Commit message: eCryptfs: Check Tag 11 literal data buffer size

Tag 11 packets are stored in the metadata section of an eCryptfs file to
store the key signature(s) used to encrypt the file encryption key.
After extracting the packet length field to determine the key signature
length, a check is not performed to see if the length would exceed the
key signature buffer size that was passed into parse_tag_11_packet().

Thanks to Ramon de Carvalho Valle for finding this bug using fsfuzzer.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: stable@kernel.org (2.6.27 and 30)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CVE: CVE-2009-2406
CWE: CWE-119
Vulnerability description: Stack-based buffer overflow in the parse_tag_11_packet function in fs/ecryptfs/keystore.c in the eCryptfs subsystem in the Linux kernel before 2.6.30.4 allows local users to cause a denial of service (system crash) or possibly gain privileges via vectors involving a crafted eCryptfs file, related to not ensuring that the key signature length in a Tag 11 packet is compatible with the key signature buffer size.

Project: linux-2.6

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 (unlikely((*tag_11_contents_size) > max_contents_bytes)) {
		printk(KERN_ERR "Literal data section in tag 11 packet exceeds "
		       "expected size\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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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:
	kzfree(s->block_aligned_filename);
out_unlock:
	mutex_unlock(s->tfm_mutex);
out:
	kfree(s);
	return rc;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
			     char *sig, u32 global_auth_tok_flags)
{
	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->flags = global_auth_tok_flags;
	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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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;
}

Project: linux-2.6

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);
	}
}

Project: linux-2.6

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;
}