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-rw-r--r--fs/ecryptfs/keystore.c802
1 files changed, 718 insertions, 84 deletions
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index 745c0f1..c209f67 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)) {
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