diff options
| -rw-r--r-- | Android.mk | 1 | ||||
| -rw-r--r-- | cryptfs.c | 102 |
2 files changed, 87 insertions, 16 deletions
@@ -26,6 +26,7 @@ common_src_files := \ common_c_includes := \ $(KERNEL_HEADERS) \ + system/extras/ext4_utils \ external/openssl/include common_shared_libraries := \ @@ -36,6 +36,7 @@ #include <openssl/sha.h> #include <errno.h> #include <sys/reboot.h> +#include <ext4.h> #include "cryptfs.h" #define LOG_TAG "Cryptfs" #include "cutils/log.h" @@ -63,6 +64,37 @@ static void ioctl_init(struct dm_ioctl *io, size_t dataSize, const char *name, u } } +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; @@ -869,7 +901,7 @@ int cryptfs_enable(char *howarg, char *passwd) property_get("ro.crypto.state", encrypted_state, ""); if (strcmp(encrypted_state, "unencrypted")) { SLOGE("Device is already running encrypted, aborting"); - return -1; + goto error_unencrypted; } if (!strcmp(howarg, "wipe")) { @@ -878,11 +910,32 @@ int cryptfs_enable(char *howarg, char *passwd) how = CRYPTO_ENABLE_INPLACE; } else { /* Shouldn't happen, as CommandListener vets the args */ - return -1; + 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; + } + } + /* The init files are setup to stop the class main and late start when * vold sets trigger_shutdown_framework. */ @@ -890,12 +943,12 @@ int cryptfs_enable(char *howarg, char *passwd) SLOGD("Just asked init to shut down class main\n"); if (wait_and_unmount("/mnt/sdcard")) { - return -1; + goto error_shutting_down; } /* Now unmount the /data partition. */ if (wait_and_unmount(DATA_MNT_POINT)) { - return -1; + goto error_shutting_down; } /* Do extra work for a better UX when doing the long inplace encryption */ @@ -907,7 +960,7 @@ int cryptfs_enable(char *howarg, char *passwd) property_get("ro.crypto.tmpfs_options", tmpfs_options, ""); if (mount("tmpfs", DATA_MNT_POINT, "tmpfs", MS_NOATIME | MS_NOSUID | MS_NODEV, tmpfs_options) < 0) { - return -1; + goto error_shutting_down; } /* Tells the framework that inplace encryption is starting */ property_set("vold.encrypt_progress", "0"); @@ -915,7 +968,7 @@ int cryptfs_enable(char *howarg, char *passwd) /* restart the framework. */ /* Create necessary paths on /data */ if (prep_data_fs()) { - return -1; + goto error_shutting_down; } /* startup service classes main and late_start */ @@ -930,13 +983,6 @@ int cryptfs_enable(char *howarg, char *passwd) } /* Start the actual work of making an encrypted filesystem */ - 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); - return -1; - } - close(fd); - /* 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); @@ -945,7 +991,7 @@ int cryptfs_enable(char *howarg, char *passwd) /* Make an encrypted master key */ if (create_encrypted_random_key(passwd, master_key, salt)) { SLOGE("Cannot create encrypted master key\n"); - return -1; + goto error_unencrypted; } /* Write the key to the end of the partition */ @@ -961,7 +1007,7 @@ int cryptfs_enable(char *howarg, char *passwd) } else { /* Shouldn't happen */ SLOGE("cryptfs_enable: internal error, unknown option\n"); - return -1; + goto error_unencrypted; } /* Undo the dm-crypt mapping whether we succeed or not */ @@ -972,10 +1018,34 @@ int cryptfs_enable(char *howarg, char *passwd) sleep(2); /* Give the UI a change to show 100% progress */ sync(); reboot(LINUX_REBOOT_CMD_RESTART); + } else { + property_set("vold.encrypt_progress", "error_partially_encrypted"); + return -1; } - /* Only returns on error */ + /* 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"); return rc; + +error_unencrypted: + property_set("vold.encrypt_progress", "error_not_encrypted"); + 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"); + sync(); + reboot(LINUX_REBOOT_CMD_RESTART); + + /* shouldn't get here */ + property_set("vold.encrypt_progress", "error_shutting_down"); + return -1; } int cryptfs_changepw(char *oldpw, char *newpw) |