Messages in this thread Patch in this message | | | Date | Wed, 28 Dec 2005 14:40:17 -0400 | From | Anderson Lizardo <> | Subject | [patch 3/5] Add MMC password protection (lock/unlock) support V2 |
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Implement key retention operations. mmc_key_instantiate() is used for unlocking and password assignment (from no-password state). mmc_key_update() is used for password change.
Signed-off-by: Anderson Briglia <anderson.briglia@indt.org.br> Signed-off-by: Anderson Lizardo <anderson.lizardo@indt.org.br> Signed-off-by: Carlos Eduardo Aguiar <carlos.aguiar@indt.org.br>
Index: linux-2.6.15-rc4-omap1/drivers/mmc/Kconfig =================================================================== --- linux-2.6.15-rc4-omap1.orig/drivers/mmc/Kconfig 2005-12-27 17:19:47.000000000 -0400 +++ linux-2.6.15-rc4-omap1/drivers/mmc/Kconfig 2005-12-27 17:20:18.000000000 -0400 @@ -19,6 +19,19 @@ config MMC_DEBUG This is an option for use by developers; most people should say N here. This enables MMC core and driver debugging. +config MMC_PASSWORDS + boolean "MMC card lock/unlock passwords (EXPERIMENTAL)" + depends on MMC && EXPERIMENTAL + select KEYS + help + Say Y here to enable the use of passwords to lock and unlock + MMC cards. This uses the access key retention support, using + request_key to look up the key associated with each card. + + For example, if you have an MMC card that was locked using + Symbian OS on your cell phone, you won't be able to read it + on Linux without this support. + config MMC_BLOCK tristate "MMC block device driver" depends on MMC Index: linux-2.6.15-rc4-omap1/drivers/mmc/mmc.h =================================================================== --- linux-2.6.15-rc4-omap1.orig/drivers/mmc/mmc.h 2005-12-27 17:19:47.000000000 -0400 +++ linux-2.6.15-rc4-omap1/drivers/mmc/mmc.h 2005-12-27 17:20:18.000000000 -0400 @@ -18,4 +18,12 @@ struct mmc_host *mmc_alloc_host_sysfs(in int mmc_add_host_sysfs(struct mmc_host *host); void mmc_remove_host_sysfs(struct mmc_host *host); void mmc_free_host_sysfs(struct mmc_host *host); + +/* core-internal data */ +extern struct key_type mmc_key_type; +struct mmc_key_payload { + struct rcu_head rcu; /* RCU destructor */ + unsigned short datalen; /* length of this data */ + char data[0]; /* actual data */ +}; #endif Index: linux-2.6.15-rc4-omap1/drivers/mmc/mmc_sysfs.c =================================================================== --- linux-2.6.15-rc4-omap1.orig/drivers/mmc/mmc_sysfs.c 2005-12-27 17:19:47.000000000 -0400 +++ linux-2.6.15-rc4-omap1/drivers/mmc/mmc_sysfs.c 2005-12-27 17:21:35.000000000 -0400 @@ -2,6 +2,8 @@ * linux/drivers/mmc/mmc_sysfs.c * * Copyright (C) 2003 Russell King, All Rights Reserved. + * MMC password protection (C) 2005 Instituto Nokia de Tecnologia (INdT), + * All Rights Reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -13,6 +15,7 @@ #include <linux/init.h> #include <linux/device.h> #include <linux/idr.h> +#include <linux/key.h> #include <linux/mmc/card.h> #include <linux/mmc/host.h> @@ -267,6 +270,150 @@ static struct class mmc_host_class = { static DEFINE_IDR(mmc_host_idr); static DEFINE_SPINLOCK(mmc_host_lock); +#ifdef CONFIG_MMC_PASSWORDS + +#define MMC_KEYLEN_MAXBYTES 32 + +static int mmc_match_lockable(struct device *dev, void *data) +{ + struct mmc_card *card = dev_to_mmc_card(dev); + + return mmc_card_lockable(card); +} + +int mmc_key_instantiate(struct key *key, const void *data, size_t datalen) +{ + struct mmc_key_payload *mpayload; + struct device *dev; + struct mmc_card *card; + int ret; + + ret = -EINVAL; + if (datalen <= 0 || datalen > MMC_KEYLEN_MAXBYTES || !data) + goto error; + + ret = key_payload_reserve(key, datalen); + if (ret < 0) + goto error; + + ret = -ENOMEM; + mpayload = kmalloc(sizeof(*mpayload) + datalen, GFP_KERNEL); + if (!mpayload) + goto error; + + /* attach the data */ + mpayload->datalen = datalen; + memcpy(mpayload->data, data, datalen); + rcu_assign_pointer(key->payload.data, mpayload); + + ret = -EINVAL; + dev = bus_find_device(&mmc_bus_type, NULL, NULL, mmc_match_lockable); + if (!dev) + goto error; + card = dev_to_mmc_card(dev); + if (mmc_card_locked(card)) { + ret = mmc_lock_unlock(card, key, MMC_LOCK_MODE_UNLOCK); + mmc_remove_card(card); + mmc_register_card(card); + } else + ret = mmc_lock_unlock(card, key, MMC_LOCK_MODE_SET_PWD); + if (ret) + ret = -EKEYREJECTED; + +error: + return ret; +} + +/* + * dispose of the old data from an updated mmc key + */ +static void mmc_key_update_rcu_disposal(struct rcu_head *rcu) +{ + struct mmc_key_key_payload *mpayload; + + mpayload = (struct mmc_key_key_payload *)container_of(rcu, struct mmc_key_payload, rcu); + + kfree(mpayload); +} + +/* + * update a mmc key + * - the key's semaphore is write-locked + */ +int mmc_key_update(struct key *key, const void *data, size_t datalen) +{ + struct mmc_key_payload *mpayload, *zap; + struct device *dev; + struct mmc_card *card; + int ret; + + ret = -EINVAL; + if (datalen <= 0 || datalen > MMC_KEYLEN_MAXBYTES || !data) + goto error; + + /* construct a replacement payload */ + ret = -ENOMEM; + mpayload = kmalloc(sizeof(*mpayload) + datalen, GFP_KERNEL); + if (!mpayload) + goto error; + + mpayload->datalen = datalen; + memcpy(mpayload->data, data, datalen); + + /* check the quota and attach the new data */ + zap = mpayload; + + ret = key_payload_reserve(key, datalen); + + if (ret == 0) { + /* attach the new data, displacing the old */ + zap = key->payload.data; + rcu_assign_pointer(key->payload.data, mpayload); + key->expiry = 0; + } + + ret = -EINVAL; + dev = bus_find_device(&mmc_bus_type, NULL, NULL, mmc_match_lockable); + if (!dev) + goto error; + card = dev_to_mmc_card(dev); + if (!mmc_card_locked(card)) + ret = mmc_lock_unlock(card, key, MMC_LOCK_MODE_SET_PWD); + if (ret) + ret = -EKEYREJECTED; + + call_rcu(&zap->rcu, mmc_key_update_rcu_disposal); + +error: + return ret; +} + +int mmc_key_match(const struct key *key, const void *description) +{ + return strcmp(key->description, description) == 0; +} + +/* + * dispose of the data dangling from the corpse of a mmc key + */ +void mmc_key_destroy(struct key *key) +{ + struct mmc_key_payload *mpayload = key->payload.data; + + kfree(mpayload); +} + +struct key_type mmc_key_type = { + .name = "mmc", + .def_datalen = MMC_KEYLEN_MAXBYTES, + .instantiate = mmc_key_instantiate, + .update = mmc_key_update, + .match = mmc_key_match, + .destroy = mmc_key_destroy, +}; + +#endif + /* * Internal function. Allocate a new MMC host. */ @@ -337,6 +484,15 @@ static int __init mmc_init(void) ret = class_register(&mmc_host_class); if (ret) bus_unregister(&mmc_bus_type); +#ifdef CONFIG_MMC_PASSWORDS + else { + ret = register_key_type(&mmc_key_type); + if (ret) { + class_unregister(&mmc_host_class); + bus_unregister(&mmc_bus_type); + } + } +#endif } return ret; } @@ -345,6 +501,9 @@ static void __exit mmc_exit(void) { class_unregister(&mmc_host_class); bus_unregister(&mmc_bus_type); +#ifdef CONFIG_MMC_PASSWORDS + unregister_key_type(&mmc_key_type); +#endif } module_init(mmc_init); -- Anderson Lizardo Embedded Linux Lab - 10LE Nokia Institute of Technology - INdT Manaus - Brazil - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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