| Kernel v2.6.24 /fs/ecryptfs/keystore.c |
|---|
  2.6.24
fs
ecryptfs
 keystore.c
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index b550dea..f458c1f 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -39,7 +39,7 @@
* determine the type of error, make appropriate log entries, and
* return an error code.
*/
-int process_request_key_err(long err_code)
+static int process_request_key_err(long err_code)
{
int rc = 0;
@@ -71,7 +71,7 @@ int process_request_key_err(long err_code)
* address; zero on error
* @length_size: The number of bytes occupied by the encoded length
*
- * Returns Zero on success
+ * Returns zero on success; non-zero on error
*/
static int parse_packet_length(unsigned char *data, size_t *size,
size_t *length_size)
@@ -106,11 +106,11 @@ out:
/**
* write_packet_length
- * @dest: The byte array target into which to write the
- * length. Must have at least 5 bytes allocated.
+ * @dest: The byte array target into which to write the length. Must
+ * have at least 5 bytes allocated.
* @size: The length to write.
- * @packet_size_length: The number of bytes used to encode the
- * packet length is written to this address.
+ * @packet_size_length: The number of bytes used to encode the packet
+ * length is written to this address.
*
* Returns zero on success; non-zero on error.
*/
@@ -396,26 +396,53 @@ out:
return rc;
}
+static int
+ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok)
+{
+ int rc = 0;
+
+ (*sig) = NULL;
+ switch (auth_tok->token_type) {
+ case ECRYPTFS_PASSWORD:
+ (*sig) = auth_tok->token.password.signature;
+ break;
+ case ECRYPTFS_PRIVATE_KEY:
+ (*sig) = auth_tok->token.private_key.signature;
+ break;
+ default:
+ printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n",
+ auth_tok->token_type);
+ rc = -EINVAL;
+ }
+ return rc;
+}
+
/**
- * decrypt_pki_encrypted_session_key - Decrypt the session key with
- * the given auth_tok.
+ * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok.
+ * @auth_tok: The key authentication token used to decrypt the session key
+ * @crypt_stat: The cryptographic context
*
- * Returns Zero on success; non-zero error otherwise.
+ * Returns zero on success; non-zero error otherwise.
*/
-static int decrypt_pki_encrypted_session_key(
- struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
- struct ecryptfs_auth_tok *auth_tok,
- struct ecryptfs_crypt_stat *crypt_stat)
+static int
+decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
+ struct ecryptfs_crypt_stat *crypt_stat)
{
u16 cipher_code = 0;
struct ecryptfs_msg_ctx *msg_ctx;
struct ecryptfs_message *msg = NULL;
+ char *auth_tok_sig;
char *netlink_message;
size_t netlink_message_length;
int rc;
- rc = write_tag_64_packet(mount_crypt_stat->global_auth_tok_sig,
- &(auth_tok->session_key),
+ rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok);
+ if (rc) {
+ printk(KERN_ERR "Unrecognized auth tok type: [%d]\n",
+ auth_tok->token_type);
+ goto out;
+ }
+ rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key),
&netlink_message, &netlink_message_length);
if (rc) {
ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet");
@@ -465,40 +492,33 @@ out:
static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
{
- struct list_head *walker;
struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
+ struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
- walker = auth_tok_list_head->next;
- while (walker != auth_tok_list_head) {
- auth_tok_list_item =
- list_entry(walker, struct ecryptfs_auth_tok_list_item,
- list);
- walker = auth_tok_list_item->list.next;
- memset(auth_tok_list_item, 0,
- sizeof(struct ecryptfs_auth_tok_list_item));
+ list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp,
+ auth_tok_list_head, list) {
+ list_del(&auth_tok_list_item->list);
kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
auth_tok_list_item);
}
- auth_tok_list_head->next = NULL;
}
struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
-
/**
* parse_tag_1_packet
- * @crypt_stat: The cryptographic context to modify based on packet
- * contents.
+ * @crypt_stat: The cryptographic context to modify based on packet contents
* @data: The raw bytes of the packet.
* @auth_tok_list: eCryptfs parses packets into authentication tokens;
- * a new authentication token will be placed at the end
- * of this list for this packet.
+ * a new authentication token will be placed at the
+ * end of this list for this packet.
* @new_auth_tok: Pointer to a pointer to memory that this function
* allocates; sets the memory address of the pointer to
* NULL on error. This object is added to the
* auth_tok_list.
* @packet_size: This function writes the size of the parsed packet
* into this memory location; zero on error.
+ * @max_packet_size: The maximum allowable packet size
*
* Returns zero on success; non-zero on error.
*/
@@ -515,72 +535,65 @@ parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
(*packet_size) = 0;
(*new_auth_tok) = NULL;
-
- /* we check that:
- * one byte for the Tag 1 ID flag
- * two bytes for the body size
- * do not exceed the maximum_packet_size
+ /**
+ * This format is inspired by OpenPGP; see RFC 2440
+ * packet tag 1
+ *
+ * Tag 1 identifier (1 byte)
+ * Max Tag 1 packet size (max 3 bytes)
+ * Version (1 byte)
+ * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE)
+ * Cipher identifier (1 byte)
+ * Encrypted key size (arbitrary)
+ *
+ * 12 bytes minimum packet size
*/
- if (unlikely((*packet_size) + 3 > max_packet_size)) {
- ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n");
+ if (unlikely(max_packet_size < 12)) {
+ printk(KERN_ERR "Invalid max packet size; must be >=12\n");
rc = -EINVAL;
goto out;
}
- /* check for Tag 1 identifier - one byte */
if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) {
- ecryptfs_printk(KERN_ERR, "Enter w/ first byte != 0x%.2x\n",
- ECRYPTFS_TAG_1_PACKET_TYPE);
+ printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n",
+ ECRYPTFS_TAG_1_PACKET_TYPE);
rc = -EINVAL;
goto out;
}
/* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
* at end of function upon failure */
auth_tok_list_item =
- kmem_cache_alloc(ecryptfs_auth_tok_list_item_cache,
- GFP_KERNEL);
+ kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache,
+ GFP_KERNEL);
if (!auth_tok_list_item) {
- ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
+ printk(KERN_ERR "Unable to allocate memory\n");
rc = -ENOMEM;
goto out;
}
- memset(auth_tok_list_item, 0,
- sizeof(struct ecryptfs_auth_tok_list_item));
(*new_auth_tok) = &auth_tok_list_item->auth_tok;
- /* check for body size - one to two bytes
- *
- * ***** TAG 1 Packet Format *****
- * | version number | 1 byte |
- * | key ID | 8 bytes |
- * | public key algorithm | 1 byte |
- * | encrypted session key | arbitrary |
- */
rc = parse_packet_length(&data[(*packet_size)], &body_size,
&length_size);
if (rc) {
- ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
- "rc = [%d]\n", rc);
+ printk(KERN_WARNING "Error parsing packet length; "
+ "rc = [%d]\n", rc);
goto out_free;
}
- if (unlikely(body_size < (0x02 + ECRYPTFS_SIG_SIZE))) {
- ecryptfs_printk(KERN_WARNING, "Invalid body size ([%d])\n",
- body_size);
+ if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) {
+ printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
rc = -EINVAL;
goto out_free;
}
(*packet_size) += length_size;
if (unlikely((*packet_size) + body_size > max_packet_size)) {
- ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n");
+ printk(KERN_WARNING "Packet size exceeds max\n");
rc = -EINVAL;
goto out_free;
}
- /* Version 3 (from RFC2440) - one byte */
if (unlikely(data[(*packet_size)++] != 0x03)) {
- ecryptfs_printk(KERN_DEBUG, "Unknown version number "
- "[%d]\n", data[(*packet_size) - 1]);
+ printk(KERN_WARNING "Unknown version number [%d]\n",
+ data[(*packet_size) - 1]);
rc = -EINVAL;
goto out_free;
}
- /* Read Signature */
ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
&data[(*packet_size)], ECRYPTFS_SIG_SIZE);
*packet_size += ECRYPTFS_SIG_SIZE;
@@ -588,27 +601,23 @@ parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
* know which public key encryption algorithm was used */
(*packet_size)++;
(*new_auth_tok)->session_key.encrypted_key_size =
- body_size - (0x02 + ECRYPTFS_SIG_SIZE);
+ body_size - (ECRYPTFS_SIG_SIZE + 2);
if ((*new_auth_tok)->session_key.encrypted_key_size
> ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
- ecryptfs_printk(KERN_ERR, "Tag 1 packet contains key larger "
- "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
+ printk(KERN_WARNING "Tag 1 packet contains key larger "
+ "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
rc = -EINVAL;
goto out;
}
- ecryptfs_printk(KERN_DEBUG, "Encrypted key size = [%d]\n",
- (*new_auth_tok)->session_key.encrypted_key_size);
memcpy((*new_auth_tok)->session_key.encrypted_key,
- &data[(*packet_size)], (body_size - 0x02 - ECRYPTFS_SIG_SIZE));
+ &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2)));
(*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size;
(*new_auth_tok)->session_key.flags &=
~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
(*new_auth_tok)->session_key.flags |=
ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
(*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY;
- (*new_auth_tok)->flags |= ECRYPTFS_PRIVATE_KEY;
- /* TODO: Why are we setting this flag here? Don't we want the
- * userspace to decrypt the session key? */
+ (*new_auth_tok)->flags = 0;
(*new_auth_tok)->session_key.flags &=
~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
(*new_auth_tok)->session_key.flags &=
@@ -658,22 +667,30 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
(*packet_size) = 0;
(*new_auth_tok) = NULL;
-
- /* we check that:
- * one byte for the Tag 3 ID flag
- * two bytes for the body size
- * do not exceed the maximum_packet_size
+ /**
+ *This format is inspired by OpenPGP; see RFC 2440
+ * packet tag 3
+ *
+ * Tag 3 identifier (1 byte)
+ * Max Tag 3 packet size (max 3 bytes)
+ * Version (1 byte)
+ * Cipher code (1 byte)
+ * S2K specifier (1 byte)
+ * Hash identifier (1 byte)
+ * Salt (ECRYPTFS_SALT_SIZE)
+ * Hash iterations (1 byte)
+ * Encrypted key (arbitrary)
+ *
+ * (ECRYPTFS_SALT_SIZE + 7) minimum packet size
*/
- if (unlikely((*packet_size) + 3 > max_packet_size)) {
- ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n");
+ if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) {
+ printk(KERN_ERR "Max packet size too large\n");
rc = -EINVAL;
goto out;
}
-
- /* check for Tag 3 identifyer - one byte */
if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) {
- ecryptfs_printk(KERN_ERR, "Enter w/ first byte != 0x%.2x\n",
- ECRYPTFS_TAG_3_PACKET_TYPE);
+ printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n",
+ ECRYPTFS_TAG_3_PACKET_TYPE);
rc = -EINVAL;
goto out;
}
@@ -682,56 +699,37 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
auth_tok_list_item =
kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
if (!auth_tok_list_item) {
- ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
+ printk(KERN_ERR "Unable to allocate memory\n");
rc = -ENOMEM;
goto out;
}
(*new_auth_tok) = &auth_tok_list_item->auth_tok;
-
- /* check for body size - one to two bytes */
rc = parse_packet_length(&data[(*packet_size)], &body_size,
&length_size);
if (rc) {
- ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
- "rc = [%d]\n", rc);
+ printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n",
+ rc);
goto out_free;
}
- if (unlikely(body_size < (0x05 + ECRYPTFS_SALT_SIZE))) {
- ecryptfs_printk(KERN_WARNING, "Invalid body size ([%d])\n",
- body_size);
+ if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) {
+ printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
rc = -EINVAL;
goto out_free;
}
(*packet_size) += length_size;
-
- /* now we know the length of the remainting Tag 3 packet size:
- * 5 fix bytes for: version string, cipher, S2K ID, hash algo,
- * number of hash iterations
- * ECRYPTFS_SALT_SIZE bytes for salt
- * body_size bytes minus the stuff above is the encrypted key size
- */
if (unlikely((*packet_size) + body_size > max_packet_size)) {
- ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n");
+ printk(KERN_ERR "Packet size exceeds max\n");
rc = -EINVAL;
goto out_free;
}
-
- /* There are 5 characters of additional information in the
- * packet */
(*new_auth_tok)->session_key.encrypted_key_size =
- body_size - (0x05 + ECRYPTFS_SALT_SIZE);
- ecryptfs_printk(KERN_DEBUG, "Encrypted key size = [%d]\n",
- (*new_auth_tok)->session_key.encrypted_key_size);
-
- /* Version 4 (from RFC2440) - one byte */
+ (body_size - (ECRYPTFS_SALT_SIZE + 5));
if (unlikely(data[(*packet_size)++] != 0x04)) {
- ecryptfs_printk(KERN_DEBUG, "Unknown version number "
- "[%d]\n", data[(*packet_size) - 1]);
+ printk(KERN_WARNING "Unknown version number [%d]\n",
+ data[(*packet_size) - 1]);
rc = -EINVAL;
goto out_free;
}
-
- /* cipher - one byte */
ecryptfs_cipher_code_to_string(crypt_stat->cipher,
(u16)data[(*packet_size)]);
/* A little extra work to differentiate among the AES key
@@ -745,33 +743,26 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
(*new_auth_tok)->session_key.encrypted_key_size;
}
ecryptfs_init_crypt_ctx(crypt_stat);
- /* S2K identifier 3 (from RFC2440) */
if (unlikely(data[(*packet_size)++] != 0x03)) {
- ecryptfs_printk(KERN_ERR, "Only S2K ID 3 is currently "
- "supported\n");
+ printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
rc = -ENOSYS;
goto out_free;
}
-
/* TODO: finish the hash mapping */
- /* hash algorithm - one byte */
switch (data[(*packet_size)++]) {
case 0x01: /* See RFC2440 for these numbers and their mappings */
/* Choose MD5 */
- /* salt - ECRYPTFS_SALT_SIZE bytes */
memcpy((*new_auth_tok)->token.password.salt,
&data[(*packet_size)], ECRYPTFS_SALT_SIZE);
(*packet_size) += ECRYPTFS_SALT_SIZE;
-
/* This conversion was taken straight from RFC2440 */
- /* number of hash iterations - one byte */
(*new_auth_tok)->token.password.hash_iterations =
((u32) 16 + (data[(*packet_size)] & 15))
<< ((data[(*packet_size)] >> 4) + 6);
(*packet_size)++;
-
- /* encrypted session key -
- * (body_size-5-ECRYPTFS_SALT_SIZE) bytes */
+ /* Friendly reminder:
+ * (*new_auth_tok)->session_key.encrypted_key_size =
+ * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */
memcpy((*new_auth_tok)->session_key.encrypted_key,
&data[(*packet_size)],
(*new_auth_tok)->session_key.encrypted_key_size);
@@ -781,7 +772,7 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
(*new_auth_tok)->session_key.flags |=
ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
- (*new_auth_tok)->token.password.hash_algo = 0x01;
+ (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */
break;
default:
ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: "
@@ -837,82 +828,61 @@ parse_tag_11_packet(unsigned char *data, unsigned char *contents,
(*packet_size) = 0;
(*tag_11_contents_size) = 0;
-
- /* check that:
- * one byte for the Tag 11 ID flag
- * two bytes for the Tag 11 length
- * do not exceed the maximum_packet_size
+ /* This format is inspired by OpenPGP; see RFC 2440
+ * packet tag 11
+ *
+ * Tag 11 identifier (1 byte)
+ * Max Tag 11 packet size (max 3 bytes)
+ * Binary format specifier (1 byte)
+ * Filename length (1 byte)
+ * Filename ("_CONSOLE") (8 bytes)
+ * Modification date (4 bytes)
+ * Literal data (arbitrary)
+ *
+ * We need at least 16 bytes of data for the packet to even be
+ * valid.
*/
- if (unlikely((*packet_size) + 3 > max_packet_size)) {
- ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n");
+ if (max_packet_size < 16) {
+ printk(KERN_ERR "Maximum packet size too small\n");
rc = -EINVAL;
goto out;
}
-
- /* check for Tag 11 identifyer - one byte */
if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) {
- ecryptfs_printk(KERN_WARNING,
- "Invalid tag 11 packet format\n");
+ printk(KERN_WARNING "Invalid tag 11 packet format\n");
rc = -EINVAL;
goto out;
}
-
- /* get Tag 11 content length - one or two bytes */
rc = parse_packet_length(&data[(*packet_size)], &body_size,
&length_size);
if (rc) {
- ecryptfs_printk(KERN_WARNING,
- "Invalid tag 11 packet format\n");
+ printk(KERN_WARNING "Invalid tag 11 packet format\n");
goto out;
}
- (*packet_size) += length_size;
-
- if (body_size < 13) {
- ecryptfs_printk(KERN_WARNING, "Invalid body size ([%d])\n",
- body_size);
+ if (body_size < 14) {
+ printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
rc = -EINVAL;
goto out;
}
- /* We have 13 bytes of surrounding packet values */
- (*tag_11_contents_size) = (body_size - 13);
-
- /* now we know the length of the remainting Tag 11 packet size:
- * 14 fix bytes for: special flag one, special flag two,
- * 12 skipped bytes
- * body_size bytes minus the stuff above is the Tag 11 content
- */
- /* FIXME why is the body size one byte smaller than the actual
- * size of the body?
- * this seems to be an error here as well as in
- * write_tag_11_packet() */
+ (*packet_size) += length_size;
+ (*tag_11_contents_size) = (body_size - 14);
if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) {
- ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n");
+ printk(KERN_ERR "Packet size exceeds max\n");
rc = -EINVAL;
goto out;
}
-
- /* special flag one - one byte */
if (data[(*packet_size)++] != 0x62) {
- ecryptfs_printk(KERN_WARNING, "Unrecognizable packet\n");
+ printk(KERN_WARNING "Unrecognizable packet\n");
rc = -EINVAL;
goto out;
}
-
- /* special flag two - one byte */
if (data[(*packet_size)++] != 0x08) {
- ecryptfs_printk(KERN_WARNING, "Unrecognizable packet\n");
+ printk(KERN_WARNING "Unrecognizable packet\n");
rc = -EINVAL;
goto out;
}
-
- /* skip the next 12 bytes */
- (*packet_size) += 12; /* We don't care about the filename or
- * the timestamp */
-
- /* get the Tag 11 contents - tag_11_contents_size bytes */
+ (*packet_size) += 12; /* Ignore filename and modification date */
memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size));
(*packet_size) += (*tag_11_contents_size);
-
out:
if (rc) {
(*packet_size) = 0;
@@ -921,130 +891,232 @@ out:
return rc;
}
+static int
+ecryptfs_find_global_auth_tok_for_sig(
+ struct ecryptfs_global_auth_tok **global_auth_tok,
+ struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig)
+{
+ struct ecryptfs_global_auth_tok *walker;
+ int rc = 0;
+
+ (*global_auth_tok) = NULL;
+ mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
+ list_for_each_entry(walker,
+ &mount_crypt_stat->global_auth_tok_list,
+ mount_crypt_stat_list) {
+ if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX) == 0) {
+ (*global_auth_tok) = walker;
+ goto out;
+ }
+ }
+ rc = -EINVAL;
+out:
+ mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
+ return rc;
+}
+
/**
- * decrypt_session_key - Decrypt the session key with the given auth_tok.
+ * ecryptfs_verify_version
+ * @version: The version number to confirm
*
- * Returns Zero on success; non-zero error otherwise.
+ * Returns zero on good version; non-zero otherwise
*/
-static int decrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
- struct ecryptfs_crypt_stat *crypt_stat)
+static int ecryptfs_verify_version(u16 version)
{
- struct ecryptfs_password *password_s_ptr;
- struct scatterlist src_sg[2], dst_sg[2];
- struct mutex *tfm_mutex = NULL;
- char *encrypted_session_key;
- char *session_key;
+ int rc = 0;
+ unsigned char major;
+ unsigned char minor;
+
+ major = ((version >> 8) & 0xFF);
+ minor = (version & 0xFF);
+ if (major != ECRYPTFS_VERSION_MAJOR) {
+ ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
+ "Expected [%d]; got [%d]\n",
+ ECRYPTFS_VERSION_MAJOR, major);
+ rc = -EINVAL;
+ goto out;
+ }
+ if (minor != ECRYPTFS_VERSION_MINOR) {
+ ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
+ "Expected [%d]; got [%d]\n",
+ ECRYPTFS_VERSION_MINOR, minor);
+ rc = -EINVAL;
+ goto out;
+ }
+out:
+ return rc;
+}
+
+int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
+ struct ecryptfs_auth_tok **auth_tok,
+ char *sig)
+{
+ int rc = 0;
+
+ (*auth_tok_key) = request_key(&key_type_user, sig, NULL);
+ if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
+ printk(KERN_ERR "Could not find key with description: [%s]\n",
+ sig);
+ process_request_key_err(PTR_ERR(*auth_tok_key));
+ rc = -EINVAL;
+ goto out;
+ }
+ (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key);
+ if (ecryptfs_verify_version((*auth_tok)->version)) {
+ printk(KERN_ERR
+ "Data structure version mismatch. "
+ "Userspace tools must match eCryptfs "
+ "kernel module with major version [%d] "
+ "and minor version [%d]\n",
+ ECRYPTFS_VERSION_MAJOR,
+ ECRYPTFS_VERSION_MINOR);
+ rc = -EINVAL;
+ goto out;
+ }
+ if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
+ && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
+ printk(KERN_ERR "Invalid auth_tok structure "
+ "returned from key query\n");
+ rc = -EINVAL;
+ goto out;
+ }
+out:
+ return rc;
+}
+
+/**
+ * ecryptfs_find_auth_tok_for_sig
+ * @auth_tok: Set to the matching auth_tok; NULL if not found
+ * @crypt_stat: inode crypt_stat crypto context
+ * @sig: Sig of auth_tok to find
+ *
+ * For now, this function simply looks at the registered auth_tok's
+ * linked off the mount_crypt_stat, so all the auth_toks that can be
+ * used must be registered at mount time. This function could
+ * potentially try a lot harder to find auth_tok's (e.g., by calling
+ * out to ecryptfsd to dynamically retrieve an auth_tok object) so
+ * that static registration of auth_tok's will no longer be necessary.
+ *
+ * Returns zero on no error; non-zero on error
+ */
+static int
+ecryptfs_find_auth_tok_for_sig(
+ struct ecryptfs_auth_tok **auth_tok,
+ struct ecryptfs_crypt_stat *crypt_stat, char *sig)
+{
+ struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
+ crypt_stat->mount_crypt_stat;
+ struct ecryptfs_global_auth_tok *global_auth_tok;
+ int rc = 0;
+
+ (*auth_tok) = NULL;
+ if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
+ mount_crypt_stat, sig)) {
+ struct key *auth_tok_key;
+
+ rc = ecryptfs_keyring_auth_tok_for_sig(&auth_tok_key, auth_tok,
+ sig);
+ } else
+ (*auth_tok) = global_auth_tok->global_auth_tok;
+ return rc;
+}
+
+/**
+ * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok.
+ * @auth_tok: The passphrase authentication token to use to encrypt the FEK
+ * @crypt_stat: The cryptographic context
+ *
+ * Returns zero on success; non-zero error otherwise
+ */
+static int
+decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
+ struct ecryptfs_crypt_stat *crypt_stat)
+{
+ struct scatterlist dst_sg;
+ struct scatterlist src_sg;
+ struct mutex *tfm_mutex;
struct blkcipher_desc desc = {
.flags = CRYPTO_TFM_REQ_MAY_SLEEP
};
int rc = 0;
- password_s_ptr = &auth_tok->token.password;
- if (password_s_ptr->flags & ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET)
- ecryptfs_printk(KERN_DEBUG, "Session key encryption key "
- "set; skipping key generation\n");
- ecryptfs_printk(KERN_DEBUG, "Session key encryption key (size [%d])"
- ":\n",
- password_s_ptr->session_key_encryption_key_bytes);
- if (ecryptfs_verbosity > 0)
- ecryptfs_dump_hex(password_s_ptr->session_key_encryption_key,
- password_s_ptr->
- session_key_encryption_key_bytes);
- if (!strcmp(crypt_stat->cipher,
- crypt_stat->mount_crypt_stat->global_default_cipher_name)
- && crypt_stat->mount_crypt_stat->global_key_tfm) {
- desc.tfm = crypt_stat->mount_crypt_stat->global_key_tfm;
- tfm_mutex = &crypt_stat->mount_crypt_stat->global_key_tfm_mutex;
- } else {
- char *full_alg_name;
+ sg_init_table(&dst_sg, 1);
+ sg_init_table(&src_sg, 1);
- rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name,
- crypt_stat->cipher,
- "ecb");
- if (rc)
- goto out;
- desc.tfm = crypto_alloc_blkcipher(full_alg_name, 0,
- CRYPTO_ALG_ASYNC);
- kfree(full_alg_name);
- if (IS_ERR(desc.tfm)) {
- rc = PTR_ERR(desc.tfm);
- printk(KERN_ERR "Error allocating crypto context; "
- "rc = [%d]\n", rc);
- goto out;
- }
- crypto_blkcipher_set_flags(desc.tfm, CRYPTO_TFM_REQ_WEAK_KEY);
+ if (unlikely(ecryptfs_verbosity > 0)) {
+ ecryptfs_printk(
+ KERN_DEBUG, "Session key encryption key (size [%d]):\n",
+ auth_tok->token.password.session_key_encryption_key_bytes);
+ ecryptfs_dump_hex(
+ auth_tok->token.password.session_key_encryption_key,
+ auth_tok->token.password.session_key_encryption_key_bytes);
+ }
+ rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
+ crypt_stat->cipher);
+ if (unlikely(rc)) {
+ printk(KERN_ERR "Internal error whilst attempting to get "
+ "tfm and mutex for cipher name [%s]; rc = [%d]\n",
+ crypt_stat->cipher, rc);
+ goto out;
}
- if (tfm_mutex)
- mutex_lock(tfm_mutex);
- rc = crypto_blkcipher_setkey(desc.tfm,
- password_s_ptr->session_key_encryption_key,
- crypt_stat->key_size);
- if (rc < 0) {
+ rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
+ auth_tok->session_key.encrypted_key_size,
+ &src_sg, 1);
+ if (rc != 1) {
+ printk(KERN_ERR "Internal error whilst attempting to convert "
+ "auth_tok->session_key.encrypted_key to scatterlist; "
+ "expected rc = 1; got rc = [%d]. "
+ "auth_tok->session_key.encrypted_key_size = [%d]\n", rc,
+ auth_tok->session_key.encrypted_key_size);
+ goto out;
+ }
+ auth_tok->session_key.decrypted_key_size =
+ auth_tok->session_key.encrypted_key_size;
+ rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key,
+ auth_tok->session_key.decrypted_key_size,
+ &dst_sg, 1);
+ if (rc != 1) {
+ printk(KERN_ERR "Internal error whilst attempting to convert "
+ "auth_tok->session_key.decrypted_key to scatterlist; "
+ "expected rc = 1; got rc = [%d]\n", rc);
+ goto out;
+ }
+ mutex_lock(tfm_mutex);
+ rc = crypto_blkcipher_setkey(
+ desc.tfm, auth_tok->token.password.session_key_encryption_key,
+ crypt_stat->key_size);
+ if (unlikely(rc < 0)) {
+ mutex_unlock(tfm_mutex);
printk(KERN_ERR "Error setting key for crypto context\n");
rc = -EINVAL;
- goto out_free_tfm;
- }
- /* TODO: virt_to_scatterlist */
- encrypted_session_key = (char *)__get_free_page(GFP_KERNEL);
- if (!encrypted_session_key) {
- ecryptfs_printk(KERN_ERR, "Out of memory\n");
- rc = -ENOMEM;
- goto out_free_tfm;
+ goto out;
}
- session_key = (char *)__get_free_page(GFP_KERNEL);
- if (!session_key) {
- kfree(encrypted_session_key);
- ecryptfs_printk(KERN_ERR, "Out of memory\n");
- rc = -ENOMEM;
- goto out_free_tfm;
- }
- memcpy(encrypted_session_key, auth_tok->session_key.encrypted_key,
- auth_tok->session_key.encrypted_key_size);
- src_sg[0].page = virt_to_page(encrypted_session_key);
- src_sg[0].offset = 0;
- BUG_ON(auth_tok->session_key.encrypted_key_size > PAGE_CACHE_SIZE);
- src_sg[0].length = auth_tok->session_key.encrypted_key_size;
- dst_sg[0].page = virt_to_page(session_key);
- dst_sg[0].offset = 0;
- auth_tok->session_key.decrypted_key_size =
- auth_tok->session_key.encrypted_key_size;
- dst_sg[0].length = auth_tok->session_key.encrypted_key_size;
- rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg,
+ rc = crypto_blkcipher_decrypt(&desc, &dst_sg, &src_sg,
auth_tok->session_key.encrypted_key_size);
- if (rc) {
+ mutex_unlock(tfm_mutex);
+ if (unlikely(rc)) {
printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
- goto out_free_memory;
+ goto out;
}
- auth_tok->session_key.decrypted_key_size =
- auth_tok->session_key.encrypted_key_size;
- memcpy(auth_tok->session_key.decrypted_key, session_key,
- auth_tok->session_key.decrypted_key_size);
auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
auth_tok->session_key.decrypted_key_size);
crypt_stat->flags |= ECRYPTFS_KEY_VALID;
- ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n");
- if (ecryptfs_verbosity > 0)
+ if (unlikely(ecryptfs_verbosity > 0)) {
+ ecryptfs_printk(KERN_DEBUG, "FEK of size [%d]:\n",
+ crypt_stat->key_size);
ecryptfs_dump_hex(crypt_stat->key,
crypt_stat->key_size);
-out_free_memory:
- memset(encrypted_session_key, 0, PAGE_CACHE_SIZE);
- free_page((unsigned long)encrypted_session_key);
- memset(session_key, 0, PAGE_CACHE_SIZE);
- free_page((unsigned long)session_key);
-out_free_tfm:
- if (tfm_mutex)
- mutex_unlock(tfm_mutex);
- else
- crypto_free_blkcipher(desc.tfm);
+ }
out:
return rc;
}
/**
* ecryptfs_parse_packet_set
- * @dest: The header page in memory
- * @version: Version of file format, to guide parsing behavior
+ * @crypt_stat: The cryptographic context
+ * @src: Virtual address of region of memory containing the packets
+ * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set
*
* Get crypt_stat to have the file's session key if the requisite key
* is available to decrypt the session key.
@@ -1058,25 +1130,22 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
struct dentry *ecryptfs_dentry)
{
size_t i = 0;
- size_t found_auth_tok = 0;
+ size_t found_auth_tok;
size_t next_packet_is_auth_tok_packet;
- char sig[ECRYPTFS_SIG_SIZE_HEX];
struct list_head auth_tok_list;
- struct list_head *walker;
- struct ecryptfs_auth_tok *chosen_auth_tok = NULL;
- struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
- &ecryptfs_superblock_to_private(
- ecryptfs_dentry->d_sb)->mount_crypt_stat;
- struct ecryptfs_auth_tok *candidate_auth_tok = NULL;
+ struct ecryptfs_auth_tok *matching_auth_tok;
+ struct ecryptfs_auth_tok *candidate_auth_tok;
+ char *candidate_auth_tok_sig;
size_t packet_size;
struct ecryptfs_auth_tok *new_auth_tok;
unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE];
+ struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
size_t tag_11_contents_size;
size_t tag_11_packet_size;
int rc = 0;
INIT_LIST_HEAD(&auth_tok_list);
- /* Parse the header to find as many packets as we can, these will be
+ /* Parse the header to find as many packets as we can; these will be
* added the our &auth_tok_list */
next_packet_is_auth_tok_packet = 1;
while (next_packet_is_auth_tok_packet) {
@@ -1155,73 +1224,85 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
}
}
if (list_empty(&auth_tok_list)) {
- rc = -EINVAL; /* Do not support non-encrypted files in
- * the 0.1 release */
+ printk(KERN_ERR "The lower file appears to be a non-encrypted "
+ "eCryptfs file; this is not supported in this version "
+ "of the eCryptfs kernel module\n");
+ rc = -EINVAL;
goto out;
}
- /* If we have a global auth tok, then we should try to use
- * it */
- if (mount_crypt_stat->global_auth_tok) {
- memcpy(sig, mount_crypt_stat->global_auth_tok_sig,
- ECRYPTFS_SIG_SIZE_HEX);
- chosen_auth_tok = mount_crypt_stat->global_auth_tok;
- } else
- BUG(); /* We should always have a global auth tok in
- * the 0.1 release */
- /* Scan list to see if our chosen_auth_tok works */
- list_for_each(walker, &auth_tok_list) {
- struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
- auth_tok_list_item =
- list_entry(walker, struct ecryptfs_auth_tok_list_item,
- list);
+ /* auth_tok_list contains the set of authentication tokens
+ * parsed from the metadata. We need to find a matching
+ * authentication token that has the secret component(s)
+ * necessary to decrypt the EFEK in the auth_tok parsed from
+ * the metadata. There may be several potential matches, but
+ * just one will be sufficient to decrypt to get the FEK. */
+find_next_matching_auth_tok:
+ found_auth_tok = 0;
+ list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) {
candidate_auth_tok = &auth_tok_list_item->auth_tok;
if (unlikely(ecryptfs_verbosity > 0)) {
ecryptfs_printk(KERN_DEBUG,
"Considering cadidate auth tok:\n");
ecryptfs_dump_auth_tok(candidate_auth_tok);
}
- /* TODO: Replace ECRYPTFS_SIG_SIZE_HEX w/ dynamic value */
- if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD
- && !strncmp(candidate_auth_tok->token.password.signature,
- sig, ECRYPTFS_SIG_SIZE_HEX)) {
- found_auth_tok = 1;
- goto leave_list;
- /* TODO: Transfer the common salt into the
- * crypt_stat salt */
- } else if ((candidate_auth_tok->token_type
- == ECRYPTFS_PRIVATE_KEY)
- && !strncmp(candidate_auth_tok->token.private_key.signature,
- sig, ECRYPTFS_SIG_SIZE_HEX)) {
+ rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig,
+ candidate_auth_tok);
+ if (rc) {
+ printk(KERN_ERR
+ "Unrecognized candidate auth tok type: [%d]\n",
+ candidate_auth_tok->token_type);
+ rc = -EINVAL;
+ goto out_wipe_list;
+ }
+ ecryptfs_find_auth_tok_for_sig(&matching_auth_tok, crypt_stat,
+ candidate_auth_tok_sig);
+ if (matching_auth_tok) {
found_auth_tok = 1;
- goto leave_list;
+ goto found_matching_auth_tok;
}
}
if (!found_auth_tok) {
- ecryptfs_printk(KERN_ERR, "Could not find authentication "
- "token on temporary list for sig [%.*s]\n",
- ECRYPTFS_SIG_SIZE_HEX, sig);
+ ecryptfs_printk(KERN_ERR, "Could not find a usable "
+ "authentication token\n");
rc = -EIO;
goto out_wipe_list;
}
-leave_list:
- rc = -ENOTSUPP;
+found_matching_auth_tok:
if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
memcpy(&(candidate_auth_tok->token.private_key),
- &(chosen_auth_tok->token.private_key),
+ &(matching_auth_tok->token.private_key),
sizeof(struct ecryptfs_private_key));
- rc = decrypt_pki_encrypted_session_key(mount_crypt_stat,
- candidate_auth_tok,
+ rc = decrypt_pki_encrypted_session_key(candidate_auth_tok,
crypt_stat);
} else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
memcpy(&(candidate_auth_tok->token.password),
- &(chosen_auth_tok->token.password),
+ &(matching_auth_tok->token.password),
sizeof(struct ecryptfs_password));
- rc = decrypt_session_key(candidate_auth_tok, crypt_stat);
+ rc = decrypt_passphrase_encrypted_session_key(
+ candidate_auth_tok, crypt_stat);
}
if (rc) {
- ecryptfs_printk(KERN_ERR, "Error decrypting the "
- "session key; rc = [%d]\n", rc);
- goto out_wipe_list;
+ struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
+
+ ecryptfs_printk(KERN_WARNING, "Error decrypting the "
+ "session key for authentication token with sig "
+ "[%.*s]; rc = [%d]. Removing auth tok "
+ "candidate from the list and searching for "
+ "the next match.\n", candidate_auth_tok_sig,
+ ECRYPTFS_SIG_SIZE_HEX, rc);
+ list_for_each_entry_safe(auth_tok_list_item,
+ auth_tok_list_item_tmp,
+ &auth_tok_list, list) {
+ if (candidate_auth_tok
+ == &auth_tok_list_item->auth_tok) {
+ list_del(&auth_tok_list_item->list);
+ kmem_cache_free(
+ ecryptfs_auth_tok_list_item_cache,
+ auth_tok_list_item);
+ goto find_next_matching_auth_tok;
+ }
+ }
+ BUG();
}
rc = ecryptfs_compute_root_iv(crypt_stat);
if (rc) {
@@ -1240,6 +1321,7 @@ out_wipe_list:
out:
return rc;
}
+
static int
pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
struct ecryptfs_crypt_stat *crypt_stat,
@@ -1284,22 +1366,25 @@ out:
/**
* write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet
* @dest: Buffer into which to write the packet
- * @max: Maximum number of bytes that can be writtn
+ * @remaining_bytes: Maximum number of bytes that can be writtn
+ * @auth_tok: The authentication token used for generating the tag 1 packet
+ * @crypt_stat: The cryptographic context
+ * @key_rec: The key record struct for the tag 1 packet
* @packet_size: This function will write the number of bytes that end
* up constituting the packet; set to zero on error
*
* Returns zero on success; non-zero on error.
*/
static int
-write_tag_1_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
+write_tag_1_packet(char *dest, size_t *remaining_bytes,
+ struct ecryptfs_auth_tok *auth_tok,
struct ecryptfs_crypt_stat *crypt_stat,
- struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
struct ecryptfs_key_record *key_rec, size_t *packet_size)
{
size_t i;
size_t encrypted_session_key_valid = 0;
- size_t key_rec_size;
size_t packet_size_length;
+ size_t max_packet_size;
int rc = 0;
(*packet_size) = 0;
@@ -1329,37 +1414,23 @@ write_tag_1_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size);
}
encrypted_session_key_set:
- /* Now we have a valid key_rec. Append it to the
- * key_rec set. */
- key_rec_size = (sizeof(struct ecryptfs_key_record)
- - ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES
- + (key_rec->enc_key_size));
- /* TODO: Include a packet size limit as a parameter to this
- * function once we have multi-packet headers (for versions
- * later than 0.1 */
- if (key_rec_size >= ECRYPTFS_MAX_KEYSET_SIZE) {
- ecryptfs_printk(KERN_ERR, "Keyset too large\n");
- rc = -EINVAL;
- goto out;
- }
- /* ***** TAG 1 Packet Format *****
- * | version number | 1 byte |
- * | key ID | 8 bytes |
- * | public key algorithm | 1 byte |
- * | encrypted session key | arbitrary |
- */
- if ((0x02 + ECRYPTFS_SIG_SIZE + key_rec->enc_key_size) >= max) {
- ecryptfs_printk(KERN_ERR,
- "Authentication token is too large\n");
+ /* This format is inspired by OpenPGP; see RFC 2440
+ * packet tag 1 */
+ max_packet_size = (1 /* Tag 1 identifier */
+ + 3 /* Max Tag 1 packet size */
+ + 1 /* Version */
+ + ECRYPTFS_SIG_SIZE /* Key identifier */
+ + 1 /* Cipher identifier */
+ + key_rec->enc_key_size); /* Encrypted key size */
+ if (max_packet_size > (*remaining_bytes)) {
+ printk(KERN_ERR "Packet length larger than maximum allowable; "
+ "need up to [%td] bytes, but there are only [%td] "
+ "available\n", max_packet_size, (*remaining_bytes));
rc = -EINVAL;
goto out;
}
dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE;
- /* This format is inspired by OpenPGP; see RFC 2440
- * packet tag 1 */
- rc = write_packet_length(&dest[(*packet_size)],
- (0x02 + ECRYPTFS_SIG_SIZE +
- key_rec->enc_key_size),
+ rc = write_packet_length(&dest[(*packet_size)], (max_packet_size - 4),
&packet_size_length);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet "
@@ -1377,13 +1448,15 @@ encrypted_session_key_set:
out:
if (rc)
(*packet_size) = 0;
+ else
+ (*remaining_bytes) -= (*packet_size);
return rc;
}
/**
* write_tag_11_packet
* @dest: Target into which Tag 11 packet is to be written
- * @max: Maximum packet length
+ * @remaining_bytes: Maximum packet length
* @contents: Byte array of contents to copy in
* @contents_length: Number of bytes in contents
* @packet_length: Length of the Tag 11 packet written; zero on error
@@ -1391,54 +1464,59 @@ out:
* Returns zero on success; non-zero on error.
*/
static int
-write_tag_11_packet(char *dest, int max, char *contents, size_t contents_length,
- size_t *packet_length)
+write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents,
+ size_t contents_length, size_t *packet_length)
{
size_t packet_size_length;
+ size_t max_packet_size;
int rc = 0;
(*packet_length) = 0;
- if ((13 + contents_length) > max) {
+ /* This format is inspired by OpenPGP; see RFC 2440
+ * packet tag 11 */
+ max_packet_size = (1 /* Tag 11 identifier */
+ + 3 /* Max Tag 11 packet size */
+ + 1 /* Binary format specifier */
+ + 1 /* Filename length */
+ + 8 /* Filename ("_CONSOLE") */
+ + 4 /* Modification date */
+ + contents_length); /* Literal data */
+ if (max_packet_size > (*remaining_bytes)) {
+ printk(KERN_ERR "Packet length larger than maximum allowable; "
+ "need up to [%td] bytes, but there are only [%td] "
+ "available\n", max_packet_size, (*remaining_bytes));
rc = -EINVAL;
- ecryptfs_printk(KERN_ERR, "Packet length larger than "
- "maximum allowable\n");
goto out;
}
- /* General packet header */
- /* Packet tag */
dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE;
- /* Packet length */
rc = write_packet_length(&dest[(*packet_length)],
- (13 + contents_length), &packet_size_length);
+ (max_packet_size - 4), &packet_size_length);
if (rc) {
- ecryptfs_printk(KERN_ERR, "Error generating tag 11 packet "
- "header; cannot generate packet length\n");
+ printk(KERN_ERR "Error generating tag 11 packet header; cannot "
+ "generate packet length. rc = [%d]\n", rc);
goto out;
}
(*packet_length) += packet_size_length;
- /* Tag 11 specific */
- /* One-octet field that describes how the data is formatted */
- dest[(*packet_length)++] = 0x62; /* binary data */
- /* One-octet filename length followed by filename */
+ dest[(*packet_length)++] = 0x62; /* binary data format specifier */
dest[(*packet_length)++] = 8;
memcpy(&dest[(*packet_length)], "_CONSOLE", 8);
(*packet_length) += 8;
- /* Four-octet number indicating modification date */
memset(&dest[(*packet_length)], 0x00, 4);
(*packet_length) += 4;
- /* Remainder is literal data */
memcpy(&dest[(*packet_length)], contents, contents_length);
(*packet_length) += contents_length;
out:
if (rc)
(*packet_length) = 0;
+ else
+ (*remaining_bytes) -= (*packet_length);
return rc;
}
/**
* write_tag_3_packet
* @dest: Buffer into which to write the packet
- * @max: Maximum number of bytes that can be written
+ * @remaining_bytes: Maximum number of bytes that can be written
* @auth_tok: Authentication token
* @crypt_stat: The cryptographic context
* @key_rec: encrypted key
@@ -1448,19 +1526,22 @@ write_tag_11_packet(char *dest, int max, char *contents, size_t contents_length,
* Returns zero on success; non-zero on error.
*/
static int
-write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
+write_tag_3_packet(char *dest, size_t *remaining_bytes,
+ struct ecryptfs_auth_tok *auth_tok,
struct ecryptfs_crypt_stat *crypt_stat,
struct ecryptfs_key_record *key_rec, size_t *packet_size)
{
size_t i;
size_t encrypted_session_key_valid = 0;
char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
- struct scatterlist dest_sg[2];
- struct scatterlist src_sg[2];
+ struct scatterlist dst_sg;
+ struct scatterlist src_sg;
struct mutex *tfm_mutex = NULL;
- size_t key_rec_size;
- size_t packet_size_length;
size_t cipher_code;
+ size_t packet_size_length;
+ size_t max_packet_size;
+ struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
+ crypt_stat->mount_crypt_stat;
struct blkcipher_desc desc = {
.tfm = NULL,
.flags = CRYPTO_TFM_REQ_MAY_SLEEP
@@ -1470,16 +1551,25 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
(*packet_size) = 0;
ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
ECRYPTFS_SIG_SIZE);
- encrypted_session_key_valid = 0;
- for (i = 0; i < crypt_stat->key_size; i++)
- encrypted_session_key_valid |=
- auth_tok->session_key.encrypted_key[i];
- if (encrypted_session_key_valid) {
- memcpy(key_rec->enc_key,
- auth_tok->session_key.encrypted_key,
- auth_tok->session_key.encrypted_key_size);
- goto encrypted_session_key_set;
+ rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
+ crypt_stat->cipher);
+ if (unlikely(rc)) {
+ printk(KERN_ERR "Internal error whilst attempting to get "
+ "tfm and mutex for cipher name [%s]; rc = [%d]\n",
+ crypt_stat->cipher, rc);
+ goto out;
}
+ if (mount_crypt_stat->global_default_cipher_key_size == 0) {
+ struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm);
+
+ printk(KERN_WARNING "No key size specified at mount; "
+ "defaulting to [%d]\n", alg->max_keysize);
+ mount_crypt_stat->global_default_cipher_key_size =
+ alg->max_keysize;
+ }
+ if (crypt_stat->key_size == 0)
+ crypt_stat->key_size =
+ mount_crypt_stat->global_default_cipher_key_size;
if (auth_tok->session_key.encrypted_key_size == 0)
auth_tok->session_key.encrypted_key_size =
crypt_stat->key_size;
@@ -1487,9 +1577,24 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
&& strcmp("aes", crypt_stat->cipher) == 0) {
memset((crypt_stat->key + 24), 0, 8);
auth_tok->session_key.encrypted_key_size = 32;
- }
+ } else
+ auth_tok->session_key.encrypted_key_size = crypt_stat->key_size;
key_rec->enc_key_size =
auth_tok->session_key.encrypted_key_size;
+ encrypted_session_key_valid = 0;
+ for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++)
+ encrypted_session_key_valid |=
+ auth_tok->session_key.encrypted_key[i];
+ if (encrypted_session_key_valid) {
+ ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; "
+ "using auth_tok->session_key.encrypted_key, "
+ "where key_rec->enc_key_size = [%d]\n",
+ key_rec->enc_key_size);
+ memcpy(key_rec->enc_key,
+ auth_tok->session_key.encrypted_key,
+ key_rec->enc_key_size);
+ goto encrypted_session_key_set;
+ }
if (auth_tok->token.password.flags &
ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) {
ecryptfs_printk(KERN_DEBUG, "Using previously generated "
@@ -1508,54 +1613,32 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n");
ecryptfs_dump_hex(session_key_encryption_key, 16);
}
- rc = virt_to_scatterlist(crypt_stat->key,
- key_rec->enc_key_size, src_sg, 2);
- if (!rc) {
+ rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size,
+ &src_sg, 1);
+ if (rc != 1) {
ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
- "for crypt_stat session key\n");
+ "for crypt_stat session key; expected rc = 1; "
+ "got rc = [%d]. key_rec->enc_key_size = [%d]\n",
+ rc, key_rec->enc_key_size);
rc = -ENOMEM;
goto out;
}
- rc = virt_to_scatterlist(key_rec->enc_key,
- key_rec->enc_key_size, dest_sg, 2);
- if (!rc) {
+ rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size,
+ &dst_sg, 1);
+ if (rc != 1) {
ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
- "for crypt_stat encrypted session key\n");
+ "for crypt_stat encrypted session key; "
+ "expected rc = 1; got rc = [%d]. "
+ "key_rec->enc_key_size = [%d]\n", rc,
+ key_rec->enc_key_size);
rc = -ENOMEM;
goto out;
}
- if (!strcmp(crypt_stat->cipher,
- crypt_stat->mount_crypt_stat->global_default_cipher_name)
- && crypt_stat->mount_crypt_stat->global_key_tfm) {
- desc.tfm = crypt_stat->mount_crypt_stat->global_key_tfm;
- tfm_mutex = &crypt_stat->mount_crypt_stat->global_key_tfm_mutex;
- } else {
- char *full_alg_name;
-
- rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name,
- crypt_stat->cipher,
- "ecb");
- if (rc)
- goto out;
- desc.tfm = crypto_alloc_blkcipher(full_alg_name, 0,
- CRYPTO_ALG_ASYNC);
- kfree(full_alg_name);
- if (IS_ERR(desc.tfm)) {
- rc = PTR_ERR(desc.tfm);
- ecryptfs_printk(KERN_ERR, "Could not initialize crypto "
- "context for cipher [%s]; rc = [%d]\n",
- crypt_stat->cipher, rc);
- goto out;
- }
- crypto_blkcipher_set_flags(desc.tfm, CRYPTO_TFM_REQ_WEAK_KEY);
- }
- if (tfm_mutex)
- mutex_lock(tfm_mutex);
+ mutex_lock(tfm_mutex);
rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key,
crypt_stat->key_size);
if (rc < 0) {
- if (tfm_mutex)
- mutex_unlock(tfm_mutex);
+ mutex_unlock(tfm_mutex);
ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
"context; rc = [%d]\n", rc);
goto out;
@@ -1563,56 +1646,53 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
rc = 0;
ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n",
crypt_stat->key_size);
- rc = crypto_blkcipher_encrypt(&desc, dest_sg, src_sg,
+ rc = crypto_blkcipher_encrypt(&desc, &dst_sg, &src_sg,
(*key_rec).enc_key_size);
+ mutex_unlock(tfm_mutex);
if (rc) {
printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc);
goto out;
}
- if (tfm_mutex)
- mutex_unlock(tfm_mutex);
ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
- if (ecryptfs_verbosity > 0)
+ if (ecryptfs_verbosity > 0) {
+ ecryptfs_printk(KERN_DEBUG, "EFEK of size [%d]:\n",
+ key_rec->enc_key_size);
ecryptfs_dump_hex(key_rec->enc_key,
key_rec->enc_key_size);
-encrypted_session_key_set:
- /* Now we have a valid key_rec. Append it to the
- * key_rec set. */
- key_rec_size = (sizeof(struct ecryptfs_key_record)
- - ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES
- + (key_rec->enc_key_size));
- /* TODO: Include a packet size limit as a parameter to this
- * function once we have multi-packet headers (for versions
- * later than 0.1 */
- if (key_rec_size >= ECRYPTFS_MAX_KEYSET_SIZE) {
- ecryptfs_printk(KERN_ERR, "Keyset too large\n");
- rc = -EINVAL;
- goto out;
}
- /* TODO: Packet size limit */
- /* We have 5 bytes of surrounding packet data */
- if ((0x05 + ECRYPTFS_SALT_SIZE
- + key_rec->enc_key_size) >= max) {
- ecryptfs_printk(KERN_ERR, "Authentication token is too "
- "large\n");
+encrypted_session_key_set:
+ /* This format is inspired by OpenPGP; see RFC 2440
+ * packet tag 3 */
+ max_packet_size = (1 /* Tag 3 identifier */
+ + 3 /* Max Tag 3 packet size */
+ + 1 /* Version */
+ + 1 /* Cipher code */
+ + 1 /* S2K specifier */
+ + 1 /* Hash identifier */
+ + ECRYPTFS_SALT_SIZE /* Salt */
+ + 1 /* Hash iterations */
+ + key_rec->enc_key_size); /* Encrypted key size */
+ if (max_packet_size > (*remaining_bytes)) {
+ printk(KERN_ERR "Packet too large; need up to [%td] bytes, but "
+ "there are only [%td] available\n", max_packet_size,
+ (*remaining_bytes));
rc = -EINVAL;
goto out;
}
- /* This format is inspired by OpenPGP; see RFC 2440
- * packet tag 3 */
dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE;
- /* ver+cipher+s2k+hash+salt+iter+enc_key */
- rc = write_packet_length(&dest[(*packet_size)],
- (0x05 + ECRYPTFS_SALT_SIZE
- + key_rec->enc_key_size),
+ /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3)
+ * to get the number of octets in the actual Tag 3 packet */
+ rc = write_packet_length(&dest[(*packet_size)], (max_packet_size - 4),
&packet_size_length);
if (rc) {
- ecryptfs_printk(KERN_ERR, "Error generating tag 3 packet "
- "header; cannot generate packet length\n");
+ printk(KERN_ERR "Error generating tag 3 packet header; cannot "
+ "generate packet length. rc = [%d]\n", rc);
goto out;
}
(*packet_size) += packet_size_length;
dest[(*packet_size)++] = 0x04; /* version 4 */
+ /* TODO: Break from RFC2440 so that arbitrary ciphers can be
+ * specified with strings */
cipher_code = ecryptfs_code_for_cipher_string(crypt_stat);
if (cipher_code == 0) {
ecryptfs_printk(KERN_WARNING, "Unable to generate code for "
@@ -1631,10 +1711,10 @@ encrypted_session_key_set:
key_rec->enc_key_size);
(*packet_size) += key_rec->enc_key_size;
out:
- if (desc.tfm && !tfm_mutex)
- crypto_free_blkcipher(desc.tfm);
if (rc)
(*packet_size) = 0;
+ else
+ (*remaining_bytes) -= (*packet_size);
return rc;
}
@@ -1642,7 +1722,7 @@ struct kmem_cache *ecryptfs_key_record_cache;
/**
* ecryptfs_generate_key_packet_set
- * @dest: Virtual address from which to write the key record set
+ * @dest_base: Virtual address from which to write the key record set
* @crypt_stat: The cryptographic context from which the
* authentication tokens will be retrieved
* @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat
@@ -1662,24 +1742,43 @@ ecryptfs_generate_key_packet_set(char *dest_base,
size_t max)
{
struct ecryptfs_auth_tok *auth_tok;
+ struct ecryptfs_global_auth_tok *global_auth_tok;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
&ecryptfs_superblock_to_private(
ecryptfs_dentry->d_sb)->mount_crypt_stat;
size_t written;
struct ecryptfs_key_record *key_rec;
+ struct ecryptfs_key_sig *key_sig;
int rc = 0;
(*len) = 0;
+ mutex_lock(&crypt_stat->keysig_list_mutex);
key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL);
if (!key_rec) {
rc = -ENOMEM;
goto out;
}
- if (mount_crypt_stat->global_auth_tok) {
- auth_tok = mount_crypt_stat->global_auth_tok;
+ list_for_each_entry(key_sig, &crypt_stat->keysig_list,
+ crypt_stat_list) {
+ memset(key_rec, 0, sizeof(*key_rec));
+ rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
+ mount_crypt_stat,
+ key_sig->keysig);
+ if (rc) {
+ printk(KERN_ERR "Error attempting to get the global "
+ "auth_tok; rc = [%d]\n", rc);
+ goto out_free;
+ }
+ if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) {
+ printk(KERN_WARNING
+ "Skipping invalid auth tok with sig = [%s]\n",
+ global_auth_tok->sig);
+ continue;
+ }
+ auth_tok = global_auth_tok->global_auth_tok;
if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
rc = write_tag_3_packet((dest_base + (*len)),
- max, auth_tok,
+ &max, auth_tok,
crypt_stat, key_rec,
&written);
if (rc) {
@@ -1689,10 +1788,9 @@ ecryptfs_generate_key_packet_set(char *dest_base,
}
(*len) += written;
/* Write auth tok signature packet */
- rc = write_tag_11_packet(
- (dest_base + (*len)),
- (max - (*len)),
- key_rec->sig, ECRYPTFS_SIG_SIZE, &written);
+ rc = write_tag_11_packet((dest_base + (*len)), &max,
+ key_rec->sig,
+ ECRYPTFS_SIG_SIZE, &written);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error writing "
"auth tok signature packet\n");
@@ -1701,9 +1799,8 @@ ecryptfs_generate_key_packet_set(char *dest_base,
(*len) += written;
} else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
rc = write_tag_1_packet(dest_base + (*len),
- max, auth_tok,
- crypt_stat,mount_crypt_stat,
- key_rec, &written);
+ &max, auth_tok,
+ crypt_stat, key_rec, &written);
if (rc) {
ecryptfs_printk(KERN_WARNING, "Error "
"writing tag 1 packet\n");
@@ -1716,19 +1813,69 @@ ecryptfs_generate_key_packet_set(char *dest_base,
rc = -EINVAL;
goto out_free;
}
- } else
- BUG();
- if (likely((max - (*len)) > 0)) {
+ }
+ if (likely(max > 0)) {
dest_base[(*len)] = 0x00;
} else {
ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n");
rc = -EIO;
}
-
out_free:
kmem_cache_free(ecryptfs_key_record_cache, key_rec);
out:
if (rc)
(*len) = 0;
+ mutex_unlock(&crypt_stat->keysig_list_mutex);
+ return rc;
+}
+
+struct kmem_cache *ecryptfs_key_sig_cache;
+
+int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig)
+{
+ struct ecryptfs_key_sig *new_key_sig;
+ int rc = 0;
+
+ new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL);
+ if (!new_key_sig) {
+ rc = -ENOMEM;
+ printk(KERN_ERR
+ "Error allocating from ecryptfs_key_sig_cache\n");
+ goto out;
+ }
+ memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
+ mutex_lock(&crypt_stat->keysig_list_mutex);
+ list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
+ mutex_unlock(&crypt_stat->keysig_list_mutex);
+out:
+ return rc;
+}
+
+struct kmem_cache *ecryptfs_global_auth_tok_cache;
+
+int
+ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
+ char *sig)
+{
+ struct ecryptfs_global_auth_tok *new_auth_tok;
+ int rc = 0;
+
+ new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache,
+ GFP_KERNEL);
+ if (!new_auth_tok) {
+ rc = -ENOMEM;
+ printk(KERN_ERR "Error allocating from "
+ "ecryptfs_global_auth_tok_cache\n");
+ goto out;
+ }
+ memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX);
+ 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,
+ &mount_crypt_stat->global_auth_tok_list);
+ mount_crypt_stat->num_global_auth_toks++;
+ mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
+out:
return rc;
}
+
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