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path: root/fs/ecryptfs/crypto.c
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Diffstat (limited to 'fs/ecryptfs/crypto.c')
-rw-r--r--fs/ecryptfs/crypto.c191
1 files changed, 103 insertions, 88 deletions
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index f8ef0af919e..a066e109ad9 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -355,8 +355,11 @@ static int encrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
}
/* Consider doing this once, when the file is opened */
mutex_lock(&crypt_stat->cs_tfm_mutex);
- rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key,
- crypt_stat->key_size);
+ if (!(crypt_stat->flags & ECRYPTFS_KEY_SET)) {
+ rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key,
+ crypt_stat->key_size);
+ crypt_stat->flags |= ECRYPTFS_KEY_SET;
+ }
if (rc) {
ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n",
rc);
@@ -376,11 +379,10 @@ out:
*
* Convert an eCryptfs page index into a lower byte offset
*/
-void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num,
- struct ecryptfs_crypt_stat *crypt_stat)
+static void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num,
+ struct ecryptfs_crypt_stat *crypt_stat)
{
- (*offset) = ((crypt_stat->extent_size
- * crypt_stat->num_header_extents_at_front)
+ (*offset) = (crypt_stat->num_header_bytes_at_front
+ (crypt_stat->extent_size * extent_num));
}
@@ -842,15 +844,13 @@ void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat)
set_extent_mask_and_shift(crypt_stat);
crypt_stat->iv_bytes = ECRYPTFS_DEFAULT_IV_BYTES;
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
- crypt_stat->num_header_extents_at_front = 0;
+ crypt_stat->num_header_bytes_at_front = 0;
else {
if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)
- crypt_stat->num_header_extents_at_front =
- (ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE
- / crypt_stat->extent_size);
+ crypt_stat->num_header_bytes_at_front =
+ ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
else
- crypt_stat->num_header_extents_at_front =
- (PAGE_CACHE_SIZE / crypt_stat->extent_size);
+ crypt_stat->num_header_bytes_at_front = PAGE_CACHE_SIZE;
}
}
@@ -1128,7 +1128,7 @@ write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat,
struct ecryptfs_cipher_code_str_map_elem {
char cipher_str[16];
- u16 cipher_code;
+ u8 cipher_code;
};
/* Add support for additional ciphers by adding elements here. The
@@ -1152,10 +1152,10 @@ ecryptfs_cipher_code_str_map[] = {
*
* Returns zero on no match, or the cipher code on match
*/
-u16 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat)
+u8 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat)
{
int i;
- u16 code = 0;
+ u8 code = 0;
struct ecryptfs_cipher_code_str_map_elem *map =
ecryptfs_cipher_code_str_map;
@@ -1187,7 +1187,7 @@ u16 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat)
*
* Returns zero on success
*/
-int ecryptfs_cipher_code_to_string(char *str, u16 cipher_code)
+int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code)
{
int rc = 0;
int i;
@@ -1236,7 +1236,8 @@ ecryptfs_write_header_metadata(char *virt,
header_extent_size = (u32)crypt_stat->extent_size;
num_header_extents_at_front =
- (u16)crypt_stat->num_header_extents_at_front;
+ (u16)(crypt_stat->num_header_bytes_at_front
+ / crypt_stat->extent_size);
header_extent_size = cpu_to_be32(header_extent_size);
memcpy(virt, &header_extent_size, 4);
virt += 4;
@@ -1311,40 +1312,16 @@ static int ecryptfs_write_headers_virt(char *page_virt, size_t *size,
static int
ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat,
struct dentry *ecryptfs_dentry,
- char *page_virt)
+ char *virt)
{
- int current_header_page;
- int header_pages;
int rc;
- rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, page_virt,
- 0, PAGE_CACHE_SIZE);
- if (rc) {
+ rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, virt,
+ 0, crypt_stat->num_header_bytes_at_front);
+ if (rc)
printk(KERN_ERR "%s: Error attempting to write header "
"information to lower file; rc = [%d]\n", __FUNCTION__,
rc);
- goto out;
- }
- header_pages = ((crypt_stat->extent_size
- * crypt_stat->num_header_extents_at_front)
- / PAGE_CACHE_SIZE);
- memset(page_virt, 0, PAGE_CACHE_SIZE);
- current_header_page = 1;
- while (current_header_page < header_pages) {
- loff_t offset;
-
- offset = (((loff_t)current_header_page) << PAGE_CACHE_SHIFT);
- if ((rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode,
- page_virt, offset,
- PAGE_CACHE_SIZE))) {
- printk(KERN_ERR "%s: Error attempting to write header "
- "information to lower file; rc = [%d]\n",
- __FUNCTION__, rc);
- goto out;
- }
- current_header_page++;
- }
-out:
return rc;
}
@@ -1370,15 +1347,13 @@ ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry,
* retrieved via a prompt. Exactly what happens at this point should
* be policy-dependent.
*
- * TODO: Support header information spanning multiple pages
- *
* Returns zero on success; non-zero on error
*/
int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry)
{
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
- char *page_virt;
+ char *virt;
size_t size = 0;
int rc = 0;
@@ -1389,40 +1364,39 @@ int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry)
goto out;
}
} else {
+ printk(KERN_WARNING "%s: Encrypted flag not set\n",
+ __FUNCTION__);
rc = -EINVAL;
- ecryptfs_printk(KERN_WARNING,
- "Called with crypt_stat->encrypted == 0\n");
goto out;
}
/* Released in this function */
- page_virt = kmem_cache_zalloc(ecryptfs_header_cache_0, GFP_USER);
- if (!page_virt) {
- ecryptfs_printk(KERN_ERR, "Out of memory\n");
+ virt = kzalloc(crypt_stat->num_header_bytes_at_front, GFP_KERNEL);
+ if (!virt) {
+ printk(KERN_ERR "%s: Out of memory\n", __FUNCTION__);
rc = -ENOMEM;
goto out;
}
- rc = ecryptfs_write_headers_virt(page_virt, &size, crypt_stat,
- ecryptfs_dentry);
+ rc = ecryptfs_write_headers_virt(virt, &size, crypt_stat,
+ ecryptfs_dentry);
if (unlikely(rc)) {
- ecryptfs_printk(KERN_ERR, "Error whilst writing headers\n");
- memset(page_virt, 0, PAGE_CACHE_SIZE);
+ printk(KERN_ERR "%s: Error whilst writing headers; rc = [%d]\n",
+ __FUNCTION__, rc);
goto out_free;
}
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
rc = ecryptfs_write_metadata_to_xattr(ecryptfs_dentry,
- crypt_stat, page_virt,
- size);
+ crypt_stat, virt, size);
else
rc = ecryptfs_write_metadata_to_contents(crypt_stat,
- ecryptfs_dentry,
- page_virt);
+ ecryptfs_dentry, virt);
if (rc) {
- printk(KERN_ERR "Error writing metadata out to lower file; "
- "rc = [%d]\n", rc);
+ printk(KERN_ERR "%s: Error writing metadata out to lower file; "
+ "rc = [%d]\n", __FUNCTION__, rc);
goto out_free;
}
out_free:
- kmem_cache_free(ecryptfs_header_cache_0, page_virt);
+ memset(virt, 0, crypt_stat->num_header_bytes_at_front);
+ kfree(virt);
out:
return rc;
}
@@ -1442,16 +1416,16 @@ static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat,
virt += sizeof(u32);
memcpy(&num_header_extents_at_front, virt, sizeof(u16));
num_header_extents_at_front = be16_to_cpu(num_header_extents_at_front);
- crypt_stat->num_header_extents_at_front =
- (int)num_header_extents_at_front;
+ crypt_stat->num_header_bytes_at_front =
+ (((size_t)num_header_extents_at_front
+ * (size_t)header_extent_size));
(*bytes_read) = (sizeof(u32) + sizeof(u16));
if ((validate_header_size == ECRYPTFS_VALIDATE_HEADER_SIZE)
- && ((crypt_stat->extent_size
- * crypt_stat->num_header_extents_at_front)
+ && (crypt_stat->num_header_bytes_at_front
< ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)) {
rc = -EINVAL;
- printk(KERN_WARNING "Invalid number of header extents: [%zd]\n",
- crypt_stat->num_header_extents_at_front);
+ printk(KERN_WARNING "Invalid header size: [%zd]\n",
+ crypt_stat->num_header_bytes_at_front);
}
return rc;
}
@@ -1466,7 +1440,8 @@ static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat,
*/
static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat)
{
- crypt_stat->num_header_extents_at_front = 2;
+ crypt_stat->num_header_bytes_at_front =
+ ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
}
/**
@@ -1552,9 +1527,10 @@ int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode)
size = ecryptfs_getxattr_lower(lower_dentry, ECRYPTFS_XATTR_NAME,
page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE);
if (size < 0) {
- printk(KERN_ERR "Error attempting to read the [%s] "
- "xattr from the lower file; return value = [%zd]\n",
- ECRYPTFS_XATTR_NAME, size);
+ if (unlikely(ecryptfs_verbosity > 0))
+ printk(KERN_INFO "Error attempting to read the [%s] "
+ "xattr from the lower file; return value = "
+ "[%zd]\n", ECRYPTFS_XATTR_NAME, size);
rc = -EINVAL;
goto out;
}
@@ -1802,7 +1778,7 @@ out:
}
struct kmem_cache *ecryptfs_key_tfm_cache;
-struct list_head key_tfm_list;
+static struct list_head key_tfm_list;
struct mutex key_tfm_list_mutex;
int ecryptfs_init_crypto(void)
@@ -1812,6 +1788,11 @@ int ecryptfs_init_crypto(void)
return 0;
}
+/**
+ * ecryptfs_destroy_crypto - free all cached key_tfms on key_tfm_list
+ *
+ * Called only at module unload time
+ */
int ecryptfs_destroy_crypto(void)
{
struct ecryptfs_key_tfm *key_tfm, *key_tfm_tmp;
@@ -1835,6 +1816,8 @@ ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name,
struct ecryptfs_key_tfm *tmp_tfm;
int rc = 0;
+ BUG_ON(!mutex_is_locked(&key_tfm_list_mutex));
+
tmp_tfm = kmem_cache_alloc(ecryptfs_key_tfm_cache, GFP_KERNEL);
if (key_tfm != NULL)
(*key_tfm) = tmp_tfm;
@@ -1861,13 +1844,50 @@ ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name,
(*key_tfm) = NULL;
goto out;
}
- mutex_lock(&key_tfm_list_mutex);
list_add(&tmp_tfm->key_tfm_list, &key_tfm_list);
- mutex_unlock(&key_tfm_list_mutex);
out:
return rc;
}
+/**
+ * ecryptfs_tfm_exists - Search for existing tfm for cipher_name.
+ * @cipher_name: the name of the cipher to search for
+ * @key_tfm: set to corresponding tfm if found
+ *
+ * Searches for cached key_tfm matching @cipher_name
+ * Must be called with &key_tfm_list_mutex held
+ * Returns 1 if found, with @key_tfm set
+ * Returns 0 if not found, with @key_tfm set to NULL
+ */
+int ecryptfs_tfm_exists(char *cipher_name, struct ecryptfs_key_tfm **key_tfm)
+{
+ struct ecryptfs_key_tfm *tmp_key_tfm;
+
+ BUG_ON(!mutex_is_locked(&key_tfm_list_mutex));
+
+ list_for_each_entry(tmp_key_tfm, &key_tfm_list, key_tfm_list) {
+ if (strcmp(tmp_key_tfm->cipher_name, cipher_name) == 0) {
+ if (key_tfm)
+ (*key_tfm) = tmp_key_tfm;
+ return 1;
+ }
+ }
+ if (key_tfm)
+ (*key_tfm) = NULL;
+ return 0;
+}
+
+/**
+ * ecryptfs_get_tfm_and_mutex_for_cipher_name
+ *
+ * @tfm: set to cached tfm found, or new tfm created
+ * @tfm_mutex: set to mutex for cached tfm found, or new tfm created
+ * @cipher_name: the name of the cipher to search for and/or add
+ *
+ * Sets pointers to @tfm & @tfm_mutex matching @cipher_name.
+ * Searches for cached item first, and creates new if not found.
+ * Returns 0 on success, non-zero if adding new cipher failed
+ */
int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm,
struct mutex **tfm_mutex,
char *cipher_name)
@@ -1877,22 +1897,17 @@ int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm,
(*tfm) = NULL;
(*tfm_mutex) = NULL;
+
mutex_lock(&key_tfm_list_mutex);
- list_for_each_entry(key_tfm, &key_tfm_list, key_tfm_list) {
- if (strcmp(key_tfm->cipher_name, cipher_name) == 0) {
- (*tfm) = key_tfm->key_tfm;
- (*tfm_mutex) = &key_tfm->key_tfm_mutex;
- mutex_unlock(&key_tfm_list_mutex);
+ if (!ecryptfs_tfm_exists(cipher_name, &key_tfm)) {
+ rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0);
+ if (rc) {
+ printk(KERN_ERR "Error adding new key_tfm to list; "
+ "rc = [%d]\n", rc);
goto out;
}
}
mutex_unlock(&key_tfm_list_mutex);
- rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0);
- if (rc) {
- printk(KERN_ERR "Error adding new key_tfm to list; rc = [%d]\n",
- rc);
- goto out;
- }
(*tfm) = key_tfm->key_tfm;
(*tfm_mutex) = &key_tfm->key_tfm_mutex;
out: