am 2c9d8de7: Merge "Prevent buffer overflows."
* commit '2c9d8de79a0dd7f894c65777a197c86486aff96c':
Prevent buffer overflows.
diff --git a/Android.mk b/Android.mk
index e353a4f..48df613 100644
--- a/Android.mk
+++ b/Android.mk
@@ -21,16 +21,19 @@
Loop.cpp \
Devmapper.cpp \
ResponseCode.cpp \
- Xwarp.cpp
+ Xwarp.cpp \
+ cryptfs.c
common_c_includes := \
$(KERNEL_HEADERS) \
+ system/extras/ext4_utils \
external/openssl/include
common_shared_libraries := \
libsysutils \
libcutils \
libdiskconfig \
+ libhardware_legacy \
libcrypto
include $(CLEAR_VARS)
diff --git a/CommandListener.cpp b/CommandListener.cpp
index b0fc551..8bfd0bc 100644
--- a/CommandListener.cpp
+++ b/CommandListener.cpp
@@ -22,6 +22,7 @@
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
+#include <string.h>
#define LOG_TAG "VoldCmdListener"
#include <cutils/log.h>
@@ -35,6 +36,7 @@
#include "Xwarp.h"
#include "Loop.h"
#include "Devmapper.h"
+#include "cryptfs.h"
CommandListener::CommandListener() :
FrameworkListener("vold") {
@@ -45,6 +47,7 @@
registerCmd(new ShareCmd());
registerCmd(new StorageCmd());
registerCmd(new XwarpCmd());
+ registerCmd(new CryptfsCmd());
}
void CommandListener::dumpArgs(int argc, char **argv, int argObscure) {
@@ -54,7 +57,7 @@
memset(buffer, 0, sizeof(buffer));
int i;
for (i = 0; i < argc; i++) {
- int len = strlen(argv[i]) + 1; // Account for space
+ unsigned int len = strlen(argv[i]) + 1; // Account for space
if (i == argObscure) {
len += 2; // Account for {}
}
@@ -505,3 +508,65 @@
return 0;
}
+CommandListener::CryptfsCmd::CryptfsCmd() :
+ VoldCommand("cryptfs") {
+}
+
+int CommandListener::CryptfsCmd::runCommand(SocketClient *cli,
+ int argc, char **argv) {
+ if (argc < 2) {
+ cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument", false);
+ return 0;
+ }
+
+ int rc = 0;
+
+ if (!strcmp(argv[1], "checkpw")) {
+ if (argc != 3) {
+ cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: cryptfs checkpw <passwd>", false);
+ return 0;
+ }
+ dumpArgs(argc, argv, 2);
+ rc = cryptfs_check_passwd(argv[2]);
+ } else if (!strcmp(argv[1], "restart")) {
+ if (argc != 2) {
+ cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: cryptfs restart", false);
+ return 0;
+ }
+ dumpArgs(argc, argv, -1);
+ rc = cryptfs_restart();
+ } else if (!strcmp(argv[1], "cryptocomplete")) {
+ if (argc != 2) {
+ cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: cryptfs cryptocomplete", false);
+ return 0;
+ }
+ dumpArgs(argc, argv, -1);
+ rc = cryptfs_crypto_complete();
+ } else if (!strcmp(argv[1], "enablecrypto")) {
+ if ( (argc != 4) || (strcmp(argv[2], "wipe") && strcmp(argv[2], "inplace")) ) {
+ cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: cryptfs enablecrypto <wipe|inplace> <passwd>", false);
+ return 0;
+ }
+ dumpArgs(argc, argv, 3);
+ rc = cryptfs_enable(argv[2], argv[3]);
+ } else if (!strcmp(argv[1], "changepw")) {
+ if (argc != 3) {
+ cli->sendMsg(ResponseCode::CommandSyntaxError, "Usage: cryptfs changepw <newpasswd>", false);
+ return 0;
+ }
+ SLOGD("cryptfs changepw {}");
+ rc = cryptfs_changepw(argv[2]);
+ } else {
+ dumpArgs(argc, argv, -1);
+ cli->sendMsg(ResponseCode::CommandSyntaxError, "Unknown cryptfs cmd", false);
+ }
+
+ // Always report that the command succeeded and return the error code.
+ // The caller will check the return value to see what the error was.
+ char msg[255];
+ snprintf(msg, sizeof(msg), "%d", rc);
+ cli->sendMsg(ResponseCode::CommandOkay, msg, false);
+
+ return 0;
+}
+
diff --git a/CommandListener.h b/CommandListener.h
index 75c7e81..7bae363 100644
--- a/CommandListener.h
+++ b/CommandListener.h
@@ -76,6 +76,13 @@
virtual ~XwarpCmd() {}
int runCommand(SocketClient *c, int argc, char ** argv);
};
+
+ class CryptfsCmd : public VoldCommand {
+ public:
+ CryptfsCmd();
+ virtual ~CryptfsCmd() {}
+ int runCommand(SocketClient *c, int argc, char ** argv);
+ };
};
#endif
diff --git a/Devmapper.cpp b/Devmapper.cpp
index 4d94e7b..7c11d12 100644
--- a/Devmapper.cpp
+++ b/Devmapper.cpp
@@ -15,6 +15,7 @@
*/
#include <stdio.h>
+#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
@@ -299,4 +300,3 @@
return (void *) (((unsigned long) ptr + agn) & ~agn);
}
-
diff --git a/Fat.cpp b/Fat.cpp
index 4754c66..82a3f7a 100644
--- a/Fat.cpp
+++ b/Fat.cpp
@@ -15,6 +15,7 @@
*/
#include <stdio.h>
+#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
@@ -30,6 +31,7 @@
#include <sys/mount.h>
#include <linux/kdev_t.h>
+#include <linux/fs.h>
#define LOG_TAG "Vold"
diff --git a/Loop.cpp b/Loop.cpp
index dbfd331..dad2c3f 100644
--- a/Loop.cpp
+++ b/Loop.cpp
@@ -15,6 +15,7 @@
*/
#include <stdio.h>
+#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
@@ -22,6 +23,7 @@
#include <sys/types.h>
#include <sys/stat.h>
+#include <sys/ioctl.h>
#include <linux/kdev_t.h>
@@ -126,7 +128,7 @@
char filename[256];
for (i = 0; i < LOOP_MAX; i++) {
- struct loop_info li;
+ struct loop_info64 li;
int rc;
sprintf(filename, "/dev/block/loop%d", i);
@@ -149,7 +151,7 @@
return -1;
}
- rc = ioctl(fd, LOOP_GET_STATUS, &li);
+ rc = ioctl(fd, LOOP_GET_STATUS64, &li);
if (rc < 0 && errno == ENXIO)
break;
diff --git a/NetlinkHandler.cpp b/NetlinkHandler.cpp
index f47d364..55b6dba 100644
--- a/NetlinkHandler.cpp
+++ b/NetlinkHandler.cpp
@@ -17,6 +17,7 @@
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
+#include <string.h>
#define LOG_TAG "Vold"
diff --git a/Volume.cpp b/Volume.cpp
index ecf7dcd..ce41455 100644
--- a/Volume.cpp
+++ b/Volume.cpp
@@ -27,11 +27,14 @@
#include <sys/mount.h>
#include <linux/kdev_t.h>
+#include <linux/fs.h>
#include <cutils/properties.h>
#include <diskconfig/diskconfig.h>
+#include <private/android_filesystem_config.h>
+
#define LOG_TAG "Vold"
#include <cutils/log.h>
@@ -279,6 +282,8 @@
dev_t deviceNodes[4];
int n, i, rc = 0;
char errmsg[255];
+ const char* externalStorage = getenv("EXTERNAL_STORAGE");
+ bool primaryStorage = externalStorage && !strcmp(getMountpoint(), externalStorage);
if (getState() == Volume::State_NoMedia) {
snprintf(errmsg, sizeof(errmsg),
@@ -335,8 +340,18 @@
* muck with it before exposing it to non priviledged users.
*/
errno = 0;
+ int gid;
+
+ if (primaryStorage) {
+ // Special case the primary SD card.
+ // For this we grant write access to the SDCARD_RW group.
+ gid = AID_SDCARD_RW;
+ } else {
+ // For secondary external storage we keep things locked up.
+ gid = AID_MEDIA_RW;
+ }
if (Fat::doMount(devicePath, "/mnt/secure/staging", false, false, false,
- 1000, 1015, 0702, true)) {
+ AID_SYSTEM, gid, 0702, true)) {
SLOGE("%s failed to mount via VFAT (%s)\n", devicePath, strerror(errno));
continue;
}
@@ -345,7 +360,8 @@
protectFromAutorunStupidity();
- if (createBindMounts()) {
+ // only create android_secure on primary storage
+ if (primaryStorage && createBindMounts()) {
SLOGE("Failed to create bindmounts (%s)", strerror(errno));
umount("/mnt/secure/staging");
setState(Volume::State_Idle);
diff --git a/VolumeManager.cpp b/VolumeManager.cpp
index 32b5679..906fb9e 100644
--- a/VolumeManager.cpp
+++ b/VolumeManager.cpp
@@ -184,8 +184,6 @@
if (newAvailable != oldAvailable) {
notifyUmsAvailable(newAvailable);
}
- } else {
- SLOGW("Ignoring unknown switch '%s'", name);
}
}
void VolumeManager::handleUsbCompositeEvent(NetlinkEvent *evt) {
diff --git a/cryptfs.c b/cryptfs.c
new file mode 100644
index 0000000..68d2787
--- /dev/null
+++ b/cryptfs.c
@@ -0,0 +1,1147 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* TO DO:
+ * 1. Perhaps keep several copies of the encrypted key, in case something
+ * goes horribly wrong?
+ *
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <linux/dm-ioctl.h>
+#include <libgen.h>
+#include <stdlib.h>
+#include <sys/param.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <openssl/evp.h>
+#include <openssl/sha.h>
+#include <errno.h>
+#include <cutils/android_reboot.h>
+#include <ext4.h>
+#include "cryptfs.h"
+#define LOG_TAG "Cryptfs"
+#include "cutils/log.h"
+#include "cutils/properties.h"
+#include "hardware_legacy/power.h"
+
+#define DM_CRYPT_BUF_SIZE 4096
+#define DATA_MNT_POINT "/data"
+
+#define HASH_COUNT 2000
+#define KEY_LEN_BYTES 16
+#define IV_LEN_BYTES 16
+
+char *me = "cryptfs";
+
+static unsigned char saved_master_key[KEY_LEN_BYTES];
+static int master_key_saved = 0;
+
+static void ioctl_init(struct dm_ioctl *io, size_t dataSize, const char *name, unsigned flags)
+{
+ memset(io, 0, dataSize);
+ io->data_size = dataSize;
+ io->data_start = sizeof(struct dm_ioctl);
+ io->version[0] = 4;
+ io->version[1] = 0;
+ io->version[2] = 0;
+ io->flags = flags;
+ if (name) {
+ strncpy(io->name, name, sizeof(io->name));
+ }
+}
+
+static unsigned int get_fs_size(char *dev)
+{
+ int fd, block_size;
+ struct ext4_super_block sb;
+ off64_t len;
+
+ if ((fd = open(dev, O_RDONLY)) < 0) {
+ SLOGE("Cannot open device to get filesystem size ");
+ return 0;
+ }
+
+ if (lseek64(fd, 1024, SEEK_SET) < 0) {
+ SLOGE("Cannot seek to superblock");
+ return 0;
+ }
+
+ if (read(fd, &sb, sizeof(sb)) != sizeof(sb)) {
+ SLOGE("Cannot read superblock");
+ return 0;
+ }
+
+ close(fd);
+
+ block_size = 1024 << sb.s_log_block_size;
+ /* compute length in bytes */
+ len = ( ((off64_t)sb.s_blocks_count_hi << 32) + sb.s_blocks_count_lo) * block_size;
+
+ /* return length in sectors */
+ return (unsigned int) (len / 512);
+}
+
+static unsigned int get_blkdev_size(int fd)
+{
+ unsigned int nr_sec;
+
+ if ( (ioctl(fd, BLKGETSIZE, &nr_sec)) == -1) {
+ nr_sec = 0;
+ }
+
+ return nr_sec;
+}
+
+/* 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)
+{
+ int fd;
+ unsigned int nr_sec, cnt;
+ off64_t off;
+ int rc = -1;
+
+ if ( (fd = open(real_blk_name, O_RDWR)) < 0) {
+ SLOGE("Cannot open real block device %s\n", real_blk_name);
+ return -1;
+ }
+
+ if ( (nr_sec = get_blkdev_size(fd)) == 0) {
+ SLOGE("Cannot get size of block device %s\n", real_blk_name);
+ 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;
+ }
+
+ if ((cnt = write(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) {
+ SLOGE("Cannot write real block device footer\n");
+ 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, real_blk_name);
+ 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);
+ 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;
+
+ if (lseek64(fd, off, SEEK_SET) == -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);
+ goto errout;
+ }
+ }
+
+ /* Success! */
+ rc = 0;
+
+errout:
+ close(fd);
+ return rc;
+
+}
+
+static int get_crypt_ftr_and_key(char *real_blk_name, struct crypt_mnt_ftr *crypt_ftr,
+ unsigned char *key, unsigned char *salt)
+{
+ int fd;
+ unsigned int nr_sec, cnt;
+ off64_t off;
+ int rc = -1;
+
+ if ( (fd = open(real_blk_name, O_RDWR)) < 0) {
+ SLOGE("Cannot open real block device %s\n", real_blk_name);
+ return -1;
+ }
+
+ if ( (nr_sec = get_blkdev_size(fd)) == 0) {
+ SLOGE("Cannot get size of block device %s\n", real_blk_name);
+ 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;
+ }
+
+ if ( (cnt = read(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) {
+ SLOGE("Cannot read real block device footer\n");
+ goto errout;
+ }
+
+ if (crypt_ftr->magic != CRYPT_MNT_MAGIC) {
+ SLOGE("Bad magic for real block device %s\n", real_blk_name);
+ goto errout;
+ }
+
+ if (crypt_ftr->major_version != 1) {
+ SLOGE("Cannot understand major version %d real block device footer\n",
+ crypt_ftr->major_version);
+ goto errout;
+ }
+
+ if (crypt_ftr->minor_version != 0) {
+ SLOGW("Warning: crypto footer minor version %d, expected 0, 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, real_blk_name);
+ 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);
+ 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", real_blk_name);
+ goto errout;
+ }
+
+ /* Success! */
+ rc = 0;
+
+errout:
+ close(fd);
+ return rc;
+}
+
+/* Convert a binary key of specified length into an ascii hex string equivalent,
+ * without the leading 0x and with null termination
+ */
+void convert_key_to_hex_ascii(unsigned char *master_key, unsigned int keysize,
+ char *master_key_ascii)
+{
+ unsigned int i, a;
+ unsigned char nibble;
+
+ for (i=0, a=0; i<keysize; i++, a+=2) {
+ /* For each byte, write out two ascii hex digits */
+ nibble = (master_key[i] >> 4) & 0xf;
+ master_key_ascii[a] = nibble + (nibble > 9 ? 0x37 : 0x30);
+
+ nibble = master_key[i] & 0xf;
+ master_key_ascii[a+1] = nibble + (nibble > 9 ? 0x37 : 0x30);
+ }
+
+ /* Add the null termination */
+ master_key_ascii[a] = '\0';
+
+}
+
+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 buffer[DM_CRYPT_BUF_SIZE];
+ char master_key_ascii[129]; /* Large enough to hold 512 bit key and null */
+ char *crypt_params;
+ struct dm_ioctl *io;
+ struct dm_target_spec *tgt;
+ 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");
+ goto errout;
+ }
+
+ io = (struct dm_ioctl *) buffer;
+
+ ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
+ if (ioctl(fd, DM_DEV_CREATE, io)) {
+ SLOGE("Cannot create dm-crypt device\n");
+ goto errout;
+ }
+
+ /* Get the device status, in particular, the name of it's device file */
+ ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
+ if (ioctl(fd, DM_DEV_STATUS, io)) {
+ SLOGE("Cannot retrieve dm-crypt device status\n");
+ goto errout;
+ }
+ minor = (io->dev & 0xff) | ((io->dev >> 12) & 0xfff00);
+ snprintf(crypto_blk_name, MAXPATHLEN, "/dev/block/dm-%u", minor);
+
+ /* Load the mapping table for this device */
+ tgt = (struct dm_target_spec *) &buffer[sizeof(struct dm_ioctl)];
+
+ ioctl_init(io, 4096, name, 0);
+ io->target_count = 1;
+ tgt->status = 0;
+ tgt->sector_start = 0;
+ tgt->length = crypt_ftr->fs_size;
+ strcpy(tgt->target_type, "crypt");
+
+ crypt_params = buffer + sizeof(struct dm_ioctl) + sizeof(struct dm_target_spec);
+ convert_key_to_hex_ascii(master_key, crypt_ftr->keysize, master_key_ascii);
+ sprintf(crypt_params, "%s %s 0 %s 0", crypt_ftr->crypto_type_name,
+ master_key_ascii, real_blk_name);
+ crypt_params += strlen(crypt_params) + 1;
+ crypt_params = (char *) (((unsigned long)crypt_params + 7) & ~8); /* Align to an 8 byte boundary */
+ tgt->next = crypt_params - buffer;
+
+ if (ioctl(fd, DM_TABLE_LOAD, io)) {
+ SLOGE("Cannot load dm-crypt mapping table.\n");
+ goto errout;
+ }
+
+ /* Resume this device to activate it */
+ ioctl_init(io, 4096, name, 0);
+
+ if (ioctl(fd, DM_DEV_SUSPEND, io)) {
+ SLOGE("Cannot resume the dm-crypt device\n");
+ goto errout;
+ }
+
+ /* We made it here with no errors. Woot! */
+ retval = 0;
+
+errout:
+ close(fd); /* If fd is <0 from a failed open call, it's safe to just ignore the close error */
+
+ return retval;
+}
+
+static int delete_crypto_blk_dev(char *crypto_blkdev)
+{
+ 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 ) {
+ SLOGE("Cannot open device-mapper\n");
+ goto errout;
+ }
+
+ io = (struct dm_ioctl *) buffer;
+
+ ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
+ if (ioctl(fd, DM_DEV_REMOVE, io)) {
+ SLOGE("Cannot remove dm-crypt device\n");
+ goto errout;
+ }
+
+ /* We made it here with no errors. Woot! */
+ retval = 0;
+
+errout:
+ close(fd); /* If fd is <0 from a failed open call, it's safe to just ignore the close error */
+
+ return retval;
+
+}
+
+static void pbkdf2(char *passwd, unsigned char *salt, unsigned char *ikey)
+{
+ /* Turn the password into a key and IV that can decrypt the master key */
+ PKCS5_PBKDF2_HMAC_SHA1(passwd, strlen(passwd), salt, SALT_LEN,
+ HASH_COUNT, KEY_LEN_BYTES+IV_LEN_BYTES, ikey);
+}
+
+static int encrypt_master_key(char *passwd, unsigned char *salt,
+ unsigned char *decrypted_master_key,
+ unsigned char *encrypted_master_key)
+{
+ unsigned char ikey[32+32] = { 0 }; /* Big enough to hold a 256 bit key and 256 bit IV */
+ EVP_CIPHER_CTX e_ctx;
+ int encrypted_len, final_len;
+
+ /* Turn the password into a key and IV that can decrypt the master key */
+ pbkdf2(passwd, salt, ikey);
+
+ /* Initialize the decryption engine */
+ if (! EVP_EncryptInit(&e_ctx, EVP_aes_128_cbc(), ikey, ikey+KEY_LEN_BYTES)) {
+ SLOGE("EVP_EncryptInit failed\n");
+ return -1;
+ }
+ EVP_CIPHER_CTX_set_padding(&e_ctx, 0); /* Turn off padding as our data is block aligned */
+
+ /* Encrypt the master key */
+ if (! EVP_EncryptUpdate(&e_ctx, encrypted_master_key, &encrypted_len,
+ decrypted_master_key, KEY_LEN_BYTES)) {
+ SLOGE("EVP_EncryptUpdate failed\n");
+ return -1;
+ }
+ if (! EVP_EncryptFinal(&e_ctx, encrypted_master_key + encrypted_len, &final_len)) {
+ SLOGE("EVP_EncryptFinal failed\n");
+ return -1;
+ }
+
+ if (encrypted_len + final_len != KEY_LEN_BYTES) {
+ SLOGE("EVP_Encryption length check failed with %d, %d bytes\n", encrypted_len, final_len);
+ return -1;
+ } else {
+ return 0;
+ }
+}
+
+static int decrypt_master_key(char *passwd, unsigned char *salt,
+ unsigned char *encrypted_master_key,
+ unsigned char *decrypted_master_key)
+{
+ unsigned char ikey[32+32] = { 0 }; /* Big enough to hold a 256 bit key and 256 bit IV */
+ EVP_CIPHER_CTX d_ctx;
+ int decrypted_len, final_len;
+
+ /* Turn the password into a key and IV that can decrypt the master key */
+ pbkdf2(passwd, salt, ikey);
+
+ /* Initialize the decryption engine */
+ if (! EVP_DecryptInit(&d_ctx, EVP_aes_128_cbc(), ikey, ikey+KEY_LEN_BYTES)) {
+ return -1;
+ }
+ EVP_CIPHER_CTX_set_padding(&d_ctx, 0); /* Turn off padding as our data is block aligned */
+ /* Decrypt the master key */
+ if (! EVP_DecryptUpdate(&d_ctx, decrypted_master_key, &decrypted_len,
+ encrypted_master_key, KEY_LEN_BYTES)) {
+ return -1;
+ }
+ if (! EVP_DecryptFinal(&d_ctx, decrypted_master_key + decrypted_len, &final_len)) {
+ return -1;
+ }
+
+ if (decrypted_len + final_len != KEY_LEN_BYTES) {
+ return -1;
+ } else {
+ return 0;
+ }
+}
+
+static int create_encrypted_random_key(char *passwd, unsigned char *master_key, unsigned char *salt)
+{
+ int fd;
+ unsigned char key_buf[KEY_LEN_BYTES];
+ EVP_CIPHER_CTX e_ctx;
+ int encrypted_len, final_len;
+
+ /* Get some random bits for a key */
+ fd = open("/dev/urandom", O_RDONLY);
+ read(fd, key_buf, sizeof(key_buf));
+ read(fd, salt, SALT_LEN);
+ close(fd);
+
+ /* Now encrypt it with the password */
+ return encrypt_master_key(passwd, salt, key_buf, 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];
+
+ property_get("ro.crypto.fs_type", fs_type, "");
+ property_get("ro.crypto.fs_real_blkdev", real_blkdev, "");
+ property_get("ro.crypto.fs_mnt_point", mount_point2, "");
+ property_get("ro.crypto.fs_options", fs_options, "");
+ property_get("ro.crypto.fs_flags", fs_flags, "");
+ *mnt_flags = strtol(fs_flags, 0, 0);
+
+ if (strcmp(mount_point, mount_point2)) {
+ /* Consistency check. These should match. If not, something odd happened. */
+ return -1;
+ }
+
+ return 0;
+}
+
+static int wait_and_unmount(char *mountpoint)
+{
+ int i, rc;
+#define WAIT_UNMOUNT_COUNT 20
+
+ /* Now umount the tmpfs filesystem */
+ for (i=0; i<WAIT_UNMOUNT_COUNT; i++) {
+ if (umount(mountpoint)) {
+ sleep(1);
+ i++;
+ } else {
+ break;
+ }
+ }
+
+ if (i < WAIT_UNMOUNT_COUNT) {
+ SLOGD("unmounting %s succeeded\n", mountpoint);
+ rc = 0;
+ } else {
+ SLOGE("unmounting %s failed\n", mountpoint);
+ rc = -1;
+ }
+
+ return rc;
+}
+
+#define DATA_PREP_TIMEOUT 100
+static int prep_data_fs(void)
+{
+ int i;
+
+ /* Do the prep of the /data filesystem */
+ property_set("vold.post_fs_data_done", "0");
+ property_set("vold.decrypt", "trigger_post_fs_data");
+ SLOGD("Just triggered post_fs_data\n");
+
+ /* Wait a max of 25 seconds, hopefully it takes much less */
+ for (i=0; i<DATA_PREP_TIMEOUT; i++) {
+ char p[16];;
+
+ property_get("vold.post_fs_data_done", p, "0");
+ if (*p == '1') {
+ break;
+ } else {
+ usleep(250000);
+ }
+ }
+ if (i == DATA_PREP_TIMEOUT) {
+ /* Ugh, we failed to prep /data in time. Bail. */
+ return -1;
+ } else {
+ SLOGD("post_fs_data done\n");
+ return 0;
+ }
+}
+
+int cryptfs_restart(void)
+{
+ char fs_type[32];
+ char real_blkdev[MAXPATHLEN];
+ char crypto_blkdev[MAXPATHLEN];
+ char fs_options[256];
+ unsigned long mnt_flags;
+ struct stat statbuf;
+ int rc = -1, i;
+ static int restart_successful = 0;
+
+ /* Validate that it's OK to call this routine */
+ if (! master_key_saved) {
+ SLOGE("Encrypted filesystem not validated, aborting");
+ return -1;
+ }
+
+ if (restart_successful) {
+ SLOGE("System already restarted with encrypted disk, aborting");
+ return -1;
+ }
+
+ /* Here is where we shut down the framework. The init scripts
+ * start all services in one of three classes: core, main or late_start.
+ * On boot, we start core and main. Now, we stop main, but not core,
+ * as core includes vold and a few other really important things that
+ * we need to keep running. Once main has stopped, we should be able
+ * to umount the tmpfs /data, then mount the encrypted /data.
+ * We then restart the class main, and also the class late_start.
+ * At the moment, I've only put a few things in late_start that I know
+ * are not needed to bring up the framework, and that also cause problems
+ * with unmounting the tmpfs /data, but I hope to add add more services
+ * to the late_start class as we optimize this to decrease the delay
+ * till the user is asked for the password to the filesystem.
+ */
+
+ /* The init files are setup to stop the class main when vold.decrypt is
+ * set to trigger_reset_main.
+ */
+ property_set("vold.decrypt", "trigger_reset_main");
+ SLOGD("Just asked init to shut down class main\n");
+
+ /* Now that the framework is shutdown, we should be able to umount()
+ * the tmpfs filesystem, and mount the real one.
+ */
+
+ property_get("ro.crypto.fs_crypto_blkdev", crypto_blkdev, "");
+ if (strlen(crypto_blkdev) == 0) {
+ SLOGE("fs_crypto_blkdev not set\n");
+ return -1;
+ }
+
+ if (! get_orig_mount_parms(DATA_MNT_POINT, fs_type, real_blkdev, &mnt_flags, fs_options)) {
+ SLOGD("Just got orig mount parms\n");
+
+ if (! (rc = wait_and_unmount(DATA_MNT_POINT)) ) {
+ /* If that succeeded, then mount the decrypted filesystem */
+ mount(crypto_blkdev, DATA_MNT_POINT, fs_type, mnt_flags, fs_options);
+
+ property_set("vold.decrypt", "trigger_load_persist_props");
+ /* Create necessary paths on /data */
+ if (prep_data_fs()) {
+ return -1;
+ }
+
+ /* startup service classes main and late_start */
+ property_set("vold.decrypt", "trigger_restart_framework");
+ SLOGD("Just triggered restart_framework\n");
+
+ /* Give it a few moments to get started */
+ sleep(1);
+ }
+ }
+
+ if (rc == 0) {
+ restart_successful = 1;
+ }
+
+ return rc;
+}
+
+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 fs_type[32];
+ char fs_options[256];
+ unsigned long mnt_flags;
+ char encrypted_state[32];
+
+ property_get("ro.crypto.state", encrypted_state, "");
+ if (strcmp(encrypted_state, "encrypted") ) {
+ SLOGE("not running with encryption, aborting");
+ return 1;
+ }
+
+ if (get_orig_mount_parms(mount_point, fs_type, real_blkdev, &mnt_flags, fs_options)) {
+ SLOGE("Error reading original mount parms for mount point %s\n", mount_point);
+ return -1;
+ }
+
+ if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) {
+ SLOGE("Error getting crypt footer and key\n");
+ return -1;
+ }
+
+ if (crypt_ftr.flags & CRYPT_ENCRYPTION_IN_PROGRESS) {
+ SLOGE("Encryption process didn't finish successfully\n");
+ return -2; /* -2 is the clue to the UI that there is no usable data on the disk,
+ * and give the user an option to wipe the disk */
+ }
+
+ /* We passed the test! We shall diminish, and return to the west */
+ return 0;
+}
+
+static int test_mount_encrypted_fs(char *passwd, char *mount_point)
+{
+ 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 crypto_blkdev[MAXPATHLEN];
+ char real_blkdev[MAXPATHLEN];
+ char fs_type[32];
+ char fs_options[256];
+ char tmp_mount_point[64];
+ unsigned long mnt_flags;
+ unsigned int orig_failed_decrypt_count;
+ char encrypted_state[32];
+ int rc;
+
+ property_get("ro.crypto.state", encrypted_state, "");
+ if ( master_key_saved || strcmp(encrypted_state, "encrypted") ) {
+ SLOGE("encrypted fs already validated or not running with encryption, aborting");
+ return -1;
+ }
+
+ if (get_orig_mount_parms(mount_point, fs_type, real_blkdev, &mnt_flags, fs_options)) {
+ SLOGE("Error reading original mount parms for mount point %s\n", mount_point);
+ return -1;
+ }
+
+ if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) {
+ SLOGE("Error getting crypt footer and key\n");
+ return -1;
+ }
+
+ SLOGD("crypt_ftr->fs_size = %lld\n", crypt_ftr.fs_size);
+ 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);
+ }
+
+ if (create_crypto_blk_dev(&crypt_ftr, decrypted_master_key,
+ real_blkdev, crypto_blkdev)) {
+ SLOGE("Error creating decrypted block device\n");
+ return -1;
+ }
+
+ /* If init detects an encrypted filesystme, it writes a file for each such
+ * encrypted fs into the tmpfs /data filesystem, and then the framework finds those
+ * files and passes that data to me */
+ /* Create a tmp mount point to try mounting the decryptd fs
+ * Since we're here, the mount_point should be a tmpfs filesystem, so make
+ * a directory in it to test mount the decrypted filesystem.
+ */
+ sprintf(tmp_mount_point, "%s/tmp_mnt", 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);
+ crypt_ftr.failed_decrypt_count++;
+ } else {
+ /* Success, so just umount and we'll mount it properly when we restart
+ * the framework.
+ */
+ umount(tmp_mount_point);
+ crypt_ftr.failed_decrypt_count = 0;
+ }
+
+ if (orig_failed_decrypt_count != crypt_ftr.failed_decrypt_count) {
+ put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, 0, 0);
+ }
+
+ if (crypt_ftr.failed_decrypt_count) {
+ /* We failed to mount the device, so return an error */
+ rc = crypt_ftr.failed_decrypt_count;
+
+ } else {
+ /* Woot! Success! Save the name of the crypto block device
+ * so we can mount it when restarting the framework.
+ */
+ property_set("ro.crypto.fs_crypto_blkdev", crypto_blkdev);
+
+ /* Also save a the master key so we can reencrypted the key
+ * the key when we want to change the password on it.
+ */
+ memcpy(saved_master_key, decrypted_master_key, KEY_LEN_BYTES);
+ master_key_saved = 1;
+ rc = 0;
+ }
+
+ return rc;
+}
+
+int cryptfs_crypto_complete(void)
+{
+ return do_crypto_complete("/data");
+}
+
+int cryptfs_check_passwd(char *passwd)
+{
+ int rc = -1;
+
+ rc = test_mount_encrypted_fs(passwd, DATA_MNT_POINT);
+
+ return rc;
+}
+
+/* Initialize a crypt_mnt_ftr structure. The keysize is
+ * defaulted to 16 bytes, and the filesystem size to 0.
+ * Presumably, at a minimum, the caller will update the
+ * filesystem size and crypto_type_name after calling this function.
+ */
+static void cryptfs_init_crypt_mnt_ftr(struct crypt_mnt_ftr *ftr)
+{
+ ftr->magic = CRYPT_MNT_MAGIC;
+ ftr->major_version = 1;
+ ftr->minor_version = 0;
+ 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';
+}
+
+static int cryptfs_enable_wipe(char *crypto_blkdev, off64_t size)
+{
+ 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 (system(cmdline)) {
+ SLOGE("Error creating empty filesystem on %s\n", crypto_blkdev);
+ } else {
+ SLOGD("Successfully created empty filesystem on %s\n", crypto_blkdev);
+ rc = 0;
+ }
+
+ 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)
+{
+ int realfd, cryptofd;
+ char *buf[CRYPT_INPLACE_BUFSIZE];
+ int rc = -1;
+ off64_t numblocks, i, remainder;
+ off64_t one_pct, cur_pct, new_pct;
+
+ if ( (realfd = open(real_blkdev, O_RDONLY)) < 0) {
+ SLOGE("Error opening real_blkdev %s for inplace encrypt\n", real_blkdev);
+ return -1;
+ }
+
+ if ( (cryptofd = open(crypto_blkdev, O_WRONLY)) < 0) {
+ SLOGE("Error opening crypto_blkdev %s for inplace encrypt\n", crypto_blkdev);
+ close(realfd);
+ return -1;
+ }
+
+ /* This is pretty much a simple loop of reading 4K, and writing 4K.
+ * The size passed in is the number of 512 byte sectors in the filesystem.
+ * So compute the number of whole 4K blocks we should read/write,
+ * and the remainder.
+ */
+ numblocks = size / CRYPT_SECTORS_PER_BUFSIZE;
+ remainder = size % CRYPT_SECTORS_PER_BUFSIZE;
+
+ SLOGE("Encrypting filesystem in place...");
+
+ one_pct = numblocks / 100;
+ cur_pct = 0;
+ /* process the majority of the filesystem in blocks */
+ for (i=0; i<numblocks; i++) {
+ new_pct = i / one_pct;
+ if (new_pct > cur_pct) {
+ char buf[8];
+
+ cur_pct = new_pct;
+ snprintf(buf, sizeof(buf), "%lld", cur_pct);
+ property_set("vold.encrypt_progress", buf);
+ }
+ if (unix_read(realfd, buf, CRYPT_INPLACE_BUFSIZE) <= 0) {
+ SLOGE("Error reading real_blkdev %s for inplace encrypt\n", crypto_blkdev);
+ goto errout;
+ }
+ if (unix_write(cryptofd, buf, CRYPT_INPLACE_BUFSIZE) <= 0) {
+ SLOGE("Error writing crypto_blkdev %s for inplace encrypt\n", crypto_blkdev);
+ goto errout;
+ }
+ }
+
+ /* Do any remaining sectors */
+ for (i=0; i<remainder; i++) {
+ if (unix_read(realfd, buf, 512) <= 0) {
+ SLOGE("Error reading rival sectors from real_blkdev %s for inplace encrypt\n", crypto_blkdev);
+ goto errout;
+ }
+ if (unix_write(cryptofd, buf, 512) <= 0) {
+ SLOGE("Error writing final sectors to crypto_blkdev %s for inplace encrypt\n", crypto_blkdev);
+ goto errout;
+ }
+ }
+
+ property_set("vold.encrypt_progress", "100");
+
+ rc = 0;
+
+errout:
+ close(realfd);
+ close(cryptofd);
+
+ return rc;
+}
+
+#define CRYPTO_ENABLE_WIPE 1
+#define CRYPTO_ENABLE_INPLACE 2
+
+#define FRAMEWORK_BOOT_WAIT 60
+
+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];
+ 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];
+ char lockid[32] = { 0 };
+
+ property_get("ro.crypto.state", encrypted_state, "");
+ if (strcmp(encrypted_state, "unencrypted")) {
+ SLOGE("Device is already running encrypted, aborting");
+ goto error_unencrypted;
+ }
+
+ if (!strcmp(howarg, "wipe")) {
+ how = CRYPTO_ENABLE_WIPE;
+ } else if (! strcmp(howarg, "inplace")) {
+ how = CRYPTO_ENABLE_INPLACE;
+ } else {
+ /* Shouldn't happen, as CommandListener vets the args */
+ goto error_unencrypted;
+ }
+
+ get_orig_mount_parms(mount_point, fs_type, real_blkdev, &mnt_flags, fs_options);
+
+ /* Get the size of the real block device */
+ fd = open(real_blkdev, O_RDONLY);
+ if ( (nr_sec = get_blkdev_size(fd)) == 0) {
+ SLOGE("Cannot get size of block device %s\n", real_blkdev);
+ goto error_unencrypted;
+ }
+ close(fd);
+
+ /* If doing inplace encryption, make sure the orig fs doesn't include the crypto footer */
+ if (how == CRYPTO_ENABLE_INPLACE) {
+ unsigned int fs_size_sec, max_fs_size_sec;
+
+ fs_size_sec = get_fs_size(real_blkdev);
+ max_fs_size_sec = nr_sec - (CRYPT_FOOTER_OFFSET / 512);
+
+ if (fs_size_sec > max_fs_size_sec) {
+ SLOGE("Orig filesystem overlaps crypto footer region. Cannot encrypt in place.");
+ goto error_unencrypted;
+ }
+ }
+
+ /* Get a wakelock as this may take a while, and we don't want the
+ * 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());
+ acquire_wake_lock(PARTIAL_WAKE_LOCK, lockid);
+
+ /* 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;
+ }
+
+ /* Now unmount the /data partition. */
+ if (wait_and_unmount(DATA_MNT_POINT)) {
+ goto error_shutting_down;
+ }
+
+ /* Do extra work for a better UX when doing the long inplace encryption */
+ if (how == CRYPTO_ENABLE_INPLACE) {
+ /* Now that /data is unmounted, we need to mount a tmpfs
+ * /data, set a property saying we're doing inplace encryption,
+ * and restart the framework.
+ */
+ property_get("ro.crypto.tmpfs_options", tmpfs_options, "");
+ if (mount("tmpfs", DATA_MNT_POINT, "tmpfs", MS_NOATIME | MS_NOSUID | MS_NODEV,
+ tmpfs_options) < 0) {
+ goto error_shutting_down;
+ }
+ /* Tells the framework that inplace encryption is starting */
+ property_set("vold.encrypt_progress", "0");
+
+ /* restart the framework. */
+ /* Create necessary paths on /data */
+ if (prep_data_fs()) {
+ goto error_shutting_down;
+ }
+
+ /* startup service classes main and late_start */
+ property_set("vold.decrypt", "trigger_restart_min_framework");
+ SLOGD("Just triggered restart_min_framework\n");
+
+ /* OK, the framework is restarted and will soon be showing a
+ * progress bar. Time to setup an encrypted mapping, and
+ * either write a new filesystem, or encrypt in place updating
+ * the progress bar as we work.
+ */
+ }
+
+ /* 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);
+ crypt_ftr.flags |= CRYPT_ENCRYPTION_IN_PROGRESS;
+ 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)) {
+ 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);
+
+ decrypt_master_key(passwd, salt, master_key, decrypted_master_key);
+ create_crypto_blk_dev(&crypt_ftr, decrypted_master_key, real_blkdev, crypto_blkdev);
+
+ if (how == CRYPTO_ENABLE_WIPE) {
+ rc = cryptfs_enable_wipe(crypto_blkdev, crypt_ftr.fs_size);
+ } else if (how == CRYPTO_ENABLE_INPLACE) {
+ rc = cryptfs_enable_inplace(crypto_blkdev, real_blkdev, crypt_ftr.fs_size);
+ } else {
+ /* Shouldn't happen */
+ SLOGE("cryptfs_enable: internal error, unknown option\n");
+ goto error_unencrypted;
+ }
+
+ /* Undo the dm-crypt mapping whether we succeed or not */
+ delete_crypto_blk_dev(crypto_blkdev);
+
+ if (! rc) {
+ /* Success */
+
+ /* 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);
+
+ sleep(2); /* Give the UI a change to show 100% progress */
+ android_reboot(ANDROID_RB_RESTART, 0, 0);
+ } else {
+ property_set("vold.encrypt_progress", "error_partially_encrypted");
+ release_wake_lock(lockid);
+ return -1;
+ }
+
+ /* hrm, the encrypt step claims success, but the reboot failed.
+ * This should not happen.
+ * Set the property and return. Hope the framework can deal with it.
+ */
+ property_set("vold.encrypt_progress", "error_reboot_failed");
+ release_wake_lock(lockid);
+ return rc;
+
+error_unencrypted:
+ property_set("vold.encrypt_progress", "error_not_encrypted");
+ if (lockid[0]) {
+ release_wake_lock(lockid);
+ }
+ return -1;
+
+error_shutting_down:
+ /* we failed, and have not encrypted anthing, so the users's data is still intact,
+ * but the framework is stopped and not restarted to show the error, so it's up to
+ * vold to restart the system.
+ */
+ SLOGE("Error enabling encryption after framework is shutdown, no data changed, restarting system");
+ android_reboot(ANDROID_RB_RESTART, 0, 0);
+
+ /* shouldn't get here */
+ property_set("vold.encrypt_progress", "error_shutting_down");
+ if (lockid[0]) {
+ release_wake_lock(lockid);
+ }
+ return -1;
+}
+
+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];
+
+ /* This is only allowed after we've successfully decrypted the master key */
+ if (! master_key_saved) {
+ SLOGE("Key not saved, aborting");
+ return -1;
+ }
+
+ property_get("ro.crypto.fs_real_blkdev", 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)) {
+ SLOGE("Error getting crypt footer and key");
+ return -1;
+ }
+
+ encrypt_master_key(newpw, salt, saved_master_key, encrypted_master_key);
+
+ /* save the key */
+ put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt);
+
+ return 0;
+}
diff --git a/cryptfs.h b/cryptfs.h
new file mode 100644
index 0000000..bb461ac
--- /dev/null
+++ b/cryptfs.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* This structure starts 16,384 bytes before the end of a hardware
+ * partition that is encrypted.
+ * Immediately following this structure is the encrypted key.
+ * The keysize field tells how long the key is, in bytes.
+ * Then there is 32 bytes of padding,
+ * Finally there is the salt used with the user password.
+ * The salt is fixed at 16 bytes long.
+ * Obviously, the filesystem does not include the last 16 kbytes
+ * of the partition.
+ */
+
+#define CRYPT_FOOTER_OFFSET 0x4000
+
+#define MAX_CRYPTO_TYPE_NAME_LEN 64
+
+#define SALT_LEN 16
+#define KEY_TO_SALT_PADDING 32
+
+/* definitions of flags in the structure below */
+#define CRYPT_MNT_KEY_UNENCRYPTED 0x1 /* The key for the partition is not encrypted. */
+#define CRYPT_ENCRYPTION_IN_PROGRESS 0x2 /* Set when starting encryption,
+ * clear when done before rebooting */
+
+#define CRYPT_MNT_MAGIC 0xD0B5B1C4
+
+#define __le32 unsigned int
+#define __le16 unsigned short int
+
+struct crypt_mnt_ftr {
+ __le32 magic; /* See above */
+ __le16 major_version;
+ __le16 minor_version;
+ __le32 ftr_size; /* in bytes, not including key following */
+ __le32 flags; /* See above */
+ __le32 keysize; /* in bytes */
+ __le32 spare1; /* ignored */
+ __le64 fs_size; /* Size of the encrypted fs, in 512 byte sectors */
+ __le32 failed_decrypt_count; /* count of # of failed attempts to decrypt and
+ mount, set to 0 on successful mount */
+ unsigned char crypto_type_name[MAX_CRYPTO_TYPE_NAME_LEN]; /* The type of encryption
+ needed to decrypt this
+ partition, null terminated */
+};
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+ int cryptfs_crypto_complete(void);
+ int cryptfs_check_passwd(char *pw);
+ int cryptfs_restart(void);
+ int cryptfs_enable(char *flag, char *passwd);
+ int cryptfs_changepw(char *newpw);
+#ifdef __cplusplus
+}
+#endif
+