[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/fs/ecryptfs/keystore.c b/src/kernel/linux/v4.14/fs/ecryptfs/keystore.c
new file mode 100644
index 0000000..b134315
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/ecryptfs/keystore.c
@@ -0,0 +1,2568 @@
+/**
+ * eCryptfs: Linux filesystem encryption layer
+ * In-kernel key management code. Includes functions to parse and
+ * write authentication token-related packets with the underlying
+ * file.
+ *
+ * Copyright (C) 2004-2006 International Business Machines Corp.
+ * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com>
+ * Michael C. Thompson <mcthomps@us.ibm.com>
+ * Trevor S. Highland <trevor.highland@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#include <crypto/hash.h>
+#include <crypto/skcipher.h>
+#include <linux/string.h>
+#include <linux/pagemap.h>
+#include <linux/key.h>
+#include <linux/random.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include "ecryptfs_kernel.h"
+
+/**
+ * request_key returned an error instead of a valid key address;
+ * determine the type of error, make appropriate log entries, and
+ * return an error code.
+ */
+static int process_request_key_err(long err_code)
+{
+ int rc = 0;
+
+ switch (err_code) {
+ case -ENOKEY:
+ ecryptfs_printk(KERN_WARNING, "No key\n");
+ rc = -ENOENT;
+ break;
+ case -EKEYEXPIRED:
+ ecryptfs_printk(KERN_WARNING, "Key expired\n");
+ rc = -ETIME;
+ break;
+ case -EKEYREVOKED:
+ ecryptfs_printk(KERN_WARNING, "Key revoked\n");
+ rc = -EINVAL;
+ break;
+ default:
+ ecryptfs_printk(KERN_WARNING, "Unknown error code: "
+ "[0x%.16lx]\n", err_code);
+ rc = -EINVAL;
+ }
+ return rc;
+}
+
+static int process_find_global_auth_tok_for_sig_err(int err_code)
+{
+ int rc = err_code;
+
+ switch (err_code) {
+ case -ENOENT:
+ ecryptfs_printk(KERN_WARNING, "Missing auth tok\n");
+ break;
+ case -EINVAL:
+ ecryptfs_printk(KERN_WARNING, "Invalid auth tok\n");
+ break;
+ default:
+ rc = process_request_key_err(err_code);
+ break;
+ }
+ return rc;
+}
+
+/**
+ * ecryptfs_parse_packet_length
+ * @data: Pointer to memory containing length at offset
+ * @size: This function writes the decoded size to this memory
+ * address; zero on error
+ * @length_size: The number of bytes occupied by the encoded length
+ *
+ * Returns zero on success; non-zero on error
+ */
+int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
+ size_t *length_size)
+{
+ int rc = 0;
+
+ (*length_size) = 0;
+ (*size) = 0;
+ if (data[0] < 192) {
+ /* One-byte length */
+ (*size) = data[0];
+ (*length_size) = 1;
+ } else if (data[0] < 224) {
+ /* Two-byte length */
+ (*size) = (data[0] - 192) * 256;
+ (*size) += data[1] + 192;
+ (*length_size) = 2;
+ } else if (data[0] == 255) {
+ /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */
+ ecryptfs_printk(KERN_ERR, "Five-byte packet length not "
+ "supported\n");
+ rc = -EINVAL;
+ goto out;
+ } else {
+ ecryptfs_printk(KERN_ERR, "Error parsing packet length\n");
+ rc = -EINVAL;
+ goto out;
+ }
+out:
+ return rc;
+}
+
+/**
+ * ecryptfs_write_packet_length
+ * @dest: The byte array target into which to write the length. Must
+ * have at least ECRYPTFS_MAX_PKT_LEN_SIZE 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.
+ *
+ * Returns zero on success; non-zero on error.
+ */
+int ecryptfs_write_packet_length(char *dest, size_t size,
+ size_t *packet_size_length)
+{
+ int rc = 0;
+
+ if (size < 192) {
+ dest[0] = size;
+ (*packet_size_length) = 1;
+ } else if (size < 65536) {
+ dest[0] = (((size - 192) / 256) + 192);
+ dest[1] = ((size - 192) % 256);
+ (*packet_size_length) = 2;
+ } else {
+ /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */
+ rc = -EINVAL;
+ ecryptfs_printk(KERN_WARNING,
+ "Unsupported packet size: [%zd]\n", size);
+ }
+ return rc;
+}
+
+static int
+write_tag_64_packet(char *signature, struct ecryptfs_session_key *session_key,
+ char **packet, size_t *packet_len)
+{
+ size_t i = 0;
+ size_t data_len;
+ size_t packet_size_len;
+ char *message;
+ int rc;
+
+ /*
+ * ***** TAG 64 Packet Format *****
+ * | Content Type | 1 byte |
+ * | Key Identifier Size | 1 or 2 bytes |
+ * | Key Identifier | arbitrary |
+ * | Encrypted File Encryption Key Size | 1 or 2 bytes |
+ * | Encrypted File Encryption Key | arbitrary |
+ */
+ data_len = (5 + ECRYPTFS_SIG_SIZE_HEX
+ + session_key->encrypted_key_size);
+ *packet = kmalloc(data_len, GFP_KERNEL);
+ message = *packet;
+ if (!message) {
+ ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
+ rc = -ENOMEM;
+ goto out;
+ }
+ message[i++] = ECRYPTFS_TAG_64_PACKET_TYPE;
+ rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
+ &packet_size_len);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet "
+ "header; cannot generate packet length\n");
+ goto out;
+ }
+ i += packet_size_len;
+ memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX);
+ i += ECRYPTFS_SIG_SIZE_HEX;
+ rc = ecryptfs_write_packet_length(&message[i],
+ session_key->encrypted_key_size,
+ &packet_size_len);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet "
+ "header; cannot generate packet length\n");
+ goto out;
+ }
+ i += packet_size_len;
+ memcpy(&message[i], session_key->encrypted_key,
+ session_key->encrypted_key_size);
+ i += session_key->encrypted_key_size;
+ *packet_len = i;
+out:
+ return rc;
+}
+
+static int
+parse_tag_65_packet(struct ecryptfs_session_key *session_key, u8 *cipher_code,
+ struct ecryptfs_message *msg)
+{
+ size_t i = 0;
+ char *data;
+ size_t data_len;
+ size_t m_size;
+ size_t message_len;
+ u16 checksum = 0;
+ u16 expected_checksum = 0;
+ int rc;
+
+ /*
+ * ***** TAG 65 Packet Format *****
+ * | Content Type | 1 byte |
+ * | Status Indicator | 1 byte |
+ * | File Encryption Key Size | 1 or 2 bytes |
+ * | File Encryption Key | arbitrary |
+ */
+ message_len = msg->data_len;
+ data = msg->data;
+ if (message_len < 4) {
+ rc = -EIO;
+ goto out;
+ }
+ if (data[i++] != ECRYPTFS_TAG_65_PACKET_TYPE) {
+ ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_65\n");
+ rc = -EIO;
+ goto out;
+ }
+ if (data[i++]) {
+ ecryptfs_printk(KERN_ERR, "Status indicator has non-zero value "
+ "[%d]\n", data[i-1]);
+ rc = -EIO;
+ goto out;
+ }
+ rc = ecryptfs_parse_packet_length(&data[i], &m_size, &data_len);
+ if (rc) {
+ ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
+ "rc = [%d]\n", rc);
+ goto out;
+ }
+ i += data_len;
+ if (message_len < (i + m_size)) {
+ ecryptfs_printk(KERN_ERR, "The message received from ecryptfsd "
+ "is shorter than expected\n");
+ rc = -EIO;
+ goto out;
+ }
+ if (m_size < 3) {
+ ecryptfs_printk(KERN_ERR,
+ "The decrypted key is not long enough to "
+ "include a cipher code and checksum\n");
+ rc = -EIO;
+ goto out;
+ }
+ *cipher_code = data[i++];
+ /* The decrypted key includes 1 byte cipher code and 2 byte checksum */
+ session_key->decrypted_key_size = m_size - 3;
+ if (session_key->decrypted_key_size > ECRYPTFS_MAX_KEY_BYTES) {
+ ecryptfs_printk(KERN_ERR, "key_size [%d] larger than "
+ "the maximum key size [%d]\n",
+ session_key->decrypted_key_size,
+ ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES);
+ rc = -EIO;
+ goto out;
+ }
+ memcpy(session_key->decrypted_key, &data[i],
+ session_key->decrypted_key_size);
+ i += session_key->decrypted_key_size;
+ expected_checksum += (unsigned char)(data[i++]) << 8;
+ expected_checksum += (unsigned char)(data[i++]);
+ for (i = 0; i < session_key->decrypted_key_size; i++)
+ checksum += session_key->decrypted_key[i];
+ if (expected_checksum != checksum) {
+ ecryptfs_printk(KERN_ERR, "Invalid checksum for file "
+ "encryption key; expected [%x]; calculated "
+ "[%x]\n", expected_checksum, checksum);
+ rc = -EIO;
+ }
+out:
+ return rc;
+}
+
+
+static int
+write_tag_66_packet(char *signature, u8 cipher_code,
+ struct ecryptfs_crypt_stat *crypt_stat, char **packet,
+ size_t *packet_len)
+{
+ size_t i = 0;
+ size_t j;
+ size_t data_len;
+ size_t checksum = 0;
+ size_t packet_size_len;
+ char *message;
+ int rc;
+
+ /*
+ * ***** TAG 66 Packet Format *****
+ * | Content Type | 1 byte |
+ * | Key Identifier Size | 1 or 2 bytes |
+ * | Key Identifier | arbitrary |
+ * | File Encryption Key Size | 1 or 2 bytes |
+ * | File Encryption Key | arbitrary |
+ */
+ data_len = (5 + ECRYPTFS_SIG_SIZE_HEX + crypt_stat->key_size);
+ *packet = kmalloc(data_len, GFP_KERNEL);
+ message = *packet;
+ if (!message) {
+ ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
+ rc = -ENOMEM;
+ goto out;
+ }
+ message[i++] = ECRYPTFS_TAG_66_PACKET_TYPE;
+ rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
+ &packet_size_len);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet "
+ "header; cannot generate packet length\n");
+ goto out;
+ }
+ i += packet_size_len;
+ memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX);
+ i += ECRYPTFS_SIG_SIZE_HEX;
+ /* The encrypted key includes 1 byte cipher code and 2 byte checksum */
+ rc = ecryptfs_write_packet_length(&message[i], crypt_stat->key_size + 3,
+ &packet_size_len);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet "
+ "header; cannot generate packet length\n");
+ goto out;
+ }
+ i += packet_size_len;
+ message[i++] = cipher_code;
+ memcpy(&message[i], crypt_stat->key, crypt_stat->key_size);
+ i += crypt_stat->key_size;
+ for (j = 0; j < crypt_stat->key_size; j++)
+ checksum += crypt_stat->key[j];
+ message[i++] = (checksum / 256) % 256;
+ message[i++] = (checksum % 256);
+ *packet_len = i;
+out:
+ return rc;
+}
+
+static int
+parse_tag_67_packet(struct ecryptfs_key_record *key_rec,
+ struct ecryptfs_message *msg)
+{
+ size_t i = 0;
+ char *data;
+ size_t data_len;
+ size_t message_len;
+ int rc;
+
+ /*
+ * ***** TAG 65 Packet Format *****
+ * | Content Type | 1 byte |
+ * | Status Indicator | 1 byte |
+ * | Encrypted File Encryption Key Size | 1 or 2 bytes |
+ * | Encrypted File Encryption Key | arbitrary |
+ */
+ message_len = msg->data_len;
+ data = msg->data;
+ /* verify that everything through the encrypted FEK size is present */
+ if (message_len < 4) {
+ rc = -EIO;
+ printk(KERN_ERR "%s: message_len is [%zd]; minimum acceptable "
+ "message length is [%d]\n", __func__, message_len, 4);
+ goto out;
+ }
+ if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) {
+ rc = -EIO;
+ printk(KERN_ERR "%s: Type should be ECRYPTFS_TAG_67\n",
+ __func__);
+ goto out;
+ }
+ if (data[i++]) {
+ rc = -EIO;
+ printk(KERN_ERR "%s: Status indicator has non zero "
+ "value [%d]\n", __func__, data[i-1]);
+
+ goto out;
+ }
+ rc = ecryptfs_parse_packet_length(&data[i], &key_rec->enc_key_size,
+ &data_len);
+ if (rc) {
+ ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
+ "rc = [%d]\n", rc);
+ goto out;
+ }
+ i += data_len;
+ if (message_len < (i + key_rec->enc_key_size)) {
+ rc = -EIO;
+ printk(KERN_ERR "%s: message_len [%zd]; max len is [%zd]\n",
+ __func__, message_len, (i + key_rec->enc_key_size));
+ goto out;
+ }
+ if (key_rec->enc_key_size > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
+ rc = -EIO;
+ printk(KERN_ERR "%s: Encrypted key_size [%zd] larger than "
+ "the maximum key size [%d]\n", __func__,
+ key_rec->enc_key_size,
+ ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES);
+ goto out;
+ }
+ memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size);
+out:
+ return rc;
+}
+
+/**
+ * ecryptfs_verify_version
+ * @version: The version number to confirm
+ *
+ * Returns zero on good version; non-zero otherwise
+ */
+static int ecryptfs_verify_version(u16 version)
+{
+ 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;
+}
+
+/**
+ * ecryptfs_verify_auth_tok_from_key
+ * @auth_tok_key: key containing the authentication token
+ * @auth_tok: authentication token
+ *
+ * Returns zero on valid auth tok; -EINVAL if the payload is invalid; or
+ * -EKEYREVOKED if the key was revoked before we acquired its semaphore.
+ */
+static int
+ecryptfs_verify_auth_tok_from_key(struct key *auth_tok_key,
+ struct ecryptfs_auth_tok **auth_tok)
+{
+ int rc = 0;
+
+ (*auth_tok) = ecryptfs_get_key_payload_data(auth_tok_key);
+ if (IS_ERR(*auth_tok)) {
+ rc = PTR_ERR(*auth_tok);
+ *auth_tok = NULL;
+ goto out;
+ }
+
+ 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;
+}
+
+static int
+ecryptfs_find_global_auth_tok_for_sig(
+ struct key **auth_tok_key,
+ struct ecryptfs_auth_tok **auth_tok,
+ struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig)
+{
+ struct ecryptfs_global_auth_tok *walker;
+ int rc = 0;
+
+ (*auth_tok_key) = NULL;
+ (*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))
+ continue;
+
+ if (walker->flags & ECRYPTFS_AUTH_TOK_INVALID) {
+ rc = -EINVAL;
+ goto out;
+ }
+
+ rc = key_validate(walker->global_auth_tok_key);
+ if (rc) {
+ if (rc == -EKEYEXPIRED)
+ goto out;
+ goto out_invalid_auth_tok;
+ }
+
+ down_write(&(walker->global_auth_tok_key->sem));
+ rc = ecryptfs_verify_auth_tok_from_key(
+ walker->global_auth_tok_key, auth_tok);
+ if (rc)
+ goto out_invalid_auth_tok_unlock;
+
+ (*auth_tok_key) = walker->global_auth_tok_key;
+ key_get(*auth_tok_key);
+ goto out;
+ }
+ rc = -ENOENT;
+ goto out;
+out_invalid_auth_tok_unlock:
+ up_write(&(walker->global_auth_tok_key->sem));
+out_invalid_auth_tok:
+ printk(KERN_WARNING "Invalidating auth tok with sig = [%s]\n", sig);
+ walker->flags |= ECRYPTFS_AUTH_TOK_INVALID;
+ key_put(walker->global_auth_tok_key);
+ walker->global_auth_tok_key = NULL;
+out:
+ mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
+ 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 key **auth_tok_key,
+ struct ecryptfs_auth_tok **auth_tok,
+ struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
+ char *sig)
+{
+ int rc = 0;
+
+ rc = ecryptfs_find_global_auth_tok_for_sig(auth_tok_key, auth_tok,
+ mount_crypt_stat, sig);
+ if (rc == -ENOENT) {
+ /* if the flag ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY is set in the
+ * mount_crypt_stat structure, we prevent to use auth toks that
+ * are not inserted through the ecryptfs_add_global_auth_tok
+ * function.
+ */
+ if (mount_crypt_stat->flags
+ & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY)
+ return -EINVAL;
+
+ rc = ecryptfs_keyring_auth_tok_for_sig(auth_tok_key, auth_tok,
+ sig);
+ }
+ return rc;
+}
+
+/**
+ * write_tag_70_packet can gobble a lot of stack space. We stuff most
+ * of the function's parameters in a kmalloc'd struct to help reduce
+ * eCryptfs' overall stack usage.
+ */
+struct ecryptfs_write_tag_70_packet_silly_stack {
+ u8 cipher_code;
+ size_t max_packet_size;
+ size_t packet_size_len;
+ size_t block_aligned_filename_size;
+ size_t block_size;
+ size_t i;
+ size_t j;
+ size_t num_rand_bytes;
+ struct mutex *tfm_mutex;
+ char *block_aligned_filename;
+ struct ecryptfs_auth_tok *auth_tok;
+ struct scatterlist src_sg[2];
+ struct scatterlist dst_sg[2];
+ struct crypto_skcipher *skcipher_tfm;
+ struct skcipher_request *skcipher_req;
+ char iv[ECRYPTFS_MAX_IV_BYTES];
+ char hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
+ char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
+ struct crypto_shash *hash_tfm;
+ struct shash_desc *hash_desc;
+};
+
+/**
+ * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK
+ * @filename: NULL-terminated filename string
+ *
+ * This is the simplest mechanism for achieving filename encryption in
+ * eCryptfs. It encrypts the given filename with the mount-wide
+ * filename encryption key (FNEK) and stores it in a packet to @dest,
+ * which the callee will encode and write directly into the dentry
+ * name.
+ */
+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)
+{
+ struct ecryptfs_write_tag_70_packet_silly_stack *s;
+ struct key *auth_tok_key = NULL;
+ int rc = 0;
+
+ s = kzalloc(sizeof(*s), GFP_KERNEL);
+ if (!s) {
+ printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
+ "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
+ return -ENOMEM;
+ }
+ (*packet_size) = 0;
+ rc = ecryptfs_find_auth_tok_for_sig(
+ &auth_tok_key,
+ &s->auth_tok, mount_crypt_stat,
+ mount_crypt_stat->global_default_fnek_sig);
+ if (rc) {
+ printk(KERN_ERR "%s: Error attempting to find auth tok for "
+ "fnek sig [%s]; rc = [%d]\n", __func__,
+ mount_crypt_stat->global_default_fnek_sig, rc);
+ goto out;
+ }
+ rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(
+ &s->skcipher_tfm,
+ &s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name);
+ if (unlikely(rc)) {
+ printk(KERN_ERR "Internal error whilst attempting to get "
+ "tfm and mutex for cipher name [%s]; rc = [%d]\n",
+ mount_crypt_stat->global_default_fn_cipher_name, rc);
+ goto out;
+ }
+ mutex_lock(s->tfm_mutex);
+ s->block_size = crypto_skcipher_blocksize(s->skcipher_tfm);
+ /* Plus one for the \0 separator between the random prefix
+ * and the plaintext filename */
+ s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1);
+ s->block_aligned_filename_size = (s->num_rand_bytes + filename_size);
+ if ((s->block_aligned_filename_size % s->block_size) != 0) {
+ s->num_rand_bytes += (s->block_size
+ - (s->block_aligned_filename_size
+ % s->block_size));
+ s->block_aligned_filename_size = (s->num_rand_bytes
+ + filename_size);
+ }
+ /* Octet 0: Tag 70 identifier
+ * Octets 1-N1: Tag 70 packet size (includes cipher identifier
+ * and block-aligned encrypted filename size)
+ * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
+ * Octet N2-N3: Cipher identifier (1 octet)
+ * Octets N3-N4: Block-aligned encrypted filename
+ * - Consists of a minimum number of random characters, a \0
+ * separator, and then the filename */
+ s->max_packet_size = (ECRYPTFS_TAG_70_MAX_METADATA_SIZE
+ + s->block_aligned_filename_size);
+ if (dest == NULL) {
+ (*packet_size) = s->max_packet_size;
+ goto out_unlock;
+ }
+ if (s->max_packet_size > (*remaining_bytes)) {
+ printk(KERN_WARNING "%s: Require [%zd] bytes to write; only "
+ "[%zd] available\n", __func__, s->max_packet_size,
+ (*remaining_bytes));
+ rc = -EINVAL;
+ goto out_unlock;
+ }
+
+ s->skcipher_req = skcipher_request_alloc(s->skcipher_tfm, GFP_KERNEL);
+ if (!s->skcipher_req) {
+ printk(KERN_ERR "%s: Out of kernel memory whilst attempting to "
+ "skcipher_request_alloc for %s\n", __func__,
+ crypto_skcipher_driver_name(s->skcipher_tfm));
+ rc = -ENOMEM;
+ goto out_unlock;
+ }
+
+ skcipher_request_set_callback(s->skcipher_req,
+ CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
+
+ s->block_aligned_filename = kzalloc(s->block_aligned_filename_size,
+ GFP_KERNEL);
+ if (!s->block_aligned_filename) {
+ printk(KERN_ERR "%s: Out of kernel memory whilst attempting to "
+ "kzalloc [%zd] bytes\n", __func__,
+ s->block_aligned_filename_size);
+ rc = -ENOMEM;
+ goto out_unlock;
+ }
+ dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE;
+ rc = ecryptfs_write_packet_length(&dest[s->i],
+ (ECRYPTFS_SIG_SIZE
+ + 1 /* Cipher code */
+ + s->block_aligned_filename_size),
+ &s->packet_size_len);
+ if (rc) {
+ printk(KERN_ERR "%s: Error generating tag 70 packet "
+ "header; cannot generate packet length; rc = [%d]\n",
+ __func__, rc);
+ goto out_free_unlock;
+ }
+ s->i += s->packet_size_len;
+ ecryptfs_from_hex(&dest[s->i],
+ mount_crypt_stat->global_default_fnek_sig,
+ ECRYPTFS_SIG_SIZE);
+ s->i += ECRYPTFS_SIG_SIZE;
+ s->cipher_code = ecryptfs_code_for_cipher_string(
+ mount_crypt_stat->global_default_fn_cipher_name,
+ mount_crypt_stat->global_default_fn_cipher_key_bytes);
+ if (s->cipher_code == 0) {
+ printk(KERN_WARNING "%s: Unable to generate code for "
+ "cipher [%s] with key bytes [%zd]\n", __func__,
+ mount_crypt_stat->global_default_fn_cipher_name,
+ mount_crypt_stat->global_default_fn_cipher_key_bytes);
+ rc = -EINVAL;
+ goto out_free_unlock;
+ }
+ dest[s->i++] = s->cipher_code;
+ /* TODO: Support other key modules than passphrase for
+ * filename encryption */
+ if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {
+ rc = -EOPNOTSUPP;
+ printk(KERN_INFO "%s: Filename encryption only supports "
+ "password tokens\n", __func__);
+ goto out_free_unlock;
+ }
+ s->hash_tfm = crypto_alloc_shash(ECRYPTFS_TAG_70_DIGEST, 0, 0);
+ if (IS_ERR(s->hash_tfm)) {
+ rc = PTR_ERR(s->hash_tfm);
+ printk(KERN_ERR "%s: Error attempting to "
+ "allocate hash crypto context; rc = [%d]\n",
+ __func__, rc);
+ goto out_free_unlock;
+ }
+
+ s->hash_desc = kmalloc(sizeof(*s->hash_desc) +
+ crypto_shash_descsize(s->hash_tfm), GFP_KERNEL);
+ if (!s->hash_desc) {
+ printk(KERN_ERR "%s: Out of kernel memory whilst attempting to "
+ "kmalloc [%zd] bytes\n", __func__,
+ sizeof(*s->hash_desc) +
+ crypto_shash_descsize(s->hash_tfm));
+ rc = -ENOMEM;
+ goto out_release_free_unlock;
+ }
+
+ s->hash_desc->tfm = s->hash_tfm;
+ s->hash_desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ rc = crypto_shash_digest(s->hash_desc,
+ (u8 *)s->auth_tok->token.password.session_key_encryption_key,
+ s->auth_tok->token.password.session_key_encryption_key_bytes,
+ s->hash);
+ if (rc) {
+ printk(KERN_ERR
+ "%s: Error computing crypto hash; rc = [%d]\n",
+ __func__, rc);
+ goto out_release_free_unlock;
+ }
+ for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) {
+ s->block_aligned_filename[s->j] =
+ s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)];
+ if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)
+ == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) {
+ rc = crypto_shash_digest(s->hash_desc, (u8 *)s->hash,
+ ECRYPTFS_TAG_70_DIGEST_SIZE,
+ s->tmp_hash);
+ if (rc) {
+ printk(KERN_ERR
+ "%s: Error computing crypto hash; "
+ "rc = [%d]\n", __func__, rc);
+ goto out_release_free_unlock;
+ }
+ memcpy(s->hash, s->tmp_hash,
+ ECRYPTFS_TAG_70_DIGEST_SIZE);
+ }
+ if (s->block_aligned_filename[s->j] == '\0')
+ s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL;
+ }
+ memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename,
+ filename_size);
+ rc = virt_to_scatterlist(s->block_aligned_filename,
+ s->block_aligned_filename_size, s->src_sg, 2);
+ if (rc < 1) {
+ printk(KERN_ERR "%s: Internal error whilst attempting to "
+ "convert filename memory to scatterlist; rc = [%d]. "
+ "block_aligned_filename_size = [%zd]\n", __func__, rc,
+ s->block_aligned_filename_size);
+ goto out_release_free_unlock;
+ }
+ rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size,
+ s->dst_sg, 2);
+ if (rc < 1) {
+ printk(KERN_ERR "%s: Internal error whilst attempting to "
+ "convert encrypted filename memory to scatterlist; "
+ "rc = [%d]. block_aligned_filename_size = [%zd]\n",
+ __func__, rc, s->block_aligned_filename_size);
+ goto out_release_free_unlock;
+ }
+ /* The characters in the first block effectively do the job
+ * of the IV here, so we just use 0's for the IV. Note the
+ * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
+ * >= ECRYPTFS_MAX_IV_BYTES. */
+ rc = crypto_skcipher_setkey(
+ s->skcipher_tfm,
+ s->auth_tok->token.password.session_key_encryption_key,
+ mount_crypt_stat->global_default_fn_cipher_key_bytes);
+ if (rc < 0) {
+ printk(KERN_ERR "%s: Error setting key for crypto context; "
+ "rc = [%d]. s->auth_tok->token.password.session_key_"
+ "encryption_key = [0x%p]; mount_crypt_stat->"
+ "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
+ rc,
+ s->auth_tok->token.password.session_key_encryption_key,
+ mount_crypt_stat->global_default_fn_cipher_key_bytes);
+ goto out_release_free_unlock;
+ }
+ skcipher_request_set_crypt(s->skcipher_req, s->src_sg, s->dst_sg,
+ s->block_aligned_filename_size, s->iv);
+ rc = crypto_skcipher_encrypt(s->skcipher_req);
+ if (rc) {
+ printk(KERN_ERR "%s: Error attempting to encrypt filename; "
+ "rc = [%d]\n", __func__, rc);
+ goto out_release_free_unlock;
+ }
+ s->i += s->block_aligned_filename_size;
+ (*packet_size) = s->i;
+ (*remaining_bytes) -= (*packet_size);
+out_release_free_unlock:
+ crypto_free_shash(s->hash_tfm);
+out_free_unlock:
+ kzfree(s->block_aligned_filename);
+out_unlock:
+ mutex_unlock(s->tfm_mutex);
+out:
+ if (auth_tok_key) {
+ up_write(&(auth_tok_key->sem));
+ key_put(auth_tok_key);
+ }
+ skcipher_request_free(s->skcipher_req);
+ kzfree(s->hash_desc);
+ kfree(s);
+ return rc;
+}
+
+struct ecryptfs_parse_tag_70_packet_silly_stack {
+ u8 cipher_code;
+ size_t max_packet_size;
+ size_t packet_size_len;
+ size_t parsed_tag_70_packet_size;
+ size_t block_aligned_filename_size;
+ size_t block_size;
+ size_t i;
+ struct mutex *tfm_mutex;
+ char *decrypted_filename;
+ struct ecryptfs_auth_tok *auth_tok;
+ struct scatterlist src_sg[2];
+ struct scatterlist dst_sg[2];
+ struct crypto_skcipher *skcipher_tfm;
+ struct skcipher_request *skcipher_req;
+ char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1];
+ char iv[ECRYPTFS_MAX_IV_BYTES];
+ char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
+};
+
+/**
+ * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet
+ * @filename: This function kmalloc's the memory for the filename
+ * @filename_size: This function sets this to the amount of memory
+ * kmalloc'd for the filename
+ * @packet_size: This function sets this to the the number of octets
+ * in the packet parsed
+ * @mount_crypt_stat: The mount-wide cryptographic context
+ * @data: The memory location containing the start of the tag 70
+ * packet
+ * @max_packet_size: The maximum legal size of the packet to be parsed
+ * from @data
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+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)
+{
+ struct ecryptfs_parse_tag_70_packet_silly_stack *s;
+ struct key *auth_tok_key = NULL;
+ int rc = 0;
+
+ (*packet_size) = 0;
+ (*filename_size) = 0;
+ (*filename) = NULL;
+ s = kzalloc(sizeof(*s), GFP_KERNEL);
+ if (!s) {
+ printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
+ "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
+ return -ENOMEM;
+ }
+ if (max_packet_size < ECRYPTFS_TAG_70_MIN_METADATA_SIZE) {
+ printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be "
+ "at least [%d]\n", __func__, max_packet_size,
+ ECRYPTFS_TAG_70_MIN_METADATA_SIZE);
+ rc = -EINVAL;
+ goto out;
+ }
+ /* Octet 0: Tag 70 identifier
+ * Octets 1-N1: Tag 70 packet size (includes cipher identifier
+ * and block-aligned encrypted filename size)
+ * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
+ * Octet N2-N3: Cipher identifier (1 octet)
+ * Octets N3-N4: Block-aligned encrypted filename
+ * - Consists of a minimum number of random numbers, a \0
+ * separator, and then the filename */
+ if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) {
+ printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be "
+ "tag [0x%.2x]\n", __func__,
+ data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE);
+ rc = -EINVAL;
+ goto out;
+ }
+ rc = ecryptfs_parse_packet_length(&data[(*packet_size)],
+ &s->parsed_tag_70_packet_size,
+ &s->packet_size_len);
+ if (rc) {
+ printk(KERN_WARNING "%s: Error parsing packet length; "
+ "rc = [%d]\n", __func__, rc);
+ goto out;
+ }
+ s->block_aligned_filename_size = (s->parsed_tag_70_packet_size
+ - ECRYPTFS_SIG_SIZE - 1);
+ if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size)
+ > max_packet_size) {
+ printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet "
+ "size is [%zd]\n", __func__, max_packet_size,
+ (1 + s->packet_size_len + 1
+ + s->block_aligned_filename_size));
+ rc = -EINVAL;
+ goto out;
+ }
+ (*packet_size) += s->packet_size_len;
+ ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)],
+ ECRYPTFS_SIG_SIZE);
+ s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0';
+ (*packet_size) += ECRYPTFS_SIG_SIZE;
+ s->cipher_code = data[(*packet_size)++];
+ rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code);
+ if (rc) {
+ printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n",
+ __func__, s->cipher_code);
+ goto out;
+ }
+ rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key,
+ &s->auth_tok, mount_crypt_stat,
+ s->fnek_sig_hex);
+ if (rc) {
+ printk(KERN_ERR "%s: Error attempting to find auth tok for "
+ "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex,
+ rc);
+ goto out;
+ }
+ rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->skcipher_tfm,
+ &s->tfm_mutex,
+ s->cipher_string);
+ if (unlikely(rc)) {
+ printk(KERN_ERR "Internal error whilst attempting to get "
+ "tfm and mutex for cipher name [%s]; rc = [%d]\n",
+ s->cipher_string, rc);
+ goto out;
+ }
+ mutex_lock(s->tfm_mutex);
+ rc = virt_to_scatterlist(&data[(*packet_size)],
+ s->block_aligned_filename_size, s->src_sg, 2);
+ if (rc < 1) {
+ printk(KERN_ERR "%s: Internal error whilst attempting to "
+ "convert encrypted filename memory to scatterlist; "
+ "rc = [%d]. block_aligned_filename_size = [%zd]\n",
+ __func__, rc, s->block_aligned_filename_size);
+ goto out_unlock;
+ }
+ (*packet_size) += s->block_aligned_filename_size;
+ s->decrypted_filename = kmalloc(s->block_aligned_filename_size,
+ GFP_KERNEL);
+ if (!s->decrypted_filename) {
+ printk(KERN_ERR "%s: Out of memory whilst attempting to "
+ "kmalloc [%zd] bytes\n", __func__,
+ s->block_aligned_filename_size);
+ rc = -ENOMEM;
+ goto out_unlock;
+ }
+ rc = virt_to_scatterlist(s->decrypted_filename,
+ s->block_aligned_filename_size, s->dst_sg, 2);
+ if (rc < 1) {
+ printk(KERN_ERR "%s: Internal error whilst attempting to "
+ "convert decrypted filename memory to scatterlist; "
+ "rc = [%d]. block_aligned_filename_size = [%zd]\n",
+ __func__, rc, s->block_aligned_filename_size);
+ goto out_free_unlock;
+ }
+
+ s->skcipher_req = skcipher_request_alloc(s->skcipher_tfm, GFP_KERNEL);
+ if (!s->skcipher_req) {
+ printk(KERN_ERR "%s: Out of kernel memory whilst attempting to "
+ "skcipher_request_alloc for %s\n", __func__,
+ crypto_skcipher_driver_name(s->skcipher_tfm));
+ rc = -ENOMEM;
+ goto out_free_unlock;
+ }
+
+ skcipher_request_set_callback(s->skcipher_req,
+ CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
+
+ /* The characters in the first block effectively do the job of
+ * the IV here, so we just use 0's for the IV. Note the
+ * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
+ * >= ECRYPTFS_MAX_IV_BYTES. */
+ /* TODO: Support other key modules than passphrase for
+ * filename encryption */
+ if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {
+ rc = -EOPNOTSUPP;
+ printk(KERN_INFO "%s: Filename encryption only supports "
+ "password tokens\n", __func__);
+ goto out_free_unlock;
+ }
+ rc = crypto_skcipher_setkey(
+ s->skcipher_tfm,
+ s->auth_tok->token.password.session_key_encryption_key,
+ mount_crypt_stat->global_default_fn_cipher_key_bytes);
+ if (rc < 0) {
+ printk(KERN_ERR "%s: Error setting key for crypto context; "
+ "rc = [%d]. s->auth_tok->token.password.session_key_"
+ "encryption_key = [0x%p]; mount_crypt_stat->"
+ "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
+ rc,
+ s->auth_tok->token.password.session_key_encryption_key,
+ mount_crypt_stat->global_default_fn_cipher_key_bytes);
+ goto out_free_unlock;
+ }
+ skcipher_request_set_crypt(s->skcipher_req, s->src_sg, s->dst_sg,
+ s->block_aligned_filename_size, s->iv);
+ rc = crypto_skcipher_decrypt(s->skcipher_req);
+ if (rc) {
+ printk(KERN_ERR "%s: Error attempting to decrypt filename; "
+ "rc = [%d]\n", __func__, rc);
+ goto out_free_unlock;
+ }
+ while (s->decrypted_filename[s->i] != '\0'
+ && s->i < s->block_aligned_filename_size)
+ s->i++;
+ if (s->i == s->block_aligned_filename_size) {
+ printk(KERN_WARNING "%s: Invalid tag 70 packet; could not "
+ "find valid separator between random characters and "
+ "the filename\n", __func__);
+ rc = -EINVAL;
+ goto out_free_unlock;
+ }
+ s->i++;
+ (*filename_size) = (s->block_aligned_filename_size - s->i);
+ if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) {
+ printk(KERN_WARNING "%s: Filename size is [%zd], which is "
+ "invalid\n", __func__, (*filename_size));
+ rc = -EINVAL;
+ goto out_free_unlock;
+ }
+ (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL);
+ if (!(*filename)) {
+ printk(KERN_ERR "%s: Out of memory whilst attempting to "
+ "kmalloc [%zd] bytes\n", __func__,
+ ((*filename_size) + 1));
+ rc = -ENOMEM;
+ goto out_free_unlock;
+ }
+ memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size));
+ (*filename)[(*filename_size)] = '\0';
+out_free_unlock:
+ kfree(s->decrypted_filename);
+out_unlock:
+ mutex_unlock(s->tfm_mutex);
+out:
+ if (rc) {
+ (*packet_size) = 0;
+ (*filename_size) = 0;
+ (*filename) = NULL;
+ }
+ if (auth_tok_key) {
+ up_write(&(auth_tok_key->sem));
+ key_put(auth_tok_key);
+ }
+ skcipher_request_free(s->skcipher_req);
+ kfree(s);
+ 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.
+ * @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.
+ */
+static int
+decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
+ struct ecryptfs_crypt_stat *crypt_stat)
+{
+ u8 cipher_code = 0;
+ struct ecryptfs_msg_ctx *msg_ctx;
+ struct ecryptfs_message *msg = NULL;
+ char *auth_tok_sig;
+ char *payload = NULL;
+ size_t payload_len = 0;
+ int rc;
+
+ 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),
+ &payload, &payload_len);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n");
+ goto out;
+ }
+ rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Error sending message to "
+ "ecryptfsd: %d\n", rc);
+ goto out;
+ }
+ rc = ecryptfs_wait_for_response(msg_ctx, &msg);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet "
+ "from the user space daemon\n");
+ rc = -EIO;
+ goto out;
+ }
+ rc = parse_tag_65_packet(&(auth_tok->session_key),
+ &cipher_code, msg);
+ if (rc) {
+ printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n",
+ rc);
+ goto out;
+ }
+ 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->key_size = auth_tok->session_key.decrypted_key_size;
+ rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n",
+ cipher_code)
+ goto out;
+ }
+ crypt_stat->flags |= ECRYPTFS_KEY_VALID;
+ if (ecryptfs_verbosity > 0) {
+ ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n");
+ ecryptfs_dump_hex(crypt_stat->key,
+ crypt_stat->key_size);
+ }
+out:
+ kfree(msg);
+ kfree(payload);
+ return rc;
+}
+
+static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
+{
+ struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
+ struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
+
+ 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);
+ }
+}
+
+struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
+
+/**
+ * parse_tag_1_packet
+ * @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.
+ * @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.
+ */
+static int
+parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
+ unsigned char *data, struct list_head *auth_tok_list,
+ struct ecryptfs_auth_tok **new_auth_tok,
+ size_t *packet_size, size_t max_packet_size)
+{
+ size_t body_size;
+ struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
+ size_t length_size;
+ int rc = 0;
+
+ (*packet_size) = 0;
+ (*new_auth_tok) = NULL;
+ /**
+ * 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(max_packet_size < 12)) {
+ printk(KERN_ERR "Invalid max packet size; must be >=12\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ if (data[(*packet_size)++] != 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_zalloc(ecryptfs_auth_tok_list_item_cache,
+ GFP_KERNEL);
+ if (!auth_tok_list_item) {
+ printk(KERN_ERR "Unable to allocate memory\n");
+ rc = -ENOMEM;
+ goto out;
+ }
+ (*new_auth_tok) = &auth_tok_list_item->auth_tok;
+ rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
+ &length_size);
+ if (rc) {
+ printk(KERN_WARNING "Error parsing packet length; "
+ "rc = [%d]\n", rc);
+ goto out_free;
+ }
+ 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)) {
+ printk(KERN_WARNING "Packet size exceeds max\n");
+ rc = -EINVAL;
+ goto out_free;
+ }
+ if (unlikely(data[(*packet_size)++] != 0x03)) {
+ printk(KERN_WARNING "Unknown version number [%d]\n",
+ data[(*packet_size) - 1]);
+ rc = -EINVAL;
+ goto out_free;
+ }
+ ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
+ &data[(*packet_size)], ECRYPTFS_SIG_SIZE);
+ *packet_size += ECRYPTFS_SIG_SIZE;
+ /* This byte is skipped because the kernel does not need to
+ * know which public key encryption algorithm was used */
+ (*packet_size)++;
+ (*new_auth_tok)->session_key.encrypted_key_size =
+ body_size - (ECRYPTFS_SIG_SIZE + 2);
+ if ((*new_auth_tok)->session_key.encrypted_key_size
+ > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
+ printk(KERN_WARNING "Tag 1 packet contains key larger "
+ "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
+ rc = -EINVAL;
+ goto out_free;
+ }
+ memcpy((*new_auth_tok)->session_key.encrypted_key,
+ &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 = 0;
+ (*new_auth_tok)->session_key.flags &=
+ ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
+ (*new_auth_tok)->session_key.flags &=
+ ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
+ list_add(&auth_tok_list_item->list, auth_tok_list);
+ goto out;
+out_free:
+ (*new_auth_tok) = NULL;
+ memset(auth_tok_list_item, 0,
+ sizeof(struct ecryptfs_auth_tok_list_item));
+ kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
+ auth_tok_list_item);
+out:
+ if (rc)
+ (*packet_size) = 0;
+ return rc;
+}
+
+/**
+ * parse_tag_3_packet
+ * @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.
+ * @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: maximum number of bytes to parse
+ *
+ * Returns zero on success; non-zero on error.
+ */
+static int
+parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
+ unsigned char *data, struct list_head *auth_tok_list,
+ struct ecryptfs_auth_tok **new_auth_tok,
+ size_t *packet_size, size_t max_packet_size)
+{
+ size_t body_size;
+ struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
+ size_t length_size;
+ int rc = 0;
+
+ (*packet_size) = 0;
+ (*new_auth_tok) = NULL;
+ /**
+ *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 (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) {
+ printk(KERN_ERR "Max packet size too large\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) {
+ printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n",
+ ECRYPTFS_TAG_3_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_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
+ if (!auth_tok_list_item) {
+ printk(KERN_ERR "Unable to allocate memory\n");
+ rc = -ENOMEM;
+ goto out;
+ }
+ (*new_auth_tok) = &auth_tok_list_item->auth_tok;
+ rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
+ &length_size);
+ if (rc) {
+ printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n",
+ rc);
+ goto out_free;
+ }
+ 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;
+ if (unlikely((*packet_size) + body_size > max_packet_size)) {
+ printk(KERN_ERR "Packet size exceeds max\n");
+ rc = -EINVAL;
+ goto out_free;
+ }
+ (*new_auth_tok)->session_key.encrypted_key_size =
+ (body_size - (ECRYPTFS_SALT_SIZE + 5));
+ if ((*new_auth_tok)->session_key.encrypted_key_size
+ > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
+ printk(KERN_WARNING "Tag 3 packet contains key larger "
+ "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n");
+ rc = -EINVAL;
+ goto out_free;
+ }
+ if (unlikely(data[(*packet_size)++] != 0x04)) {
+ printk(KERN_WARNING "Unknown version number [%d]\n",
+ data[(*packet_size) - 1]);
+ rc = -EINVAL;
+ goto out_free;
+ }
+ rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher,
+ (u16)data[(*packet_size)]);
+ if (rc)
+ goto out_free;
+ /* A little extra work to differentiate among the AES key
+ * sizes; see RFC2440 */
+ switch(data[(*packet_size)++]) {
+ case RFC2440_CIPHER_AES_192:
+ crypt_stat->key_size = 24;
+ break;
+ default:
+ crypt_stat->key_size =
+ (*new_auth_tok)->session_key.encrypted_key_size;
+ }
+ rc = ecryptfs_init_crypt_ctx(crypt_stat);
+ if (rc)
+ goto out_free;
+ if (unlikely(data[(*packet_size)++] != 0x03)) {
+ printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
+ rc = -ENOSYS;
+ goto out_free;
+ }
+ /* TODO: finish the hash mapping */
+ switch (data[(*packet_size)++]) {
+ case 0x01: /* See RFC2440 for these numbers and their mappings */
+ /* Choose MD5 */
+ 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 */
+ (*new_auth_tok)->token.password.hash_iterations =
+ ((u32) 16 + (data[(*packet_size)] & 15))
+ << ((data[(*packet_size)] >> 4) + 6);
+ (*packet_size)++;
+ /* 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);
+ (*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.password.hash_algo = 0x01; /* MD5 */
+ break;
+ default:
+ ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: "
+ "[%d]\n", data[(*packet_size) - 1]);
+ rc = -ENOSYS;
+ goto out_free;
+ }
+ (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD;
+ /* TODO: Parametarize; we might actually want userspace to
+ * decrypt the session key. */
+ (*new_auth_tok)->session_key.flags &=
+ ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
+ (*new_auth_tok)->session_key.flags &=
+ ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
+ list_add(&auth_tok_list_item->list, auth_tok_list);
+ goto out;
+out_free:
+ (*new_auth_tok) = NULL;
+ memset(auth_tok_list_item, 0,
+ sizeof(struct ecryptfs_auth_tok_list_item));
+ kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
+ auth_tok_list_item);
+out:
+ if (rc)
+ (*packet_size) = 0;
+ return rc;
+}
+
+/**
+ * parse_tag_11_packet
+ * @data: The raw bytes of the packet
+ * @contents: This function writes the data contents of the literal
+ * packet into this memory location
+ * @max_contents_bytes: The maximum number of bytes that this function
+ * is allowed to write into contents
+ * @tag_11_contents_size: This function writes the size of the parsed
+ * contents into this memory location; zero on
+ * error
+ * @packet_size: This function writes the size of the parsed packet
+ * into this memory location; zero on error
+ * @max_packet_size: maximum number of bytes to parse
+ *
+ * Returns zero on success; non-zero on error.
+ */
+static int
+parse_tag_11_packet(unsigned char *data, unsigned char *contents,
+ size_t max_contents_bytes, size_t *tag_11_contents_size,
+ size_t *packet_size, size_t max_packet_size)
+{
+ size_t body_size;
+ size_t length_size;
+ int rc = 0;
+
+ (*packet_size) = 0;
+ (*tag_11_contents_size) = 0;
+ /* 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 (max_packet_size < 16) {
+ printk(KERN_ERR "Maximum packet size too small\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) {
+ printk(KERN_WARNING "Invalid tag 11 packet format\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
+ &length_size);
+ if (rc) {
+ printk(KERN_WARNING "Invalid tag 11 packet format\n");
+ goto out;
+ }
+ if (body_size < 14) {
+ printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
+ rc = -EINVAL;
+ goto out;
+ }
+ (*packet_size) += length_size;
+ (*tag_11_contents_size) = (body_size - 14);
+ if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) {
+ printk(KERN_ERR "Packet size exceeds max\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ if (unlikely((*tag_11_contents_size) > max_contents_bytes)) {
+ printk(KERN_ERR "Literal data section in tag 11 packet exceeds "
+ "expected size\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ if (data[(*packet_size)++] != 0x62) {
+ printk(KERN_WARNING "Unrecognizable packet\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ if (data[(*packet_size)++] != 0x08) {
+ printk(KERN_WARNING "Unrecognizable packet\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ (*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;
+ (*tag_11_contents_size) = 0;
+ }
+ 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)) {
+ (*auth_tok_key) = ecryptfs_get_encrypted_key(sig);
+ if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
+ printk(KERN_ERR "Could not find key with description: [%s]\n",
+ sig);
+ rc = process_request_key_err(PTR_ERR(*auth_tok_key));
+ (*auth_tok_key) = NULL;
+ goto out;
+ }
+ }
+ down_write(&(*auth_tok_key)->sem);
+ rc = ecryptfs_verify_auth_tok_from_key(*auth_tok_key, auth_tok);
+ if (rc) {
+ up_write(&(*auth_tok_key)->sem);
+ key_put(*auth_tok_key);
+ (*auth_tok_key) = NULL;
+ goto out;
+ }
+out:
+ 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[2];
+ struct scatterlist src_sg[2];
+ struct mutex *tfm_mutex;
+ struct crypto_skcipher *tfm;
+ struct skcipher_request *req = NULL;
+ int rc = 0;
+
+ 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(&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;
+ }
+ rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
+ auth_tok->session_key.encrypted_key_size,
+ src_sg, 2);
+ if (rc < 1 || rc > 2) {
+ 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, 2);
+ if (rc < 1 || rc > 2) {
+ 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);
+ req = skcipher_request_alloc(tfm, GFP_KERNEL);
+ if (!req) {
+ mutex_unlock(tfm_mutex);
+ printk(KERN_ERR "%s: Out of kernel memory whilst attempting to "
+ "skcipher_request_alloc for %s\n", __func__,
+ crypto_skcipher_driver_name(tfm));
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
+ NULL, NULL);
+ rc = crypto_skcipher_setkey(
+ 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;
+ }
+ skcipher_request_set_crypt(req, src_sg, dst_sg,
+ auth_tok->session_key.encrypted_key_size,
+ NULL);
+ rc = crypto_skcipher_decrypt(req);
+ mutex_unlock(tfm_mutex);
+ if (unlikely(rc)) {
+ printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
+ goto out;
+ }
+ 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;
+ if (unlikely(ecryptfs_verbosity > 0)) {
+ ecryptfs_printk(KERN_DEBUG, "FEK of size [%zd]:\n",
+ crypt_stat->key_size);
+ ecryptfs_dump_hex(crypt_stat->key,
+ crypt_stat->key_size);
+ }
+out:
+ skcipher_request_free(req);
+ return rc;
+}
+
+/**
+ * ecryptfs_parse_packet_set
+ * @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.
+ *
+ * Returns Zero if a valid authentication token was retrieved and
+ * processed; negative value for file not encrypted or for error
+ * conditions.
+ */
+int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
+ unsigned char *src,
+ struct dentry *ecryptfs_dentry)
+{
+ size_t i = 0;
+ size_t found_auth_tok;
+ size_t next_packet_is_auth_tok_packet;
+ struct list_head auth_tok_list;
+ 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;
+ struct key *auth_tok_key = NULL;
+ int rc = 0;
+
+ INIT_LIST_HEAD(&auth_tok_list);
+ /* 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) {
+ size_t max_packet_size = ((PAGE_SIZE - 8) - i);
+
+ switch (src[i]) {
+ case ECRYPTFS_TAG_3_PACKET_TYPE:
+ rc = parse_tag_3_packet(crypt_stat,
+ (unsigned char *)&src[i],
+ &auth_tok_list, &new_auth_tok,
+ &packet_size, max_packet_size);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Error parsing "
+ "tag 3 packet\n");
+ rc = -EIO;
+ goto out_wipe_list;
+ }
+ i += packet_size;
+ rc = parse_tag_11_packet((unsigned char *)&src[i],
+ sig_tmp_space,
+ ECRYPTFS_SIG_SIZE,
+ &tag_11_contents_size,
+ &tag_11_packet_size,
+ max_packet_size);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "No valid "
+ "(ecryptfs-specific) literal "
+ "packet containing "
+ "authentication token "
+ "signature found after "
+ "tag 3 packet\n");
+ rc = -EIO;
+ goto out_wipe_list;
+ }
+ i += tag_11_packet_size;
+ if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) {
+ ecryptfs_printk(KERN_ERR, "Expected "
+ "signature of size [%d]; "
+ "read size [%zd]\n",
+ ECRYPTFS_SIG_SIZE,
+ tag_11_contents_size);
+ rc = -EIO;
+ goto out_wipe_list;
+ }
+ ecryptfs_to_hex(new_auth_tok->token.password.signature,
+ sig_tmp_space, tag_11_contents_size);
+ new_auth_tok->token.password.signature[
+ ECRYPTFS_PASSWORD_SIG_SIZE] = '\0';
+ crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
+ break;
+ case ECRYPTFS_TAG_1_PACKET_TYPE:
+ rc = parse_tag_1_packet(crypt_stat,
+ (unsigned char *)&src[i],
+ &auth_tok_list, &new_auth_tok,
+ &packet_size, max_packet_size);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Error parsing "
+ "tag 1 packet\n");
+ rc = -EIO;
+ goto out_wipe_list;
+ }
+ i += packet_size;
+ crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
+ break;
+ case ECRYPTFS_TAG_11_PACKET_TYPE:
+ ecryptfs_printk(KERN_WARNING, "Invalid packet set "
+ "(Tag 11 not allowed by itself)\n");
+ rc = -EIO;
+ goto out_wipe_list;
+ default:
+ ecryptfs_printk(KERN_DEBUG, "No packet at offset [%zd] "
+ "of the file header; hex value of "
+ "character is [0x%.2x]\n", i, src[i]);
+ next_packet_is_auth_tok_packet = 0;
+ }
+ }
+ if (list_empty(&auth_tok_list)) {
+ 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;
+ }
+ /* 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);
+ }
+ 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;
+ }
+ rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key,
+ &matching_auth_tok,
+ crypt_stat->mount_crypt_stat,
+ candidate_auth_tok_sig);
+ if (!rc) {
+ found_auth_tok = 1;
+ goto found_matching_auth_tok;
+ }
+ }
+ if (!found_auth_tok) {
+ ecryptfs_printk(KERN_ERR, "Could not find a usable "
+ "authentication token\n");
+ rc = -EIO;
+ goto out_wipe_list;
+ }
+found_matching_auth_tok:
+ if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
+ memcpy(&(candidate_auth_tok->token.private_key),
+ &(matching_auth_tok->token.private_key),
+ sizeof(struct ecryptfs_private_key));
+ up_write(&(auth_tok_key->sem));
+ key_put(auth_tok_key);
+ 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),
+ &(matching_auth_tok->token.password),
+ sizeof(struct ecryptfs_password));
+ up_write(&(auth_tok_key->sem));
+ key_put(auth_tok_key);
+ rc = decrypt_passphrase_encrypted_session_key(
+ candidate_auth_tok, crypt_stat);
+ } else {
+ up_write(&(auth_tok_key->sem));
+ key_put(auth_tok_key);
+ rc = -EINVAL;
+ }
+ if (rc) {
+ 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", ECRYPTFS_SIG_SIZE_HEX,
+ candidate_auth_tok_sig, 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) {
+ ecryptfs_printk(KERN_ERR, "Error computing "
+ "the root IV\n");
+ goto out_wipe_list;
+ }
+ rc = ecryptfs_init_crypt_ctx(crypt_stat);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Error initializing crypto "
+ "context for cipher [%s]; rc = [%d]\n",
+ crypt_stat->cipher, rc);
+ }
+out_wipe_list:
+ wipe_auth_tok_list(&auth_tok_list);
+out:
+ return rc;
+}
+
+static int
+pki_encrypt_session_key(struct key *auth_tok_key,
+ struct ecryptfs_auth_tok *auth_tok,
+ struct ecryptfs_crypt_stat *crypt_stat,
+ struct ecryptfs_key_record *key_rec)
+{
+ struct ecryptfs_msg_ctx *msg_ctx = NULL;
+ char *payload = NULL;
+ size_t payload_len = 0;
+ struct ecryptfs_message *msg;
+ int rc;
+
+ rc = write_tag_66_packet(auth_tok->token.private_key.signature,
+ ecryptfs_code_for_cipher_string(
+ crypt_stat->cipher,
+ crypt_stat->key_size),
+ crypt_stat, &payload, &payload_len);
+ up_write(&(auth_tok_key->sem));
+ key_put(auth_tok_key);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
+ goto out;
+ }
+ rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Error sending message to "
+ "ecryptfsd: %d\n", rc);
+ goto out;
+ }
+ rc = ecryptfs_wait_for_response(msg_ctx, &msg);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet "
+ "from the user space daemon\n");
+ rc = -EIO;
+ goto out;
+ }
+ rc = parse_tag_67_packet(key_rec, msg);
+ if (rc)
+ ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n");
+ kfree(msg);
+out:
+ kfree(payload);
+ return rc;
+}
+/**
+ * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet
+ * @dest: Buffer into which to write the packet
+ * @remaining_bytes: Maximum number of bytes that can be writtn
+ * @auth_tok_key: The authentication token key to unlock and put when done with
+ * @auth_tok
+ * @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 *remaining_bytes,
+ struct key *auth_tok_key, 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;
+ size_t packet_size_length;
+ size_t max_packet_size;
+ int rc = 0;
+
+ (*packet_size) = 0;
+ ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.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);
+ up_write(&(auth_tok_key->sem));
+ key_put(auth_tok_key);
+ goto encrypted_session_key_set;
+ }
+ if (auth_tok->session_key.encrypted_key_size == 0)
+ auth_tok->session_key.encrypted_key_size =
+ auth_tok->token.private_key.key_size;
+ rc = pki_encrypt_session_key(auth_tok_key, auth_tok, crypt_stat,
+ key_rec);
+ if (rc) {
+ printk(KERN_ERR "Failed to encrypt session key via a key "
+ "module; rc = [%d]\n", rc);
+ goto out;
+ }
+ if (ecryptfs_verbosity > 0) {
+ ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n");
+ ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size);
+ }
+encrypted_session_key_set:
+ /* 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;
+ rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
+ (max_packet_size - 4),
+ &packet_size_length);
+ if (rc) {
+ ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet "
+ "header; cannot generate packet length\n");
+ goto out;
+ }
+ (*packet_size) += packet_size_length;
+ dest[(*packet_size)++] = 0x03; /* version 3 */
+ memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE);
+ (*packet_size) += ECRYPTFS_SIG_SIZE;
+ dest[(*packet_size)++] = RFC2440_CIPHER_RSA;
+ memcpy(&dest[(*packet_size)], key_rec->enc_key,
+ key_rec->enc_key_size);
+ (*packet_size) += key_rec->enc_key_size;
+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
+ * @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
+ *
+ * Returns zero on success; non-zero on error.
+ */
+static int
+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;
+ /* 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;
+ goto out;
+ }
+ dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE;
+ rc = ecryptfs_write_packet_length(&dest[(*packet_length)],
+ (max_packet_size - 4),
+ &packet_size_length);
+ if (rc) {
+ printk(KERN_ERR "Error generating tag 11 packet header; cannot "
+ "generate packet length. rc = [%d]\n", rc);
+ goto out;
+ }
+ (*packet_length) += packet_size_length;
+ dest[(*packet_length)++] = 0x62; /* binary data format specifier */
+ dest[(*packet_length)++] = 8;
+ memcpy(&dest[(*packet_length)], "_CONSOLE", 8);
+ (*packet_length) += 8;
+ memset(&dest[(*packet_length)], 0x00, 4);
+ (*packet_length) += 4;
+ 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
+ * @remaining_bytes: Maximum number of bytes that can be written
+ * @auth_tok: Authentication token
+ * @crypt_stat: The cryptographic context
+ * @key_rec: encrypted key
+ * @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_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 dst_sg[2];
+ struct scatterlist src_sg[2];
+ struct mutex *tfm_mutex = NULL;
+ u8 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 crypto_skcipher *tfm;
+ struct skcipher_request *req;
+ int rc = 0;
+
+ (*packet_size) = 0;
+ ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
+ ECRYPTFS_SIG_SIZE);
+ rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&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) {
+ printk(KERN_WARNING "No key size specified at mount; "
+ "defaulting to [%d]\n",
+ crypto_skcipher_default_keysize(tfm));
+ mount_crypt_stat->global_default_cipher_key_size =
+ crypto_skcipher_default_keysize(tfm);
+ }
+ 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;
+ if (crypt_stat->key_size == 24
+ && 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 = [%zd]\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 "
+ "session key encryption key of size [%d]\n",
+ auth_tok->token.password.
+ session_key_encryption_key_bytes);
+ memcpy(session_key_encryption_key,
+ auth_tok->token.password.session_key_encryption_key,
+ crypt_stat->key_size);
+ ecryptfs_printk(KERN_DEBUG,
+ "Cached session key encryption key:\n");
+ if (ecryptfs_verbosity > 0)
+ ecryptfs_dump_hex(session_key_encryption_key, 16);
+ }
+ if (unlikely(ecryptfs_verbosity > 0)) {
+ 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 < 1 || rc > 2) {
+ ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
+ "for crypt_stat session key; expected rc = 1; "
+ "got rc = [%d]. key_rec->enc_key_size = [%zd]\n",
+ rc, key_rec->enc_key_size);
+ rc = -ENOMEM;
+ goto out;
+ }
+ rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size,
+ dst_sg, 2);
+ if (rc < 1 || rc > 2) {
+ ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
+ "for crypt_stat encrypted session key; "
+ "expected rc = 1; got rc = [%d]. "
+ "key_rec->enc_key_size = [%zd]\n", rc,
+ key_rec->enc_key_size);
+ rc = -ENOMEM;
+ goto out;
+ }
+ mutex_lock(tfm_mutex);
+ rc = crypto_skcipher_setkey(tfm, session_key_encryption_key,
+ crypt_stat->key_size);
+ if (rc < 0) {
+ mutex_unlock(tfm_mutex);
+ ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
+ "context; rc = [%d]\n", rc);
+ goto out;
+ }
+
+ req = skcipher_request_alloc(tfm, GFP_KERNEL);
+ if (!req) {
+ mutex_unlock(tfm_mutex);
+ ecryptfs_printk(KERN_ERR, "Out of kernel memory whilst "
+ "attempting to skcipher_request_alloc for "
+ "%s\n", crypto_skcipher_driver_name(tfm));
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
+ NULL, NULL);
+
+ rc = 0;
+ ecryptfs_printk(KERN_DEBUG, "Encrypting [%zd] bytes of the key\n",
+ crypt_stat->key_size);
+ skcipher_request_set_crypt(req, src_sg, dst_sg,
+ (*key_rec).enc_key_size, NULL);
+ rc = crypto_skcipher_encrypt(req);
+ mutex_unlock(tfm_mutex);
+ skcipher_request_free(req);
+ if (rc) {
+ printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc);
+ goto out;
+ }
+ ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
+ if (ecryptfs_verbosity > 0) {
+ ecryptfs_printk(KERN_DEBUG, "EFEK of size [%zd]:\n",
+ key_rec->enc_key_size);
+ ecryptfs_dump_hex(key_rec->enc_key,
+ key_rec->enc_key_size);
+ }
+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;
+ }
+ dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE;
+ /* 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 = ecryptfs_write_packet_length(&dest[(*packet_size)],
+ (max_packet_size - 4),
+ &packet_size_length);
+ if (rc) {
+ 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->cipher,
+ crypt_stat->key_size);
+ if (cipher_code == 0) {
+ ecryptfs_printk(KERN_WARNING, "Unable to generate code for "
+ "cipher [%s]\n", crypt_stat->cipher);
+ rc = -EINVAL;
+ goto out;
+ }
+ dest[(*packet_size)++] = cipher_code;
+ dest[(*packet_size)++] = 0x03; /* S2K */
+ dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */
+ memcpy(&dest[(*packet_size)], auth_tok->token.password.salt,
+ ECRYPTFS_SALT_SIZE);
+ (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */
+ dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */
+ memcpy(&dest[(*packet_size)], key_rec->enc_key,
+ key_rec->enc_key_size);
+ (*packet_size) += key_rec->enc_key_size;
+out:
+ if (rc)
+ (*packet_size) = 0;
+ else
+ (*remaining_bytes) -= (*packet_size);
+ return rc;
+}
+
+struct kmem_cache *ecryptfs_key_record_cache;
+
+/**
+ * ecryptfs_generate_key_packet_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
+ * for the global parameters
+ * @len: The amount written
+ * @max: The maximum amount of data allowed to be written
+ *
+ * Generates a key packet set and writes it to the virtual address
+ * passed in.
+ *
+ * Returns zero on success; non-zero on error.
+ */
+int
+ecryptfs_generate_key_packet_set(char *dest_base,
+ struct ecryptfs_crypt_stat *crypt_stat,
+ struct dentry *ecryptfs_dentry, size_t *len,
+ size_t max)
+{
+ struct ecryptfs_auth_tok *auth_tok;
+ struct key *auth_tok_key = NULL;
+ 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;
+ }
+ 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(&auth_tok_key,
+ &auth_tok,
+ mount_crypt_stat,
+ key_sig->keysig);
+ if (rc) {
+ printk(KERN_WARNING "Unable to retrieve auth tok with "
+ "sig = [%s]\n", key_sig->keysig);
+ rc = process_find_global_auth_tok_for_sig_err(rc);
+ goto out_free;
+ }
+ if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
+ rc = write_tag_3_packet((dest_base + (*len)),
+ &max, auth_tok,
+ crypt_stat, key_rec,
+ &written);
+ up_write(&(auth_tok_key->sem));
+ key_put(auth_tok_key);
+ if (rc) {
+ ecryptfs_printk(KERN_WARNING, "Error "
+ "writing tag 3 packet\n");
+ goto out_free;
+ }
+ (*len) += written;
+ /* Write auth tok signature packet */
+ 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");
+ goto out_free;
+ }
+ (*len) += written;
+ } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
+ rc = write_tag_1_packet(dest_base + (*len), &max,
+ auth_tok_key, auth_tok,
+ crypt_stat, key_rec, &written);
+ if (rc) {
+ ecryptfs_printk(KERN_WARNING, "Error "
+ "writing tag 1 packet\n");
+ goto out_free;
+ }
+ (*len) += written;
+ } else {
+ up_write(&(auth_tok_key->sem));
+ key_put(auth_tok_key);
+ ecryptfs_printk(KERN_WARNING, "Unsupported "
+ "authentication token type\n");
+ rc = -EINVAL;
+ goto out_free;
+ }
+ }
+ 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;
+
+ new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL);
+ if (!new_key_sig) {
+ printk(KERN_ERR
+ "Error allocating from ecryptfs_key_sig_cache\n");
+ return -ENOMEM;
+ }
+ memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
+ new_key_sig->keysig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
+ /* Caller must hold keysig_list_mutex */
+ list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
+
+ return 0;
+}
+
+struct kmem_cache *ecryptfs_global_auth_tok_cache;
+
+int
+ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
+ char *sig, u32 global_auth_tok_flags)
+{
+ 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->flags = global_auth_tok_flags;
+ new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
+ mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
+ list_add(&new_auth_tok->mount_crypt_stat_list,
+ &mount_crypt_stat->global_auth_tok_list);
+ mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
+out:
+ return rc;
+}
+