| /** |
| * eCryptfs: Linux filesystem encryption layer |
| * In-kernel key management code. Includes functions to parse and |
| * write authentication token-related packets with the underlying |
| * file. |
| * |
| * 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 |
| * published by the Free Software Foundation; either version 2 of the |
| * License, or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA |
| * 02111-1307, USA. |
| */ |
| |
| #include <linux/string.h> |
| #include <linux/syscalls.h> |
| #include <linux/pagemap.h> |
| #include <linux/key.h> |
| #include <linux/random.h> |
| #include <linux/crypto.h> |
| #include <linux/scatterlist.h> |
| #include "ecryptfs_kernel.h" |
| |
| /** |
| * request_key returned an error instead of a valid key address; |
| * determine the type of error, make appropriate log entries, and |
| * return an error code. |
| */ |
| static int process_request_key_err(long err_code) |
| { |
| int rc = 0; |
| |
| switch (err_code) { |
| case -ENOKEY: |
| ecryptfs_printk(KERN_WARNING, "No key\n"); |
| rc = -ENOENT; |
| break; |
| case -EKEYEXPIRED: |
| ecryptfs_printk(KERN_WARNING, "Key expired\n"); |
| rc = -ETIME; |
| break; |
| case -EKEYREVOKED: |
| ecryptfs_printk(KERN_WARNING, "Key revoked\n"); |
| rc = -EINVAL; |
| break; |
| default: |
| ecryptfs_printk(KERN_WARNING, "Unknown error code: " |
| "[0x%.16x]\n", err_code); |
| rc = -EINVAL; |
| } |
| return rc; |
| } |
| |
| /** |
| * ecryptfs_parse_packet_length |
| * @data: Pointer to memory containing length at offset |
| * @size: This function writes the decoded size to this memory |
| * address; zero on error |
| * @length_size: The number of bytes occupied by the encoded length |
| * |
| * Returns zero on success; non-zero on error |
| */ |
| int ecryptfs_parse_packet_length(unsigned char *data, size_t *size, |
| size_t *length_size) |
| { |
| int rc = 0; |
| |
| (*length_size) = 0; |
| (*size) = 0; |
| if (data[0] < 192) { |
| /* One-byte length */ |
| (*size) = (unsigned char)data[0]; |
| (*length_size) = 1; |
| } else if (data[0] < 224) { |
| /* Two-byte length */ |
| (*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 */ |
| ecryptfs_printk(KERN_ERR, "Five-byte packet length not " |
| "supported\n"); |
| rc = -EINVAL; |
| goto out; |
| } else { |
| ecryptfs_printk(KERN_ERR, "Error parsing packet length\n"); |
| rc = -EINVAL; |
| goto out; |
| } |
| out: |
| return rc; |
| } |
| |
| /** |
| * ecryptfs_write_packet_length |
| * @dest: The byte array target into which to write the length. Must |
| * have at least 5 bytes allocated. |
| * @size: The length to write. |
| * @packet_size_length: The number of bytes used to encode the packet |
| * length is written to this address. |
| * |
| * Returns zero on success; non-zero on error. |
| */ |
| int ecryptfs_write_packet_length(char *dest, size_t size, |
| size_t *packet_size_length) |
| { |
| int rc = 0; |
| |
| if (size < 192) { |
| dest[0] = size; |
| (*packet_size_length) = 1; |
| } else if (size < 65536) { |
| dest[0] = (((size - 192) / 256) + 192); |
| dest[1] = ((size - 192) % 256); |
| (*packet_size_length) = 2; |
| } else { |
| rc = -EINVAL; |
| ecryptfs_printk(KERN_WARNING, |
| "Unsupported packet size: [%d]\n", 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 = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX, |
| &packet_size_len); |
| if (rc) { |
| ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet " |
| "header; cannot generate packet length\n"); |
| goto out; |
| } |
| i += packet_size_len; |
| memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX); |
| i += ECRYPTFS_SIG_SIZE_HEX; |
| rc = ecryptfs_write_packet_length(&message[i], |
| session_key->encrypted_key_size, |
| &packet_size_len); |
| if (rc) { |
| ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet " |
| "header; cannot generate packet length\n"); |
| 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, u8 *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 = ecryptfs_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 message received from ecryptfsd " |
| "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, u8 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 = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX, |
| &packet_size_len); |
| if (rc) { |
| ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet " |
| "header; cannot generate packet length\n"); |
| 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 = ecryptfs_write_packet_length(&message[i], crypt_stat->key_size + 3, |
| &packet_size_len); |
| if (rc) { |
| ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet " |
| "header; cannot generate packet length\n"); |
| 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; |
| printk(KERN_ERR "%s: message_len is [%zd]; minimum acceptable " |
| "message length is [%d]\n", __func__, message_len, 4); |
| goto out; |
| } |
| if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) { |
| rc = -EIO; |
| printk(KERN_ERR "%s: Type should be ECRYPTFS_TAG_67\n", |
| __func__); |
| goto out; |
| } |
| if (data[i++]) { |
| rc = -EIO; |
| printk(KERN_ERR "%s: Status indicator has non zero " |
| "value [%d]\n", __func__, data[i-1]); |
| |
| goto out; |
| } |
| rc = ecryptfs_parse_packet_length(&data[i], &key_rec->enc_key_size, |
| &data_len); |
| if (rc) { |
| ecryptfs_printk(KERN_WARNING, "Error parsing packet length; " |
| "rc = [%d]\n", rc); |
| goto out; |
| } |
| i += data_len; |
| if (message_len < (i + key_rec->enc_key_size)) { |
| rc = -EIO; |
| printk(KERN_ERR "%s: message_len [%zd]; max len is [%zd]\n", |
| __func__, message_len, (i + key_rec->enc_key_size)); |
| goto out; |
| } |
| if (key_rec->enc_key_size > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { |
| rc = -EIO; |
| printk(KERN_ERR "%s: Encrypted key_size [%zd] larger than " |
| "the maximum key size [%d]\n", __func__, |
| key_rec->enc_key_size, |
| ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES); |
| goto out; |
| } |
| memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size); |
| out: |
| return rc; |
| } |
| |
| static int |
| ecryptfs_find_global_auth_tok_for_sig( |
| struct ecryptfs_global_auth_tok **global_auth_tok, |
| struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig) |
| { |
| struct ecryptfs_global_auth_tok *walker; |
| int rc = 0; |
| |
| (*global_auth_tok) = NULL; |
| mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); |
| list_for_each_entry(walker, |
| &mount_crypt_stat->global_auth_tok_list, |
| mount_crypt_stat_list) { |
| if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX) == 0) { |
| (*global_auth_tok) = walker; |
| goto out; |
| } |
| } |
| rc = -EINVAL; |
| out: |
| mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); |
| return rc; |
| } |
| |
| /** |
| * ecryptfs_find_auth_tok_for_sig |
| * @auth_tok: Set to the matching auth_tok; NULL if not found |
| * @crypt_stat: inode crypt_stat crypto context |
| * @sig: Sig of auth_tok to find |
| * |
| * For now, this function simply looks at the registered auth_tok's |
| * linked off the mount_crypt_stat, so all the auth_toks that can be |
| * used must be registered at mount time. This function could |
| * potentially try a lot harder to find auth_tok's (e.g., by calling |
| * out to ecryptfsd to dynamically retrieve an auth_tok object) so |
| * that static registration of auth_tok's will no longer be necessary. |
| * |
| * Returns zero on no error; non-zero on error |
| */ |
| static int |
| ecryptfs_find_auth_tok_for_sig( |
| struct ecryptfs_auth_tok **auth_tok, |
| struct ecryptfs_mount_crypt_stat *mount_crypt_stat, |
| char *sig) |
| { |
| struct ecryptfs_global_auth_tok *global_auth_tok; |
| int rc = 0; |
| |
| (*auth_tok) = NULL; |
| if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok, |
| mount_crypt_stat, sig)) { |
| struct key *auth_tok_key; |
| |
| rc = ecryptfs_keyring_auth_tok_for_sig(&auth_tok_key, auth_tok, |
| sig); |
| } else |
| (*auth_tok) = global_auth_tok->global_auth_tok; |
| return rc; |
| } |
| |
| /** |
| * write_tag_70_packet can gobble a lot of stack space. We stuff most |
| * of the function's parameters in a kmalloc'd struct to help reduce |
| * eCryptfs' overall stack usage. |
| */ |
| struct ecryptfs_write_tag_70_packet_silly_stack { |
| u8 cipher_code; |
| size_t max_packet_size; |
| size_t packet_size_len; |
| size_t block_aligned_filename_size; |
| size_t block_size; |
| size_t i; |
| size_t j; |
| size_t num_rand_bytes; |
| struct mutex *tfm_mutex; |
| char *block_aligned_filename; |
| struct ecryptfs_auth_tok *auth_tok; |
| struct scatterlist src_sg; |
| struct scatterlist dst_sg; |
| struct blkcipher_desc desc; |
| char iv[ECRYPTFS_MAX_IV_BYTES]; |
| char hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; |
| char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; |
| struct hash_desc hash_desc; |
| struct scatterlist hash_sg; |
| }; |
| |
| /** |
| * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK |
| * @filename: NULL-terminated filename string |
| * |
| * This is the simplest mechanism for achieving filename encryption in |
| * eCryptfs. It encrypts the given filename with the mount-wide |
| * filename encryption key (FNEK) and stores it in a packet to @dest, |
| * which the callee will encode and write directly into the dentry |
| * name. |
| */ |
| int |
| ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, |
| size_t *packet_size, |
| struct ecryptfs_mount_crypt_stat *mount_crypt_stat, |
| char *filename, size_t filename_size) |
| { |
| struct ecryptfs_write_tag_70_packet_silly_stack *s; |
| int rc = 0; |
| |
| s = kmalloc(sizeof(*s), GFP_KERNEL); |
| if (!s) { |
| printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc " |
| "[%zd] bytes of kernel memory\n", __func__, sizeof(*s)); |
| goto out; |
| } |
| s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
| (*packet_size) = 0; |
| rc = ecryptfs_get_tfm_and_mutex_for_cipher_name( |
| &s->desc.tfm, |
| &s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name); |
| if (unlikely(rc)) { |
| printk(KERN_ERR "Internal error whilst attempting to get " |
| "tfm and mutex for cipher name [%s]; rc = [%d]\n", |
| mount_crypt_stat->global_default_fn_cipher_name, rc); |
| goto out; |
| } |
| mutex_lock(s->tfm_mutex); |
| s->block_size = crypto_blkcipher_blocksize(s->desc.tfm); |
| /* Plus one for the \0 separator between the random prefix |
| * and the plaintext filename */ |
| s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1); |
| s->block_aligned_filename_size = (s->num_rand_bytes + filename_size); |
| if ((s->block_aligned_filename_size % s->block_size) != 0) { |
| s->num_rand_bytes += (s->block_size |
| - (s->block_aligned_filename_size |
| % s->block_size)); |
| s->block_aligned_filename_size = (s->num_rand_bytes |
| + filename_size); |
| } |
| /* Octet 0: Tag 70 identifier |
| * Octets 1-N1: Tag 70 packet size (includes cipher identifier |
| * and block-aligned encrypted filename size) |
| * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) |
| * Octet N2-N3: Cipher identifier (1 octet) |
| * Octets N3-N4: Block-aligned encrypted filename |
| * - Consists of a minimum number of random characters, a \0 |
| * separator, and then the filename */ |
| s->max_packet_size = (1 /* Tag 70 identifier */ |
| + 3 /* Max Tag 70 packet size */ |
| + ECRYPTFS_SIG_SIZE /* FNEK sig */ |
| + 1 /* Cipher identifier */ |
| + s->block_aligned_filename_size); |
| if (dest == NULL) { |
| (*packet_size) = s->max_packet_size; |
| goto out_unlock; |
| } |
| if (s->max_packet_size > (*remaining_bytes)) { |
| printk(KERN_WARNING "%s: Require [%zd] bytes to write; only " |
| "[%zd] available\n", __func__, s->max_packet_size, |
| (*remaining_bytes)); |
| rc = -EINVAL; |
| goto out_unlock; |
| } |
| s->block_aligned_filename = kzalloc(s->block_aligned_filename_size, |
| GFP_KERNEL); |
| if (!s->block_aligned_filename) { |
| printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " |
| "kzalloc [%zd] bytes\n", __func__, |
| s->block_aligned_filename_size); |
| rc = -ENOMEM; |
| goto out_unlock; |
| } |
| s->i = 0; |
| dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE; |
| rc = ecryptfs_write_packet_length(&dest[s->i], |
| (ECRYPTFS_SIG_SIZE |
| + 1 /* Cipher code */ |
| + s->block_aligned_filename_size), |
| &s->packet_size_len); |
| if (rc) { |
| printk(KERN_ERR "%s: Error generating tag 70 packet " |
| "header; cannot generate packet length; rc = [%d]\n", |
| __func__, rc); |
| goto out_free_unlock; |
| } |
| s->i += s->packet_size_len; |
| ecryptfs_from_hex(&dest[s->i], |
| mount_crypt_stat->global_default_fnek_sig, |
| ECRYPTFS_SIG_SIZE); |
| s->i += ECRYPTFS_SIG_SIZE; |
| s->cipher_code = ecryptfs_code_for_cipher_string( |
| mount_crypt_stat->global_default_fn_cipher_name, |
| mount_crypt_stat->global_default_fn_cipher_key_bytes); |
| if (s->cipher_code == 0) { |
| printk(KERN_WARNING "%s: Unable to generate code for " |
| "cipher [%s] with key bytes [%zd]\n", __func__, |
| mount_crypt_stat->global_default_fn_cipher_name, |
| mount_crypt_stat->global_default_fn_cipher_key_bytes); |
| rc = -EINVAL; |
| goto out_free_unlock; |
| } |
| dest[s->i++] = s->cipher_code; |
| rc = ecryptfs_find_auth_tok_for_sig( |
| &s->auth_tok, mount_crypt_stat, |
| mount_crypt_stat->global_default_fnek_sig); |
| if (rc) { |
| printk(KERN_ERR "%s: Error attempting to find auth tok for " |
| "fnek sig [%s]; rc = [%d]\n", __func__, |
| mount_crypt_stat->global_default_fnek_sig, rc); |
| goto out_free_unlock; |
| } |
| /* TODO: Support other key modules than passphrase for |
| * filename encryption */ |
| BUG_ON(s->auth_tok->token_type != ECRYPTFS_PASSWORD); |
| sg_init_one( |
| &s->hash_sg, |
| (u8 *)s->auth_tok->token.password.session_key_encryption_key, |
| s->auth_tok->token.password.session_key_encryption_key_bytes); |
| s->hash_desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
| s->hash_desc.tfm = crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST, 0, |
| CRYPTO_ALG_ASYNC); |
| if (IS_ERR(s->hash_desc.tfm)) { |
| rc = PTR_ERR(s->hash_desc.tfm); |
| printk(KERN_ERR "%s: Error attempting to " |
| "allocate hash crypto context; rc = [%d]\n", |
| __func__, rc); |
| goto out_free_unlock; |
| } |
| rc = crypto_hash_init(&s->hash_desc); |
| if (rc) { |
| printk(KERN_ERR |
| "%s: Error initializing crypto hash; rc = [%d]\n", |
| __func__, rc); |
| goto out_release_free_unlock; |
| } |
| rc = crypto_hash_update( |
| &s->hash_desc, &s->hash_sg, |
| s->auth_tok->token.password.session_key_encryption_key_bytes); |
| if (rc) { |
| printk(KERN_ERR |
| "%s: Error updating crypto hash; rc = [%d]\n", |
| __func__, rc); |
| goto out_release_free_unlock; |
| } |
| rc = crypto_hash_final(&s->hash_desc, s->hash); |
| if (rc) { |
| printk(KERN_ERR |
| "%s: Error finalizing crypto hash; rc = [%d]\n", |
| __func__, rc); |
| goto out_release_free_unlock; |
| } |
| for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) { |
| s->block_aligned_filename[s->j] = |
| s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)]; |
| if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE) |
| == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) { |
| sg_init_one(&s->hash_sg, (u8 *)s->hash, |
| ECRYPTFS_TAG_70_DIGEST_SIZE); |
| rc = crypto_hash_init(&s->hash_desc); |
| if (rc) { |
| printk(KERN_ERR |
| "%s: Error initializing crypto hash; " |
| "rc = [%d]\n", __func__, rc); |
| goto out_release_free_unlock; |
| } |
| rc = crypto_hash_update(&s->hash_desc, &s->hash_sg, |
| ECRYPTFS_TAG_70_DIGEST_SIZE); |
| if (rc) { |
| printk(KERN_ERR |
| "%s: Error updating crypto hash; " |
| "rc = [%d]\n", __func__, rc); |
| goto out_release_free_unlock; |
| } |
| rc = crypto_hash_final(&s->hash_desc, s->tmp_hash); |
| if (rc) { |
| printk(KERN_ERR |
| "%s: Error finalizing crypto hash; " |
| "rc = [%d]\n", __func__, rc); |
| goto out_release_free_unlock; |
| } |
| memcpy(s->hash, s->tmp_hash, |
| ECRYPTFS_TAG_70_DIGEST_SIZE); |
| } |
| if (s->block_aligned_filename[s->j] == '\0') |
| s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL; |
| } |
| memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename, |
| filename_size); |
| rc = virt_to_scatterlist(s->block_aligned_filename, |
| s->block_aligned_filename_size, &s->src_sg, 1); |
| if (rc != 1) { |
| printk(KERN_ERR "%s: Internal error whilst attempting to " |
| "convert filename memory to scatterlist; " |
| "expected rc = 1; got rc = [%d]. " |
| "block_aligned_filename_size = [%zd]\n", __func__, rc, |
| s->block_aligned_filename_size); |
| goto out_release_free_unlock; |
| } |
| rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size, |
| &s->dst_sg, 1); |
| if (rc != 1) { |
| printk(KERN_ERR "%s: Internal error whilst attempting to " |
| "convert encrypted filename memory to scatterlist; " |
| "expected rc = 1; got rc = [%d]. " |
| "block_aligned_filename_size = [%zd]\n", __func__, rc, |
| s->block_aligned_filename_size); |
| goto out_release_free_unlock; |
| } |
| /* The characters in the first block effectively do the job |
| * of the IV here, so we just use 0's for the IV. Note the |
| * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES |
| * >= ECRYPTFS_MAX_IV_BYTES. */ |
| memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES); |
| s->desc.info = s->iv; |
| rc = crypto_blkcipher_setkey( |
| s->desc.tfm, |
| s->auth_tok->token.password.session_key_encryption_key, |
| mount_crypt_stat->global_default_fn_cipher_key_bytes); |
| if (rc < 0) { |
| printk(KERN_ERR "%s: Error setting key for crypto context; " |
| "rc = [%d]. s->auth_tok->token.password.session_key_" |
| "encryption_key = [0x%p]; mount_crypt_stat->" |
| "global_default_fn_cipher_key_bytes = [%zd]\n", __func__, |
| rc, |
| s->auth_tok->token.password.session_key_encryption_key, |
| mount_crypt_stat->global_default_fn_cipher_key_bytes); |
| goto out_release_free_unlock; |
| } |
| rc = crypto_blkcipher_encrypt_iv(&s->desc, &s->dst_sg, &s->src_sg, |
| s->block_aligned_filename_size); |
| if (rc) { |
| printk(KERN_ERR "%s: Error attempting to encrypt filename; " |
| "rc = [%d]\n", __func__, rc); |
| goto out_release_free_unlock; |
| } |
| s->i += s->block_aligned_filename_size; |
| (*packet_size) = s->i; |
| (*remaining_bytes) -= (*packet_size); |
| out_release_free_unlock: |
| crypto_free_hash(s->hash_desc.tfm); |
| out_free_unlock: |
| memset(s->block_aligned_filename, 0, s->block_aligned_filename_size); |
| kfree(s->block_aligned_filename); |
| out_unlock: |
| mutex_unlock(s->tfm_mutex); |
| out: |
| kfree(s); |
| return rc; |
| } |
| |
| struct ecryptfs_parse_tag_70_packet_silly_stack { |
| u8 cipher_code; |
| size_t max_packet_size; |
| size_t packet_size_len; |
| size_t parsed_tag_70_packet_size; |
| size_t block_aligned_filename_size; |
| size_t block_size; |
| size_t i; |
| struct mutex *tfm_mutex; |
| char *decrypted_filename; |
| struct ecryptfs_auth_tok *auth_tok; |
| struct scatterlist src_sg; |
| struct scatterlist dst_sg; |
| struct blkcipher_desc desc; |
| char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1]; |
| char iv[ECRYPTFS_MAX_IV_BYTES]; |
| char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE]; |
| }; |
| |
| /** |
| * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet |
| * @filename: This function kmalloc's the memory for the filename |
| */ |
| int |
| ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, |
| size_t *packet_size, |
| struct ecryptfs_mount_crypt_stat *mount_crypt_stat, |
| char *data, size_t max_packet_size) |
| { |
| struct ecryptfs_parse_tag_70_packet_silly_stack *s; |
| int rc = 0; |
| |
| (*packet_size) = 0; |
| (*filename_size) = 0; |
| (*filename) = NULL; |
| s = kmalloc(sizeof(*s), GFP_KERNEL); |
| if (!s) { |
| printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc " |
| "[%zd] bytes of kernel memory\n", __func__, sizeof(*s)); |
| goto out; |
| } |
| s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
| if (max_packet_size < (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)) { |
| printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be " |
| "at least [%d]\n", __func__, max_packet_size, |
| (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)); |
| rc = -EINVAL; |
| goto out; |
| } |
| /* Octet 0: Tag 70 identifier |
| * Octets 1-N1: Tag 70 packet size (includes cipher identifier |
| * and block-aligned encrypted filename size) |
| * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) |
| * Octet N2-N3: Cipher identifier (1 octet) |
| * Octets N3-N4: Block-aligned encrypted filename |
| * - Consists of a minimum number of random numbers, a \0 |
| * separator, and then the filename */ |
| if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) { |
| printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be " |
| "tag [0x%.2x]\n", __func__, |
| data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE); |
| rc = -EINVAL; |
| goto out; |
| } |
| rc = ecryptfs_parse_packet_length(&data[(*packet_size)], |
| &s->parsed_tag_70_packet_size, |
| &s->packet_size_len); |
| if (rc) { |
| printk(KERN_WARNING "%s: Error parsing packet length; " |
| "rc = [%d]\n", __func__, rc); |
| goto out; |
| } |
| s->block_aligned_filename_size = (s->parsed_tag_70_packet_size |
| - ECRYPTFS_SIG_SIZE - 1); |
| if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size) |
| > max_packet_size) { |
| printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet " |
| "size is [%zd]\n", __func__, max_packet_size, |
| (1 + s->packet_size_len + 1 |
| + s->block_aligned_filename_size)); |
| rc = -EINVAL; |
| goto out; |
| } |
| (*packet_size) += s->packet_size_len; |
| ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)], |
| ECRYPTFS_SIG_SIZE); |
| s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
| (*packet_size) += ECRYPTFS_SIG_SIZE; |
| s->cipher_code = data[(*packet_size)++]; |
| rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code); |
| if (rc) { |
| printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n", |
| __func__, s->cipher_code); |
| goto out; |
| } |
| rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm, |
| &s->tfm_mutex, |
| s->cipher_string); |
| if (unlikely(rc)) { |
| printk(KERN_ERR "Internal error whilst attempting to get " |
| "tfm and mutex for cipher name [%s]; rc = [%d]\n", |
| s->cipher_string, rc); |
| goto out; |
| } |
| mutex_lock(s->tfm_mutex); |
| rc = virt_to_scatterlist(&data[(*packet_size)], |
| s->block_aligned_filename_size, &s->src_sg, 1); |
| if (rc != 1) { |
| printk(KERN_ERR "%s: Internal error whilst attempting to " |
| "convert encrypted filename memory to scatterlist; " |
| "expected rc = 1; got rc = [%d]. " |
| "block_aligned_filename_size = [%zd]\n", __func__, rc, |
| s->block_aligned_filename_size); |
| goto out_unlock; |
| } |
| (*packet_size) += s->block_aligned_filename_size; |
| s->decrypted_filename = kmalloc(s->block_aligned_filename_size, |
| GFP_KERNEL); |
| if (!s->decrypted_filename) { |
| printk(KERN_ERR "%s: Out of memory whilst attempting to " |
| "kmalloc [%zd] bytes\n", __func__, |
| s->block_aligned_filename_size); |
| rc = -ENOMEM; |
| goto out_unlock; |
| } |
| rc = virt_to_scatterlist(s->decrypted_filename, |
| s->block_aligned_filename_size, &s->dst_sg, 1); |
| if (rc != 1) { |
| printk(KERN_ERR "%s: Internal error whilst attempting to " |
| "convert decrypted filename memory to scatterlist; " |
| "expected rc = 1; got rc = [%d]. " |
| "block_aligned_filename_size = [%zd]\n", __func__, rc, |
| s->block_aligned_filename_size); |
| goto out_free_unlock; |
| } |
| /* The characters in the first block effectively do the job of |
| * the IV here, so we just use 0's for the IV. Note the |
| * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES |
| * >= ECRYPTFS_MAX_IV_BYTES. */ |
| memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES); |
| s->desc.info = s->iv; |
| rc = ecryptfs_find_auth_tok_for_sig(&s->auth_tok, mount_crypt_stat, |
| s->fnek_sig_hex); |
| if (rc) { |
| printk(KERN_ERR "%s: Error attempting to find auth tok for " |
| "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex, |
| rc); |
| goto out_free_unlock; |
| } |
| /* TODO: Support other key modules than passphrase for |
| * filename encryption */ |
| BUG_ON(s->auth_tok->token_type != ECRYPTFS_PASSWORD); |
| rc = crypto_blkcipher_setkey( |
| s->desc.tfm, |
| s->auth_tok->token.password.session_key_encryption_key, |
| mount_crypt_stat->global_default_fn_cipher_key_bytes); |
| if (rc < 0) { |
| printk(KERN_ERR "%s: Error setting key for crypto context; " |
| "rc = [%d]. s->auth_tok->token.password.session_key_" |
| "encryption_key = [0x%p]; mount_crypt_stat->" |
| "global_default_fn_cipher_key_bytes = [%zd]\n", __func__, |
| rc, |
| s->auth_tok->token.password.session_key_encryption_key, |
| mount_crypt_stat->global_default_fn_cipher_key_bytes); |
| goto out_free_unlock; |
| } |
| rc = crypto_blkcipher_decrypt_iv(&s->desc, &s->dst_sg, &s->src_sg, |
| s->block_aligned_filename_size); |
| if (rc) { |
| printk(KERN_ERR "%s: Error attempting to decrypt filename; " |
| "rc = [%d]\n", __func__, rc); |
| goto out_free_unlock; |
| } |
| s->i = 0; |
| while (s->decrypted_filename[s->i] != '\0' |
| && s->i < s->block_aligned_filename_size) |
| s->i++; |
| if (s->i == s->block_aligned_filename_size) { |
| printk(KERN_WARNING "%s: Invalid tag 70 packet; could not " |
| "find valid separator between random characters and " |
| "the filename\n", __func__); |
| rc = -EINVAL; |
| goto out_free_unlock; |
| } |
| s->i++; |
| (*filename_size) = (s->block_aligned_filename_size - s->i); |
| if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) { |
| printk(KERN_WARNING "%s: Filename size is [%zd], which is " |
| "invalid\n", __func__, (*filename_size)); |
| rc = -EINVAL; |
| goto out_free_unlock; |
| } |
| (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL); |
| if (!(*filename)) { |
| printk(KERN_ERR "%s: Out of memory whilst attempting to " |
| "kmalloc [%zd] bytes\n", __func__, |
| ((*filename_size) + 1)); |
| rc = -ENOMEM; |
| goto out_free_unlock; |
| } |
| memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size)); |
| (*filename)[(*filename_size)] = '\0'; |
| out_free_unlock: |
| kfree(s->decrypted_filename); |
| out_unlock: |
| mutex_unlock(s->tfm_mutex); |
| out: |
| if (rc) { |
| (*packet_size) = 0; |
| (*filename_size) = 0; |
| (*filename) = NULL; |
| } |
| kfree(s); |
| return rc; |
| } |
| |
| static int |
| ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok) |
| { |
| int rc = 0; |
| |
| (*sig) = NULL; |
| switch (auth_tok->token_type) { |
| case ECRYPTFS_PASSWORD: |
| (*sig) = auth_tok->token.password.signature; |
| break; |
| case ECRYPTFS_PRIVATE_KEY: |
| (*sig) = auth_tok->token.private_key.signature; |
| break; |
| default: |
| printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n", |
| auth_tok->token_type); |
| rc = -EINVAL; |
| } |
| return rc; |
| } |
| |
| /** |
| * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok. |
| * @auth_tok: The key authentication token used to decrypt the session key |
| * @crypt_stat: The cryptographic context |
| * |
| * Returns zero on success; non-zero error otherwise. |
| */ |
| static int |
| decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, |
| struct ecryptfs_crypt_stat *crypt_stat) |
| { |
| u8 cipher_code = 0; |
| struct ecryptfs_msg_ctx *msg_ctx; |
| struct ecryptfs_message *msg = NULL; |
| char *auth_tok_sig; |
| char *payload; |
| size_t payload_len; |
| int rc; |
| |
| rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok); |
| if (rc) { |
| printk(KERN_ERR "Unrecognized auth tok type: [%d]\n", |
| auth_tok->token_type); |
| goto out; |
| } |
| rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key), |
| &payload, &payload_len); |
| if (rc) { |
| ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n"); |
| goto out; |
| } |
| rc = ecryptfs_send_message(payload, payload_len, &msg_ctx); |
| if (rc) { |
| ecryptfs_printk(KERN_ERR, "Error sending message to " |
| "ecryptfsd\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 ecryptfs_auth_tok_list_item *auth_tok_list_item; |
| struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
| |
| list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp, |
| auth_tok_list_head, list) { |
| list_del(&auth_tok_list_item->list); |
| kmem_cache_free(ecryptfs_auth_tok_list_item_cache, |
| auth_tok_list_item); |
| } |
| } |
| |
| 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. |
| * @max_packet_size: The maximum allowable packet size |
| * |
| * 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; |
| /** |
| * This format is inspired by OpenPGP; see RFC 2440 |
| * packet tag 1 |
| * |
| * Tag 1 identifier (1 byte) |
| * Max Tag 1 packet size (max 3 bytes) |
| * Version (1 byte) |
| * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE) |
| * Cipher identifier (1 byte) |
| * Encrypted key size (arbitrary) |
| * |
| * 12 bytes minimum packet size |
| */ |
| if (unlikely(max_packet_size < 12)) { |
| printk(KERN_ERR "Invalid max packet size; must be >=12\n"); |
| rc = -EINVAL; |
| goto out; |
| } |
| if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) { |
| 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_zalloc(ecryptfs_auth_tok_list_item_cache, |
| GFP_KERNEL); |
| if (!auth_tok_list_item) { |
| printk(KERN_ERR "Unable to allocate memory\n"); |
| rc = -ENOMEM; |
| goto out; |
| } |
| (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
| rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
| &length_size); |
| if (rc) { |
| printk(KERN_WARNING "Error parsing packet length; " |
| "rc = [%d]\n", rc); |
| goto out_free; |
| } |
| if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) { |
| printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
| rc = -EINVAL; |
| goto out_free; |
| } |
| (*packet_size) += length_size; |
| if (unlikely((*packet_size) + body_size > max_packet_size)) { |
| printk(KERN_WARNING "Packet size exceeds max\n"); |
| rc = -EINVAL; |
| goto out_free; |
| } |
| if (unlikely(data[(*packet_size)++] != 0x03)) { |
| printk(KERN_WARNING "Unknown version number [%d]\n", |
| data[(*packet_size) - 1]); |
| rc = -EINVAL; |
| goto out_free; |
| } |
| 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 - (ECRYPTFS_SIG_SIZE + 2); |
| if ((*new_auth_tok)->session_key.encrypted_key_size |
| > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { |
| printk(KERN_WARNING "Tag 1 packet contains key larger " |
| "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES"); |
| rc = -EINVAL; |
| goto out; |
| } |
| memcpy((*new_auth_tok)->session_key.encrypted_key, |
| &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2))); |
| (*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 = 0; |
| (*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 |
| * 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. |
| * @max_packet_size: maximum number of bytes to parse |
| * |
| * Returns zero on success; non-zero on error. |
| */ |
| static int |
| parse_tag_3_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; |
| /** |
| *This format is inspired by OpenPGP; see RFC 2440 |
| * packet tag 3 |
| * |
| * Tag 3 identifier (1 byte) |
| * Max Tag 3 packet size (max 3 bytes) |
| * Version (1 byte) |
| * Cipher code (1 byte) |
| * S2K specifier (1 byte) |
| * Hash identifier (1 byte) |
| * Salt (ECRYPTFS_SALT_SIZE) |
| * Hash iterations (1 byte) |
| * Encrypted key (arbitrary) |
| * |
| * (ECRYPTFS_SALT_SIZE + 7) minimum packet size |
| */ |
| if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) { |
| printk(KERN_ERR "Max packet size too large\n"); |
| rc = -EINVAL; |
| goto out; |
| } |
| if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) { |
| printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n", |
| ECRYPTFS_TAG_3_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_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL); |
| if (!auth_tok_list_item) { |
| printk(KERN_ERR "Unable to allocate memory\n"); |
| rc = -ENOMEM; |
| goto out; |
| } |
| (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
| rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
| &length_size); |
| if (rc) { |
| printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n", |
| rc); |
| goto out_free; |
| } |
| if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) { |
| printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
| rc = -EINVAL; |
| goto out_free; |
| } |
| (*packet_size) += length_size; |
| if (unlikely((*packet_size) + body_size > max_packet_size)) { |
| printk(KERN_ERR "Packet size exceeds max\n"); |
| rc = -EINVAL; |
| goto out_free; |
| } |
| (*new_auth_tok)->session_key.encrypted_key_size = |
| (body_size - (ECRYPTFS_SALT_SIZE + 5)); |
| if (unlikely(data[(*packet_size)++] != 0x04)) { |
| printk(KERN_WARNING "Unknown version number [%d]\n", |
| data[(*packet_size) - 1]); |
| rc = -EINVAL; |
| goto out_free; |
| } |
| ecryptfs_cipher_code_to_string(crypt_stat->cipher, |
| (u16)data[(*packet_size)]); |
| /* A little extra work to differentiate among the AES key |
| * sizes; see RFC2440 */ |
| switch(data[(*packet_size)++]) { |
| case RFC2440_CIPHER_AES_192: |
| crypt_stat->key_size = 24; |
| break; |
| default: |
| crypt_stat->key_size = |
| (*new_auth_tok)->session_key.encrypted_key_size; |
| } |
| ecryptfs_init_crypt_ctx(crypt_stat); |
| if (unlikely(data[(*packet_size)++] != 0x03)) { |
| printk(KERN_WARNING "Only S2K ID 3 is currently supported\n"); |
| rc = -ENOSYS; |
| goto out_free; |
| } |
| /* TODO: finish the hash mapping */ |
| switch (data[(*packet_size)++]) { |
| case 0x01: /* See RFC2440 for these numbers and their mappings */ |
| /* Choose MD5 */ |
| memcpy((*new_auth_tok)->token.password.salt, |
| &data[(*packet_size)], ECRYPTFS_SALT_SIZE); |
| (*packet_size) += ECRYPTFS_SALT_SIZE; |
| /* This conversion was taken straight from RFC2440 */ |
| (*new_auth_tok)->token.password.hash_iterations = |
| ((u32) 16 + (data[(*packet_size)] & 15)) |
| << ((data[(*packet_size)] >> 4) + 6); |
| (*packet_size)++; |
| /* Friendly reminder: |
| * (*new_auth_tok)->session_key.encrypted_key_size = |
| * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */ |
| memcpy((*new_auth_tok)->session_key.encrypted_key, |
| &data[(*packet_size)], |
| (*new_auth_tok)->session_key.encrypted_key_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.password.hash_algo = 0x01; /* MD5 */ |
| break; |
| default: |
| ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: " |
| "[%d]\n", data[(*packet_size) - 1]); |
| rc = -ENOSYS; |
| goto out_free; |
| } |
| (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD; |
| /* TODO: Parametarize; we might actually want 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_11_packet |
| * @data: The raw bytes of the packet |
| * @contents: This function writes the data contents of the literal |
| * packet into this memory location |
| * @max_contents_bytes: The maximum number of bytes that this function |
| * is allowed to write into contents |
| * @tag_11_contents_size: This function writes the size of the parsed |
| * contents into this memory location; zero on |
| * error |
| * @packet_size: This function writes the size of the parsed packet |
| * into this memory location; zero on error |
| * @max_packet_size: maximum number of bytes to parse |
| * |
| * Returns zero on success; non-zero on error. |
| */ |
| static int |
| 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) |
| { |
| size_t body_size; |
| size_t length_size; |
| int rc = 0; |
| |
| (*packet_size) = 0; |
| (*tag_11_contents_size) = 0; |
| /* This format is inspired by OpenPGP; see RFC 2440 |
| * packet tag 11 |
| * |
| * Tag 11 identifier (1 byte) |
| * Max Tag 11 packet size (max 3 bytes) |
| * Binary format specifier (1 byte) |
| * Filename length (1 byte) |
| * Filename ("_CONSOLE") (8 bytes) |
| * Modification date (4 bytes) |
| * Literal data (arbitrary) |
| * |
| * We need at least 16 bytes of data for the packet to even be |
| * valid. |
| */ |
| if (max_packet_size < 16) { |
| printk(KERN_ERR "Maximum packet size too small\n"); |
| rc = -EINVAL; |
| goto out; |
| } |
| if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) { |
| printk(KERN_WARNING "Invalid tag 11 packet format\n"); |
| rc = -EINVAL; |
| goto out; |
| } |
| rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
| &length_size); |
| if (rc) { |
| printk(KERN_WARNING "Invalid tag 11 packet format\n"); |
| goto out; |
| } |
| if (body_size < 14) { |
| printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
| rc = -EINVAL; |
| goto out; |
| } |
| (*packet_size) += length_size; |
| (*tag_11_contents_size) = (body_size - 14); |
| if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) { |
| printk(KERN_ERR "Packet size exceeds max\n"); |
| rc = -EINVAL; |
| goto out; |
| } |
| if (data[(*packet_size)++] != 0x62) { |
| printk(KERN_WARNING "Unrecognizable packet\n"); |
| rc = -EINVAL; |
| goto out; |
| } |
| if (data[(*packet_size)++] != 0x08) { |
| printk(KERN_WARNING "Unrecognizable packet\n"); |
| rc = -EINVAL; |
| goto out; |
| } |
| (*packet_size) += 12; /* Ignore filename and modification date */ |
| memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size)); |
| (*packet_size) += (*tag_11_contents_size); |
| out: |
| if (rc) { |
| (*packet_size) = 0; |
| (*tag_11_contents_size) = 0; |
| } |
| return rc; |
| } |
| |
| /** |
| * ecryptfs_verify_version |
| * @version: The version number to confirm |
| * |
| * Returns zero on good version; non-zero otherwise |
| */ |
| static int ecryptfs_verify_version(u16 version) |
| { |
| int rc = 0; |
| unsigned char major; |
| unsigned char minor; |
| |
| major = ((version >> 8) & 0xFF); |
| minor = (version & 0xFF); |
| if (major != ECRYPTFS_VERSION_MAJOR) { |
| ecryptfs_printk(KERN_ERR, "Major version number mismatch. " |
| "Expected [%d]; got [%d]\n", |
| ECRYPTFS_VERSION_MAJOR, major); |
| rc = -EINVAL; |
| goto out; |
| } |
| if (minor != ECRYPTFS_VERSION_MINOR) { |
| ecryptfs_printk(KERN_ERR, "Minor version number mismatch. " |
| "Expected [%d]; got [%d]\n", |
| ECRYPTFS_VERSION_MINOR, minor); |
| rc = -EINVAL; |
| goto out; |
| } |
| out: |
| return rc; |
| } |
| |
| int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key, |
| struct ecryptfs_auth_tok **auth_tok, |
| char *sig) |
| { |
| int rc = 0; |
| |
| (*auth_tok_key) = request_key(&key_type_user, sig, NULL); |
| if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) { |
| printk(KERN_ERR "Could not find key with description: [%s]\n", |
| sig); |
| rc = process_request_key_err(PTR_ERR(*auth_tok_key)); |
| goto out; |
| } |
| (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key); |
| if (ecryptfs_verify_version((*auth_tok)->version)) { |
| printk(KERN_ERR |
| "Data structure version mismatch. " |
| "Userspace tools must match eCryptfs " |
| "kernel module with major version [%d] " |
| "and minor version [%d]\n", |
| ECRYPTFS_VERSION_MAJOR, |
| ECRYPTFS_VERSION_MINOR); |
| rc = -EINVAL; |
| goto out; |
| } |
| if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD |
| && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) { |
| printk(KERN_ERR "Invalid auth_tok structure " |
| "returned from key query\n"); |
| rc = -EINVAL; |
| goto out; |
| } |
| out: |
| return rc; |
| } |
| |
| /** |
| * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok. |
| * @auth_tok: The passphrase authentication token to use to encrypt the FEK |
| * @crypt_stat: The cryptographic context |
| * |
| * Returns zero on success; non-zero error otherwise |
| */ |
| static int |
| decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, |
| struct ecryptfs_crypt_stat *crypt_stat) |
| { |
| struct scatterlist dst_sg[2]; |
| struct scatterlist src_sg[2]; |
| struct mutex *tfm_mutex; |
| struct blkcipher_desc desc = { |
| .flags = CRYPTO_TFM_REQ_MAY_SLEEP |
| }; |
| int rc = 0; |
| |
| if (unlikely(ecryptfs_verbosity > 0)) { |
| ecryptfs_printk( |
| KERN_DEBUG, "Session key encryption key (size [%d]):\n", |
| auth_tok->token.password.session_key_encryption_key_bytes); |
| ecryptfs_dump_hex( |
| auth_tok->token.password.session_key_encryption_key, |
| auth_tok->token.password.session_key_encryption_key_bytes); |
| } |
| rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex, |
| crypt_stat->cipher); |
| if (unlikely(rc)) { |
| printk(KERN_ERR "Internal error whilst attempting to get " |
| "tfm and mutex for cipher name [%s]; rc = [%d]\n", |
| crypt_stat->cipher, rc); |
| goto out; |
| } |
| rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key, |
| auth_tok->session_key.encrypted_key_size, |
| src_sg, 2); |
| if (rc < 1 || rc > 2) { |
| printk(KERN_ERR "Internal error whilst attempting to convert " |
| "auth_tok->session_key.encrypted_key to scatterlist; " |
| "expected rc = 1; got rc = [%d]. " |
| "auth_tok->session_key.encrypted_key_size = [%d]\n", rc, |
| auth_tok->session_key.encrypted_key_size); |
| goto out; |
| } |
| auth_tok->session_key.decrypted_key_size = |
| auth_tok->session_key.encrypted_key_size; |
| rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key, |
| auth_tok->session_key.decrypted_key_size, |
| dst_sg, 2); |
| if (rc < 1 || rc > 2) { |
| printk(KERN_ERR "Internal error whilst attempting to convert " |
| "auth_tok->session_key.decrypted_key to scatterlist; " |
| "expected rc = 1; got rc = [%d]\n", rc); |
| goto out; |
| } |
| mutex_lock(tfm_mutex); |
| rc = crypto_blkcipher_setkey( |
| desc.tfm, auth_tok->token.password.session_key_encryption_key, |
| crypt_stat->key_size); |
| if (unlikely(rc < 0)) { |
| mutex_unlock(tfm_mutex); |
| printk(KERN_ERR "Error setting key for crypto context\n"); |
| rc = -EINVAL; |
| goto out; |
| } |
| rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg, |
| auth_tok->session_key.encrypted_key_size); |
| mutex_unlock(tfm_mutex); |
| if (unlikely(rc)) { |
| printk(KERN_ERR "Error decrypting; 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->flags |= ECRYPTFS_KEY_VALID; |
| if (unlikely(ecryptfs_verbosity > 0)) { |
| ecryptfs_printk(KERN_DEBUG, "FEK of size [%d]:\n", |
| crypt_stat->key_size); |
| ecryptfs_dump_hex(crypt_stat->key, |
| crypt_stat->key_size); |
| } |
| out: |
| return rc; |
| } |
| |
| /** |
| * ecryptfs_parse_packet_set |
| * @crypt_stat: The cryptographic context |
| * @src: Virtual address of region of memory containing the packets |
| * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set |
| * |
| * Get crypt_stat to have the file's session key if the requisite key |
| * is available to decrypt the session key. |
| * |
| * Returns Zero if a valid authentication token was retrieved and |
| * processed; negative value for file not encrypted or for error |
| * conditions. |
| */ |
| int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat, |
| unsigned char *src, |
| struct dentry *ecryptfs_dentry) |
| { |
| size_t i = 0; |
| size_t found_auth_tok; |
| size_t next_packet_is_auth_tok_packet; |
| struct list_head auth_tok_list; |
| struct ecryptfs_auth_tok *matching_auth_tok; |
| struct ecryptfs_auth_tok *candidate_auth_tok; |
| char *candidate_auth_tok_sig; |
| size_t packet_size; |
| struct ecryptfs_auth_tok *new_auth_tok; |
| unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE]; |
| struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
| 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 |
| * added the our &auth_tok_list */ |
| next_packet_is_auth_tok_packet = 1; |
| while (next_packet_is_auth_tok_packet) { |
| size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i); |
| |
| switch (src[i]) { |
| case ECRYPTFS_TAG_3_PACKET_TYPE: |
| rc = parse_tag_3_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 3 packet\n"); |
| rc = -EIO; |
| goto out_wipe_list; |
| } |
| i += packet_size; |
| rc = parse_tag_11_packet((unsigned char *)&src[i], |
| sig_tmp_space, |
| ECRYPTFS_SIG_SIZE, |
| &tag_11_contents_size, |
| &tag_11_packet_size, |
| max_packet_size); |
| if (rc) { |
| ecryptfs_printk(KERN_ERR, "No valid " |
| "(ecryptfs-specific) literal " |
| "packet containing " |
| "authentication token " |
| "signature found after " |
| "tag 3 packet\n"); |
| rc = -EIO; |
| goto out_wipe_list; |
| } |
| i += tag_11_packet_size; |
| if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) { |
| ecryptfs_printk(KERN_ERR, "Expected " |
| "signature of size [%d]; " |
| "read size [%d]\n", |
| ECRYPTFS_SIG_SIZE, |
| tag_11_contents_size); |
| rc = -EIO; |
| goto out_wipe_list; |
| } |
| ecryptfs_to_hex(new_auth_tok->token.password.signature, |
| sig_tmp_space, tag_11_contents_size); |
| new_auth_tok->token.password.signature[ |
| ECRYPTFS_PASSWORD_SIG_SIZE] = '\0'; |
| 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 " |
| "(Tag 11 not allowed by itself)\n"); |
| rc = -EIO; |
| goto out_wipe_list; |
| break; |
| default: |
| ecryptfs_printk(KERN_DEBUG, "No packet at offset " |
| "[%d] of the file header; hex value of " |
| "character is [0x%.2x]\n", i, src[i]); |
| next_packet_is_auth_tok_packet = 0; |
| } |
| } |
| if (list_empty(&auth_tok_list)) { |
| printk(KERN_ERR "The lower file appears to be a non-encrypted " |
| "eCryptfs file; this is not supported in this version " |
| "of the eCryptfs kernel module\n"); |
| rc = -EINVAL; |
| goto out; |
| } |
| /* auth_tok_list contains the set of authentication tokens |
| * parsed from the metadata. We need to find a matching |
| * authentication token that has the secret component(s) |
| * necessary to decrypt the EFEK in the auth_tok parsed from |
| * the metadata. There may be several potential matches, but |
| * just one will be sufficient to decrypt to get the FEK. */ |
| find_next_matching_auth_tok: |
| found_auth_tok = 0; |
| list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) { |
| candidate_auth_tok = &auth_tok_list_item->auth_tok; |
| if (unlikely(ecryptfs_verbosity > 0)) { |
| ecryptfs_printk(KERN_DEBUG, |
| "Considering cadidate auth tok:\n"); |
| ecryptfs_dump_auth_tok(candidate_auth_tok); |
| } |
| rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig, |
| candidate_auth_tok); |
| if (rc) { |
| printk(KERN_ERR |
| "Unrecognized candidate auth tok type: [%d]\n", |
| candidate_auth_tok->token_type); |
| rc = -EINVAL; |
| goto out_wipe_list; |
| } |
| ecryptfs_find_auth_tok_for_sig(&matching_auth_tok, |
| crypt_stat->mount_crypt_stat, |
| candidate_auth_tok_sig); |
| if (matching_auth_tok) { |
| found_auth_tok = 1; |
| goto found_matching_auth_tok; |
| } |
| } |
| if (!found_auth_tok) { |
| ecryptfs_printk(KERN_ERR, "Could not find a usable " |
| "authentication token\n"); |
| rc = -EIO; |
| goto out_wipe_list; |
| } |
| found_matching_auth_tok: |
| if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
| memcpy(&(candidate_auth_tok->token.private_key), |
| &(matching_auth_tok->token.private_key), |
| sizeof(struct ecryptfs_private_key)); |
| rc = decrypt_pki_encrypted_session_key(candidate_auth_tok, |
| crypt_stat); |
| } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) { |
| memcpy(&(candidate_auth_tok->token.password), |
| &(matching_auth_tok->token.password), |
| sizeof(struct ecryptfs_password)); |
| rc = decrypt_passphrase_encrypted_session_key( |
| candidate_auth_tok, crypt_stat); |
| } |
| if (rc) { |
| struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
| |
| ecryptfs_printk(KERN_WARNING, "Error decrypting the " |
| "session key for authentication token with sig " |
| "[%.*s]; rc = [%d]. Removing auth tok " |
| "candidate from the list and searching for " |
| "the next match.\n", candidate_auth_tok_sig, |
| ECRYPTFS_SIG_SIZE_HEX, rc); |
| list_for_each_entry_safe(auth_tok_list_item, |
| auth_tok_list_item_tmp, |
| &auth_tok_list, list) { |
| if (candidate_auth_tok |
| == &auth_tok_list_item->auth_tok) { |
| list_del(&auth_tok_list_item->list); |
| kmem_cache_free( |
| ecryptfs_auth_tok_list_item_cache, |
| auth_tok_list_item); |
| goto find_next_matching_auth_tok; |
| } |
| } |
| BUG(); |
| } |
| 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) { |
| ecryptfs_printk(KERN_ERR, "Error initializing crypto " |
| "context for cipher [%s]; rc = [%d]\n", |
| crypt_stat->cipher, rc); |
| } |
| out_wipe_list: |
| wipe_auth_tok_list(&auth_tok_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 *payload = NULL; |
| size_t payload_len; |
| struct ecryptfs_message *msg; |
| int rc; |
| |
| rc = write_tag_66_packet(auth_tok->token.private_key.signature, |
| ecryptfs_code_for_cipher_string( |
| crypt_stat->cipher, |
| crypt_stat->key_size), |
| crypt_stat, &payload, &payload_len); |
| if (rc) { |
| ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n"); |
| goto out; |
| } |
| rc = ecryptfs_send_message(payload, payload_len, &msg_ctx); |
| if (rc) { |
| ecryptfs_printk(KERN_ERR, "Error sending message to " |
| "ecryptfsd\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: |
| kfree(payload); |
| return rc; |
| } |
| /** |
| * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet |
| * @dest: Buffer into which to write the packet |
| * @remaining_bytes: Maximum number of bytes that can be writtn |
| * @auth_tok: The authentication token used for generating the tag 1 packet |
| * @crypt_stat: The cryptographic context |
| * @key_rec: The key record struct for the tag 1 packet |
| * @packet_size: This function will write the number of bytes that end |
| * up constituting the packet; set to zero on error |
| * |
| * Returns zero on success; non-zero on error. |
| */ |
| static int |
| write_tag_1_packet(char *dest, size_t *remaining_bytes, |
| struct ecryptfs_auth_tok *auth_tok, |
| struct ecryptfs_crypt_stat *crypt_stat, |
| struct ecryptfs_key_record *key_rec, size_t *packet_size) |
| { |
| size_t i; |
| size_t encrypted_session_key_valid = 0; |
| size_t packet_size_length; |
| size_t max_packet_size; |
| 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) { |
| printk(KERN_ERR "Failed to encrypt session key via a key " |
| "module; rc = [%d]\n", rc); |
| 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: |
| /* This format is inspired by OpenPGP; see RFC 2440 |
| * packet tag 1 */ |
| max_packet_size = (1 /* Tag 1 identifier */ |
| + 3 /* Max Tag 1 packet size */ |
| + 1 /* Version */ |
| + ECRYPTFS_SIG_SIZE /* Key identifier */ |
| + 1 /* Cipher identifier */ |
| + key_rec->enc_key_size); /* Encrypted key size */ |
| if (max_packet_size > (*remaining_bytes)) { |
| printk(KERN_ERR "Packet length larger than maximum allowable; " |
| "need up to [%td] bytes, but there are only [%td] " |
| "available\n", max_packet_size, (*remaining_bytes)); |
| rc = -EINVAL; |
| goto out; |
| } |
| dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE; |
| rc = ecryptfs_write_packet_length(&dest[(*packet_size)], |
| (max_packet_size - 4), |
| &packet_size_length); |
| if (rc) { |
| ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet " |
| "header; cannot generate packet length\n"); |
| 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; |
| else |
| (*remaining_bytes) -= (*packet_size); |
| return rc; |
| } |
| |
| /** |
| * write_tag_11_packet |
| * @dest: Target into which Tag 11 packet is to be written |
| * @remaining_bytes: Maximum packet length |
| * @contents: Byte array of contents to copy in |
| * @contents_length: Number of bytes in contents |
| * @packet_length: Length of the Tag 11 packet written; zero on error |
| * |
| * Returns zero on success; non-zero on error. |
| */ |
| static int |
| write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents, |
| size_t contents_length, size_t *packet_length) |
| { |
| size_t packet_size_length; |
| size_t max_packet_size; |
| int rc = 0; |
| |
| (*packet_length) = 0; |
| /* This format is inspired by OpenPGP; see RFC 2440 |
| * packet tag 11 */ |
| max_packet_size = (1 /* Tag 11 identifier */ |
| + 3 /* Max Tag 11 packet size */ |
| + 1 /* Binary format specifier */ |
| + 1 /* Filename length */ |
| + 8 /* Filename ("_CONSOLE") */ |
| + 4 /* Modification date */ |
| + contents_length); /* Literal data */ |
| if (max_packet_size > (*remaining_bytes)) { |
| printk(KERN_ERR "Packet length larger than maximum allowable; " |
| "need up to [%td] bytes, but there are only [%td] " |
| "available\n", max_packet_size, (*remaining_bytes)); |
| rc = -EINVAL; |
| goto out; |
| } |
| dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE; |
| rc = ecryptfs_write_packet_length(&dest[(*packet_length)], |
| (max_packet_size - 4), |
| &packet_size_length); |
| if (rc) { |
| printk(KERN_ERR "Error generating tag 11 packet header; cannot " |
| "generate packet length. rc = [%d]\n", rc); |
| goto out; |
| } |
| (*packet_length) += packet_size_length; |
| dest[(*packet_length)++] = 0x62; /* binary data format specifier */ |
| dest[(*packet_length)++] = 8; |
| memcpy(&dest[(*packet_length)], "_CONSOLE", 8); |
| (*packet_length) += 8; |
| memset(&dest[(*packet_length)], 0x00, 4); |
| (*packet_length) += 4; |
| memcpy(&dest[(*packet_length)], contents, contents_length); |
| (*packet_length) += contents_length; |
| out: |
| if (rc) |
| (*packet_length) = 0; |
| else |
| (*remaining_bytes) -= (*packet_length); |
| return rc; |
| } |
| |
| /** |
| * write_tag_3_packet |
| * @dest: Buffer into which to write the packet |
| * @remaining_bytes: Maximum number of bytes that can be written |
| * @auth_tok: Authentication token |
| * @crypt_stat: The cryptographic context |
| * @key_rec: encrypted key |
| * @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_3_packet(char *dest, size_t *remaining_bytes, |
| struct ecryptfs_auth_tok *auth_tok, |
| struct ecryptfs_crypt_stat *crypt_stat, |
| struct ecryptfs_key_record *key_rec, size_t *packet_size) |
| { |
| size_t i; |
| size_t encrypted_session_key_valid = 0; |
| char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES]; |
| struct scatterlist dst_sg[2]; |
| struct scatterlist src_sg[2]; |
| struct mutex *tfm_mutex = NULL; |
| u8 cipher_code; |
| size_t packet_size_length; |
| size_t max_packet_size; |
| struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
| crypt_stat->mount_crypt_stat; |
| struct blkcipher_desc desc = { |
| .tfm = NULL, |
| .flags = CRYPTO_TFM_REQ_MAY_SLEEP |
| }; |
| int rc = 0; |
| |
| (*packet_size) = 0; |
| ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature, |
| ECRYPTFS_SIG_SIZE); |
| rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex, |
| crypt_stat->cipher); |
| if (unlikely(rc)) { |
| printk(KERN_ERR "Internal error whilst attempting to get " |
| "tfm and mutex for cipher name [%s]; rc = [%d]\n", |
| crypt_stat->cipher, rc); |
| goto out; |
| } |
| if (mount_crypt_stat->global_default_cipher_key_size == 0) { |
| struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm); |
| |
| printk(KERN_WARNING "No key size specified at mount; " |
| "defaulting to [%d]\n", alg->max_keysize); |
| mount_crypt_stat->global_default_cipher_key_size = |
| alg->max_keysize; |
| } |
| if (crypt_stat->key_size == 0) |
| crypt_stat->key_size = |
| mount_crypt_stat->global_default_cipher_key_size; |
| if (auth_tok->session_key.encrypted_key_size == 0) |
| auth_tok->session_key.encrypted_key_size = |
| crypt_stat->key_size; |
| if (crypt_stat->key_size == 24 |
| && strcmp("aes", crypt_stat->cipher) == 0) { |
| memset((crypt_stat->key + 24), 0, 8); |
| auth_tok->session_key.encrypted_key_size = 32; |
| } else |
| auth_tok->session_key.encrypted_key_size = crypt_stat->key_size; |
| key_rec->enc_key_size = |
| auth_tok->session_key.encrypted_key_size; |
| encrypted_session_key_valid = 0; |
| for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++) |
| encrypted_session_key_valid |= |
| auth_tok->session_key.encrypted_key[i]; |
| if (encrypted_session_key_valid) { |
| ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; " |
| "using auth_tok->session_key.encrypted_key, " |
| "where key_rec->enc_key_size = [%d]\n", |
| key_rec->enc_key_size); |
| memcpy(key_rec->enc_key, |
| auth_tok->session_key.encrypted_key, |
| key_rec->enc_key_size); |
| goto encrypted_session_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. |
| session_key_encryption_key_bytes); |
| memcpy(session_key_encryption_key, |
| auth_tok->token.password.session_key_encryption_key, |
| crypt_stat->key_size); |
| ecryptfs_printk(KERN_DEBUG, |
| "Cached session key " "encryption key: \n"); |
| if (ecryptfs_verbosity > 0) |
| ecryptfs_dump_hex(session_key_encryption_key, 16); |
| } |
| if (unlikely(ecryptfs_verbosity > 0)) { |
| ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n"); |
| ecryptfs_dump_hex(session_key_encryption_key, 16); |
| } |
| rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size, |
| src_sg, 2); |
| if (rc < 1 || rc > 2) { |
| ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
| "for crypt_stat session key; expected rc = 1; " |
| "got rc = [%d]. key_rec->enc_key_size = [%d]\n", |
| rc, key_rec->enc_key_size); |
| rc = -ENOMEM; |
| goto out; |
| } |
| rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size, |
| dst_sg, 2); |
| if (rc < 1 || rc > 2) { |
| ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
| "for crypt_stat encrypted session key; " |
| "expected rc = 1; got rc = [%d]. " |
| "key_rec->enc_key_size = [%d]\n", rc, |
| key_rec->enc_key_size); |
| rc = -ENOMEM; |
| goto out; |
| } |
| mutex_lock(tfm_mutex); |
| rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key, |
| crypt_stat->key_size); |
| if (rc < 0) { |
| mutex_unlock(tfm_mutex); |
| ecryptfs_printk(KERN_ERR, "Error setting key for crypto " |
| "context; rc = [%d]\n", rc); |
| goto out; |
| } |
| rc = 0; |
| ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n", |
| crypt_stat->key_size); |
| rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg, |
| (*key_rec).enc_key_size); |
| mutex_unlock(tfm_mutex); |
| if (rc) { |
| printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc); |
| goto out; |
| } |
| ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n"); |
| if (ecryptfs_verbosity > 0) { |
| ecryptfs_printk(KERN_DEBUG, "EFEK of size [%d]:\n", |
| key_rec->enc_key_size); |
| ecryptfs_dump_hex(key_rec->enc_key, |
| key_rec->enc_key_size); |
| } |
| encrypted_session_key_set: |
| /* This format is inspired by OpenPGP; see RFC 2440 |
| * packet tag 3 */ |
| max_packet_size = (1 /* Tag 3 identifier */ |
| + 3 /* Max Tag 3 packet size */ |
| + 1 /* Version */ |
| + 1 /* Cipher code */ |
| + 1 /* S2K specifier */ |
| + 1 /* Hash identifier */ |
| + ECRYPTFS_SALT_SIZE /* Salt */ |
| + 1 /* Hash iterations */ |
| + key_rec->enc_key_size); /* Encrypted key size */ |
| if (max_packet_size > (*remaining_bytes)) { |
| printk(KERN_ERR "Packet too large; need up to [%td] bytes, but " |
| "there are only [%td] available\n", max_packet_size, |
| (*remaining_bytes)); |
| rc = -EINVAL; |
| goto out; |
| } |
| dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE; |
| /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3) |
| * to get the number of octets in the actual Tag 3 packet */ |
| rc = ecryptfs_write_packet_length(&dest[(*packet_size)], |
| (max_packet_size - 4), |
| &packet_size_length); |
| if (rc) { |
| printk(KERN_ERR "Error generating tag 3 packet header; cannot " |
| "generate packet length. rc = [%d]\n", rc); |
| goto out; |
| } |
| (*packet_size) += packet_size_length; |
| dest[(*packet_size)++] = 0x04; /* version 4 */ |
| /* TODO: Break from RFC2440 so that arbitrary ciphers can be |
| * specified with strings */ |
| cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher, |
| crypt_stat->key_size); |
| if (cipher_code == 0) { |
| ecryptfs_printk(KERN_WARNING, "Unable to generate code for " |
| "cipher [%s]\n", crypt_stat->cipher); |
| rc = -EINVAL; |
| goto out; |
| } |
| dest[(*packet_size)++] = cipher_code; |
| dest[(*packet_size)++] = 0x03; /* S2K */ |
| dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */ |
| memcpy(&dest[(*packet_size)], auth_tok->token.password.salt, |
| 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; |
| out: |
| if (rc) |
| (*packet_size) = 0; |
| else |
| (*remaining_bytes) -= (*packet_size); |
| return rc; |
| } |
| |
| struct kmem_cache *ecryptfs_key_record_cache; |
| |
| /** |
| * ecryptfs_generate_key_packet_set |
| * @dest_base: Virtual address from which to write the key record set |
| * @crypt_stat: The cryptographic context from which the |
| * authentication tokens will be retrieved |
| * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat |
| * for the global parameters |
| * @len: The amount written |
| * @max: The maximum amount of data allowed to be written |
| * |
| * Generates a key packet set and writes it to the virtual address |
| * passed in. |
| * |
| * Returns zero on success; non-zero on error. |
| */ |
| int |
| ecryptfs_generate_key_packet_set(char *dest_base, |
| struct ecryptfs_crypt_stat *crypt_stat, |
| struct dentry *ecryptfs_dentry, size_t *len, |
| size_t max) |
| { |
| struct ecryptfs_auth_tok *auth_tok; |
| struct ecryptfs_global_auth_tok *global_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; |
| struct ecryptfs_key_sig *key_sig; |
| int rc = 0; |
| |
| (*len) = 0; |
| mutex_lock(&crypt_stat->keysig_list_mutex); |
| key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL); |
| if (!key_rec) { |
| rc = -ENOMEM; |
| goto out; |
| } |
| list_for_each_entry(key_sig, &crypt_stat->keysig_list, |
| crypt_stat_list) { |
| memset(key_rec, 0, sizeof(*key_rec)); |
| rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok, |
| mount_crypt_stat, |
| key_sig->keysig); |
| if (rc) { |
| printk(KERN_ERR "Error attempting to get the global " |
| "auth_tok; rc = [%d]\n", rc); |
| goto out_free; |
| } |
| if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) { |
| printk(KERN_WARNING |
| "Skipping invalid auth tok with sig = [%s]\n", |
| global_auth_tok->sig); |
| continue; |
| } |
| auth_tok = global_auth_tok->global_auth_tok; |
| if (auth_tok->token_type == ECRYPTFS_PASSWORD) { |
| rc = write_tag_3_packet((dest_base + (*len)), |
| &max, auth_tok, |
| crypt_stat, key_rec, |
| &written); |
| if (rc) { |
| ecryptfs_printk(KERN_WARNING, "Error " |
| "writing tag 3 packet\n"); |
| goto out_free; |
| } |
| (*len) += written; |
| /* Write auth tok signature packet */ |
| rc = write_tag_11_packet((dest_base + (*len)), &max, |
| key_rec->sig, |
| ECRYPTFS_SIG_SIZE, &written); |
| if (rc) { |
| ecryptfs_printk(KERN_ERR, "Error writing " |
| "auth tok signature packet\n"); |
| goto out_free; |
| } |
| (*len) += written; |
| } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
| rc = write_tag_1_packet(dest_base + (*len), |
| &max, auth_tok, |
| crypt_stat, key_rec, &written); |
| if (rc) { |
| ecryptfs_printk(KERN_WARNING, "Error " |
| "writing tag 1 packet\n"); |
| goto out_free; |
| } |
| (*len) += written; |
| } else { |
| ecryptfs_printk(KERN_WARNING, "Unsupported " |
| "authentication token type\n"); |
| rc = -EINVAL; |
| goto out_free; |
| } |
| } |
| if (likely(max > 0)) { |
| dest_base[(*len)] = 0x00; |
| } else { |
| ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n"); |
| rc = -EIO; |
| } |
| out_free: |
| kmem_cache_free(ecryptfs_key_record_cache, key_rec); |
| out: |
| if (rc) |
| (*len) = 0; |
| mutex_unlock(&crypt_stat->keysig_list_mutex); |
| return rc; |
| } |
| |
| struct kmem_cache *ecryptfs_key_sig_cache; |
| |
| int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig) |
| { |
| struct ecryptfs_key_sig *new_key_sig; |
| int rc = 0; |
| |
| new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL); |
| if (!new_key_sig) { |
| rc = -ENOMEM; |
| printk(KERN_ERR |
| "Error allocating from ecryptfs_key_sig_cache\n"); |
| goto out; |
| } |
| memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX); |
| mutex_lock(&crypt_stat->keysig_list_mutex); |
| list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list); |
| mutex_unlock(&crypt_stat->keysig_list_mutex); |
| out: |
| return rc; |
| } |
| |
| struct kmem_cache *ecryptfs_global_auth_tok_cache; |
| |
| int |
| ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, |
| char *sig) |
| { |
| struct ecryptfs_global_auth_tok *new_auth_tok; |
| int rc = 0; |
| |
| new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache, |
| GFP_KERNEL); |
| if (!new_auth_tok) { |
| rc = -ENOMEM; |
| printk(KERN_ERR "Error allocating from " |
| "ecryptfs_global_auth_tok_cache\n"); |
| goto out; |
| } |
| memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX); |
| new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
| mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); |
| list_add(&new_auth_tok->mount_crypt_stat_list, |
| &mount_crypt_stat->global_auth_tok_list); |
| mount_crypt_stat->num_global_auth_toks++; |
| mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); |
| out: |
| return rc; |
| } |
| |