECRYPTFS_GLOBAL_ENCFN_USE_FEK          0x00000040
> +#define ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY    0x00000080
>  	u32 flags;
>  	struct list_head global_auth_tok_list;
>  	struct mutex global_auth_tok_list_mutex;
> diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
> index 643d011..93f7785 100644
> --- a/fs/ecryptfs/keystore.c
> +++ b/fs/ecryptfs/keystore.c
> @@ -459,6 +459,13 @@ ecryptfs_find_auth_tok_for_sig(
>  	if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
>  						  mount_crypt_stat, sig)) {
>  
> +		/* if the flag ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY is set in the
> +		 * mount_crypt_stat structure, we prevent to use auth toks that are
> +		 * not inserted through the ecryptfs_add_global_auth_tok function.
> +		 */
> +		if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY)
> +			return -EINVAL;
> +
>  		rc = ecryptfs_keyring_auth_tok_for_sig(auth_tok_key, auth_tok,
>  						       sig);
>  	} else
> diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
> index cbd4e18..e372226 100644
> --- a/fs/ecryptfs/main.c
> +++ b/fs/ecryptfs/main.c
> @@ -208,7 +208,8 @@ enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
>         ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
>         ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig,
>         ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes,
> -       ecryptfs_opt_unlink_sigs, ecryptfs_opt_err };
> +       ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only,
> +       ecryptfs_opt_err };
>  
>  static const match_table_t tokens = {
>  	{ecryptfs_opt_sig, "sig=%s"},
> @@ -223,6 +224,7 @@ static const match_table_t tokens = {
>  	{ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"},
>  	{ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"},
>  	{ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"},
> +	{ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"},
>  	{ecryptfs_opt_err, NULL}
>  };
>  
> @@ -406,6 +408,10 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options)
>  		case ecryptfs_opt_unlink_sigs:
>  			mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
>  			break;
> +		case ecryptfs_opt_mount_auth_tok_only:
> +			mount_crypt_stat->flags |= 
> +				ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
> +			break;
>  		case ecryptfs_opt_err:
>  		default:
>  			printk(KERN_WARNING
>

Attachment: smime.p7s
Description: S/MIME cryptographic signature