1 files changed, 718 insertions, 84 deletions

diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index 745c0f1bfbbd..c209f67e7a26 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -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, GFP_KERNEL);
+	    kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
 	if (!auth_tok_list_item) {
 		ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
 		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)) {