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vold: allow to store key in a file on another partition

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Add support for keeping the keys in a separate file on another partition,
for devices with no space reserved for a footer after the userdata filesystem.

Add support for encrypting the volumes managed by vold, if they meet certain
criteria, namely being marked as nonremovable and encryptable in vold.fstab.
A bit of trickiness is required to keep vold happy.

Change-Id: Idf0611f74b56c1026c45742ca82e0c26e58828fe
This commit is contained in:
Ken Sumrall 2011-05-18 17:20:07 -07:00
parent 10a9e42835
commit 29d8da8cef
9 changed files with 552 additions and 89 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

63
DirectVolume.cpp
View file

@ -29,6 +29,7 @@
#include "DirectVolume.h"
#include "VolumeManager.h"
#include "ResponseCode.h"
#include "cryptfs.h"
// #define PARTITION_DEBUG
@ -61,6 +62,10 @@ int DirectVolume::addPath(const char *path) {
return 0;
}
void DirectVolume::setFlags(int flags) {
mFlags = flags;
}
dev_t DirectVolume::getDiskDevice() {
return MKDEV(mDiskMajor, mDiskMinor);
}
@ -354,3 +359,61 @@ int DirectVolume::getDeviceNodes(dev_t *devs, int max) {
devs[0] = MKDEV(mDiskMajor, mPartMinors[mPartIdx -1]);
return 1;
}
/*
* Called from base to update device info,
* e.g. When setting up an dm-crypt mapping for the sd card.
*/
int DirectVolume::updateDeviceInfo(char *new_path, int new_major, int new_minor)
{
PathCollection::iterator it;
if (mPartIdx == -1) {
SLOGE("Can only change device info on a partition\n");
return -1;
}
/*
* This is to change the sysfs path associated with a partition, in particular,
* for an internal SD card partition that is encrypted. Thus, the list is
* expected to be only 1 entry long. Check that and bail if not.
*/
if (mPaths->size() != 1) {
SLOGE("Cannot change path if there are more than one for a volume\n");
return -1;
}
it = mPaths->begin();
free(*it); /* Free the string storage */
mPaths->erase(it); /* Remove it from the list */
addPath(new_path); /* Put the new path on the list */
mDiskMajor = new_major;
mDiskMinor = new_minor;
/* Ugh, virual block devices don't use minor 0 for whole disk and minor > 0 for
* partition number. They don't have partitions, they are just virtual block
* devices, and minor number 0 is the first dm-crypt device. Luckily the first
* dm-crypt device is for the userdata partition, which gets minor number 0, and
* it is not managed by vold. So the next device is minor number one, which we
* will call partition one.
*/
mPartIdx = new_minor;
mPartMinors[new_minor-1] = new_minor;
mIsDecrypted = 1;
return 0;
}
/*
* Called from base to give cryptfs all the info it needs to encrypt eligible volumes
*/
int DirectVolume::getVolInfo(struct volume_info *v)
{
strcpy(v->label, mLabel);
strcpy(v->mnt_point, mMountpoint);
v->flags=mFlags;
/* Other fields of struct volume_info are filled in by the caller or cryptfs.c */
return 0;
}

7
DirectVolume.h
View file

@ -35,6 +35,8 @@ protected:
int mPartMinors[MAX_PARTITIONS];
int mDiskNumParts;
unsigned char mPendingPartMap;
int mIsDecrypted;
int mFlags;
public:
DirectVolume(VolumeManager *vm, const char *label, const char *mount_point, int partIdx);
@ -47,9 +49,14 @@ public:
dev_t getShareDevice();
void handleVolumeShared();
void handleVolumeUnshared();
int getVolInfo(struct volume_info *v);
void setFlags(int flags);
protected:
int getDeviceNodes(dev_t *devs, int max);
int updateDeviceInfo(char *new_path, int new_major, int new_minor);
int isDecrypted() { return mIsDecrypted; }
int getFlags() { return mFlags; }
private:
void handleDiskAdded(const char *devpath, NetlinkEvent *evt);

65
Volume.cpp
View file

@ -25,6 +25,7 @@
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/param.h>
#include <linux/kdev_t.h>
#include <linux/fs.h>
@ -44,6 +45,7 @@
#include "ResponseCode.h"
#include "Fat.h"
#include "Process.h"
#include "cryptfs.h"
extern "C" void dos_partition_dec(void const *pp, struct dos_partition *d);
extern "C" void dos_partition_enc(void *pp, struct dos_partition *d);
@ -284,8 +286,19 @@ int Volume::mountVol() {
char errmsg[255];
const char* externalStorage = getenv("EXTERNAL_STORAGE");
bool primaryStorage = externalStorage && !strcmp(getMountpoint(), externalStorage);
char decrypt_state[PROPERTY_VALUE_MAX];
char crypto_state[PROPERTY_VALUE_MAX];
char encrypt_progress[PROPERTY_VALUE_MAX];
int flags;
if (getState() == Volume::State_NoMedia) {
property_get("vold.decrypt", decrypt_state, "");
property_get("vold.encrypt_progress", encrypt_progress, "");
/* Don't try to mount the volumes if we have not yet entered the disk password
* or are in the process of encrypting.
*/
if ((getState() == Volume::State_NoMedia) ||
((!strcmp(decrypt_state, "1") || encrypt_progress[0]) && primaryStorage)) {
snprintf(errmsg, sizeof(errmsg),
"Volume %s %s mount failed - no media",
getLabel(), getMountpoint());
@ -312,6 +325,56 @@ int Volume::mountVol() {
return -1;
}
/* If we're running encrypted, and the volume is marked as encryptable and nonremovable,
* and vold is asking to mount the primaryStorage device, then we need to decrypt
* that partition, and update the volume object to point to it's new decrypted
* block device
*/
property_get("ro.crypto.state", crypto_state, "");
flags = getFlags();
if (primaryStorage &&
((flags & (VOL_NONREMOVABLE | VOL_ENCRYPTABLE))==(VOL_NONREMOVABLE | VOL_ENCRYPTABLE)) &&
!strcmp(crypto_state, "encrypted") && !isDecrypted()) {
char new_sys_path[MAXPATHLEN];
char nodepath[256];
int new_major, new_minor;
if (n != 1) {
/* We only expect one device node returned when mounting encryptable volumes */
SLOGE("Too many device nodes returned when mounting %d\n", getMountpoint());
return -1;
}
if (cryptfs_setup_volume(getLabel(), MAJOR(deviceNodes[0]), MINOR(deviceNodes[0]),
new_sys_path, sizeof(new_sys_path),
&new_major, &new_minor)) {
SLOGE("Cannot setup encryption mapping for %d\n", getMountpoint());
return -1;
}
/* We now have the new sysfs path for the decrypted block device, and the
* majore and minor numbers for it. So, create the device, update the
* path to the new sysfs path, and continue.
*/
snprintf(nodepath,
sizeof(nodepath), "/dev/block/vold/%d:%d",
new_major, new_minor);
if (createDeviceNode(nodepath, new_major, new_minor)) {
SLOGE("Error making device node '%s' (%s)", nodepath,
strerror(errno));
}
// Todo: Either create sys filename from nodepath, or pass in bogus path so
// vold ignores state changes on this internal device.
updateDeviceInfo(nodepath, new_major, new_minor);
/* Get the device nodes again, because they just changed */
n = getDeviceNodes((dev_t *) &deviceNodes, 4);
if (!n) {
SLOGE("Failed to get device nodes (%s)\n", strerror(errno));
return -1;
}
}
for (i = 0; i < n; i++) {
char devicePath[255];

4
Volume.h
View file

@ -77,11 +77,15 @@ public:
virtual void handleVolumeUnshared();
void setDebug(bool enable);
virtual int getVolInfo(struct volume_info *v) = 0;
protected:
void setState(int state);
virtual int getDeviceNodes(dev_t *devs, int max) = 0;
virtual int updateDeviceInfo(char *new_path, int new_major, int new_minor) = 0;
virtual int isDecrypted(void) = 0;
virtual int getFlags(void) = 0;
int createDeviceNode(const char *path, int major, int minor);

45
VolumeManager.cpp
View file

@ -41,6 +41,7 @@
#include "Devmapper.h"
#include "Process.h"
#include "Asec.h"
#include "cryptfs.h"
VolumeManager *VolumeManager::sInstance = NULL;
@ -1130,6 +1131,50 @@ int VolumeManager::unshareVolume(const char *label, const char *method) {
return 0;
}
extern "C" int vold_unmountVol(const char *label) {
VolumeManager *vm = VolumeManager::Instance();
return vm->unmountVolume(label, true);
}
extern "C" int vold_getNumDirectVolumes(void) {
VolumeManager *vm = VolumeManager::Instance();
return vm->getNumDirectVolumes();
}
int VolumeManager::getNumDirectVolumes(void) {
VolumeCollection::iterator i;
int n=0;
for (i = mVolumes->begin(); i != mVolumes->end(); ++i) {
if ((*i)->getShareDevice() != (dev_t)0) {
n++;
}
}
return n;
}
extern "C" int vold_getDirectVolumeList(struct volume_info *vol_list) {
VolumeManager *vm = VolumeManager::Instance();
return vm->getDirectVolumeList(vol_list);
}
int VolumeManager::getDirectVolumeList(struct volume_info *vol_list) {
VolumeCollection::iterator i;
int n=0;
dev_t d;
for (i = mVolumes->begin(); i != mVolumes->end(); ++i) {
if ((d=(*i)->getShareDevice()) != (dev_t)0) {
(*i)->getVolInfo(&vol_list[n]);
snprintf(vol_list[n].blk_dev, sizeof(vol_list[n].blk_dev),
"/dev/block/vold/%d:%d",MAJOR(d), MINOR(d));
n++;
}
}
return 0;
}
int VolumeManager::unmountVolume(const char *label, bool force) {
Volume *v = lookupVolume(label);

16
VolumeManager.h
View file

@ -19,6 +19,7 @@
#include <pthread.h>
#ifdef __cplusplus
#include <utils/List.h>
#include <sysutils/SocketListener.h>
@ -121,13 +122,26 @@ public:
static char *asecHash(const char *id, char *buffer, size_t len);
Volume *lookupVolume(const char *label);
int getNumDirectVolumes(void);
int getDirectVolumeList(struct volume_info *vol_list);
private:
VolumeManager();
void readInitialState();
Volume *lookupVolume(const char *label);
bool isMountpointMounted(const char *mp);
inline bool massStorageAvailable() const { return mUsbMassStorageEnabled && mUsbConnected; }
void notifyUmsAvailable(bool available);
};
extern "C" {
#endif /* __cplusplus */
int vold_unmountVol(const char *label);
int vold_getNumDirectVolumes(void);
int vold_getDirectVolumeList(struct volume_info *v);
#ifdef __cplusplus
}
#endif
#endif

390
cryptfs.c
View file

@ -37,11 +37,13 @@
#include <errno.h>
#include <cutils/android_reboot.h>
#include <ext4.h>
#include <linux/kdev_t.h>
#include "cryptfs.h"
#define LOG_TAG "Cryptfs"
#include "cutils/log.h"
#include "cutils/properties.h"
#include "hardware_legacy/power.h"
#include "VolumeManager.h"
#define DM_CRYPT_BUF_SIZE 4096
#define DATA_MNT_POINT "/data"
@ -50,9 +52,16 @@
#define KEY_LEN_BYTES 16
#define IV_LEN_BYTES 16
#define KEY_LOC_PROP "ro.crypto.keyfile.userdata"
#define KEY_IN_FOOTER "footer"
#define EXT4_FS 1
#define FAT_FS 2
char *me = "cryptfs";
static unsigned char saved_master_key[KEY_LEN_BYTES];
static char *saved_data_blkdev;
static int master_key_saved = 0;
static void ioctl_init(struct dm_ioctl *io, size_t dataSize, const char *name, unsigned flags)
@ -121,26 +130,42 @@ static int put_crypt_ftr_and_key(char *real_blk_name, struct crypt_mnt_ftr *cryp
unsigned int nr_sec, cnt;
off64_t off;
int rc = -1;
char *fname;
char key_loc[PROPERTY_VALUE_MAX];
if ( (fd = open(real_blk_name, O_RDWR)) < 0) {
SLOGE("Cannot open real block device %s\n", real_blk_name);
return -1;
}
property_get(KEY_LOC_PROP, key_loc, KEY_IN_FOOTER);
if ( (nr_sec = get_blkdev_size(fd)) == 0) {
SLOGE("Cannot get size of block device %s\n", real_blk_name);
goto errout;
}
if (!strcmp(key_loc, KEY_IN_FOOTER)) {
fname = real_blk_name;
if ( (fd = open(fname, O_RDWR)) < 0) {
SLOGE("Cannot open real block device %s\n", fname);
return -1;
}
/* If it's an encrypted Android partition, the last 16 Kbytes contain the
* encryption info footer and key, and plenty of bytes to spare for future
* growth.
*/
off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET;
if ( (nr_sec = get_blkdev_size(fd)) == 0) {
SLOGE("Cannot get size of block device %s\n", fname);
goto errout;
}
if (lseek64(fd, off, SEEK_SET) == -1) {
SLOGE("Cannot seek to real block device footer\n");
goto errout;
/* If it's an encrypted Android partition, the last 16 Kbytes contain the
* encryption info footer and key, and plenty of bytes to spare for future
* growth.
*/
off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET;
if (lseek64(fd, off, SEEK_SET) == -1) {
SLOGE("Cannot seek to real block device footer\n");
goto errout;
}
} else if (key_loc[0] == '/') {
fname = key_loc;
if ( (fd = open(fname, O_RDWR | O_CREAT, 0600)) < 0) {
SLOGE("Cannot open footer file %s\n", fname);
return -1;
}
} else {
SLOGE("Unexpected value for" KEY_LOC_PROP "\n");
return -1;;
}
if ((cnt = write(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) {
@ -151,29 +176,36 @@ static int put_crypt_ftr_and_key(char *real_blk_name, struct crypt_mnt_ftr *cryp
if (key) {
if (crypt_ftr->keysize != KEY_LEN_BYTES) {
SLOGE("Keysize of %d bits not supported for real block device %s\n",
crypt_ftr->keysize * 8, real_blk_name);
crypt_ftr->keysize*8, fname);
goto errout;
}
if ( (cnt = write(fd, key, crypt_ftr->keysize)) != crypt_ftr->keysize) {
SLOGE("Cannot write key for real block device %s\n", real_blk_name);
SLOGE("Cannot write key for real block device %s\n", fname);
goto errout;
}
}
if (salt) {
/* Compute the offset for start of the crypt footer */
off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET;
/* Add in the length of the footer, key and padding */
off += sizeof(struct crypt_mnt_ftr) + crypt_ftr->keysize + KEY_TO_SALT_PADDING;
/* Compute the offset from the last write to the salt */
off = KEY_TO_SALT_PADDING;
if (! key)
off += crypt_ftr->keysize;
if (lseek64(fd, off, SEEK_SET) == -1) {
if (lseek64(fd, off, SEEK_CUR) == -1) {
SLOGE("Cannot seek to real block device salt \n");
goto errout;
}
if ( (cnt = write(fd, salt, SALT_LEN)) != SALT_LEN) {
SLOGE("Cannot write salt for real block device %s\n", real_blk_name);
SLOGE("Cannot write salt for real block device %s\n", fname);
goto errout;
}
}
if (key_loc[0] == '/') {
if (ftruncate(fd, 0x4000)) {
SLOGE("Cannot set footer file sizen", fname);
goto errout;
}
}
@ -194,26 +226,50 @@ static int get_crypt_ftr_and_key(char *real_blk_name, struct crypt_mnt_ftr *cryp
unsigned int nr_sec, cnt;
off64_t off;
int rc = -1;
char key_loc[PROPERTY_VALUE_MAX];
char *fname;
struct stat statbuf;
if ( (fd = open(real_blk_name, O_RDWR)) < 0) {
SLOGE("Cannot open real block device %s\n", real_blk_name);
return -1;
}
property_get(KEY_LOC_PROP, key_loc, KEY_IN_FOOTER);
if ( (nr_sec = get_blkdev_size(fd)) == 0) {
SLOGE("Cannot get size of block device %s\n", real_blk_name);
goto errout;
}
if (!strcmp(key_loc, KEY_IN_FOOTER)) {
fname = real_blk_name;
if ( (fd = open(fname, O_RDONLY)) < 0) {
SLOGE("Cannot open real block device %s\n", fname);
return -1;
}
/* If it's an encrypted Android partition, the last 16 Kbytes contain the
* encryption info footer and key, and plenty of bytes to spare for future
* growth.
*/
off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET;
if ( (nr_sec = get_blkdev_size(fd)) == 0) {
SLOGE("Cannot get size of block device %s\n", fname);
goto errout;
}
if (lseek64(fd, off, SEEK_SET) == -1) {
SLOGE("Cannot seek to real block device footer\n");
goto errout;
/* If it's an encrypted Android partition, the last 16 Kbytes contain the
* encryption info footer and key, and plenty of bytes to spare for future
* growth.
*/
off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET;
if (lseek64(fd, off, SEEK_SET) == -1) {
SLOGE("Cannot seek to real block device footer\n");
goto errout;
}
} else if (key_loc[0] == '/') {
fname = key_loc;
if ( (fd = open(fname, O_RDONLY)) < 0) {
SLOGE("Cannot open footer file %s\n", fname);
return -1;
}
/* Make sure it's 16 Kbytes in length */
fstat(fd, &statbuf);
if (statbuf.st_size != 0x4000) {
SLOGE("footer file %s is not the expected size!\n", fname);
goto errout;
}
} else {
SLOGE("Unexpected value for" KEY_LOC_PROP "\n");
return -1;;
}
if ( (cnt = read(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) {
@ -222,7 +278,7 @@ static int get_crypt_ftr_and_key(char *real_blk_name, struct crypt_mnt_ftr *cryp
}
if (crypt_ftr->magic != CRYPT_MNT_MAGIC) {
SLOGE("Bad magic for real block device %s\n", real_blk_name);
SLOGE("Bad magic for real block device %s\n", fname);
goto errout;
}
@ -249,12 +305,12 @@ static int get_crypt_ftr_and_key(char *real_blk_name, struct crypt_mnt_ftr *cryp
if (crypt_ftr->keysize != KEY_LEN_BYTES) {
SLOGE("Keysize of %d bits not supported for real block device %s\n",
crypt_ftr->keysize * 8, real_blk_name);
crypt_ftr->keysize * 8, fname);
goto errout;
}
if ( (cnt = read(fd, key, crypt_ftr->keysize)) != crypt_ftr->keysize) {
SLOGE("Cannot read key for real block device %s\n", real_blk_name);
SLOGE("Cannot read key for real block device %s\n", fname);
goto errout;
}
@ -264,7 +320,7 @@ static int get_crypt_ftr_and_key(char *real_blk_name, struct crypt_mnt_ftr *cryp
}
if ( (cnt = read(fd, salt, SALT_LEN)) != SALT_LEN) {
SLOGE("Cannot read salt for real block device %s\n", real_blk_name);
SLOGE("Cannot read salt for real block device %s\n", fname);
goto errout;
}
@ -300,7 +356,7 @@ void convert_key_to_hex_ascii(unsigned char *master_key, unsigned int keysize,
}
static int create_crypto_blk_dev(struct crypt_mnt_ftr *crypt_ftr, unsigned char *master_key,
char *real_blk_name, char *crypto_blk_name)
char *real_blk_name, char *crypto_blk_name, const char *name)
{
char buffer[DM_CRYPT_BUF_SIZE];
char master_key_ascii[129]; /* Large enough to hold 512 bit key and null */
@ -310,7 +366,6 @@ static int create_crypto_blk_dev(struct crypt_mnt_ftr *crypt_ftr, unsigned char
unsigned int minor;
int fd;
int retval = -1;
char *name ="datadev"; /* FIX ME: Make me a parameter */
if ((fd = open("/dev/device-mapper", O_RDWR)) < 0 ) {
SLOGE("Cannot open device-mapper\n");
@ -374,12 +429,11 @@ errout:
return retval;
}
static int delete_crypto_blk_dev(char *crypto_blkdev)
static int delete_crypto_blk_dev(char *name)
{
int fd;
char buffer[DM_CRYPT_BUF_SIZE];
struct dm_ioctl *io;
char *name ="datadev"; /* FIX ME: Make me a paraameter */
int retval = -1;
if ((fd = open("/dev/device-mapper", O_RDWR)) < 0 ) {
@ -501,8 +555,8 @@ static int create_encrypted_random_key(char *passwd, unsigned char *master_key,
static int get_orig_mount_parms(char *mount_point, char *fs_type, char *real_blkdev,
unsigned long *mnt_flags, char *fs_options)
{
char mount_point2[32];
char fs_flags[32];
char mount_point2[PROPERTY_VALUE_MAX];
char fs_flags[PROPERTY_VALUE_MAX];
property_get("ro.crypto.fs_type", fs_type, "");
property_get("ro.crypto.fs_real_blkdev", real_blkdev, "");
@ -527,6 +581,12 @@ static int wait_and_unmount(char *mountpoint)
/* Now umount the tmpfs filesystem */
for (i=0; i<WAIT_UNMOUNT_COUNT; i++) {
if (umount(mountpoint)) {
if (errno == EINVAL) {
/* EINVAL is returned if the directory is not a mountpoint,
* i.e. there is no filesystem mounted there. So just get out.
*/
break;
}
sleep(1);
i++;
} else {
@ -557,7 +617,7 @@ static int prep_data_fs(void)
/* Wait a max of 25 seconds, hopefully it takes much less */
for (i=0; i<DATA_PREP_TIMEOUT; i++) {
char p[16];;
char p[PROPERTY_VALUE_MAX];
property_get("vold.post_fs_data_done", p, "0");
if (*p == '1') {
@ -662,10 +722,10 @@ static int do_crypto_complete(char *mount_point)
unsigned char encrypted_master_key[32];
unsigned char salt[SALT_LEN];
char real_blkdev[MAXPATHLEN];
char fs_type[32];
char fs_options[256];
char fs_type[PROPERTY_VALUE_MAX];
char fs_options[PROPERTY_VALUE_MAX];
unsigned long mnt_flags;
char encrypted_state[32];
char encrypted_state[PROPERTY_VALUE_MAX];
property_get("ro.crypto.state", encrypted_state, "");
if (strcmp(encrypted_state, "encrypted") ) {
@ -693,7 +753,7 @@ static int do_crypto_complete(char *mount_point)
return 0;
}
static int test_mount_encrypted_fs(char *passwd, char *mount_point)
static int test_mount_encrypted_fs(char *passwd, char *mount_point, char *label)
{
struct crypt_mnt_ftr crypt_ftr;
/* Allocate enough space for a 256 bit key, but we may use less */
@ -701,12 +761,12 @@ static int test_mount_encrypted_fs(char *passwd, char *mount_point)
unsigned char salt[SALT_LEN];
char crypto_blkdev[MAXPATHLEN];
char real_blkdev[MAXPATHLEN];
char fs_type[32];
char fs_options[256];
char fs_type[PROPERTY_VALUE_MAX];
char fs_options[PROPERTY_VALUE_MAX];
char tmp_mount_point[64];
unsigned long mnt_flags;
unsigned int orig_failed_decrypt_count;
char encrypted_state[32];
char encrypted_state[PROPERTY_VALUE_MAX];
int rc;
property_get("ro.crypto.state", encrypted_state, "");
@ -733,7 +793,7 @@ static int test_mount_encrypted_fs(char *passwd, char *mount_point)
}
if (create_crypto_blk_dev(&crypt_ftr, decrypted_master_key,
real_blkdev, crypto_blkdev)) {
real_blkdev, crypto_blkdev, label)) {
SLOGE("Error creating decrypted block device\n");
return -1;
}
@ -749,7 +809,7 @@ static int test_mount_encrypted_fs(char *passwd, char *mount_point)
mkdir(tmp_mount_point, 0755);
if ( mount(crypto_blkdev, tmp_mount_point, "ext4", MS_RDONLY, "") ) {
SLOGE("Error temp mounting decrypted block device\n");
delete_crypto_blk_dev(crypto_blkdev);
delete_crypto_blk_dev(label);
crypt_ftr.failed_decrypt_count++;
} else {
/* Success, so just umount and we'll mount it properly when we restart
@ -777,6 +837,7 @@ static int test_mount_encrypted_fs(char *passwd, char *mount_point)
* the key when we want to change the password on it.
*/
memcpy(saved_master_key, decrypted_master_key, KEY_LEN_BYTES);
saved_data_blkdev = strdup(real_blkdev);
master_key_saved = 1;
rc = 0;
}
@ -784,6 +845,49 @@ static int test_mount_encrypted_fs(char *passwd, char *mount_point)
return rc;
}
/*
* Called by vold when it's asked to mount an encrypted, nonremovable volume.
* Setup a dm-crypt mapping, use the saved master key from
* setting up the /data mapping, and return the new device path.
*/
int cryptfs_setup_volume(const char *label, int major, int minor,
char *crypto_sys_path, unsigned int max_path,
int *new_major, int *new_minor)
{
char real_blkdev[MAXPATHLEN], crypto_blkdev[MAXPATHLEN];
struct crypt_mnt_ftr sd_crypt_ftr;
unsigned char key[32], salt[32];
struct stat statbuf;
int nr_sec, fd;
sprintf(real_blkdev, "/dev/block/vold/%d:%d", major, minor);
/* Just want the footer, but gotta get it all */
get_crypt_ftr_and_key(saved_data_blkdev, &sd_crypt_ftr, key, salt);
/* Update the fs_size field to be the size of the volume */
fd = open(real_blkdev, O_RDONLY);
nr_sec = get_blkdev_size(fd);
close(fd);
if (nr_sec == 0) {
SLOGE("Cannot get size of volume %s\n", real_blkdev);
return -1;
}
sd_crypt_ftr.fs_size = nr_sec;
create_crypto_blk_dev(&sd_crypt_ftr, saved_master_key, real_blkdev,
crypto_blkdev, label);
stat(crypto_blkdev, &statbuf);
*new_major = MAJOR(statbuf.st_rdev);
*new_minor = MINOR(statbuf.st_rdev);
/* Create path to sys entry for this block device */
snprintf(crypto_sys_path, max_path, "/devices/virtual/block/%s", strrchr(crypto_blkdev, '/')+1);
return 0;
}
int cryptfs_crypto_complete(void)
{
return do_crypto_complete("/data");
@ -793,7 +897,7 @@ int cryptfs_check_passwd(char *passwd)
{
int rc = -1;
rc = test_mount_encrypted_fs(passwd, DATA_MNT_POINT);
rc = test_mount_encrypted_fs(passwd, DATA_MNT_POINT, "userdata");
return rc;
}
@ -817,14 +921,24 @@ static void cryptfs_init_crypt_mnt_ftr(struct crypt_mnt_ftr *ftr)
ftr->crypto_type_name[0] = '\0';
}
static int cryptfs_enable_wipe(char *crypto_blkdev, off64_t size)
static int cryptfs_enable_wipe(char *crypto_blkdev, off64_t size, int type)
{
char cmdline[256];
int rc = -1;
snprintf(cmdline, sizeof(cmdline), "/system/bin/make_ext4fs -a /data -l %lld %s",
size * 512, crypto_blkdev);
SLOGI("Making empty filesystem with command %s\n", cmdline);
if (type == EXT4_FS) {
snprintf(cmdline, sizeof(cmdline), "/system/bin/make_ext4fs -a /data -l %lld %s",
size * 512, crypto_blkdev);
SLOGI("Making empty filesystem with command %s\n", cmdline);
} else if (type== FAT_FS) {
snprintf(cmdline, sizeof(cmdline), "/system/bin/newfs_msdos -F 32 -O android -c 8 -s %lld %s",
size, crypto_blkdev);
SLOGI("Making empty filesystem with command %s\n", cmdline);
} else {
SLOGE("cryptfs_enable_wipe(): unknown filesystem type %d\n", type);
return -1;
}
if (system(cmdline)) {
SLOGE("Error creating empty filesystem on %s\n", crypto_blkdev);
} else {
@ -851,13 +965,15 @@ static inline int unix_write(int fd, const void* buff, int len)
#define CRYPT_INPLACE_BUFSIZE 4096
#define CRYPT_SECTORS_PER_BUFSIZE (CRYPT_INPLACE_BUFSIZE / 512)
static int cryptfs_enable_inplace(char *crypto_blkdev, char *real_blkdev, off64_t size)
static int cryptfs_enable_inplace(char *crypto_blkdev, char *real_blkdev, off64_t size,
off64_t *size_already_done, off64_t tot_size)
{
int realfd, cryptofd;
char *buf[CRYPT_INPLACE_BUFSIZE];
int rc = -1;
off64_t numblocks, i, remainder;
off64_t one_pct, cur_pct, new_pct;
off64_t blocks_already_done, tot_numblocks;
if ( (realfd = open(real_blkdev, O_RDONLY)) < 0) {
SLOGE("Error opening real_blkdev %s for inplace encrypt\n", real_blkdev);
@ -877,14 +993,16 @@ static int cryptfs_enable_inplace(char *crypto_blkdev, char *real_blkdev, off64_
*/
numblocks = size / CRYPT_SECTORS_PER_BUFSIZE;
remainder = size % CRYPT_SECTORS_PER_BUFSIZE;
tot_numblocks = tot_size / CRYPT_SECTORS_PER_BUFSIZE;
blocks_already_done = *size_already_done / CRYPT_SECTORS_PER_BUFSIZE;
SLOGE("Encrypting filesystem in place...");
one_pct = numblocks / 100;
one_pct = tot_numblocks / 100;
cur_pct = 0;
/* process the majority of the filesystem in blocks */
for (i=0; i<numblocks; i++) {
new_pct = i / one_pct;
new_pct = (i + blocks_already_done) / one_pct;
if (new_pct > cur_pct) {
char buf[8];
@ -914,8 +1032,7 @@ static int cryptfs_enable_inplace(char *crypto_blkdev, char *real_blkdev, off64_
}
}
property_set("vold.encrypt_progress", "100");
*size_already_done += size;
rc = 0;
errout:
@ -930,19 +1047,33 @@ errout:
#define FRAMEWORK_BOOT_WAIT 60
static inline int should_encrypt(struct volume_info *volume)
{
return (volume->flags & (VOL_ENCRYPTABLE | VOL_NONREMOVABLE)) ==
(VOL_ENCRYPTABLE | VOL_NONREMOVABLE);
}
int cryptfs_enable(char *howarg, char *passwd)
{
int how = 0;
char crypto_blkdev[MAXPATHLEN], real_blkdev[MAXPATHLEN];
char fs_type[32], fs_options[256], mount_point[32];
char crypto_blkdev[MAXPATHLEN], real_blkdev[MAXPATHLEN], sd_crypto_blkdev[MAXPATHLEN];
char fs_type[PROPERTY_VALUE_MAX], fs_options[PROPERTY_VALUE_MAX],
mount_point[PROPERTY_VALUE_MAX];
unsigned long mnt_flags, nr_sec;
unsigned char master_key[KEY_LEN_BYTES], decrypted_master_key[KEY_LEN_BYTES];
unsigned char salt[SALT_LEN];
int rc=-1, fd, i;
struct crypt_mnt_ftr crypt_ftr;
char tmpfs_options[80];
char encrypted_state[32];
struct crypt_mnt_ftr crypt_ftr, sd_crypt_ftr;;
char tmpfs_options[PROPERTY_VALUE_MAX];
char encrypted_state[PROPERTY_VALUE_MAX];
char lockid[32] = { 0 };
char key_loc[PROPERTY_VALUE_MAX];
char fuse_sdcard[PROPERTY_VALUE_MAX];
char *sd_mnt_point;
char sd_blk_dev[256] = { 0 };
int num_vols;
struct volume_info *vol_list = 0;
off64_t cur_encryption_done=0, tot_encryption_size=0;
property_get("ro.crypto.state", encrypted_state, "");
if (strcmp(encrypted_state, "unencrypted")) {
@ -950,6 +1081,8 @@ int cryptfs_enable(char *howarg, char *passwd)
goto error_unencrypted;
}
property_get(KEY_LOC_PROP, key_loc, KEY_IN_FOOTER);
if (!strcmp(howarg, "wipe")) {
how = CRYPTO_ENABLE_WIPE;
} else if (! strcmp(howarg, "inplace")) {
@ -970,7 +1103,7 @@ int cryptfs_enable(char *howarg, char *passwd)
close(fd);
/* If doing inplace encryption, make sure the orig fs doesn't include the crypto footer */
if (how == CRYPTO_ENABLE_INPLACE) {
if ((how == CRYPTO_ENABLE_INPLACE) && (!strcmp(key_loc, KEY_IN_FOOTER))) {
unsigned int fs_size_sec, max_fs_size_sec;
fs_size_sec = get_fs_size(real_blkdev);
@ -986,17 +1119,52 @@ int cryptfs_enable(char *howarg, char *passwd)
* device to sleep on us. We'll grab a partial wakelock, and if the UI
* wants to keep the screen on, it can grab a full wakelock.
*/
snprintf(lockid, 32, "enablecrypto%d", (int) getpid());
snprintf(lockid, sizeof(lockid), "enablecrypto%d", (int) getpid());
acquire_wake_lock(PARTIAL_WAKE_LOCK, lockid);
/* Get the sdcard mount point */
sd_mnt_point = getenv("EXTERNAL_STORAGE");
if (! sd_mnt_point) {
sd_mnt_point = "/mnt/sdcard";
}
num_vols=vold_getNumDirectVolumes();
vol_list = malloc(sizeof(struct volume_info) * num_vols);
vold_getDirectVolumeList(vol_list);
for (i=0; i<num_vols; i++) {
if (should_encrypt(&vol_list[i])) {
fd = open(vol_list[i].blk_dev, O_RDONLY);
if ( (vol_list[i].size = get_blkdev_size(fd)) == 0) {
SLOGE("Cannot get size of block device %s\n", vol_list[i].blk_dev);
goto error_unencrypted;
}
close(fd);
if (vold_unmountVol(vol_list[i].label)) {
SLOGE("Failed to unmount volume %s\n", vol_list[i].label);
goto error_unencrypted;
}
}
}
/* The init files are setup to stop the class main and late start when
* vold sets trigger_shutdown_framework.
*/
property_set("vold.decrypt", "trigger_shutdown_framework");
SLOGD("Just asked init to shut down class main\n");
if (wait_and_unmount("/mnt/sdcard")) {
goto error_shutting_down;
property_get("ro.crypto.fuse_sdcard", fuse_sdcard, "");
if (!strcmp(fuse_sdcard, "true")) {
/* This is a device using the fuse layer to emulate the sdcard semantics
* on top of the userdata partition. vold does not manage it, it is managed
* by the sdcard service. The sdcard service was killed by the property trigger
* above, so just unmount it now. We must do this _AFTER_ killing the framework,
* unlike the case for vold managed devices above.
*/
if (wait_and_unmount(sd_mnt_point)) {
goto error_shutting_down;
}
}
/* Now unmount the /data partition. */
@ -1038,7 +1206,11 @@ int cryptfs_enable(char *howarg, char *passwd)
/* Start the actual work of making an encrypted filesystem */
/* Initialize a crypt_mnt_ftr for the partition */
cryptfs_init_crypt_mnt_ftr(&crypt_ftr);
crypt_ftr.fs_size = nr_sec - (CRYPT_FOOTER_OFFSET / 512);
if (!strcmp(key_loc, KEY_IN_FOOTER)) {
crypt_ftr.fs_size = nr_sec - (CRYPT_FOOTER_OFFSET / 512);
} else {
crypt_ftr.fs_size = nr_sec;
}
crypt_ftr.flags |= CRYPT_ENCRYPTION_IN_PROGRESS;
strcpy((char *)crypt_ftr.crypto_type_name, "aes-cbc-essiv:sha256");
@ -1052,12 +1224,51 @@ int cryptfs_enable(char *howarg, char *passwd)
put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, master_key, salt);
decrypt_master_key(passwd, salt, master_key, decrypted_master_key);
create_crypto_blk_dev(&crypt_ftr, decrypted_master_key, real_blkdev, crypto_blkdev);
create_crypto_blk_dev(&crypt_ftr, decrypted_master_key, real_blkdev, crypto_blkdev,
"userdata");
/* setup crypto mapping for all encryptable volumes handled by vold */
for (i=0; i<num_vols; i++) {
if (should_encrypt(&vol_list[i])) {
vol_list[i].crypt_ftr = crypt_ftr; /* gotta love struct assign */
vol_list[i].crypt_ftr.fs_size = vol_list[i].size;
create_crypto_blk_dev(&vol_list[i].crypt_ftr, decrypted_master_key,
vol_list[i].blk_dev, vol_list[i].crypto_blkdev,
vol_list[i].label);
tot_encryption_size += vol_list[i].size;
}
}
if (how == CRYPTO_ENABLE_WIPE) {
rc = cryptfs_enable_wipe(crypto_blkdev, crypt_ftr.fs_size);
rc = cryptfs_enable_wipe(crypto_blkdev, crypt_ftr.fs_size, EXT4_FS);
/* Encrypt all encryptable volumes handled by vold */
if (!rc) {
for (i=0; i<num_vols; i++) {
if (should_encrypt(&vol_list[i])) {
rc = cryptfs_enable_wipe(vol_list[i].crypto_blkdev,
vol_list[i].crypt_ftr.fs_size, FAT_FS);
}
}
}
} else if (how == CRYPTO_ENABLE_INPLACE) {
rc = cryptfs_enable_inplace(crypto_blkdev, real_blkdev, crypt_ftr.fs_size);
rc = cryptfs_enable_inplace(crypto_blkdev, real_blkdev, crypt_ftr.fs_size,
&cur_encryption_done, tot_encryption_size);
/* Encrypt all encryptable volumes handled by vold */
if (!rc) {
for (i=0; i<num_vols; i++) {
if (should_encrypt(&vol_list[i])) {
rc = cryptfs_enable_inplace(vol_list[i].crypto_blkdev,
vol_list[i].blk_dev,
vol_list[i].crypt_ftr.fs_size,
&cur_encryption_done, tot_encryption_size);
}
}
}
if (!rc) {
/* The inplace routine never actually sets the progress to 100%
* due to the round down nature of integer division, so set it here */
property_set("vold.encrypt_progress", "100");
}
} else {
/* Shouldn't happen */
SLOGE("cryptfs_enable: internal error, unknown option\n");
@ -1065,7 +1276,14 @@ int cryptfs_enable(char *howarg, char *passwd)
}
/* Undo the dm-crypt mapping whether we succeed or not */
delete_crypto_blk_dev(crypto_blkdev);
delete_crypto_blk_dev("userdata");
for (i=0; i<num_vols; i++) {
if (should_encrypt(&vol_list[i])) {
delete_crypto_blk_dev(vol_list[i].label);
}
}
free(vol_list);
if (! rc) {
/* Success */
@ -1074,7 +1292,7 @@ int cryptfs_enable(char *howarg, char *passwd)
crypt_ftr.flags &= ~CRYPT_ENCRYPTION_IN_PROGRESS;
put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, 0, 0);
sleep(2); /* Give the UI a change to show 100% progress */
sleep(2); /* Give the UI a chance to show 100% progress */
android_reboot(ANDROID_RB_RESTART, 0, 0);
} else {
property_set("vold.encrypt_progress", "error_partially_encrypted");
@ -1091,6 +1309,7 @@ int cryptfs_enable(char *howarg, char *passwd)
return rc;
error_unencrypted:
free(vol_list);
property_set("vold.encrypt_progress", "error_not_encrypted");
if (lockid[0]) {
release_wake_lock(lockid);
@ -1107,6 +1326,7 @@ error_shutting_down:
/* shouldn't get here */
property_set("vold.encrypt_progress", "error_shutting_down");
free(vol_list);
if (lockid[0]) {
release_wake_lock(lockid);
}

15
cryptfs.h
View file

@ -58,6 +58,18 @@ struct crypt_mnt_ftr {
partition, null terminated */
};
struct volume_info {
unsigned int size;
unsigned int flags;
struct crypt_mnt_ftr crypt_ftr;
char mnt_point[256];
char blk_dev[256];
char crypto_blkdev[256];
char label[256];
};
#define VOL_NONREMOVABLE 0x1
#define VOL_ENCRYPTABLE 0x2
#ifdef __cplusplus
extern "C" {
#endif
@ -66,6 +78,9 @@ extern "C" {
int cryptfs_restart(void);
int cryptfs_enable(char *flag, char *passwd);
int cryptfs_changepw(char *newpw);
int cryptfs_setup_volume(const char *label, int major, int minor,
char *crypto_dev_path, unsigned int max_pathlen,
int *new_major, int *new_minor);
#ifdef __cplusplus
}
#endif

36
main.cpp
View file

@ -32,6 +32,7 @@
#include "CommandListener.h"
#include "NetlinkManager.h"
#include "DirectVolume.h"
#include "cryptfs.h"
static int process_config(VolumeManager *vm);
static void coldboot(const char *path);
@ -141,6 +142,22 @@ static void coldboot(const char *path)
}
}
static int parse_mount_flags(char *mount_flags)
{
char *save_ptr;
int flags = 0;
if (strcasestr(mount_flags, "encryptable")) {
flags |= VOL_ENCRYPTABLE;
}
if (strcasestr(mount_flags, "nonremovable")) {
flags |= VOL_NONREMOVABLE;
}
return flags;
}
static int process_config(VolumeManager *vm) {
FILE *fp;
int n = 0;
@ -153,7 +170,8 @@ static int process_config(VolumeManager *vm) {
while(fgets(line, sizeof(line), fp)) {
const char *delim = " \t";
char *save_ptr;
char *type, *label, *mount_point;
char *type, *label, *mount_point, *mount_flags, *sysfs_path;
int flags;
n++;
line[strlen(line)-1] = '\0';
@ -193,13 +211,27 @@ static int process_config(VolumeManager *vm) {
dv = new DirectVolume(vm, label, mount_point, atoi(part));
}
while (char *sysfs_path = strtok_r(NULL, delim, &save_ptr)) {
while ((sysfs_path = strtok_r(NULL, delim, &save_ptr))) {
if (*sysfs_path != '/') {
/* If the first character is not a '/', it must be flags */
break;
}
if (dv->addPath(sysfs_path)) {
SLOGE("Failed to add devpath %s to volume %s", sysfs_path,
label);
goto out_fail;
}
}
/* If sysfs_path is non-null at this point, then it contains
* the optional flags for this volume
*/
if (sysfs_path)
flags = parse_mount_flags(sysfs_path);
else
flags = 0;
dv->setFlags(flags);
vm->addVolume(dv);
} else if (!strcmp(type, "map_mount")) {
} else {