From 9c79f34f7ee71cd28272332b424ca64b2be006ab Mon Sep 17 00:00:00 2001 From: Michael Halcrow Date: Tue, 6 Jan 2009 14:41:57 -0800 Subject: eCryptfs: Filename Encryption: Tag 70 packets This patchset implements filename encryption via a passphrase-derived mount-wide Filename Encryption Key (FNEK) specified as a mount parameter. Each encrypted filename has a fixed prefix indicating that eCryptfs should try to decrypt the filename. When eCryptfs encounters this prefix, it decodes the filename into a tag 70 packet and then decrypts the packet contents using the FNEK, setting the filename to the decrypted filename. Both unencrypted and encrypted filenames can reside in the same lower filesystem. Because filename encryption expands the length of the filename during the encoding stage, eCryptfs will not properly handle filenames that are already near the maximum filename length. In the present implementation, eCryptfs must be able to produce a match against the lower encrypted and encoded filename representation when given a plaintext filename. Therefore, two files having the same plaintext name will encrypt and encode into the same lower filename if they are both encrypted using the same FNEK. This can be changed by finding a way to replace the prepended bytes in the blocked-aligned filename with random characters; they are hashes of the FNEK right now, so that it is possible to deterministically map from a plaintext filename to an encrypted and encoded filename in the lower filesystem. An implementation using random characters will have to decode and decrypt every single directory entry in any given directory any time an event occurs wherein the VFS needs to determine whether a particular file exists in the lower directory and the decrypted and decoded filenames have not yet been extracted for that directory. Thanks to Tyler Hicks and David Kleikamp for assistance in the development of this patchset. This patch: A tag 70 packet contains a filename encrypted with a Filename Encryption Key (FNEK). This patch implements functions for writing and parsing tag 70 packets. This patch also adds definitions and extends structures to support filename encryption. Signed-off-by: Michael Halcrow Cc: Dustin Kirkland Cc: Eric Sandeen Cc: Tyler Hicks Cc: David Kleikamp Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/ecryptfs_kernel.h | 38 +++++++++++++++++++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) (limited to 'fs/ecryptfs/ecryptfs_kernel.h') diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index a75026d35d16..76a95bd8819b 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -199,6 +199,7 @@ ecryptfs_get_key_payload_data(struct key *key) #define ECRYPTFS_DEFAULT_CIPHER "aes" #define ECRYPTFS_DEFAULT_KEY_BYTES 16 #define ECRYPTFS_DEFAULT_HASH "md5" +#define ECRYPTFS_TAG_70_DIGEST ECRYPTFS_DEFAULT_HASH #define ECRYPTFS_TAG_1_PACKET_TYPE 0x01 #define ECRYPTFS_TAG_3_PACKET_TYPE 0x8C #define ECRYPTFS_TAG_11_PACKET_TYPE 0xED @@ -206,7 +207,25 @@ ecryptfs_get_key_payload_data(struct key *key) #define ECRYPTFS_TAG_65_PACKET_TYPE 0x41 #define ECRYPTFS_TAG_66_PACKET_TYPE 0x42 #define ECRYPTFS_TAG_67_PACKET_TYPE 0x43 +#define ECRYPTFS_TAG_70_PACKET_TYPE 0x46 /* FNEK-encrypted filename + * as dentry name */ +#define ECRYPTFS_TAG_71_PACKET_TYPE 0x47 /* FNEK-encrypted filename in + * metadata */ +#define ECRYPTFS_TAG_72_PACKET_TYPE 0x48 /* FEK-encrypted filename as + * dentry name */ +#define ECRYPTFS_TAG_73_PACKET_TYPE 0x49 /* FEK-encrypted filename as + * metadata */ +/* Constraint: ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES >= + * ECRYPTFS_MAX_IV_BYTES */ +#define ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES 16 +#define ECRYPTFS_NON_NULL 0x42 /* A reasonable substitute for NULL */ #define MD5_DIGEST_SIZE 16 +#define ECRYPTFS_TAG_70_DIGEST_SIZE MD5_DIGEST_SIZE +#define ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX "ECRYPTFS_FEK_ENCRYPTED." +#define ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX_SIZE 23 +#define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX "ECRYPTFS_FNEK_ENCRYPTED." +#define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE 24 +#define ECRYPTFS_ENCRYPTED_DENTRY_NAME_LEN (18 + 1 + 4 + 1 + 32) struct ecryptfs_key_sig { struct list_head crypt_stat_list; @@ -332,13 +351,20 @@ struct ecryptfs_mount_crypt_stat { #define ECRYPTFS_XATTR_METADATA_ENABLED 0x00000002 #define ECRYPTFS_ENCRYPTED_VIEW_ENABLED 0x00000004 #define ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED 0x00000008 +#define ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 0x00000010 +#define ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK 0x00000020 +#define ECRYPTFS_GLOBAL_ENCFN_USE_FEK 0x00000040 u32 flags; struct list_head global_auth_tok_list; struct mutex global_auth_tok_list_mutex; size_t num_global_auth_toks; size_t global_default_cipher_key_size; + size_t global_default_fn_cipher_key_bytes; unsigned char global_default_cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1]; + unsigned char global_default_fn_cipher_name[ + ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1]; + char global_default_fnek_sig[ECRYPTFS_SIG_SIZE_HEX + 1]; }; /* superblock private data. */ @@ -599,7 +625,7 @@ int ecryptfs_read_and_validate_header_region(char *data, struct inode *ecryptfs_inode); int ecryptfs_read_and_validate_xattr_region(char *page_virt, struct dentry *ecryptfs_dentry); -u8 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat); +u8 ecryptfs_code_for_cipher_string(char *cipher_name, size_t key_bytes); int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code); void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat); int ecryptfs_generate_key_packet_set(char *dest_base, @@ -694,5 +720,15 @@ int ecryptfs_privileged_open(struct file **lower_file, struct vfsmount *lower_mnt, const struct cred *cred); int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry); +int +ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, + size_t *packet_size, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat, + char *filename, size_t filename_size); +int +ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, + size_t *packet_size, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat, + char *data, size_t max_packet_size); #endif /* #ifndef ECRYPTFS_KERNEL_H */ -- cgit v1.2.3 From a34f60f748c6fe5d791e9b54cffe442201428254 Mon Sep 17 00:00:00 2001 From: Michael Halcrow Date: Tue, 6 Jan 2009 14:41:58 -0800 Subject: eCryptfs: Filename Encryption: Header updates Extensions to the header file to support filename encryption. Signed-off-by: Michael Halcrow Cc: Dustin Kirkland Cc: Eric Sandeen Cc: Tyler Hicks Cc: David Kleikamp Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/crypto.c | 4 +-- fs/ecryptfs/ecryptfs_kernel.h | 61 ++++++++++++++++++++++++++++++++++--------- 2 files changed, 51 insertions(+), 14 deletions(-) (limited to 'fs/ecryptfs/ecryptfs_kernel.h') diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index 485732751f09..c9839df37c7d 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -175,8 +175,8 @@ out: * * Returns zero on success; non-zero on error. */ -static int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat, - loff_t offset) +int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat, + loff_t offset) { int rc = 0; char dst[MD5_DIGEST_SIZE]; diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index 76a95bd8819b..b648175a44cd 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -51,12 +51,16 @@ #define ECRYPTFS_VERSIONING_XATTR 0x00000010 #define ECRYPTFS_VERSIONING_MULTKEY 0x00000020 #define ECRYPTFS_VERSIONING_DEVMISC 0x00000040 +#define ECRYPTFS_VERSIONING_HMAC 0x00000080 +#define ECRYPTFS_VERSIONING_FILENAME_ENCRYPTION 0x00000100 +#define ECRYPTFS_VERSIONING_GCM 0x00000200 #define ECRYPTFS_VERSIONING_MASK (ECRYPTFS_VERSIONING_PASSPHRASE \ | ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH \ | ECRYPTFS_VERSIONING_PUBKEY \ | ECRYPTFS_VERSIONING_XATTR \ | ECRYPTFS_VERSIONING_MULTKEY \ - | ECRYPTFS_VERSIONING_DEVMISC) + | ECRYPTFS_VERSIONING_DEVMISC \ + | ECRYPTFS_VERSIONING_FILENAME_ENCRYPTION) #define ECRYPTFS_MAX_PASSWORD_LENGTH 64 #define ECRYPTFS_MAX_PASSPHRASE_BYTES ECRYPTFS_MAX_PASSWORD_LENGTH #define ECRYPTFS_SALT_SIZE 8 @@ -232,23 +236,39 @@ struct ecryptfs_key_sig { char keysig[ECRYPTFS_SIG_SIZE_HEX]; }; +struct ecryptfs_filename { + struct list_head crypt_stat_list; +#define ECRYPTFS_FILENAME_CONTAINS_DECRYPTED 0x00000001 + u32 flags; + u32 seq_no; + char *filename; + char *encrypted_filename; + size_t filename_size; + size_t encrypted_filename_size; + char fnek_sig[ECRYPTFS_SIG_SIZE_HEX]; + char dentry_name[ECRYPTFS_ENCRYPTED_DENTRY_NAME_LEN + 1]; +}; + /** * This is the primary struct associated with each encrypted file. * * TODO: cache align/pack? */ struct ecryptfs_crypt_stat { -#define ECRYPTFS_STRUCT_INITIALIZED 0x00000001 -#define ECRYPTFS_POLICY_APPLIED 0x00000002 -#define ECRYPTFS_NEW_FILE 0x00000004 -#define ECRYPTFS_ENCRYPTED 0x00000008 -#define ECRYPTFS_SECURITY_WARNING 0x00000010 -#define ECRYPTFS_ENABLE_HMAC 0x00000020 -#define ECRYPTFS_ENCRYPT_IV_PAGES 0x00000040 -#define ECRYPTFS_KEY_VALID 0x00000080 -#define ECRYPTFS_METADATA_IN_XATTR 0x00000100 -#define ECRYPTFS_VIEW_AS_ENCRYPTED 0x00000200 -#define ECRYPTFS_KEY_SET 0x00000400 +#define ECRYPTFS_STRUCT_INITIALIZED 0x00000001 +#define ECRYPTFS_POLICY_APPLIED 0x00000002 +#define ECRYPTFS_NEW_FILE 0x00000004 +#define ECRYPTFS_ENCRYPTED 0x00000008 +#define ECRYPTFS_SECURITY_WARNING 0x00000010 +#define ECRYPTFS_ENABLE_HMAC 0x00000020 +#define ECRYPTFS_ENCRYPT_IV_PAGES 0x00000040 +#define ECRYPTFS_KEY_VALID 0x00000080 +#define ECRYPTFS_METADATA_IN_XATTR 0x00000100 +#define ECRYPTFS_VIEW_AS_ENCRYPTED 0x00000200 +#define ECRYPTFS_KEY_SET 0x00000400 +#define ECRYPTFS_ENCRYPT_FILENAMES 0x00000800 +#define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00001000 +#define ECRYPTFS_ENCFN_USE_FEK 0x00002000 u32 flags; unsigned int file_version; size_t iv_bytes; @@ -597,6 +617,15 @@ struct ecryptfs_open_req { int ecryptfs_interpose(struct dentry *hidden_dentry, struct dentry *this_dentry, struct super_block *sb, u32 flags); +int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, + struct dentry *lower_dentry, + struct ecryptfs_crypt_stat *crypt_stat, + struct inode *ecryptfs_dir_inode, + struct nameidata *ecryptfs_nd); +int ecryptfs_decode_and_decrypt_filename(char **decrypted_name, + size_t *decrypted_name_size, + struct dentry *ecryptfs_dentry, + const char *name, size_t name_size); int ecryptfs_fill_zeros(struct file *file, loff_t new_length); int ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat, const char *name, int length, @@ -604,6 +633,12 @@ int ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat, int ecryptfs_encode_filename(struct ecryptfs_crypt_stat *crypt_stat, const char *name, int length, char **encoded_name); +int ecryptfs_encrypt_and_encode_filename( + char **encoded_name, + size_t *encoded_name_size, + struct ecryptfs_crypt_stat *crypt_stat, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat, + const char *name, size_t name_size); struct dentry *ecryptfs_lower_dentry(struct dentry *this_dentry); void ecryptfs_dump_hex(char *data, int bytes); int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg, @@ -730,5 +765,7 @@ ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, size_t *packet_size, struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *data, size_t max_packet_size); +int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat, + loff_t offset); #endif /* #ifndef ECRYPTFS_KERNEL_H */ -- cgit v1.2.3 From addd65ad8d19a7d7982130b16f957d5d01d3f8df Mon Sep 17 00:00:00 2001 From: Michael Halcrow Date: Tue, 6 Jan 2009 14:42:00 -0800 Subject: eCryptfs: Filename Encryption: filldir, lookup, and readlink Make the requisite modifications to ecryptfs_filldir(), ecryptfs_lookup(), and ecryptfs_readlink() to call out to filename encryption functions. Propagate filename encryption policy flags from mount-wide crypt_stat to inode crypt_stat. Signed-off-by: Michael Halcrow Cc: Dustin Kirkland Cc: Eric Sandeen Cc: Tyler Hicks Cc: David Kleikamp Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/crypto.c | 107 ++------------- fs/ecryptfs/ecryptfs_kernel.h | 6 - fs/ecryptfs/file.c | 30 ++--- fs/ecryptfs/inode.c | 294 ++++++++++++++++++++++++------------------ 4 files changed, 195 insertions(+), 242 deletions(-) (limited to 'fs/ecryptfs/ecryptfs_kernel.h') diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index 18c78abba683..ea2afd2ce222 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -924,6 +924,15 @@ static void ecryptfs_copy_mount_wide_flags_to_inode_flags( crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) crypt_stat->flags |= ECRYPTFS_VIEW_AS_ENCRYPTED; + if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) { + crypt_stat->flags |= ECRYPTFS_ENCRYPT_FILENAMES; + if (mount_crypt_stat->flags + & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK) + crypt_stat->flags |= ECRYPTFS_ENCFN_USE_MOUNT_FNEK; + else if (mount_crypt_stat->flags + & ECRYPTFS_GLOBAL_ENCFN_USE_FEK) + crypt_stat->flags |= ECRYPTFS_ENCFN_USE_FEK; + } } static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs( @@ -1060,7 +1069,8 @@ struct ecryptfs_flag_map_elem { static struct ecryptfs_flag_map_elem ecryptfs_flag_map[] = { {0x00000001, ECRYPTFS_ENABLE_HMAC}, {0x00000002, ECRYPTFS_ENCRYPTED}, - {0x00000004, ECRYPTFS_METADATA_IN_XATTR} + {0x00000004, ECRYPTFS_METADATA_IN_XATTR}, + {0x00000008, ECRYPTFS_ENCRYPT_FILENAMES} }; /** @@ -1213,6 +1223,8 @@ int ecryptfs_read_and_validate_header_region(char *data, &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); int rc; + if (crypt_stat->extent_size == 0) + crypt_stat->extent_size = ECRYPTFS_DEFAULT_EXTENT_SIZE; rc = ecryptfs_read_lower(data, 0, crypt_stat->extent_size, ecryptfs_inode); if (rc) { @@ -1222,7 +1234,6 @@ int ecryptfs_read_and_validate_header_region(char *data, } if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) { rc = -EINVAL; - ecryptfs_printk(KERN_DEBUG, "Valid marker not found\n"); } out: return rc; @@ -1628,98 +1639,6 @@ out: return rc; } -/** - * ecryptfs_encode_filename - converts a plaintext file name to cipher text - * @crypt_stat: The crypt_stat struct associated with the file anem to encode - * @name: The plaintext name - * @length: The length of the plaintext - * @encoded_name: The encypted name - * - * Encrypts and encodes a filename into something that constitutes a - * valid filename for a filesystem, with printable characters. - * - * We assume that we have a properly initialized crypto context, - * pointed to by crypt_stat->tfm. - * - * TODO: Implement filename decoding and decryption here, in place of - * memcpy. We are keeping the framework around for now to (1) - * facilitate testing of the components needed to implement filename - * encryption and (2) to provide a code base from which other - * developers in the community can easily implement this feature. - * - * Returns the length of encoded filename; negative if error - */ -int -ecryptfs_encode_filename(struct ecryptfs_crypt_stat *crypt_stat, - const char *name, int length, char **encoded_name) -{ - int error = 0; - - (*encoded_name) = kmalloc(length + 2, GFP_KERNEL); - if (!(*encoded_name)) { - error = -ENOMEM; - goto out; - } - /* TODO: Filename encryption is a scheduled feature for a - * future version of eCryptfs. This function is here only for - * the purpose of providing a framework for other developers - * to easily implement filename encryption. Hint: Replace this - * memcpy() with a call to encrypt and encode the - * filename, the set the length accordingly. */ - memcpy((void *)(*encoded_name), (void *)name, length); - (*encoded_name)[length] = '\0'; - error = length + 1; -out: - return error; -} - -/** - * ecryptfs_decode_filename - converts the cipher text name to plaintext - * @crypt_stat: The crypt_stat struct associated with the file - * @name: The filename in cipher text - * @length: The length of the cipher text name - * @decrypted_name: The plaintext name - * - * Decodes and decrypts the filename. - * - * We assume that we have a properly initialized crypto context, - * pointed to by crypt_stat->tfm. - * - * TODO: Implement filename decoding and decryption here, in place of - * memcpy. We are keeping the framework around for now to (1) - * facilitate testing of the components needed to implement filename - * encryption and (2) to provide a code base from which other - * developers in the community can easily implement this feature. - * - * Returns the length of decoded filename; negative if error - */ -int -ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat, - const char *name, int length, char **decrypted_name) -{ - int error = 0; - - (*decrypted_name) = kmalloc(length + 2, GFP_KERNEL); - if (!(*decrypted_name)) { - error = -ENOMEM; - goto out; - } - /* TODO: Filename encryption is a scheduled feature for a - * future version of eCryptfs. This function is here only for - * the purpose of providing a framework for other developers - * to easily implement filename encryption. Hint: Replace this - * memcpy() with a call to decode and decrypt the - * filename, the set the length accordingly. */ - memcpy((void *)(*decrypted_name), (void *)name, length); - (*decrypted_name)[length + 1] = '\0'; /* Only for convenience - * in printing out the - * string in debug - * messages */ - error = length; -out: - return error; -} - /** * ecryptfs_encrypt_filename - encrypt filename * diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index b648175a44cd..c11fc95714ab 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -627,12 +627,6 @@ int ecryptfs_decode_and_decrypt_filename(char **decrypted_name, struct dentry *ecryptfs_dentry, const char *name, size_t name_size); int ecryptfs_fill_zeros(struct file *file, loff_t new_length); -int ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat, - const char *name, int length, - char **decrypted_name); -int ecryptfs_encode_filename(struct ecryptfs_crypt_stat *crypt_stat, - const char *name, int length, - char **encoded_name); int ecryptfs_encrypt_and_encode_filename( char **encoded_name, size_t *encoded_name_size, diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index 713834371229..567eb4bee1b6 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -77,27 +77,27 @@ struct ecryptfs_getdents_callback { /* Inspired by generic filldir in fs/readdir.c */ static int -ecryptfs_filldir(void *dirent, const char *name, int namelen, loff_t offset, - u64 ino, unsigned int d_type) +ecryptfs_filldir(void *dirent, const char *lower_name, int lower_namelen, + loff_t offset, u64 ino, unsigned int d_type) { - struct ecryptfs_crypt_stat *crypt_stat; struct ecryptfs_getdents_callback *buf = (struct ecryptfs_getdents_callback *)dirent; + int name_size; + char *name; int rc; - int decoded_length; - char *decoded_name; - crypt_stat = ecryptfs_dentry_to_private(buf->dentry)->crypt_stat; buf->filldir_called++; - decoded_length = ecryptfs_decode_filename(crypt_stat, name, namelen, - &decoded_name); - if (decoded_length < 0) { - rc = decoded_length; + rc = ecryptfs_decode_and_decrypt_filename(&name, &name_size, + buf->dentry, lower_name, + lower_namelen); + if (rc) { + printk(KERN_ERR "%s: Error attempting to decode and decrypt " + "filename [%s]; rc = [%d]\n", __func__, lower_name, + rc); goto out; } - rc = buf->filldir(buf->dirent, decoded_name, decoded_length, offset, - ino, d_type); - kfree(decoded_name); + rc = buf->filldir(buf->dirent, name, name_size, offset, ino, d_type); + kfree(name); if (rc >= 0) buf->entries_written++; out: @@ -106,8 +106,8 @@ out: /** * ecryptfs_readdir - * @file: The ecryptfs file struct - * @dirent: Directory entry + * @file: The eCryptfs directory file + * @dirent: Directory entry handle * @filldir: The filldir callback function */ static int ecryptfs_readdir(struct file *file, void *dirent, filldir_t filldir) diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 0111906a8877..38309ce94d71 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -228,8 +228,7 @@ ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry, { int rc; - /* ecryptfs_do_create() calls ecryptfs_interpose(), which opens - * the crypt_stat->lower_file (persistent file) */ + /* ecryptfs_do_create() calls ecryptfs_interpose() */ rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd); if (unlikely(rc)) { ecryptfs_printk(KERN_WARNING, "Failed to create file in" @@ -244,141 +243,91 @@ out: } /** - * ecryptfs_lookup - * @dir: inode - * @dentry: The dentry - * @nd: nameidata, may be NULL - * - * Find a file on disk. If the file does not exist, then we'll add it to the - * dentry cache and continue on to read it from the disk. + * ecryptfs_lookup_and_interpose_lower - Perform a lookup */ -static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry, - struct nameidata *nd) +int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, + struct dentry *lower_dentry, + struct ecryptfs_crypt_stat *crypt_stat, + struct inode *ecryptfs_dir_inode, + struct nameidata *ecryptfs_nd) { - int rc = 0; struct dentry *lower_dir_dentry; - struct dentry *lower_dentry; struct vfsmount *lower_mnt; - char *encoded_name; - int encoded_namelen; - struct ecryptfs_crypt_stat *crypt_stat = NULL; + struct inode *lower_inode; struct ecryptfs_mount_crypt_stat *mount_crypt_stat; char *page_virt = NULL; - struct inode *lower_inode; u64 file_size; + int rc = 0; - lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent); - dentry->d_op = &ecryptfs_dops; - if ((dentry->d_name.len == 1 && !strcmp(dentry->d_name.name, ".")) - || (dentry->d_name.len == 2 - && !strcmp(dentry->d_name.name, ".."))) { - d_drop(dentry); - goto out; - } - encoded_namelen = ecryptfs_encode_filename(crypt_stat, - dentry->d_name.name, - dentry->d_name.len, - &encoded_name); - if (encoded_namelen < 0) { - rc = encoded_namelen; - d_drop(dentry); - goto out; - } - ecryptfs_printk(KERN_DEBUG, "encoded_name = [%s]; encoded_namelen " - "= [%d]\n", encoded_name, encoded_namelen); - lower_dentry = lookup_one_len(encoded_name, lower_dir_dentry, - encoded_namelen - 1); - kfree(encoded_name); - if (IS_ERR(lower_dentry)) { - ecryptfs_printk(KERN_ERR, "ERR from lower_dentry\n"); - rc = PTR_ERR(lower_dentry); - d_drop(dentry); - goto out; - } - lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent)); - ecryptfs_printk(KERN_DEBUG, "lower_dentry = [%p]; lower_dentry->" - "d_name.name = [%s]\n", lower_dentry, - lower_dentry->d_name.name); + lower_dir_dentry = lower_dentry->d_parent; + lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt( + ecryptfs_dentry->d_parent)); lower_inode = lower_dentry->d_inode; - fsstack_copy_attr_atime(dir, lower_dir_dentry->d_inode); + fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode); BUG_ON(!atomic_read(&lower_dentry->d_count)); - ecryptfs_set_dentry_private(dentry, + ecryptfs_set_dentry_private(ecryptfs_dentry, kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL)); - if (!ecryptfs_dentry_to_private(dentry)) { + if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) { rc = -ENOMEM; - ecryptfs_printk(KERN_ERR, "Out of memory whilst attempting " - "to allocate ecryptfs_dentry_info struct\n"); + printk(KERN_ERR "%s: Out of memory whilst attempting " + "to allocate ecryptfs_dentry_info struct\n", + __func__); goto out_dput; } - ecryptfs_set_dentry_lower(dentry, lower_dentry); - ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt); + ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry); + ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt); if (!lower_dentry->d_inode) { /* We want to add because we couldn't find in lower */ - d_add(dentry, NULL); + d_add(ecryptfs_dentry, NULL); goto out; } - rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, - ECRYPTFS_INTERPOSE_FLAG_D_ADD); + rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry, + ecryptfs_dir_inode->i_sb, 1); if (rc) { - ecryptfs_printk(KERN_ERR, "Error interposing\n"); + printk(KERN_ERR "%s: Error interposing; rc = [%d]\n", + __func__, rc); goto out; } - if (S_ISDIR(lower_inode->i_mode)) { - ecryptfs_printk(KERN_DEBUG, "Is a directory; returning\n"); + if (S_ISDIR(lower_inode->i_mode)) goto out; - } - if (S_ISLNK(lower_inode->i_mode)) { - ecryptfs_printk(KERN_DEBUG, "Is a symlink; returning\n"); + if (S_ISLNK(lower_inode->i_mode)) goto out; - } - if (special_file(lower_inode->i_mode)) { - ecryptfs_printk(KERN_DEBUG, "Is a special file; returning\n"); + if (special_file(lower_inode->i_mode)) goto out; - } - if (!nd) { - ecryptfs_printk(KERN_DEBUG, "We have a NULL nd, just leave" - "as we *think* we are about to unlink\n"); + if (!ecryptfs_nd) goto out; - } /* Released in this function */ - page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, - GFP_USER); + page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER); if (!page_virt) { + printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n", + __func__); rc = -ENOMEM; - ecryptfs_printk(KERN_ERR, - "Cannot ecryptfs_kmalloc a page\n"); goto out; } - crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; - if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) - ecryptfs_set_default_sizes(crypt_stat); - if (!ecryptfs_inode_to_private(dentry->d_inode)->lower_file) { - rc = ecryptfs_init_persistent_file(dentry); + if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) { + rc = ecryptfs_init_persistent_file(ecryptfs_dentry); if (rc) { printk(KERN_ERR "%s: Error attempting to initialize " "the persistent file for the dentry with name " "[%s]; rc = [%d]\n", __func__, - dentry->d_name.name, rc); - goto out; + ecryptfs_dentry->d_name.name, rc); + goto out_free_kmem; } } rc = ecryptfs_read_and_validate_header_region(page_virt, - dentry->d_inode); + ecryptfs_dentry->d_inode); if (rc) { - rc = ecryptfs_read_and_validate_xattr_region(page_virt, dentry); + rc = ecryptfs_read_and_validate_xattr_region(page_virt, + ecryptfs_dentry); if (rc) { - printk(KERN_DEBUG "Valid metadata not found in header " - "region or xattr region; treating file as " - "unencrypted\n"); rc = 0; - kmem_cache_free(ecryptfs_header_cache_2, page_virt); - goto out; + goto out_free_kmem; } crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; } mount_crypt_stat = &ecryptfs_superblock_to_private( - dentry->d_sb)->mount_crypt_stat; + ecryptfs_dentry->d_sb)->mount_crypt_stat; if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) { if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) file_size = (crypt_stat->num_header_bytes_at_front @@ -388,14 +337,103 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry, } else { file_size = get_unaligned_be64(page_virt); } - i_size_write(dentry->d_inode, (loff_t)file_size); + i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size); +out_free_kmem: kmem_cache_free(ecryptfs_header_cache_2, page_virt); goto out; - out_dput: dput(lower_dentry); - d_drop(dentry); + d_drop(ecryptfs_dentry); out: + return rc; +} + +/** + * ecryptfs_lookup + * @ecryptfs_dir_inode: The eCryptfs directory inode + * @ecryptfs_dentry: The eCryptfs dentry that we are looking up + * @ecryptfs_nd: nameidata; may be NULL + * + * Find a file on disk. If the file does not exist, then we'll add it to the + * dentry cache and continue on to read it from the disk. + */ +static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode, + struct dentry *ecryptfs_dentry, + struct nameidata *ecryptfs_nd) +{ + char *encrypted_and_encoded_name = NULL; + int encrypted_and_encoded_name_size; + struct ecryptfs_crypt_stat *crypt_stat = NULL; + struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL; + struct ecryptfs_inode_info *inode_info; + struct dentry *lower_dir_dentry, *lower_dentry; + int rc = 0; + + ecryptfs_dentry->d_op = &ecryptfs_dops; + if ((ecryptfs_dentry->d_name.len == 1 + && !strcmp(ecryptfs_dentry->d_name.name, ".")) + || (ecryptfs_dentry->d_name.len == 2 + && !strcmp(ecryptfs_dentry->d_name.name, ".."))) { + goto out_d_drop; + } + lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent); + lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name, + lower_dir_dentry, + ecryptfs_dentry->d_name.len); + if (IS_ERR(lower_dentry)) { + rc = PTR_ERR(lower_dentry); + printk(KERN_ERR "%s: lookup_one_len() returned [%d] on " + "lower_dentry = [%s]\n", __func__, rc, + ecryptfs_dentry->d_name.name); + goto out_d_drop; + } + if (lower_dentry->d_inode) + goto lookup_and_interpose; + inode_info = ecryptfs_inode_to_private(ecryptfs_dentry->d_inode); + if (inode_info) { + crypt_stat = &inode_info->crypt_stat; + /* TODO: lock for crypt_stat comparison */ + if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) + ecryptfs_set_default_sizes(crypt_stat); + } + if (crypt_stat) + mount_crypt_stat = crypt_stat->mount_crypt_stat; + else + mount_crypt_stat = &ecryptfs_superblock_to_private( + ecryptfs_dentry->d_sb)->mount_crypt_stat; + if (!(crypt_stat && (crypt_stat->flags & ECRYPTFS_ENCRYPT_FILENAMES)) + && !(mount_crypt_stat && (mount_crypt_stat->flags + & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES))) + goto lookup_and_interpose; + dput(lower_dentry); + rc = ecryptfs_encrypt_and_encode_filename( + &encrypted_and_encoded_name, &encrypted_and_encoded_name_size, + crypt_stat, mount_crypt_stat, ecryptfs_dentry->d_name.name, + ecryptfs_dentry->d_name.len); + if (rc) { + printk(KERN_ERR "%s: Error attempting to encrypt and encode " + "filename; rc = [%d]\n", __func__, rc); + goto out_d_drop; + } + lower_dentry = lookup_one_len(encrypted_and_encoded_name, + lower_dir_dentry, + encrypted_and_encoded_name_size - 1); + if (IS_ERR(lower_dentry)) { + rc = PTR_ERR(lower_dentry); + printk(KERN_ERR "%s: lookup_one_len() returned [%d] on " + "lower_dentry = [%s]\n", __func__, rc, + encrypted_and_encoded_name); + goto out_d_drop; + } +lookup_and_interpose: + rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry, + crypt_stat, ecryptfs_dir_inode, + ecryptfs_nd); + goto out; +out_d_drop: + d_drop(ecryptfs_dentry); +out: + kfree(encrypted_and_encoded_name); return ERR_PTR(rc); } @@ -466,19 +504,21 @@ static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry, struct dentry *lower_dentry; struct dentry *lower_dir_dentry; char *encoded_symname; - int encoded_symlen; - struct ecryptfs_crypt_stat *crypt_stat = NULL; + size_t encoded_symlen; + struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL; lower_dentry = ecryptfs_dentry_to_lower(dentry); dget(lower_dentry); lower_dir_dentry = lock_parent(lower_dentry); - encoded_symlen = ecryptfs_encode_filename(crypt_stat, symname, - strlen(symname), - &encoded_symname); - if (encoded_symlen < 0) { - rc = encoded_symlen; + mount_crypt_stat = &ecryptfs_superblock_to_private( + dir->i_sb)->mount_crypt_stat; + rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname, + &encoded_symlen, + NULL, + mount_crypt_stat, symname, + strlen(symname)); + if (rc) goto out_lock; - } rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry, encoded_symname); kfree(encoded_symname); @@ -602,52 +642,54 @@ out_lock: } static int -ecryptfs_readlink(struct dentry *dentry, char __user * buf, int bufsiz) +ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz) { - int rc; - struct dentry *lower_dentry; - char *decoded_name; char *lower_buf; - mm_segment_t old_fs; + struct dentry *lower_dentry; struct ecryptfs_crypt_stat *crypt_stat; + char *plaintext_name; + size_t plaintext_name_size; + mm_segment_t old_fs; + int rc; lower_dentry = ecryptfs_dentry_to_lower(dentry); if (!lower_dentry->d_inode->i_op->readlink) { rc = -EINVAL; goto out; } + crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; /* Released in this function */ lower_buf = kmalloc(bufsiz, GFP_KERNEL); if (lower_buf == NULL) { - ecryptfs_printk(KERN_ERR, "Out of memory\n"); + printk(KERN_ERR "%s: Out of memory whilst attempting to " + "kmalloc [%d] bytes\n", __func__, bufsiz); rc = -ENOMEM; goto out; } old_fs = get_fs(); set_fs(get_ds()); - ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ " - "lower_dentry->d_name.name = [%s]\n", - lower_dentry->d_name.name); rc = lower_dentry->d_inode->i_op->readlink(lower_dentry, (char __user *)lower_buf, bufsiz); set_fs(old_fs); if (rc >= 0) { - crypt_stat = NULL; - rc = ecryptfs_decode_filename(crypt_stat, lower_buf, rc, - &decoded_name); - if (rc == -ENOMEM) + rc = ecryptfs_decode_and_decrypt_filename(&plaintext_name, + &plaintext_name_size, + dentry, lower_buf, + rc); + if (rc) { + printk(KERN_ERR "%s: Error attempting to decode and " + "decrypt filename; rc = [%d]\n", __func__, + rc); goto out_free_lower_buf; - if (rc > 0) { - ecryptfs_printk(KERN_DEBUG, "Copying [%d] bytes " - "to userspace: [%*s]\n", rc, - decoded_name); - if (copy_to_user(buf, decoded_name, rc)) - rc = -EFAULT; } - kfree(decoded_name); - fsstack_copy_attr_atime(dentry->d_inode, - lower_dentry->d_inode); + rc = copy_to_user(buf, plaintext_name, plaintext_name_size); + if (rc) + rc = -EFAULT; + else + rc = plaintext_name_size; + kfree(plaintext_name); + fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode); } out_free_lower_buf: kfree(lower_buf); @@ -669,8 +711,6 @@ static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd) } old_fs = get_fs(); set_fs(get_ds()); - ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ " - "dentry->d_name.name = [%s]\n", dentry->d_name.name); rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len); set_fs(old_fs); if (rc < 0) -- cgit v1.2.3