vold: Add support for unencrypted persistent info
In order to display the correct language, timezone, airplane
mode and other settings on the decrypt screen, a copy of those
settings needs to be stored unencrypted so the framework can
query them. This adds support to vold to store up to 32
property like key/value pairs that are not encrypted.
Change-Id: Id5c936d2c57d46ed5cff9325d92ba1e8d2ec8972
diff --git a/cryptfs.c b/cryptfs.c
index d926334..de7097b 100644
--- a/cryptfs.c
+++ b/cryptfs.c
@@ -64,9 +64,9 @@
char *me = "cryptfs";
static unsigned char saved_master_key[KEY_LEN_BYTES];
-static char *saved_data_blkdev;
static char *saved_mount_point;
static int master_key_saved = 0;
+static struct crypt_persist_data *persist_data = NULL;
extern struct fstab *fstab;
@@ -126,53 +126,91 @@
return nr_sec;
}
+static int get_crypt_ftr_info(char **metadata_fname, off64_t *off)
+{
+ static int cached_data = 0;
+ static off64_t cached_off = 0;
+ static char cached_metadata_fname[PROPERTY_VALUE_MAX] = "";
+ int fd;
+ char key_loc[PROPERTY_VALUE_MAX];
+ char real_blkdev[PROPERTY_VALUE_MAX];
+ unsigned int nr_sec;
+ int rc = -1;
+
+ if (!cached_data) {
+ fs_mgr_get_crypt_info(fstab, key_loc, real_blkdev, sizeof(key_loc));
+
+ if (!strcmp(key_loc, KEY_IN_FOOTER)) {
+ if ( (fd = open(real_blkdev, O_RDWR)) < 0) {
+ SLOGE("Cannot open real block device %s\n", real_blkdev);
+ return -1;
+ }
+
+ if ((nr_sec = get_blkdev_size(fd))) {
+ /* 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.
+ */
+ strlcpy(cached_metadata_fname, real_blkdev, sizeof(cached_metadata_fname));
+ cached_off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET;
+ cached_data = 1;
+ } else {
+ SLOGE("Cannot get size of block device %s\n", real_blkdev);
+ }
+ close(fd);
+ } else {
+ strlcpy(cached_metadata_fname, key_loc, sizeof(cached_metadata_fname));
+ cached_off = 0;
+ cached_data = 1;
+ }
+ }
+
+ if (cached_data) {
+ if (metadata_fname) {
+ *metadata_fname = cached_metadata_fname;
+ }
+ if (off) {
+ *off = cached_off;
+ }
+ rc = 0;
+ }
+
+ return rc;
+}
+
/* key or salt can be NULL, in which case just skip writing that value. Useful to
* update the failed mount count but not change the key.
*/
-static int put_crypt_ftr_and_key(char *real_blk_name, struct crypt_mnt_ftr *crypt_ftr,
- unsigned char *key, unsigned char *salt)
+static int put_crypt_ftr_and_key(struct crypt_mnt_ftr *crypt_ftr)
{
int fd;
unsigned int nr_sec, cnt;
- off64_t off;
+ /* starting_off is set to the SEEK_SET offset
+ * where the crypto structure starts
+ */
+ off64_t starting_off;
int rc = -1;
- char *fname;
+ char *fname = NULL;
char key_loc[PROPERTY_VALUE_MAX];
struct stat statbuf;
- fs_mgr_get_crypt_info(fstab, key_loc, 0, sizeof(key_loc));
-
- 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 ( (nr_sec = get_blkdev_size(fd)) == 0) {
- SLOGE("Cannot get size of block device %s\n", fname);
- 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 {
+ if (get_crypt_ftr_info(&fname, &starting_off)) {
+ SLOGE("Unable to get crypt_ftr_info\n");
+ return -1;
+ }
+ if (fname[0] != '/') {
SLOGE("Unexpected value for crypto key location\n");
- return -1;;
+ return -1;
+ }
+ if ( (fd = open(fname, O_RDWR)) < 0) {
+ SLOGE("Cannot open footer file %s\n", fname);
+ return -1;
+ }
+
+ /* Seek to the start of the crypt footer */
+ if (lseek64(fd, starting_off, SEEK_SET) == -1) {
+ SLOGE("Cannot seek to real block device footer\n");
+ goto errout;
}
if ((cnt = write(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) {
@@ -180,36 +218,6 @@
goto errout;
}
- 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, fname);
- goto errout;
- }
-
- if ( (cnt = write(fd, key, crypt_ftr->keysize)) != crypt_ftr->keysize) {
- SLOGE("Cannot write key for real block device %s\n", fname);
- goto errout;
- }
- }
-
- if (salt) {
- /* 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_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", fname);
- goto errout;
- }
- }
-
fstat(fd, &statbuf);
/* If the keys are kept on a raw block device, do not try to truncate it. */
if (S_ISREG(statbuf.st_mode) && (key_loc[0] == '/')) {
@@ -228,57 +236,107 @@
}
-static int get_crypt_ftr_and_key(char *real_blk_name, struct crypt_mnt_ftr *crypt_ftr,
- unsigned char *key, unsigned char *salt)
+static inline int unix_read(int fd, void* buff, int len)
+{
+ return TEMP_FAILURE_RETRY(read(fd, buff, len));
+}
+
+static inline int unix_write(int fd, const void* buff, int len)
+{
+ return TEMP_FAILURE_RETRY(write(fd, buff, len));
+}
+
+static void init_empty_persist_data(struct crypt_persist_data *pdata, int len)
+{
+ memset(pdata, 0, len);
+ pdata->persist_magic = PERSIST_DATA_MAGIC;
+ pdata->persist_valid_entries = 0;
+}
+
+/* A routine to update the passed in crypt_ftr to the lastest version.
+ * fd is open read/write on the device that holds the crypto footer and persistent
+ * data, crypt_ftr is a pointer to the struct to be updated, and offset is the
+ * absolute offset to the start of the crypt_mnt_ftr on the passed in fd.
+ */
+static void upgrade_crypt_ftr(int fd, struct crypt_mnt_ftr *crypt_ftr, off64_t offset)
+{
+ struct crypt_persist_data *pdata;
+ off64_t pdata_offset = offset + CRYPT_FOOTER_TO_PERSIST_OFFSET;
+
+ /* This routine can currently only handle upgrading from 1.0 to 1.1.
+ * Do nothing if the passed structure is not version 1.0
+ */
+
+ if ((crypt_ftr->major_version != 1) && (crypt_ftr->minor_version != 0)) {
+ return;
+ }
+
+ pdata = malloc(CRYPT_PERSIST_DATA_SIZE);
+ if (pdata == NULL) {
+ SLOGE("Cannot allocate persisent data\n");
+ return;
+ }
+ memset(pdata, 0, CRYPT_PERSIST_DATA_SIZE);
+
+ /* Need to initialize the persistent data area */
+ if (lseek64(fd, pdata_offset, SEEK_SET) == -1) {
+ SLOGE("Cannot seek to persisent data offset\n");
+ return;
+ }
+ /* Write all zeros to the first copy, making it invalid */
+ unix_write(fd, pdata, CRYPT_PERSIST_DATA_SIZE);
+
+ /* Write a valid but empty structure to the second copy */
+ init_empty_persist_data(pdata, CRYPT_PERSIST_DATA_SIZE);
+ unix_write(fd, pdata, CRYPT_PERSIST_DATA_SIZE);
+
+ /* Update the footer */
+ crypt_ftr->persist_data_size = CRYPT_PERSIST_DATA_SIZE;
+ crypt_ftr->persist_data_offset[0] = pdata_offset;
+ crypt_ftr->persist_data_offset[1] = pdata_offset + CRYPT_PERSIST_DATA_SIZE;
+ crypt_ftr->minor_version = 1;
+ if (lseek64(fd, offset, SEEK_SET) == -1) {
+ SLOGE("Cannot seek to crypt footer\n");
+ return;
+ }
+ unix_write(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr));
+}
+
+
+static int get_crypt_ftr_and_key(struct crypt_mnt_ftr *crypt_ftr)
{
int fd;
unsigned int nr_sec, cnt;
- off64_t off;
+ off64_t starting_off;
int rc = -1;
char key_loc[PROPERTY_VALUE_MAX];
- char *fname;
+ char *fname = NULL;
struct stat statbuf;
- fs_mgr_get_crypt_info(fstab, key_loc, 0, sizeof(key_loc));
-
- 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 ( (nr_sec = get_blkdev_size(fd)) == 0) {
- SLOGE("Cannot get size of block device %s\n", fname);
- 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 (S_ISREG(statbuf.st_mode) && (statbuf.st_size != 0x4000)) {
- SLOGE("footer file %s is not the expected size!\n", fname);
- goto errout;
- }
- } else {
+ if (get_crypt_ftr_info(&fname, &starting_off)) {
+ SLOGE("Unable to get crypt_ftr_info\n");
+ return -1;
+ }
+ if (fname[0] != '/') {
SLOGE("Unexpected value for crypto key location\n");
- return -1;;
+ return -1;
+ }
+ if ( (fd = open(fname, O_RDWR)) < 0) {
+ SLOGE("Cannot open footer file %s\n", fname);
+ return -1;
+ }
+
+ /* Make sure it's 16 Kbytes in length */
+ fstat(fd, &statbuf);
+ if (S_ISREG(statbuf.st_mode) && (statbuf.st_size != 0x4000)) {
+ SLOGE("footer file %s is not the expected size!\n", fname);
+ goto errout;
+ }
+
+ /* Seek to the start of the crypt footer */
+ if (lseek64(fd, starting_off, SEEK_SET) == -1) {
+ SLOGE("Cannot seek to real block device footer\n");
+ goto errout;
}
if ( (cnt = read(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) {
@@ -297,40 +355,16 @@
goto errout;
}
- if (crypt_ftr->minor_version != 0) {
- SLOGW("Warning: crypto footer minor version %d, expected 0, continuing...\n",
+ if ((crypt_ftr->minor_version != 0) && (crypt_ftr->minor_version != 1)) {
+ SLOGW("Warning: crypto footer minor version %d, expected 0 or 1, continuing...\n",
crypt_ftr->minor_version);
}
- if (crypt_ftr->ftr_size > sizeof(struct crypt_mnt_ftr)) {
- /* the footer size is bigger than we expected.
- * Skip to it's stated end so we can read the key.
- */
- if (lseek(fd, crypt_ftr->ftr_size - sizeof(struct crypt_mnt_ftr), SEEK_CUR) == -1) {
- SLOGE("Cannot seek to start of key\n");
- goto errout;
- }
- }
-
- if (crypt_ftr->keysize != KEY_LEN_BYTES) {
- SLOGE("Keysize of %d bits not supported for real block device %s\n",
- 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", fname);
- goto errout;
- }
-
- if (lseek64(fd, KEY_TO_SALT_PADDING, SEEK_CUR) == -1) {
- SLOGE("Cannot seek to real block device salt\n");
- goto errout;
- }
-
- if ( (cnt = read(fd, salt, SALT_LEN)) != SALT_LEN) {
- SLOGE("Cannot read salt for real block device %s\n", fname);
- goto errout;
+ /* If this is a verion 1.0 crypt_ftr, make it a 1.1 crypt footer, and update the
+ * copy on disk before returning.
+ */
+ if (crypt_ftr->minor_version == 0) {
+ upgrade_crypt_ftr(fd, crypt_ftr, starting_off);
}
/* Success! */
@@ -341,6 +375,227 @@
return rc;
}
+static int validate_persistent_data_storage(struct crypt_mnt_ftr *crypt_ftr)
+{
+ if (crypt_ftr->persist_data_offset[0] + crypt_ftr->persist_data_size >
+ crypt_ftr->persist_data_offset[1]) {
+ SLOGE("Crypt_ftr persist data regions overlap");
+ return -1;
+ }
+
+ if (crypt_ftr->persist_data_offset[0] >= crypt_ftr->persist_data_offset[1]) {
+ SLOGE("Crypt_ftr persist data region 0 starts after region 1");
+ return -1;
+ }
+
+ if (((crypt_ftr->persist_data_offset[1] + crypt_ftr->persist_data_size) -
+ (crypt_ftr->persist_data_offset[0] - CRYPT_FOOTER_TO_PERSIST_OFFSET)) >
+ CRYPT_FOOTER_OFFSET) {
+ SLOGE("Persistent data extends past crypto footer");
+ return -1;
+ }
+
+ return 0;
+}
+
+static int load_persistent_data(void)
+{
+ struct crypt_mnt_ftr crypt_ftr;
+ struct crypt_persist_data *pdata = NULL;
+ char encrypted_state[PROPERTY_VALUE_MAX];
+ char *fname;
+ int found = 0;
+ int fd;
+ int ret;
+ int i;
+
+ if (persist_data) {
+ /* Nothing to do, we've already loaded or initialized it */
+ return 0;
+ }
+
+
+ /* If not encrypted, just allocate an empty table and initialize it */
+ property_get("ro.crypto.state", encrypted_state, "");
+ if (strcmp(encrypted_state, "encrypted") ) {
+ pdata = malloc(CRYPT_PERSIST_DATA_SIZE);
+ if (pdata) {
+ init_empty_persist_data(pdata, CRYPT_PERSIST_DATA_SIZE);
+ persist_data = pdata;
+ return 0;
+ }
+ return -1;
+ }
+
+ if(get_crypt_ftr_and_key(&crypt_ftr)) {
+ return -1;
+ }
+
+ if ((crypt_ftr.major_version != 1) || (crypt_ftr.minor_version != 1)) {
+ SLOGE("Crypt_ftr version doesn't support persistent data");
+ return -1;
+ }
+
+ if (get_crypt_ftr_info(&fname, NULL)) {
+ return -1;
+ }
+
+ ret = validate_persistent_data_storage(&crypt_ftr);
+ if (ret) {
+ return -1;
+ }
+
+ fd = open(fname, O_RDONLY);
+ if (fd < 0) {
+ SLOGE("Cannot open %s metadata file", fname);
+ return -1;
+ }
+
+ if (persist_data == NULL) {
+ pdata = malloc(crypt_ftr.persist_data_size);
+ if (pdata == NULL) {
+ SLOGE("Cannot allocate memory for persistent data");
+ goto err;
+ }
+ }
+
+ for (i = 0; i < 2; i++) {
+ if (lseek64(fd, crypt_ftr.persist_data_offset[i], SEEK_SET) < 0) {
+ SLOGE("Cannot seek to read persistent data on %s", fname);
+ goto err2;
+ }
+ if (unix_read(fd, pdata, crypt_ftr.persist_data_size) < 0){
+ SLOGE("Error reading persistent data on iteration %d", i);
+ goto err2;
+ }
+ if (pdata->persist_magic == PERSIST_DATA_MAGIC) {
+ found = 1;
+ break;
+ }
+ }
+
+ if (!found) {
+ SLOGI("Could not find valid persistent data, creating");
+ init_empty_persist_data(pdata, crypt_ftr.persist_data_size);
+ }
+
+ /* Success */
+ persist_data = pdata;
+ close(fd);
+ return 0;
+
+err2:
+ free(pdata);
+
+err:
+ close(fd);
+ return -1;
+}
+
+static int save_persistent_data(void)
+{
+ struct crypt_mnt_ftr crypt_ftr;
+ struct crypt_persist_data *pdata;
+ char *fname;
+ off64_t write_offset;
+ off64_t erase_offset;
+ int found = 0;
+ int fd;
+ int ret;
+
+ if (persist_data == NULL) {
+ SLOGE("No persistent data to save");
+ return -1;
+ }
+
+ if(get_crypt_ftr_and_key(&crypt_ftr)) {
+ return -1;
+ }
+
+ if ((crypt_ftr.major_version != 1) || (crypt_ftr.minor_version != 1)) {
+ SLOGE("Crypt_ftr version doesn't support persistent data");
+ return -1;
+ }
+
+ ret = validate_persistent_data_storage(&crypt_ftr);
+ if (ret) {
+ return -1;
+ }
+
+ if (get_crypt_ftr_info(&fname, NULL)) {
+ return -1;
+ }
+
+ fd = open(fname, O_RDWR);
+ if (fd < 0) {
+ SLOGE("Cannot open %s metadata file", fname);
+ return -1;
+ }
+
+ pdata = malloc(crypt_ftr.persist_data_size);
+ if (pdata == NULL) {
+ SLOGE("Cannot allocate persistant data");
+ goto err;
+ }
+
+ if (lseek64(fd, crypt_ftr.persist_data_offset[0], SEEK_SET) < 0) {
+ SLOGE("Cannot seek to read persistent data on %s", fname);
+ goto err2;
+ }
+
+ if (unix_read(fd, pdata, crypt_ftr.persist_data_size) < 0) {
+ SLOGE("Error reading persistent data before save");
+ goto err2;
+ }
+
+ if (pdata->persist_magic == PERSIST_DATA_MAGIC) {
+ /* The first copy is the curent valid copy, so write to
+ * the second copy and erase this one */
+ write_offset = crypt_ftr.persist_data_offset[1];
+ erase_offset = crypt_ftr.persist_data_offset[0];
+ } else {
+ /* The second copy must be the valid copy, so write to
+ * the first copy, and erase the second */
+ write_offset = crypt_ftr.persist_data_offset[0];
+ erase_offset = crypt_ftr.persist_data_offset[1];
+ }
+
+ /* Write the new copy first, if successful, then erase the old copy */
+ if (lseek(fd, write_offset, SEEK_SET) < 0) {
+ SLOGE("Cannot seek to write persistent data");
+ goto err2;
+ }
+ if (unix_write(fd, persist_data, crypt_ftr.persist_data_size) ==
+ (int) crypt_ftr.persist_data_size) {
+ if (lseek(fd, erase_offset, SEEK_SET) < 0) {
+ SLOGE("Cannot seek to erase previous persistent data");
+ goto err2;
+ }
+ fsync(fd);
+ memset(pdata, 0, crypt_ftr.persist_data_size);
+ if (unix_write(fd, pdata, crypt_ftr.persist_data_size) !=
+ (int) crypt_ftr.persist_data_size) {
+ SLOGE("Cannot write to erase previous persistent data");
+ goto err2;
+ }
+ fsync(fd);
+ } else {
+ SLOGE("Cannot write to save persistent data");
+ goto err2;
+ }
+
+ /* Success */
+ free(pdata);
+ close(fd);
+ return 0;
+
+err2:
+ free(pdata);
+err:
+ close(fd);
+ return -1;
+}
+
/* Convert a binary key of specified length into an ascii hex string equivalent,
* without the leading 0x and with null termination
*/
@@ -790,9 +1045,6 @@
static int do_crypto_complete(char *mount_point)
{
struct crypt_mnt_ftr crypt_ftr;
- unsigned char encrypted_master_key[32];
- unsigned char salt[SALT_LEN];
- char real_blkdev[MAXPATHLEN];
char encrypted_state[PROPERTY_VALUE_MAX];
char key_loc[PROPERTY_VALUE_MAX];
@@ -802,9 +1054,7 @@
return 1;
}
- fs_mgr_get_crypt_info(fstab, 0, real_blkdev, sizeof(real_blkdev));
-
- if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) {
+ if (get_crypt_ftr_and_key(&crypt_ftr)) {
fs_mgr_get_crypt_info(fstab, key_loc, 0, sizeof(key_loc));
/*
@@ -837,8 +1087,7 @@
{
struct crypt_mnt_ftr crypt_ftr;
/* Allocate enough space for a 256 bit key, but we may use less */
- unsigned char encrypted_master_key[32], decrypted_master_key[32];
- unsigned char salt[SALT_LEN];
+ unsigned char decrypted_master_key[32];
char crypto_blkdev[MAXPATHLEN];
char real_blkdev[MAXPATHLEN];
char tmp_mount_point[64];
@@ -854,7 +1103,7 @@
fs_mgr_get_crypt_info(fstab, 0, real_blkdev, sizeof(real_blkdev));
- if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) {
+ if (get_crypt_ftr_and_key(&crypt_ftr)) {
SLOGE("Error getting crypt footer and key\n");
return -1;
}
@@ -863,7 +1112,7 @@
orig_failed_decrypt_count = crypt_ftr.failed_decrypt_count;
if (! (crypt_ftr.flags & CRYPT_MNT_KEY_UNENCRYPTED) ) {
- decrypt_master_key(passwd, salt, encrypted_master_key, decrypted_master_key);
+ decrypt_master_key(passwd, crypt_ftr.salt, crypt_ftr.master_key, decrypted_master_key);
}
if (create_crypto_blk_dev(&crypt_ftr, decrypted_master_key,
@@ -894,7 +1143,7 @@
}
if (orig_failed_decrypt_count != crypt_ftr.failed_decrypt_count) {
- put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, 0, 0);
+ put_crypt_ftr_and_key(&crypt_ftr);
}
if (crypt_ftr.failed_decrypt_count) {
@@ -911,7 +1160,6 @@
* 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);
saved_mount_point = strdup(mount_point);
master_key_saved = 1;
rc = 0;
@@ -940,14 +1188,12 @@
{
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);
+ get_crypt_ftr_and_key(&sd_crypt_ftr);
/* Update the fs_size field to be the size of the volume */
fd = open(real_blkdev, O_RDONLY);
@@ -990,9 +1236,7 @@
{
struct crypt_mnt_ftr crypt_ftr;
/* Allocate enough space for a 256 bit key, but we may use less */
- unsigned char encrypted_master_key[32], decrypted_master_key[32];
- unsigned char salt[SALT_LEN];
- char real_blkdev[MAXPATHLEN];
+ unsigned char decrypted_master_key[32];
char encrypted_state[PROPERTY_VALUE_MAX];
int rc;
@@ -1012,9 +1256,7 @@
return -1;
}
- fs_mgr_get_crypt_info(fstab, 0, real_blkdev, sizeof(real_blkdev));
-
- if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) {
+ if (get_crypt_ftr_and_key(&crypt_ftr)) {
SLOGE("Error getting crypt footer and key\n");
return -1;
}
@@ -1023,7 +1265,8 @@
/* If the device has no password, then just say the password is valid */
rc = 0;
} else {
- decrypt_master_key(passwd, salt, encrypted_master_key, decrypted_master_key);
+ decrypt_master_key(passwd, crypt_ftr.salt, crypt_ftr.master_key,
+ decrypted_master_key);
if (!memcmp(decrypted_master_key, saved_master_key, crypt_ftr.keysize)) {
/* They match, the password is correct */
rc = 0;
@@ -1044,16 +1287,21 @@
*/
static void cryptfs_init_crypt_mnt_ftr(struct crypt_mnt_ftr *ftr)
{
+ off64_t off;
+
+ memset(ftr, 0, sizeof(struct crypt_mnt_ftr));
ftr->magic = CRYPT_MNT_MAGIC;
ftr->major_version = 1;
- ftr->minor_version = 0;
+ ftr->minor_version = 1;
ftr->ftr_size = sizeof(struct crypt_mnt_ftr);
- ftr->flags = 0;
ftr->keysize = KEY_LEN_BYTES;
- ftr->spare1 = 0;
- ftr->fs_size = 0;
- ftr->failed_decrypt_count = 0;
- ftr->crypto_type_name[0] = '\0';
+
+ ftr->persist_data_size = CRYPT_PERSIST_DATA_SIZE;
+ if (get_crypt_ftr_info(NULL, &off) == 0) {
+ ftr->persist_data_offset[0] = off + CRYPT_FOOTER_TO_PERSIST_OFFSET;
+ ftr->persist_data_offset[1] = off + CRYPT_FOOTER_TO_PERSIST_OFFSET +
+ ftr->persist_data_size;
+ }
}
static int cryptfs_enable_wipe(char *crypto_blkdev, off64_t size, int type)
@@ -1084,20 +1332,6 @@
return rc;
}
-static inline int unix_read(int fd, void* buff, int len)
-{
- int ret;
- do { ret = read(fd, buff, len); } while (ret < 0 && errno == EINTR);
- return ret;
-}
-
-static inline int unix_write(int fd, const void* buff, int len)
-{
- int ret;
- do { ret = write(fd, buff, len); } while (ret < 0 && errno == EINTR);
- return ret;
-}
-
#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,
@@ -1193,10 +1427,10 @@
int how = 0;
char crypto_blkdev[MAXPATHLEN], real_blkdev[MAXPATHLEN], sd_crypto_blkdev[MAXPATHLEN];
unsigned long nr_sec;
- unsigned char master_key[KEY_LEN_BYTES], decrypted_master_key[KEY_LEN_BYTES];
- unsigned char salt[SALT_LEN];
+ unsigned char decrypted_master_key[KEY_LEN_BYTES];
int rc=-1, fd, i, ret;
struct crypt_mnt_ftr crypt_ftr, sd_crypt_ftr;;
+ struct crypt_persist_data *pdata;
char tmpfs_options[PROPERTY_VALUE_MAX];
char encrypted_state[PROPERTY_VALUE_MAX];
char lockid[32] = { 0 };
@@ -1357,6 +1591,7 @@
/* Start the actual work of making an encrypted filesystem */
/* Initialize a crypt_mnt_ftr for the partition */
cryptfs_init_crypt_mnt_ftr(&crypt_ftr);
+
if (!strcmp(key_loc, KEY_IN_FOOTER)) {
crypt_ftr.fs_size = nr_sec - (CRYPT_FOOTER_OFFSET / 512);
} else {
@@ -1366,15 +1601,29 @@
strcpy((char *)crypt_ftr.crypto_type_name, "aes-cbc-essiv:sha256");
/* Make an encrypted master key */
- if (create_encrypted_random_key(passwd, master_key, salt)) {
+ if (create_encrypted_random_key(passwd, crypt_ftr.master_key, crypt_ftr.salt)) {
SLOGE("Cannot create encrypted master key\n");
goto error_unencrypted;
}
/* Write the key to the end of the partition */
- put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, master_key, salt);
+ put_crypt_ftr_and_key(&crypt_ftr);
- decrypt_master_key(passwd, salt, master_key, decrypted_master_key);
+ /* If any persistent data has been remembered, save it.
+ * If none, create a valid empty table and save that.
+ */
+ if (!persist_data) {
+ pdata = malloc(CRYPT_PERSIST_DATA_SIZE);
+ if (pdata) {
+ init_empty_persist_data(pdata, CRYPT_PERSIST_DATA_SIZE);
+ persist_data = pdata;
+ }
+ }
+ if (persist_data) {
+ save_persistent_data();
+ }
+
+ decrypt_master_key(passwd, crypt_ftr.salt, crypt_ftr.master_key, decrypted_master_key);
create_crypto_blk_dev(&crypt_ftr, decrypted_master_key, real_blkdev, crypto_blkdev,
"userdata");
@@ -1444,7 +1693,7 @@
/* Clear the encryption in progres flag in the footer */
crypt_ftr.flags &= ~CRYPT_ENCRYPTION_IN_PROGRESS;
- put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, 0, 0);
+ put_crypt_ftr_and_key(&crypt_ftr);
sleep(2); /* Give the UI a chance to show 100% progress */
android_reboot(ANDROID_RB_RESTART, 0, 0);
@@ -1508,9 +1757,7 @@
int cryptfs_changepw(char *newpw)
{
struct crypt_mnt_ftr crypt_ftr;
- unsigned char encrypted_master_key[KEY_LEN_BYTES], decrypted_master_key[KEY_LEN_BYTES];
- unsigned char salt[SALT_LEN];
- char real_blkdev[MAXPATHLEN];
+ unsigned char decrypted_master_key[KEY_LEN_BYTES];
/* This is only allowed after we've successfully decrypted the master key */
if (! master_key_saved) {
@@ -1518,22 +1765,156 @@
return -1;
}
- fs_mgr_get_crypt_info(fstab, 0, real_blkdev, sizeof(real_blkdev));
- if (strlen(real_blkdev) == 0) {
- SLOGE("Can't find real blkdev");
- return -1;
- }
-
/* get key */
- if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) {
+ if (get_crypt_ftr_and_key(&crypt_ftr)) {
SLOGE("Error getting crypt footer and key");
return -1;
}
- encrypt_master_key(newpw, salt, saved_master_key, encrypted_master_key);
+ encrypt_master_key(newpw, crypt_ftr.salt, saved_master_key, crypt_ftr.master_key);
/* save the key */
- put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt);
+ put_crypt_ftr_and_key(&crypt_ftr);
return 0;
}
+
+static int persist_get_key(char *fieldname, char *value)
+{
+ unsigned int i;
+
+ if (persist_data == NULL) {
+ return -1;
+ }
+ for (i = 0; i < persist_data->persist_valid_entries; i++) {
+ if (!strncmp(persist_data->persist_entry[i].key, fieldname, PROPERTY_KEY_MAX)) {
+ /* We found it! */
+ strlcpy(value, persist_data->persist_entry[i].val, PROPERTY_VALUE_MAX);
+ return 0;
+ }
+ }
+
+ return -1;
+}
+
+static int persist_set_key(char *fieldname, char *value, int encrypted)
+{
+ unsigned int i;
+ unsigned int num;
+ struct crypt_mnt_ftr crypt_ftr;
+ unsigned int max_persistent_entries;
+ unsigned int dsize;
+
+ if (persist_data == NULL) {
+ return -1;
+ }
+
+ /* If encrypted, use the values from the crypt_ftr, otherwise
+ * use the values for the current spec.
+ */
+ if (encrypted) {
+ if(get_crypt_ftr_and_key(&crypt_ftr)) {
+ return -1;
+ }
+ dsize = crypt_ftr.persist_data_size;
+ } else {
+ dsize = CRYPT_PERSIST_DATA_SIZE;
+ }
+ max_persistent_entries = (dsize - sizeof(struct crypt_persist_data)) /
+ sizeof(struct crypt_persist_entry);
+
+ num = persist_data->persist_valid_entries;
+
+ for (i = 0; i < num; i++) {
+ if (!strncmp(persist_data->persist_entry[i].key, fieldname, PROPERTY_KEY_MAX)) {
+ /* We found an existing entry, update it! */
+ memset(persist_data->persist_entry[i].val, 0, PROPERTY_VALUE_MAX);
+ strlcpy(persist_data->persist_entry[i].val, value, PROPERTY_VALUE_MAX);
+ return 0;
+ }
+ }
+
+ /* We didn't find it, add it to the end, if there is room */
+ if (persist_data->persist_valid_entries < max_persistent_entries) {
+ memset(&persist_data->persist_entry[num], 0, sizeof(struct crypt_persist_entry));
+ strlcpy(persist_data->persist_entry[num].key, fieldname, PROPERTY_KEY_MAX);
+ strlcpy(persist_data->persist_entry[num].val, value, PROPERTY_VALUE_MAX);
+ persist_data->persist_valid_entries++;
+ return 0;
+ }
+
+ return -1;
+}
+
+/* Return the value of the specified field. */
+int cryptfs_getfield(char *fieldname, char *value, int len)
+{
+ char temp_value[PROPERTY_VALUE_MAX];
+ char real_blkdev[MAXPATHLEN];
+ /* 0 is success, 1 is not encrypted,
+ * -1 is value not set, -2 is any other error
+ */
+ int rc = -2;
+
+ if (persist_data == NULL) {
+ load_persistent_data();
+ if (persist_data == NULL) {
+ SLOGE("Getfield error, cannot load persistent data");
+ goto out;
+ }
+ }
+
+ if (!persist_get_key(fieldname, temp_value)) {
+ /* We found it, copy it to the caller's buffer and return */
+ strlcpy(value, temp_value, len);
+ rc = 0;
+ } else {
+ /* Sadness, it's not there. Return the error */
+ rc = -1;
+ }
+
+out:
+ return rc;
+}
+
+/* Set the value of the specified field. */
+int cryptfs_setfield(char *fieldname, char *value)
+{
+ struct crypt_persist_data stored_pdata;
+ struct crypt_persist_data *pdata_p;
+ struct crypt_mnt_ftr crypt_ftr;
+ char encrypted_state[PROPERTY_VALUE_MAX];
+ /* 0 is success, -1 is an error */
+ int rc = -1;
+ int encrypted = 0;
+
+ if (persist_data == NULL) {
+ load_persistent_data();
+ if (persist_data == NULL) {
+ SLOGE("Setfield error, cannot load persistent data");
+ goto out;
+ }
+ }
+
+ property_get("ro.crypto.state", encrypted_state, "");
+ if (!strcmp(encrypted_state, "encrypted") ) {
+ encrypted = 1;
+ }
+
+ if (persist_set_key(fieldname, value, encrypted)) {
+ goto out;
+ }
+
+ /* If we are running encrypted, save the persistent data now */
+ if (encrypted) {
+ if (save_persistent_data()) {
+ SLOGE("Setfield error, cannot save persistent data");
+ goto out;
+ }
+ }
+
+ rc = 0;
+
+out:
+ return rc;
+}