diff options
author | Jeff Garzik <jeff@garzik.org> | 2007-02-17 15:09:59 -0500 |
---|---|---|
committer | Jeff Garzik <jeff@garzik.org> | 2007-02-17 15:09:59 -0500 |
commit | 48c871c1f6a7c7044dd76774fb469e65c7e2e4e8 (patch) | |
tree | da3aa535c98cc0957851354ceb0fbff7482d7a9d /fs/ecryptfs/keystore.c | |
parent | 1a1689344add3333d28d1b5495d8043a3877d01c (diff) | |
parent | 4409d28140d9a6e6e3f4f1fdaf7234c4b965d954 (diff) |
Merge branch 'gfar' of master.kernel.org:/pub/scm/linux/kernel/git/galak/powerpc into upstream
Diffstat (limited to 'fs/ecryptfs/keystore.c')
-rw-r--r-- | fs/ecryptfs/keystore.c | 802 |
1 files changed, 718 insertions, 84 deletions
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c index 745c0f1bfbb..c209f67e7a2 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)) { |