Merge branch 'master' into for_paulus
[linux-drm-fsl-dcu.git] / fs / ecryptfs / keystore.c
index c3746f56d1627ab2246d5086731103353f9537d3..c209f67e7a26a2e3e4ef4267cf99c7633c2a49e4 100644 (file)
@@ -7,6 +7,7 @@
  * 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
@@ -64,26 +65,6 @@ int process_request_key_err(long err_code)
        return rc;
 }
 
-static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
-{
-       struct list_head *walker;
-       struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
-
-       walker = auth_tok_list_head->next;
-       while (walker != auth_tok_list_head) {
-               auth_tok_list_item =
-                   list_entry(walker, struct ecryptfs_auth_tok_list_item,
-                              list);
-               walker = auth_tok_list_item->list.next;
-               memset(auth_tok_list_item, 0,
-                      sizeof(struct ecryptfs_auth_tok_list_item));
-               kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
-                               auth_tok_list_item);
-       }
-}
-
-struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
-
 /**
  * parse_packet_length
  * @data: Pointer to memory containing length at offset
@@ -102,12 +83,12 @@ static int parse_packet_length(unsigned char *data, size_t *size,
        (*size) = 0;
        if (data[0] < 192) {
                /* One-byte length */
-               (*size) = data[0];
+               (*size) = (unsigned char)data[0];
                (*length_size) = 1;
        } else if (data[0] < 224) {
                /* Two-byte length */
-               (*size) = ((data[0] - 192) * 256);
-               (*size) += (data[1] + 192);
+               (*size) = (((unsigned char)(data[0]) - 192) * 256);
+               (*size) += ((unsigned char)(data[1]) + 192);
                (*length_size) = 2;
        } else if (data[0] == 255) {
                /* Five-byte length; we're not supposed to see this */
@@ -154,6 +135,499 @@ static int write_packet_length(char *dest, size_t 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 = 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 = 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, u16 *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 = 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 received netlink message 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, size_t 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 = 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 = 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;
+               goto out;
+       }
+       if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) {
+               ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_67\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 = 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)) {
+               ecryptfs_printk(KERN_ERR, "message_len [%d]; max len is [%d]\n",
+                               message_len, (i + key_rec->enc_key_size));
+               rc = -EIO;
+               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;
+               goto out;
+       }
+       memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size);
+out:
+       return rc;
+}
+
+/**
+ * decrypt_pki_encrypted_session_key - Decrypt the session key with
+ * the given auth_tok.
+ *
+ * Returns Zero on success; non-zero error otherwise.
+ */
+static int decrypt_pki_encrypted_session_key(
+       struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
+       struct ecryptfs_auth_tok *auth_tok,
+       struct ecryptfs_crypt_stat *crypt_stat)
+{
+       u16 cipher_code = 0;
+       struct ecryptfs_msg_ctx *msg_ctx;
+       struct ecryptfs_message *msg = NULL;
+       char *netlink_message;
+       size_t netlink_message_length;
+       int rc;
+
+       rc = write_tag_64_packet(mount_crypt_stat->global_auth_tok_sig,
+                                &(auth_tok->session_key),
+                                &netlink_message, &netlink_message_length);
+       if (rc) {
+               ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet");
+               goto out;
+       }
+       rc = ecryptfs_send_message(ecryptfs_transport, netlink_message,
+                                  netlink_message_length, &msg_ctx);
+       if (rc) {
+               ecryptfs_printk(KERN_ERR, "Error sending netlink message\n");
+               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:
+       if (msg)
+               kfree(msg);
+       return rc;
+}
+
+static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
+{
+       struct list_head *walker;
+       struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
+
+       walker = auth_tok_list_head->next;
+       while (walker != auth_tok_list_head) {
+               auth_tok_list_item =
+                   list_entry(walker, struct ecryptfs_auth_tok_list_item,
+                              list);
+               walker = auth_tok_list_item->list.next;
+               memset(auth_tok_list_item, 0,
+                      sizeof(struct ecryptfs_auth_tok_list_item));
+               kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
+                               auth_tok_list_item);
+       }
+       auth_tok_list_head->next = NULL;
+}
+
+struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
+
+
+/**
+ * parse_tag_1_packet
+ * @crypt_stat: The cryptographic context to modify based on packet
+ *              contents.
+ * @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.
+ *
+ * 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;
+
+       /* we check that:
+        *   one byte for the Tag 1 ID flag
+        *   two bytes for the body size
+        * do not exceed the maximum_packet_size
+        */
+       if (unlikely((*packet_size) + 3 > max_packet_size)) {
+               ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n");
+               rc = -EINVAL;
+               goto out;
+       }
+       /* check for Tag 1 identifier - one byte */
+       if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) {
+               ecryptfs_printk(KERN_ERR, "Enter w/ first byte != 0x%.2x\n",
+                               ECRYPTFS_TAG_1_PACKET_TYPE);
+               rc = -EINVAL;
+               goto out;
+       }
+       /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
+        * at end of function upon failure */
+       auth_tok_list_item =
+               kmem_cache_alloc(ecryptfs_auth_tok_list_item_cache,
+                                GFP_KERNEL);
+       if (!auth_tok_list_item) {
+               ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
+               rc = -ENOMEM;
+               goto out;
+       }
+       memset(auth_tok_list_item, 0,
+              sizeof(struct ecryptfs_auth_tok_list_item));
+       (*new_auth_tok) = &auth_tok_list_item->auth_tok;
+       /* check for body size - one to two bytes
+        *
+        *              ***** TAG 1 Packet Format *****
+        *    | version number                     | 1 byte       |
+        *    | key ID                             | 8 bytes      |
+        *    | public key algorithm               | 1 byte       |
+        *    | encrypted session key              | arbitrary    |
+        */
+       rc = parse_packet_length(&data[(*packet_size)], &body_size,
+                                &length_size);
+       if (rc) {
+               ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
+                               "rc = [%d]\n", rc);
+               goto out_free;
+       }
+       if (unlikely(body_size < (0x02 + ECRYPTFS_SIG_SIZE))) {
+               ecryptfs_printk(KERN_WARNING, "Invalid body size ([%d])\n",
+                               body_size);
+               rc = -EINVAL;
+               goto out_free;
+       }
+       (*packet_size) += length_size;
+       if (unlikely((*packet_size) + body_size > max_packet_size)) {
+               ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n");
+               rc = -EINVAL;
+               goto out_free;
+       }
+       /* Version 3 (from RFC2440) - one byte */
+       if (unlikely(data[(*packet_size)++] != 0x03)) {
+               ecryptfs_printk(KERN_DEBUG, "Unknown version number "
+                               "[%d]\n", data[(*packet_size) - 1]);
+               rc = -EINVAL;
+               goto out_free;
+       }
+       /* Read Signature */
+       ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
+                       &data[(*packet_size)], ECRYPTFS_SIG_SIZE);
+       *packet_size += ECRYPTFS_SIG_SIZE;
+       /* 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 - (0x02 + ECRYPTFS_SIG_SIZE);
+       if ((*new_auth_tok)->session_key.encrypted_key_size
+           > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
+               ecryptfs_printk(KERN_ERR, "Tag 1 packet contains key larger "
+                               "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
+               rc = -EINVAL;
+               goto out;
+       }
+       ecryptfs_printk(KERN_DEBUG, "Encrypted key size = [%d]\n",
+                       (*new_auth_tok)->session_key.encrypted_key_size);
+       memcpy((*new_auth_tok)->session_key.encrypted_key,
+              &data[(*packet_size)], (body_size - 0x02 - ECRYPTFS_SIG_SIZE));
+       (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size;
+       (*new_auth_tok)->session_key.flags &=
+               ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
+       (*new_auth_tok)->session_key.flags |=
+               ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
+       (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY;
+       (*new_auth_tok)->flags |= ECRYPTFS_PRIVATE_KEY;
+       /* TODO: Why are we setting this flag here? Don't we want the
+        * userspace to decrypt the session key? */
+       (*new_auth_tok)->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
@@ -178,10 +652,10 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
                   struct ecryptfs_auth_tok **new_auth_tok,
                   size_t *packet_size, size_t max_packet_size)
 {
-       int rc = 0;
        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;
@@ -207,14 +681,12 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
        /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
         * at end of function upon failure */
        auth_tok_list_item =
-           kmem_cache_alloc(ecryptfs_auth_tok_list_item_cache, SLAB_KERNEL);
+           kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
        if (!auth_tok_list_item) {
                ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
                rc = -ENOMEM;
                goto out;
        }
-       memset(auth_tok_list_item, 0,
-              sizeof(struct ecryptfs_auth_tok_list_item));
        (*new_auth_tok) = &auth_tok_list_item->auth_tok;
 
        /* check for body size - one to two bytes */
@@ -321,10 +793,10 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
        (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD;
        /* TODO: Parametarize; we might actually want userspace to
         * decrypt the session key. */
-       ECRYPTFS_CLEAR_FLAG((*new_auth_tok)->session_key.flags,
-                           ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
-       ECRYPTFS_CLEAR_FLAG((*new_auth_tok)->session_key.flags,
-                           ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
+       (*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:
@@ -360,9 +832,9 @@ 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)
 {
-       int rc = 0;
        size_t body_size;
        size_t length_size;
+       int rc = 0;
 
        (*packet_size) = 0;
        (*tag_11_contents_size) = 0;
@@ -461,7 +933,6 @@ static int decrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
        struct ecryptfs_password *password_s_ptr;
        struct scatterlist src_sg[2], dst_sg[2];
        struct mutex *tfm_mutex = NULL;
-       /* TODO: Use virt_to_scatterlist for these */
        char *encrypted_session_key;
        char *session_key;
        struct blkcipher_desc desc = {
@@ -470,8 +941,7 @@ static int decrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
        int rc = 0;
 
        password_s_ptr = &auth_tok->token.password;
-       if (ECRYPTFS_CHECK_FLAG(password_s_ptr->flags,
-                               ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET))
+       if (password_s_ptr->flags & ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET)
                ecryptfs_printk(KERN_DEBUG, "Session key encryption key "
                                "set; skipping key generation\n");
        ecryptfs_printk(KERN_DEBUG, "Session key encryption key (size [%d])"
@@ -553,7 +1023,7 @@ static int decrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
        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);
-       ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_KEY_VALID);
+       crypt_stat->flags |= ECRYPTFS_KEY_VALID;
        ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n");
        if (ecryptfs_verbosity > 0)
                ecryptfs_dump_hex(crypt_stat->key,
@@ -589,7 +1059,6 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
                              struct dentry *ecryptfs_dentry)
 {
        size_t i = 0;
-       int rc = 0;
        size_t found_auth_tok = 0;
        size_t next_packet_is_auth_tok_packet;
        char sig[ECRYPTFS_SIG_SIZE_HEX];
@@ -605,6 +1074,7 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
        unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE];
        size_t tag_11_contents_size;
        size_t tag_11_packet_size;
+       int rc = 0;
 
        INIT_LIST_HEAD(&auth_tok_list);
        /* Parse the header to find as many packets as we can, these will be
@@ -656,8 +1126,21 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
                                        sig_tmp_space, tag_11_contents_size);
                        new_auth_tok->token.password.signature[
                                ECRYPTFS_PASSWORD_SIG_SIZE] = '\0';
-                       ECRYPTFS_SET_FLAG(crypt_stat->flags,
-                                         ECRYPTFS_ENCRYPTED);
+                       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 "
@@ -706,31 +1189,46 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
                        goto leave_list;
                        /* TODO: Transfer the common salt into the
                         * crypt_stat salt */
+               } else if ((candidate_auth_tok->token_type
+                           == ECRYPTFS_PRIVATE_KEY)
+                          && !strncmp(candidate_auth_tok->token.private_key.signature,
+                                    sig, ECRYPTFS_SIG_SIZE_HEX)) {
+                       found_auth_tok = 1;
+                       goto leave_list;
                }
        }
-leave_list:
        if (!found_auth_tok) {
                ecryptfs_printk(KERN_ERR, "Could not find authentication "
                                "token on temporary list for sig [%.*s]\n",
                                ECRYPTFS_SIG_SIZE_HEX, sig);
                rc = -EIO;
                goto out_wipe_list;
-       } else {
+       }
+leave_list:
+       rc = -ENOTSUPP;
+       if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
+               memcpy(&(candidate_auth_tok->token.private_key),
+                      &(chosen_auth_tok->token.private_key),
+                      sizeof(struct ecryptfs_private_key));
+               rc = decrypt_pki_encrypted_session_key(mount_crypt_stat,
+                                                      candidate_auth_tok,
+                                                      crypt_stat);
+       } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
                memcpy(&(candidate_auth_tok->token.password),
                       &(chosen_auth_tok->token.password),
                       sizeof(struct ecryptfs_password));
                rc = decrypt_session_key(candidate_auth_tok, crypt_stat);
-               if (rc) {
-                       ecryptfs_printk(KERN_ERR, "Error decrypting the "
-                                       "session key\n");
-                       goto out_wipe_list;
-               }
-               rc = ecryptfs_compute_root_iv(crypt_stat);
-               if (rc) {
-                       ecryptfs_printk(KERN_ERR, "Error computing "
-                                       "the root IV\n");
-                       goto out_wipe_list;
-               }
+       }
+       if (rc) {
+               ecryptfs_printk(KERN_ERR, "Error decrypting the "
+                               "session key; rc = [%d]\n", rc);
+               goto out_wipe_list;
+       }
+       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) {
@@ -743,6 +1241,145 @@ out_wipe_list:
 out:
        return rc;
 }
+static int
+pki_encrypt_session_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 *netlink_payload;
+       size_t netlink_payload_length;
+       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);
+       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);
+       if (rc) {
+               ecryptfs_printk(KERN_ERR, "Error sending netlink message\n");
+               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:
+       if (netlink_payload)
+               kfree(netlink_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
+ * @packet_size: This function will write the number of bytes that end
+ *               up constituting the packet; set to zero on error
+ *
+ * Returns zero on success; non-zero on error.
+ */
+static int
+write_tag_1_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
+                  struct ecryptfs_crypt_stat *crypt_stat,
+                  struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
+                  struct ecryptfs_key_record *key_rec, size_t *packet_size)
+{
+       size_t i;
+       size_t encrypted_session_key_valid = 0;
+       size_t key_rec_size;
+       size_t packet_size_length;
+       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);
+               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, crypt_stat, key_rec);
+       if (rc) {
+               ecryptfs_printk(KERN_ERR, "Failed to encrypt session key "
+                               "via a pki");
+               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:
+       /* Now we have a valid key_rec.  Append it to the
+        * key_rec set. */
+       key_rec_size = (sizeof(struct ecryptfs_key_record)
+                       - ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES
+                       + (key_rec->enc_key_size));
+       /* TODO: Include a packet size limit as a parameter to this
+        * function once we have multi-packet headers (for versions
+        * later than 0.1 */
+       if (key_rec_size >= ECRYPTFS_MAX_KEYSET_SIZE) {
+               ecryptfs_printk(KERN_ERR, "Keyset too large\n");
+               rc = -EINVAL;
+               goto out;
+       }
+       /*              ***** TAG 1 Packet Format *****
+        *    | version number                     | 1 byte       |
+        *    | key ID                             | 8 bytes      |
+        *    | public key algorithm               | 1 byte       |
+        *    | encrypted session key              | arbitrary    |
+        */
+       if ((0x02 + ECRYPTFS_SIG_SIZE + key_rec->enc_key_size) >= max) {
+               ecryptfs_printk(KERN_ERR,
+                               "Authentication token is too large\n");
+               rc = -EINVAL;
+               goto out;
+       }
+       dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE;
+       /* This format is inspired by OpenPGP; see RFC 2440
+        * packet tag 1 */
+       rc = write_packet_length(&dest[(*packet_size)],
+                                (0x02 + ECRYPTFS_SIG_SIZE +
+                                key_rec->enc_key_size),
+                                &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;
+       return rc;
+}
 
 /**
  * write_tag_11_packet
@@ -758,8 +1395,8 @@ static int
 write_tag_11_packet(char *dest, int max, char *contents, size_t contents_length,
                    size_t *packet_length)
 {
-       int rc = 0;
        size_t packet_size_length;
+       int rc = 0;
 
        (*packet_length) = 0;
        if ((13 + contents_length) > max) {
@@ -817,7 +1454,6 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
                   struct ecryptfs_key_record *key_rec, size_t *packet_size)
 {
        size_t i;
-       size_t signature_is_valid = 0;
        size_t encrypted_session_key_valid = 0;
        char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
        struct scatterlist dest_sg[2];
@@ -833,19 +1469,14 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
        int rc = 0;
 
        (*packet_size) = 0;
-       /* Check for a valid signature on the auth_tok */
-       for (i = 0; i < ECRYPTFS_SIG_SIZE_HEX; i++)
-               signature_is_valid |= auth_tok->token.password.signature[i];
-       if (!signature_is_valid)
-               BUG();
-       ecryptfs_from_hex((*key_rec).sig, auth_tok->token.password.signature,
+       ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
                          ECRYPTFS_SIG_SIZE);
        encrypted_session_key_valid = 0;
        for (i = 0; i < crypt_stat->key_size; i++)
                encrypted_session_key_valid |=
                        auth_tok->session_key.encrypted_key[i];
        if (encrypted_session_key_valid) {
-               memcpy((*key_rec).enc_key,
+               memcpy(key_rec->enc_key,
                       auth_tok->session_key.encrypted_key,
                       auth_tok->session_key.encrypted_key_size);
                goto encrypted_session_key_set;
@@ -858,10 +1489,10 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
                memset((crypt_stat->key + 24), 0, 8);
                auth_tok->session_key.encrypted_key_size = 32;
        }
-       (*key_rec).enc_key_size =
+       key_rec->enc_key_size =
                auth_tok->session_key.encrypted_key_size;
-       if (ECRYPTFS_CHECK_FLAG(auth_tok->token.password.flags,
-                               ECRYPTFS_SESSION_KEY_ENCRYPTION_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.
@@ -879,15 +1510,15 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
                ecryptfs_dump_hex(session_key_encryption_key, 16);
        }
        rc = virt_to_scatterlist(crypt_stat->key,
-                                (*key_rec).enc_key_size, src_sg, 2);
+                                key_rec->enc_key_size, src_sg, 2);
        if (!rc) {
                ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
                                "for crypt_stat session key\n");
                rc = -ENOMEM;
                goto out;
        }
-       rc = virt_to_scatterlist((*key_rec).enc_key,
-                                (*key_rec).enc_key_size, dest_sg, 2);
+       rc = virt_to_scatterlist(key_rec->enc_key,
+                                key_rec->enc_key_size, dest_sg, 2);
        if (!rc) {
                ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
                                "for crypt_stat encrypted session key\n");
@@ -943,14 +1574,14 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
                mutex_unlock(tfm_mutex);
        ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
        if (ecryptfs_verbosity > 0)
-               ecryptfs_dump_hex((*key_rec).enc_key,
-                                 (*key_rec).enc_key_size);
+               ecryptfs_dump_hex(key_rec->enc_key,
+                                 key_rec->enc_key_size);
 encrypted_session_key_set:
        /* Now we have a valid key_rec.  Append it to the
         * key_rec set. */
        key_rec_size = (sizeof(struct ecryptfs_key_record)
                        - ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES
-                       + ((*key_rec).enc_key_size));
+                       + (key_rec->enc_key_size));
        /* TODO: Include a packet size limit as a parameter to this
         * function once we have multi-packet headers (for versions
         * later than 0.1 */
@@ -962,7 +1593,7 @@ encrypted_session_key_set:
        /* TODO: Packet size limit */
        /* We have 5 bytes of surrounding packet data */
        if ((0x05 + ECRYPTFS_SALT_SIZE
-            + (*key_rec).enc_key_size) >= max) {
+            + key_rec->enc_key_size) >= max) {
                ecryptfs_printk(KERN_ERR, "Authentication token is too "
                                "large\n");
                rc = -EINVAL;
@@ -974,7 +1605,7 @@ encrypted_session_key_set:
        /* ver+cipher+s2k+hash+salt+iter+enc_key */
        rc = write_packet_length(&dest[(*packet_size)],
                                 (0x05 + ECRYPTFS_SALT_SIZE
-                                 + (*key_rec).enc_key_size),
+                                 + key_rec->enc_key_size),
                                 &packet_size_length);
        if (rc) {
                ecryptfs_printk(KERN_ERR, "Error generating tag 3 packet "
@@ -997,9 +1628,9 @@ encrypted_session_key_set:
               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;
+       memcpy(&dest[(*packet_size)], key_rec->enc_key,
+              key_rec->enc_key_size);
+       (*packet_size) += key_rec->enc_key_size;
 out:
        if (desc.tfm && !tfm_mutex)
                crypto_free_blkcipher(desc.tfm);
@@ -1029,13 +1660,13 @@ ecryptfs_generate_key_packet_set(char *dest_base,
                                 struct dentry *ecryptfs_dentry, size_t *len,
                                 size_t max)
 {
-       int rc = 0;
        struct ecryptfs_auth_tok *auth_tok;
        struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
                &ecryptfs_superblock_to_private(
                        ecryptfs_dentry->d_sb)->mount_crypt_stat;
        size_t written;
        struct ecryptfs_key_record key_rec;
+       int rc = 0;
 
        (*len) = 0;
        if (mount_crypt_stat->global_auth_tok) {
@@ -1062,20 +1693,23 @@ ecryptfs_generate_key_packet_set(char *dest_base,
                                goto out;
                        }
                        (*len) += written;
+               } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
+                       rc = write_tag_1_packet(dest_base + (*len),
+                                               max, auth_tok,
+                                               crypt_stat,mount_crypt_stat,
+                                               &key_rec, &written);
+                       if (rc) {
+                               ecryptfs_printk(KERN_WARNING, "Error "
+                                               "writing tag 1 packet\n");
+                               goto out;
+                       }
+                       (*len) += written;
                } else {
                        ecryptfs_printk(KERN_WARNING, "Unsupported "
                                        "authentication token type\n");
                        rc = -EINVAL;
                        goto out;
                }
-               if (rc) {
-                       ecryptfs_printk(KERN_WARNING, "Error writing "
-                                       "authentication token packet with sig "
-                                       "= [%s]\n",
-                                       mount_crypt_stat->global_auth_tok_sig);
-                       rc = -EIO;
-                       goto out;
-               }
        } else
                BUG();
        if (likely((max - (*len)) > 0)) {