eCryptfs: don't encrypt file key with filename key
[safe/jmp/linux-2.6] / fs / ecryptfs / keystore.c
index 190e2a0..e4a6223 100644 (file)
  * 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;
 
        switch (err_code) {
-       case ENOKEY:
+       case -ENOKEY:
                ecryptfs_printk(KERN_WARNING, "No key\n");
                rc = -ENOENT;
                break;
-       case EKEYEXPIRED:
+       case -EKEYEXPIRED:
                ecryptfs_printk(KERN_WARNING, "Key expired\n");
                rc = -ETIME;
                break;
-       case EKEYREVOKED:
+       case -EKEYREVOKED:
                ecryptfs_printk(KERN_WARNING, "Key revoked\n");
                rc = -EINVAL;
                break;
@@ -65,16 +65,16 @@ int process_request_key_err(long err_code)
 }
 
 /**
- * parse_packet_length
+ * 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
+ * Returns zero on success; non-zero on error
  */
-static int parse_packet_length(unsigned char *data, size_t *size,
-                              size_t *length_size)
+int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
+                                size_t *length_size)
 {
        int rc = 0;
 
@@ -105,17 +105,17 @@ out:
 }
 
 /**
- * write_packet_length
- * @dest: The byte array target into which to write the
- *       length. Must have at least 5 bytes allocated.
+ * ecryptfs_write_packet_length
+ * @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.
  */
-static int write_packet_length(char *dest, size_t size,
-                              size_t *packet_size_length)
+int ecryptfs_write_packet_length(char *dest, size_t size,
+                                size_t *packet_size_length)
 {
        int rc = 0;
 
@@ -162,8 +162,8 @@ write_tag_64_packet(char *signature, struct ecryptfs_session_key *session_key,
                goto out;
        }
        message[i++] = ECRYPTFS_TAG_64_PACKET_TYPE;
-       rc = write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
-                                &packet_size_len);
+       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");
@@ -172,8 +172,9 @@ write_tag_64_packet(char *signature, struct ecryptfs_session_key *session_key,
        i += packet_size_len;
        memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX);
        i += ECRYPTFS_SIG_SIZE_HEX;
-       rc = write_packet_length(&message[i], session_key->encrypted_key_size,
-                                &packet_size_len);
+       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");
@@ -189,7 +190,7 @@ out:
 }
 
 static int
-parse_tag_65_packet(struct ecryptfs_session_key *session_key, u16 *cipher_code,
+parse_tag_65_packet(struct ecryptfs_session_key *session_key, u8 *cipher_code,
                    struct ecryptfs_message *msg)
 {
        size_t i = 0;
@@ -225,7 +226,7 @@ parse_tag_65_packet(struct ecryptfs_session_key *session_key, u16 *cipher_code,
                rc = -EIO;
                goto out;
        }
-       rc = parse_packet_length(&data[i], &m_size, &data_len);
+       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);
@@ -233,8 +234,8 @@ parse_tag_65_packet(struct ecryptfs_session_key *session_key, u16 *cipher_code,
        }
        i += data_len;
        if (message_len < (i + m_size)) {
-               ecryptfs_printk(KERN_ERR, "The received netlink message is "
-                               "shorter than expected\n");
+               ecryptfs_printk(KERN_ERR, "The message received from ecryptfsd "
+                               "is shorter than expected\n");
                rc = -EIO;
                goto out;
        }
@@ -275,7 +276,7 @@ out:
 
 
 static int
-write_tag_66_packet(char *signature, size_t cipher_code,
+write_tag_66_packet(char *signature, u8 cipher_code,
                    struct ecryptfs_crypt_stat *crypt_stat, char **packet,
                    size_t *packet_len)
 {
@@ -304,8 +305,8 @@ write_tag_66_packet(char *signature, size_t cipher_code,
                goto out;
        }
        message[i++] = ECRYPTFS_TAG_66_PACKET_TYPE;
-       rc = write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
-                                &packet_size_len);
+       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");
@@ -315,8 +316,8 @@ write_tag_66_packet(char *signature, size_t cipher_code,
        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 = write_packet_length(&message[i], crypt_stat->key_size + 3,
-                                &packet_size_len);
+       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");
@@ -357,20 +358,25 @@ parse_tag_67_packet(struct ecryptfs_key_record *key_rec,
        /* 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) {
-               ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_67\n");
                rc = -EIO;
+               printk(KERN_ERR "%s: Type should be ECRYPTFS_TAG_67\n",
+                      __func__);
                goto out;
        }
        if (data[i++]) {
-               ecryptfs_printk(KERN_ERR, "Status indicator has non zero value"
-                               " [%d]\n", data[i-1]);
                rc = -EIO;
+               printk(KERN_ERR "%s: Status indicator has non zero "
+                      "value [%d]\n", __func__, data[i-1]);
+
                goto out;
        }
-       rc = parse_packet_length(&data[i], &key_rec->enc_key_size, &data_len);
+       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);
@@ -378,17 +384,17 @@ parse_tag_67_packet(struct ecryptfs_key_record *key_rec,
        }
        i += data_len;
        if (message_len < (i + key_rec->enc_key_size)) {
-               ecryptfs_printk(KERN_ERR, "message_len [%d]; max len is [%d]\n",
-                               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) {
-               ecryptfs_printk(KERN_ERR, "Encrypted key_size [%d] larger than "
-                               "the maximum key size [%d]\n",
-                               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);
@@ -396,39 +402,636 @@ 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;
+}
+
+/**
+ * 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_mount_crypt_stat *mount_crypt_stat,
+       char *sig)
+{
+       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;
+}
+
+/**
+ * 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;
+       struct scatterlist dst_sg;
+       struct blkcipher_desc desc;
+       char iv[ECRYPTFS_MAX_IV_BYTES];
+       char hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
+       char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
+       struct hash_desc hash_desc;
+       struct scatterlist hash_sg;
+};
+
+/**
+ * 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;
+       int rc = 0;
+
+       s = kmalloc(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));
+               goto out;
+       }
+       s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+       (*packet_size) = 0;
+       rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(
+               &s->desc.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_blkcipher_blocksize(s->desc.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 = (1                   /* Tag 70 identifier */
+                             + 3                 /* Max Tag 70 packet size */
+                             + ECRYPTFS_SIG_SIZE /* FNEK sig */
+                             + 1                 /* Cipher identifier */
+                             + 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->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;
+       }
+       s->i = 0;
+       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;
+       rc = ecryptfs_find_auth_tok_for_sig(
+               &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_free_unlock;
+       }
+       /* TODO: Support other key modules than passphrase for
+        * filename encryption */
+       BUG_ON(s->auth_tok->token_type != ECRYPTFS_PASSWORD);
+       sg_init_one(
+               &s->hash_sg,
+               (u8 *)s->auth_tok->token.password.session_key_encryption_key,
+               s->auth_tok->token.password.session_key_encryption_key_bytes);
+       s->hash_desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+       s->hash_desc.tfm = crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST, 0,
+                                            CRYPTO_ALG_ASYNC);
+       if (IS_ERR(s->hash_desc.tfm)) {
+                       rc = PTR_ERR(s->hash_desc.tfm);
+                       printk(KERN_ERR "%s: Error attempting to "
+                              "allocate hash crypto context; rc = [%d]\n",
+                              __func__, rc);
+                       goto out_free_unlock;
+       }
+       rc = crypto_hash_init(&s->hash_desc);
+       if (rc) {
+               printk(KERN_ERR
+                      "%s: Error initializing crypto hash; rc = [%d]\n",
+                      __func__, rc);
+               goto out_release_free_unlock;
+       }
+       rc = crypto_hash_update(
+               &s->hash_desc, &s->hash_sg,
+               s->auth_tok->token.password.session_key_encryption_key_bytes);
+       if (rc) {
+               printk(KERN_ERR
+                      "%s: Error updating crypto hash; rc = [%d]\n",
+                      __func__, rc);
+               goto out_release_free_unlock;
+       }
+       rc = crypto_hash_final(&s->hash_desc, s->hash);
+       if (rc) {
+               printk(KERN_ERR
+                      "%s: Error finalizing 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)) {
+                       sg_init_one(&s->hash_sg, (u8 *)s->hash,
+                                   ECRYPTFS_TAG_70_DIGEST_SIZE);
+                       rc = crypto_hash_init(&s->hash_desc);
+                       if (rc) {
+                               printk(KERN_ERR
+                                      "%s: Error initializing crypto hash; "
+                                      "rc = [%d]\n", __func__, rc);
+                               goto out_release_free_unlock;
+                       }
+                       rc = crypto_hash_update(&s->hash_desc, &s->hash_sg,
+                                               ECRYPTFS_TAG_70_DIGEST_SIZE);
+                       if (rc) {
+                               printk(KERN_ERR
+                                      "%s: Error updating crypto hash; "
+                                      "rc = [%d]\n", __func__, rc);
+                               goto out_release_free_unlock;
+                       }
+                       rc = crypto_hash_final(&s->hash_desc, s->tmp_hash);
+                       if (rc) {
+                               printk(KERN_ERR
+                                      "%s: Error finalizing 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, 1);
+       if (rc != 1) {
+               printk(KERN_ERR "%s: Internal error whilst attempting to "
+                      "convert filename memory to scatterlist; "
+                      "expected rc = 1; got 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, 1);
+       if (rc != 1) {
+               printk(KERN_ERR "%s: Internal error whilst attempting to "
+                      "convert encrypted filename memory to scatterlist; "
+                      "expected rc = 1; got 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. */
+       memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
+       s->desc.info = s->iv;
+       rc = crypto_blkcipher_setkey(
+               s->desc.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;
+       }
+       rc = crypto_blkcipher_encrypt_iv(&s->desc, &s->dst_sg, &s->src_sg,
+                                        s->block_aligned_filename_size);
+       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_hash(s->hash_desc.tfm);
+out_free_unlock:
+       memset(s->block_aligned_filename, 0, s->block_aligned_filename_size);
+       kfree(s->block_aligned_filename);
+out_unlock:
+       mutex_unlock(s->tfm_mutex);
+out:
+       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;
+       struct scatterlist dst_sg;
+       struct blkcipher_desc desc;
+       char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1];
+       char iv[ECRYPTFS_MAX_IV_BYTES];
+       char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE];
+};
+
+/**
+ * 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;
+       int rc = 0;
+
+       (*packet_size) = 0;
+       (*filename_size) = 0;
+       (*filename) = NULL;
+       s = kmalloc(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));
+               goto out;
+       }
+       s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+       if (max_packet_size < (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)) {
+               printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be "
+                      "at least [%d]\n", __func__, max_packet_size,
+                       (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1));
+               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_get_tfm_and_mutex_for_cipher_name(&s->desc.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, 1);
+       if (rc != 1) {
+               printk(KERN_ERR "%s: Internal error whilst attempting to "
+                      "convert encrypted filename memory to scatterlist; "
+                      "expected rc = 1; got 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, 1);
+       if (rc != 1) {
+               printk(KERN_ERR "%s: Internal error whilst attempting to "
+                      "convert decrypted filename memory to scatterlist; "
+                      "expected rc = 1; got rc = [%d]. "
+                      "block_aligned_filename_size = [%zd]\n", __func__, rc,
+                      s->block_aligned_filename_size);
+               goto out_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. */
+       memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
+       s->desc.info = s->iv;
+       rc = ecryptfs_find_auth_tok_for_sig(&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_free_unlock;
+       }
+       /* TODO: Support other key modules than passphrase for
+        * filename encryption */
+       BUG_ON(s->auth_tok->token_type != ECRYPTFS_PASSWORD);
+       rc = crypto_blkcipher_setkey(
+               s->desc.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;
+       }
+       rc = crypto_blkcipher_decrypt_iv(&s->desc, &s->dst_sg, &s->src_sg,
+                                        s->block_aligned_filename_size);
+       if (rc) {
+               printk(KERN_ERR "%s: Error attempting to decrypt filename; "
+                      "rc = [%d]\n", __func__, rc);
+               goto out_free_unlock;
+       }
+       s->i = 0;
+       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;
+       }
+       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.
+ * 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_auth_tok *auth_tok,
                                  struct ecryptfs_crypt_stat *crypt_stat)
 {
-       u16 cipher_code = 0;
+       u8 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;
+       char *payload;
+       size_t payload_len;
        int rc;
 
-       if ((rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok))) {
+       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);
+                                &payload, &payload_len);
        if (rc) {
-               ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet");
+               ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n");
                goto out;
        }
-       rc = ecryptfs_send_message(ecryptfs_transport, netlink_message,
-                                  netlink_message_length, &msg_ctx);
+       rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
        if (rc) {
-               ecryptfs_printk(KERN_ERR, "Error sending netlink message\n");
+               ecryptfs_printk(KERN_ERR, "Error sending message to "
+                               "ecryptfsd\n");
                goto out;
        }
        rc = ecryptfs_wait_for_response(msg_ctx, &msg);
@@ -484,18 +1087,18 @@ 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.
  */
@@ -547,14 +1150,15 @@ parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
                goto out;
        }
        (*new_auth_tok) = &auth_tok_list_item->auth_tok;
-       if ((rc = parse_packet_length(&data[(*packet_size)], &body_size,
-                                     &length_size))) {
+       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 ([%d])\n", body_size);
+               printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
                rc = -EINVAL;
                goto out_free;
        }
@@ -680,14 +1284,15 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
                goto out;
        }
        (*new_auth_tok) = &auth_tok_list_item->auth_tok;
-       if ((rc = parse_packet_length(&data[(*packet_size)], &body_size,
-                                     &length_size))) {
+       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 ([%d])\n", body_size);
+               printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
                rc = -EINVAL;
                goto out_free;
        }
@@ -827,13 +1432,14 @@ parse_tag_11_packet(unsigned char *data, unsigned char *contents,
                rc = -EINVAL;
                goto out;
        }
-       if ((rc = parse_packet_length(&data[(*packet_size)], &body_size,
-                                     &length_size))) {
+       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 ([%d])\n", body_size);
+               printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
                rc = -EINVAL;
                goto out;
        }
@@ -865,30 +1471,6 @@ 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;
-}
-
 /**
  * ecryptfs_verify_version
  * @version: The version number to confirm
@@ -931,8 +1513,7 @@ int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
        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;
+               rc = process_request_key_err(PTR_ERR(*auth_tok_key));
                goto out;
        }
        (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key);
@@ -959,55 +1540,19 @@ out:
 }
 
 /**
- * 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.
+ * 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.
+ * 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 = NULL;
+       struct scatterlist dst_sg[2];
+       struct scatterlist src_sg[2];
+       struct mutex *tfm_mutex;
        struct blkcipher_desc desc = {
                .flags = CRYPTO_TFM_REQ_MAY_SLEEP
        };
@@ -1029,9 +1574,10 @@ decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
                       crypt_stat->cipher, rc);
                goto out;
        }
-       if ((rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
-                                     auth_tok->session_key.encrypted_key_size,
-                                     &src_sg, 1)) != 1) {
+       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]. "
@@ -1041,9 +1587,10 @@ decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
        }
        auth_tok->session_key.decrypted_key_size =
                auth_tok->session_key.encrypted_key_size;
-       if ((rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key,
-                                     auth_tok->session_key.decrypted_key_size,
-                                     &dst_sg, 1)) != 1) {
+       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);
@@ -1059,7 +1606,7 @@ decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
                rc = -EINVAL;
                goto out;
        }
-       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);
        mutex_unlock(tfm_mutex);
        if (unlikely(rc)) {
@@ -1080,30 +1627,11 @@ out:
        return rc;
 }
 
-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;
-}
-
 /**
  * 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.
@@ -1120,8 +1648,8 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
        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 = NULL;
-       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;
@@ -1232,18 +1760,18 @@ find_next_matching_auth_tok:
                                        "Considering cadidate auth tok:\n");
                        ecryptfs_dump_auth_tok(candidate_auth_tok);
                }
-               if ((rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig,
-                                                   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;
                }
-               if ((rc = ecryptfs_find_auth_tok_for_sig(
-                            &matching_auth_tok, crypt_stat,
-                            candidate_auth_tok_sig)))
-                       rc = 0;
+               ecryptfs_find_auth_tok_for_sig(&matching_auth_tok,
+                                              crypt_stat->mount_crypt_stat,
+                                              candidate_auth_tok_sig);
                if (matching_auth_tok) {
                        found_auth_tok = 1;
                        goto found_matching_auth_tok;
@@ -1316,23 +1844,24 @@ pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
                        struct ecryptfs_key_record *key_rec)
 {
        struct ecryptfs_msg_ctx *msg_ctx = NULL;
-       char *netlink_payload;
-       size_t netlink_payload_length;
+       char *payload = NULL;
+       size_t payload_len;
        struct ecryptfs_message *msg;
        int rc;
 
        rc = write_tag_66_packet(auth_tok->token.private_key.signature,
-                                ecryptfs_code_for_cipher_string(crypt_stat),
-                                crypt_stat, &netlink_payload,
-                                &netlink_payload_length);
+                                ecryptfs_code_for_cipher_string(
+                                        crypt_stat->cipher,
+                                        crypt_stat->key_size),
+                                crypt_stat, &payload, &payload_len);
        if (rc) {
                ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
                goto out;
        }
-       rc = ecryptfs_send_message(ecryptfs_transport, netlink_payload,
-                                  netlink_payload_length, &msg_ctx);
+       rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
        if (rc) {
-               ecryptfs_printk(KERN_ERR, "Error sending netlink message\n");
+               ecryptfs_printk(KERN_ERR, "Error sending message to "
+                               "ecryptfsd\n");
                goto out;
        }
        rc = ecryptfs_wait_for_response(msg_ctx, &msg);
@@ -1347,14 +1876,16 @@ pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
                ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n");
        kfree(msg);
 out:
-       if (netlink_payload)
-               kfree(netlink_payload);
+       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
- * @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
  *
@@ -1390,8 +1921,8 @@ write_tag_1_packet(char *dest, size_t *remaining_bytes,
                        auth_tok->token.private_key.key_size;
        rc = pki_encrypt_session_key(auth_tok, crypt_stat, key_rec);
        if (rc) {
-               ecryptfs_printk(KERN_ERR, "Failed to encrypt session key "
-                               "via a pki");
+               printk(KERN_ERR "Failed to encrypt session key via a key "
+                      "module; rc = [%d]\n", rc);
                goto out;
        }
        if (ecryptfs_verbosity > 0) {
@@ -1409,14 +1940,15 @@ encrypted_session_key_set:
                           + 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 [%d] bytes, but there are only [%d] "
+                      "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 = write_packet_length(&dest[(*packet_size)], (max_packet_size - 4),
-                                &packet_size_length);
+       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");
@@ -1441,7 +1973,7 @@ out:
 /**
  * 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
@@ -1449,7 +1981,7 @@ out:
  * Returns zero on success; non-zero on error.
  */
 static int
-write_tag_11_packet(char *dest, int *remaining_bytes, char *contents,
+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;
@@ -1468,14 +2000,15 @@ write_tag_11_packet(char *dest, int *remaining_bytes, char *contents,
                           + contents_length); /* Literal data */
        if (max_packet_size > (*remaining_bytes)) {
                printk(KERN_ERR "Packet length larger than maximum allowable; "
-                      "need up to [%d] bytes, but there are only [%d] "
+                      "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 = write_packet_length(&dest[(*packet_length)],
-                                (max_packet_size - 4), &packet_size_length);
+       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);
@@ -1501,7 +2034,7 @@ write_tag_11_packet(char *dest, int *remaining_bytes, char *contents,
 /**
  * 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
@@ -1519,10 +2052,10 @@ write_tag_3_packet(char *dest, size_t *remaining_bytes,
        size_t i;
        size_t encrypted_session_key_valid = 0;
        char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
-       struct scatterlist dst_sg;
-       struct scatterlist src_sg;
+       struct scatterlist dst_sg[2];
+       struct scatterlist src_sg[2];
        struct mutex *tfm_mutex = NULL;
-       size_t cipher_code;
+       u8 cipher_code;
        size_t packet_size_length;
        size_t max_packet_size;
        struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
@@ -1598,9 +2131,9 @@ write_tag_3_packet(char *dest, size_t *remaining_bytes,
                ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n");
                ecryptfs_dump_hex(session_key_encryption_key, 16);
        }
-       if ((rc = virt_to_scatterlist(crypt_stat->key,
-                                     key_rec->enc_key_size, &src_sg, 1))
-           != 1) {
+       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 = [%d]\n",
@@ -1608,9 +2141,9 @@ write_tag_3_packet(char *dest, size_t *remaining_bytes,
                rc = -ENOMEM;
                goto out;
        }
-       if ((rc = virt_to_scatterlist(key_rec->enc_key,
-                                     key_rec->enc_key_size, &dst_sg, 1))
-           != 1) {
+       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]. "
@@ -1631,7 +2164,7 @@ write_tag_3_packet(char *dest, size_t *remaining_bytes,
        rc = 0;
        ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n",
                        crypt_stat->key_size);
-       rc = crypto_blkcipher_encrypt(&desc, &dst_sg, &src_sg,
+       rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg,
                                      (*key_rec).enc_key_size);
        mutex_unlock(tfm_mutex);
        if (rc) {
@@ -1658,8 +2191,8 @@ encrypted_session_key_set:
                           + 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 [%d] bytes, but "
-                      "there are only [%d] available\n", max_packet_size,
+               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;
@@ -1667,8 +2200,9 @@ encrypted_session_key_set:
        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 = write_packet_length(&dest[(*packet_size)], (max_packet_size - 4),
-                                &packet_size_length);
+       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);
@@ -1678,7 +2212,8 @@ encrypted_session_key_set:
        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_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);
@@ -1707,7 +2242,7 @@ 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
@@ -1840,12 +2375,12 @@ struct kmem_cache *ecryptfs_global_auth_tok_cache;
 
 int
 ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
-                            char *sig)
+                            char *sig, u32 global_auth_tok_flags)
 {
        struct ecryptfs_global_auth_tok *new_auth_tok;
        int rc = 0;
 
-       new_auth_tok = kmem_cache_alloc(ecryptfs_global_auth_tok_cache,
+       new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache,
                                        GFP_KERNEL);
        if (!new_auth_tok) {
                rc = -ENOMEM;
@@ -1854,6 +2389,7 @@ ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
                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,