diff options
Diffstat (limited to 'src/shared/dissect-image.c')
| -rw-r--r-- | src/shared/dissect-image.c | 1072 |
1 files changed, 1072 insertions, 0 deletions
diff --git a/src/shared/dissect-image.c b/src/shared/dissect-image.c new file mode 100644 index 0000000000..d3ba9b9dde --- /dev/null +++ b/src/shared/dissect-image.c @@ -0,0 +1,1072 @@ +/*** + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#ifdef HAVE_LIBCRYPTSETUP +#include <libcryptsetup.h> +#endif +#include <linux/dm-ioctl.h> +#include <sys/mount.h> + +#include "architecture.h" +#include "ask-password-api.h" +#include "blkid-util.h" +#include "dissect-image.h" +#include "fd-util.h" +#include "gpt.h" +#include "mount-util.h" +#include "path-util.h" +#include "stat-util.h" +#include "stdio-util.h" +#include "string-table.h" +#include "string-util.h" +#include "udev-util.h" + +static int probe_filesystem(const char *node, char **ret_fstype) { +#ifdef HAVE_BLKID + _cleanup_blkid_free_probe_ blkid_probe b = NULL; + const char *fstype; + int r; + + b = blkid_new_probe_from_filename(node); + if (!b) + return -ENOMEM; + + blkid_probe_enable_superblocks(b, 1); + blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE); + + errno = 0; + r = blkid_do_safeprobe(b); + if (r == -2 || r == 1) { + log_debug("Failed to identify any partition type on partition %s", node); + goto not_found; + } + if (r != 0) { + if (errno == 0) + return -EIO; + + return -errno; + } + + (void) blkid_probe_lookup_value(b, "TYPE", &fstype, NULL); + + if (fstype) { + char *t; + + t = strdup(fstype); + if (!t) + return -ENOMEM; + + *ret_fstype = t; + return 1; + } + +not_found: + *ret_fstype = NULL; + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +int dissect_image(int fd, const void *root_hash, size_t root_hash_size, DissectedImage **ret) { + +#ifdef HAVE_BLKID + sd_id128_t root_uuid = SD_ID128_NULL, verity_uuid = SD_ID128_NULL; + _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL; + bool is_gpt, is_mbr, generic_rw, multiple_generic = false; + _cleanup_udev_device_unref_ struct udev_device *d = NULL; + _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL; + _cleanup_blkid_free_probe_ blkid_probe b = NULL; + _cleanup_udev_unref_ struct udev *udev = NULL; + _cleanup_free_ char *generic_node = NULL; + const char *pttype = NULL, *usage = NULL; + struct udev_list_entry *first, *item; + blkid_partlist pl; + int r, generic_nr; + struct stat st; + unsigned i; + + assert(fd >= 0); + assert(ret); + assert(root_hash || root_hash_size == 0); + + /* Probes a disk image, and returns information about what it found in *ret. + * + * Returns -ENOPKG if no suitable partition table or file system could be found. + * Returns -EADDRNOTAVAIL if a root hash was specified but no matching root/verity partitions found. */ + + if (root_hash) { + /* If a root hash is supplied, then we use the root partition that has a UUID that match the first + * 128bit of the root hash. And we use the verity partition that has a UUID that match the final + * 128bit. */ + + if (root_hash_size < sizeof(sd_id128_t)) + return -EINVAL; + + memcpy(&root_uuid, root_hash, sizeof(sd_id128_t)); + memcpy(&verity_uuid, (const uint8_t*) root_hash + root_hash_size - sizeof(sd_id128_t), sizeof(sd_id128_t)); + + if (sd_id128_is_null(root_uuid)) + return -EINVAL; + if (sd_id128_is_null(verity_uuid)) + return -EINVAL; + } + + if (fstat(fd, &st) < 0) + return -errno; + + if (!S_ISBLK(st.st_mode)) + return -ENOTBLK; + + b = blkid_new_probe(); + if (!b) + return -ENOMEM; + + errno = 0; + r = blkid_probe_set_device(b, fd, 0, 0); + if (r != 0) { + if (errno == 0) + return -ENOMEM; + + return -errno; + } + + blkid_probe_enable_superblocks(b, 1); + blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE|BLKID_SUBLKS_USAGE); + blkid_probe_enable_partitions(b, 1); + blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS); + + errno = 0; + r = blkid_do_safeprobe(b); + if (r == -2 || r == 1) { + log_debug("Failed to identify any partition table."); + return -ENOPKG; + } + if (r != 0) { + if (errno == 0) + return -EIO; + + return -errno; + } + + m = new0(DissectedImage, 1); + if (!m) + return -ENOMEM; + + (void) blkid_probe_lookup_value(b, "USAGE", &usage, NULL); + if (STRPTR_IN_SET(usage, "filesystem", "crypto")) { + _cleanup_free_ char *t = NULL, *n = NULL; + const char *fstype = NULL; + + /* OK, we have found a file system, that's our root partition then. */ + (void) blkid_probe_lookup_value(b, "TYPE", &fstype, NULL); + + if (fstype) { + t = strdup(fstype); + if (!t) + return -ENOMEM; + } + + if (asprintf(&n, "/dev/block/%u:%u", major(st.st_rdev), minor(st.st_rdev)) < 0) + return -ENOMEM; + + m->partitions[PARTITION_ROOT] = (DissectedPartition) { + .found = true, + .rw = true, + .partno = -1, + .architecture = _ARCHITECTURE_INVALID, + .fstype = t, + .node = n, + }; + + t = n = NULL; + + m->encrypted = streq(fstype, "crypto_LUKS"); + + *ret = m; + m = NULL; + + return 0; + } + + (void) blkid_probe_lookup_value(b, "PTTYPE", &pttype, NULL); + if (!pttype) + return -ENOPKG; + + is_gpt = streq_ptr(pttype, "gpt"); + is_mbr = streq_ptr(pttype, "dos"); + + if (!is_gpt && !is_mbr) + return -ENOPKG; + + errno = 0; + pl = blkid_probe_get_partitions(b); + if (!pl) { + if (errno == 0) + return -ENOMEM; + + return -errno; + } + + udev = udev_new(); + if (!udev) + return -errno; + + d = udev_device_new_from_devnum(udev, 'b', st.st_rdev); + if (!d) + return -ENOMEM; + + for (i = 0;; i++) { + int n, z; + + if (i >= 10) { + log_debug("Kernel partitions never appeared."); + return -ENXIO; + } + + e = udev_enumerate_new(udev); + if (!e) + return -errno; + + r = udev_enumerate_add_match_parent(e, d); + if (r < 0) + return r; + + r = udev_enumerate_scan_devices(e); + if (r < 0) + return r; + + /* Count the partitions enumerated by the kernel */ + n = 0; + first = udev_enumerate_get_list_entry(e); + udev_list_entry_foreach(item, first) + n++; + + /* Count the partitions enumerated by blkid */ + z = blkid_partlist_numof_partitions(pl); + if (n == z + 1) + break; + if (n > z + 1) { + log_debug("blkid and kernel partition list do not match."); + return -EIO; + } + if (n < z + 1) { + unsigned j; + + /* The kernel has probed fewer partitions than blkid? Maybe the kernel prober is still running + * or it got EBUSY because udev already opened the device. Let's reprobe the device, which is a + * synchronous call that waits until probing is complete. */ + + for (j = 0; j < 20; j++) { + + r = ioctl(fd, BLKRRPART, 0); + if (r < 0) + r = -errno; + if (r >= 0 || r != -EBUSY) + break; + + /* If something else has the device open, such as an udev rule, the ioctl will return + * EBUSY. Since there's no way to wait until it isn't busy anymore, let's just wait a + * bit, and try again. + * + * This is really something they should fix in the kernel! */ + + usleep(50 * USEC_PER_MSEC); + } + + if (r < 0) + return r; + } + + e = udev_enumerate_unref(e); + } + + first = udev_enumerate_get_list_entry(e); + udev_list_entry_foreach(item, first) { + _cleanup_udev_device_unref_ struct udev_device *q; + unsigned long long flags; + blkid_partition pp; + const char *node; + dev_t qn; + int nr; + + q = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)); + if (!q) + return -errno; + + qn = udev_device_get_devnum(q); + if (major(qn) == 0) + continue; + + if (st.st_rdev == qn) + continue; + + node = udev_device_get_devnode(q); + if (!node) + continue; + + pp = blkid_partlist_devno_to_partition(pl, qn); + if (!pp) + continue; + + flags = blkid_partition_get_flags(pp); + + nr = blkid_partition_get_partno(pp); + if (nr < 0) + continue; + + if (is_gpt) { + int designator = _PARTITION_DESIGNATOR_INVALID, architecture = _ARCHITECTURE_INVALID; + const char *stype, *sid, *fstype = NULL; + sd_id128_t type_id, id; + bool rw = true; + + if (flags & GPT_FLAG_NO_AUTO) + continue; + + sid = blkid_partition_get_uuid(pp); + if (!sid) + continue; + if (sd_id128_from_string(sid, &id) < 0) + continue; + + stype = blkid_partition_get_type_string(pp); + if (!stype) + continue; + if (sd_id128_from_string(stype, &type_id) < 0) + continue; + + if (sd_id128_equal(type_id, GPT_HOME)) { + designator = PARTITION_HOME; + rw = !(flags & GPT_FLAG_READ_ONLY); + } else if (sd_id128_equal(type_id, GPT_SRV)) { + designator = PARTITION_SRV; + rw = !(flags & GPT_FLAG_READ_ONLY); + } else if (sd_id128_equal(type_id, GPT_ESP)) { + designator = PARTITION_ESP; + fstype = "vfat"; + } +#ifdef GPT_ROOT_NATIVE + else if (sd_id128_equal(type_id, GPT_ROOT_NATIVE)) { + + /* If a root ID is specified, ignore everything but the root id */ + if (!sd_id128_is_null(root_uuid) && !sd_id128_equal(root_uuid, id)) + continue; + + designator = PARTITION_ROOT; + architecture = native_architecture(); + rw = !(flags & GPT_FLAG_READ_ONLY); + } else if (sd_id128_equal(type_id, GPT_ROOT_NATIVE_VERITY)) { + + m->can_verity = true; + + /* Ignore verity unless a root hash is specified */ + if (sd_id128_is_null(verity_uuid) || !sd_id128_equal(verity_uuid, id)) + continue; + + designator = PARTITION_ROOT_VERITY; + fstype = "DM_verity_hash"; + architecture = native_architecture(); + rw = false; + } +#endif +#ifdef GPT_ROOT_SECONDARY + else if (sd_id128_equal(type_id, GPT_ROOT_SECONDARY)) { + + /* If a root ID is specified, ignore everything but the root id */ + if (!sd_id128_is_null(root_uuid) && !sd_id128_equal(root_uuid, id)) + continue; + + designator = PARTITION_ROOT_SECONDARY; + architecture = SECONDARY_ARCHITECTURE; + rw = !(flags & GPT_FLAG_READ_ONLY); + } else if (sd_id128_equal(type_id, GPT_ROOT_SECONDARY_VERITY)) { + + m->can_verity = true; + + /* Ignore verity unless root has is specified */ + if (sd_id128_is_null(verity_uuid) || !sd_id128_equal(verity_uuid, id)) + continue; + + designator = PARTITION_ROOT_SECONDARY_VERITY; + fstype = "DM_verity_hash"; + architecture = SECONDARY_ARCHITECTURE; + rw = false; + } +#endif + else if (sd_id128_equal(type_id, GPT_SWAP)) { + designator = PARTITION_SWAP; + fstype = "swap"; + } else if (sd_id128_equal(type_id, GPT_LINUX_GENERIC)) { + + if (generic_node) + multiple_generic = true; + else { + generic_nr = nr; + generic_rw = !(flags & GPT_FLAG_READ_ONLY); + generic_node = strdup(node); + if (!generic_node) + return -ENOMEM; + } + } + + if (designator != _PARTITION_DESIGNATOR_INVALID) { + _cleanup_free_ char *t = NULL, *n = NULL; + + /* First one wins */ + if (m->partitions[designator].found) + continue; + + if (fstype) { + t = strdup(fstype); + if (!t) + return -ENOMEM; + } + + n = strdup(node); + if (!n) + return -ENOMEM; + + m->partitions[designator] = (DissectedPartition) { + .found = true, + .partno = nr, + .rw = rw, + .architecture = architecture, + .node = n, + .fstype = t, + }; + + n = t = NULL; + } + + } else if (is_mbr) { + + if (flags != 0x80) /* Bootable flag */ + continue; + + if (blkid_partition_get_type(pp) != 0x83) /* Linux partition */ + continue; + + if (generic_node) + multiple_generic = true; + else { + generic_nr = nr; + generic_rw = true; + generic_node = strdup(node); + if (!generic_node) + return -ENOMEM; + } + } + } + + if (!m->partitions[PARTITION_ROOT].found) { + /* No root partition found? Then let's see if ther's one for the secondary architecture. And if not + * either, then check if there's a single generic one, and use that. */ + + if (m->partitions[PARTITION_ROOT_VERITY].found) + return -ENXIO; + + if (m->partitions[PARTITION_ROOT_SECONDARY].found) { + m->partitions[PARTITION_ROOT] = m->partitions[PARTITION_ROOT_SECONDARY]; + zero(m->partitions[PARTITION_ROOT_SECONDARY]); + + m->partitions[PARTITION_ROOT_VERITY] = m->partitions[PARTITION_ROOT_SECONDARY_VERITY]; + zero(m->partitions[PARTITION_ROOT_SECONDARY_VERITY]); + + } else if (generic_node && !root_hash) { + + if (multiple_generic) + return -ENOTUNIQ; + + m->partitions[PARTITION_ROOT] = (DissectedPartition) { + .found = true, + .rw = generic_rw, + .partno = generic_nr, + .architecture = _ARCHITECTURE_INVALID, + .node = generic_node, + }; + + generic_node = NULL; + } else + return -ENXIO; + } + + assert(m->partitions[PARTITION_ROOT].found); + + if (root_hash) { + if (!m->partitions[PARTITION_ROOT_VERITY].found) + return -EADDRNOTAVAIL; + + /* If we found the primary root with the hash, then we definitely want to suppress any secondary root + * (which would be weird, after all the root hash should only be assigned to one pair of + * partitions... */ + m->partitions[PARTITION_ROOT_SECONDARY].found = false; + m->partitions[PARTITION_ROOT_SECONDARY_VERITY].found = false; + + /* If we found a verity setup, then the root partition is necessarily read-only. */ + m->partitions[PARTITION_ROOT].rw = false; + + m->verity = true; + } + + blkid_free_probe(b); + b = NULL; + + /* Fill in file system types if we don't know them yet. */ + for (i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) { + DissectedPartition *p = m->partitions + i; + + if (!p->found) + continue; + + if (!p->fstype && p->node) { + r = probe_filesystem(p->node, &p->fstype); + if (r < 0) + return r; + } + + if (streq_ptr(p->fstype, "crypto_LUKS")) + m->encrypted = true; + } + + *ret = m; + m = NULL; + + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +DissectedImage* dissected_image_unref(DissectedImage *m) { + unsigned i; + + if (!m) + return NULL; + + for (i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) { + free(m->partitions[i].fstype); + free(m->partitions[i].node); + free(m->partitions[i].decrypted_fstype); + free(m->partitions[i].decrypted_node); + } + + free(m); + return NULL; +} + +static int is_loop_device(const char *path) { + char s[strlen("/sys/dev/block/") + DECIMAL_STR_MAX(dev_t) + 1 + DECIMAL_STR_MAX(dev_t) + strlen("/../loop/")]; + struct stat st; + + assert(path); + + if (stat(path, &st) < 0) + return -errno; + + if (!S_ISBLK(st.st_mode)) + return -ENOTBLK; + + xsprintf(s, "/sys/dev/block/%u:%u/loop/", major(st.st_rdev), minor(st.st_rdev)); + if (access(s, F_OK) < 0) { + if (errno != ENOENT) + return -errno; + + /* The device itself isn't a loop device, but maybe it's a partition and its parent is? */ + xsprintf(s, "/sys/dev/block/%u:%u/../loop/", major(st.st_rdev), minor(st.st_rdev)); + if (access(s, F_OK) < 0) + return errno == ENOENT ? false : -errno; + } + + return true; +} + +static int mount_partition( + DissectedPartition *m, + const char *where, + const char *directory, + DissectImageFlags flags) { + + const char *p, *options = NULL, *node, *fstype; + bool rw; + + assert(m); + assert(where); + + node = m->decrypted_node ?: m->node; + fstype = m->decrypted_fstype ?: m->fstype; + + if (!m->found || !node || !fstype) + return 0; + + /* Stacked encryption? Yuck */ + if (streq_ptr(fstype, "crypto_LUKS")) + return -ELOOP; + + rw = m->rw && !(flags & DISSECT_IMAGE_READ_ONLY); + + if (directory) + p = strjoina(where, directory); + else + p = where; + + /* If requested, turn on discard support. */ + if (STR_IN_SET(fstype, "btrfs", "ext4", "vfat", "xfs") && + ((flags & DISSECT_IMAGE_DISCARD) || + ((flags & DISSECT_IMAGE_DISCARD_ON_LOOP) && is_loop_device(m->node)))) + options = "discard"; + + return mount_verbose(LOG_DEBUG, node, p, fstype, MS_NODEV|(rw ? 0 : MS_RDONLY), options); +} + +int dissected_image_mount(DissectedImage *m, const char *where, DissectImageFlags flags) { + int r; + + assert(m); + assert(where); + + if (!m->partitions[PARTITION_ROOT].found) + return -ENXIO; + + r = mount_partition(m->partitions + PARTITION_ROOT, where, NULL, flags); + if (r < 0) + return r; + + r = mount_partition(m->partitions + PARTITION_HOME, where, "/home", flags); + if (r < 0) + return r; + + r = mount_partition(m->partitions + PARTITION_SRV, where, "/srv", flags); + if (r < 0) + return r; + + if (m->partitions[PARTITION_ESP].found) { + const char *mp, *x; + + /* Mount the ESP to /efi if it exists and is empty. If it doesn't exist, use /boot instead. */ + + mp = "/efi"; + x = strjoina(where, mp); + r = dir_is_empty(x); + if (r == -ENOENT) { + mp = "/boot"; + x = strjoina(where, mp); + r = dir_is_empty(x); + } + if (r > 0) { + r = mount_partition(m->partitions + PARTITION_ESP, where, mp, flags); + if (r < 0) + return r; + } + } + + return 0; +} + +#ifdef HAVE_LIBCRYPTSETUP +typedef struct DecryptedPartition { + struct crypt_device *device; + char *name; + bool relinquished; +} DecryptedPartition; + +struct DecryptedImage { + DecryptedPartition *decrypted; + size_t n_decrypted; + size_t n_allocated; +}; +#endif + +DecryptedImage* decrypted_image_unref(DecryptedImage* d) { +#ifdef HAVE_LIBCRYPTSETUP + size_t i; + int r; + + if (!d) + return NULL; + + for (i = 0; i < d->n_decrypted; i++) { + DecryptedPartition *p = d->decrypted + i; + + if (p->device && p->name && !p->relinquished) { + r = crypt_deactivate(p->device, p->name); + if (r < 0) + log_debug_errno(r, "Failed to deactivate encrypted partition %s", p->name); + } + + if (p->device) + crypt_free(p->device); + free(p->name); + } + + free(d); +#endif + return NULL; +} + +#ifdef HAVE_LIBCRYPTSETUP + +static int make_dm_name_and_node(const void *original_node, const char *suffix, char **ret_name, char **ret_node) { + _cleanup_free_ char *name = NULL, *node = NULL; + const char *base; + + assert(original_node); + assert(suffix); + assert(ret_name); + assert(ret_node); + + base = strrchr(original_node, '/'); + if (!base) + return -EINVAL; + base++; + if (isempty(base)) + return -EINVAL; + + name = strjoin(base, suffix); + if (!name) + return -ENOMEM; + if (!filename_is_valid(name)) + return -EINVAL; + + node = strjoin(crypt_get_dir(), "/", name); + if (!node) + return -ENOMEM; + + *ret_name = name; + *ret_node = node; + + name = node = NULL; + return 0; +} + +static int decrypt_partition( + DissectedPartition *m, + const char *passphrase, + DissectImageFlags flags, + DecryptedImage *d) { + + _cleanup_free_ char *node = NULL, *name = NULL; + struct crypt_device *cd; + int r; + + assert(m); + assert(d); + + if (!m->found || !m->node || !m->fstype) + return 0; + + if (!streq(m->fstype, "crypto_LUKS")) + return 0; + + r = make_dm_name_and_node(m->node, "-decrypted", &name, &node); + if (r < 0) + return r; + + if (!GREEDY_REALLOC0(d->decrypted, d->n_allocated, d->n_decrypted + 1)) + return -ENOMEM; + + r = crypt_init(&cd, m->node); + if (r < 0) + return r; + + r = crypt_load(cd, CRYPT_LUKS1, NULL); + if (r < 0) + goto fail; + + r = crypt_activate_by_passphrase(cd, name, CRYPT_ANY_SLOT, passphrase, strlen(passphrase), + ((flags & DISSECT_IMAGE_READ_ONLY) ? CRYPT_ACTIVATE_READONLY : 0) | + ((flags & DISSECT_IMAGE_DISCARD_ON_CRYPTO) ? CRYPT_ACTIVATE_ALLOW_DISCARDS : 0)); + if (r == -EPERM) { + r = -EKEYREJECTED; + goto fail; + } + if (r < 0) + goto fail; + + d->decrypted[d->n_decrypted].name = name; + name = NULL; + + d->decrypted[d->n_decrypted].device = cd; + d->n_decrypted++; + + m->decrypted_node = node; + node = NULL; + + return 0; + +fail: + crypt_free(cd); + return r; +} + +static int verity_partition( + DissectedPartition *m, + DissectedPartition *v, + const void *root_hash, + size_t root_hash_size, + DissectImageFlags flags, + DecryptedImage *d) { + + _cleanup_free_ char *node = NULL, *name = NULL; + struct crypt_device *cd; + int r; + + assert(m); + assert(v); + + if (!root_hash) + return 0; + + if (!m->found || !m->node || !m->fstype) + return 0; + if (!v->found || !v->node || !v->fstype) + return 0; + + if (!streq(v->fstype, "DM_verity_hash")) + return 0; + + r = make_dm_name_and_node(m->node, "-verity", &name, &node); + if (r < 0) + return r; + + if (!GREEDY_REALLOC0(d->decrypted, d->n_allocated, d->n_decrypted + 1)) + return -ENOMEM; + + r = crypt_init(&cd, v->node); + if (r < 0) + return r; + + r = crypt_load(cd, CRYPT_VERITY, NULL); + if (r < 0) + goto fail; + + r = crypt_set_data_device(cd, m->node); + if (r < 0) + goto fail; + + r = crypt_activate_by_volume_key(cd, name, root_hash, root_hash_size, CRYPT_ACTIVATE_READONLY); + if (r < 0) + goto fail; + + d->decrypted[d->n_decrypted].name = name; + name = NULL; + + d->decrypted[d->n_decrypted].device = cd; + d->n_decrypted++; + + m->decrypted_node = node; + node = NULL; + + return 0; + +fail: + crypt_free(cd); + return r; +} +#endif + +int dissected_image_decrypt( + DissectedImage *m, + const char *passphrase, + const void *root_hash, + size_t root_hash_size, + DissectImageFlags flags, + DecryptedImage **ret) { + + _cleanup_(decrypted_image_unrefp) DecryptedImage *d = NULL; +#ifdef HAVE_LIBCRYPTSETUP + unsigned i; + int r; +#endif + + assert(m); + assert(root_hash || root_hash_size == 0); + + /* Returns: + * + * = 0 → There was nothing to decrypt + * > 0 → Decrypted successfully + * -ENOKEY → There's some to decrypt but no key was supplied + * -EKEYREJECTED → Passed key was not correct + */ + + if (root_hash && root_hash_size < sizeof(sd_id128_t)) + return -EINVAL; + + if (!m->encrypted && !m->verity) { + *ret = NULL; + return 0; + } + +#ifdef HAVE_LIBCRYPTSETUP + if (m->encrypted && !passphrase) + return -ENOKEY; + + d = new0(DecryptedImage, 1); + if (!d) + return -ENOMEM; + + for (i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) { + DissectedPartition *p = m->partitions + i; + int k; + + if (!p->found) + continue; + + r = decrypt_partition(p, passphrase, flags, d); + if (r < 0) + return r; + + k = PARTITION_VERITY_OF(i); + if (k >= 0) { + r = verity_partition(p, m->partitions + k, root_hash, root_hash_size, flags, d); + if (r < 0) + return r; + } + + if (!p->decrypted_fstype && p->decrypted_node) { + r = probe_filesystem(p->decrypted_node, &p->decrypted_fstype); + if (r < 0) + return r; + } + } + + *ret = d; + d = NULL; + + return 1; +#else + return -EOPNOTSUPP; +#endif +} + +int dissected_image_decrypt_interactively( + DissectedImage *m, + const char *passphrase, + const void *root_hash, + size_t root_hash_size, + DissectImageFlags flags, + DecryptedImage **ret) { + + _cleanup_strv_free_erase_ char **z = NULL; + int n = 3, r; + + if (passphrase) + n--; + + for (;;) { + r = dissected_image_decrypt(m, passphrase, root_hash, root_hash_size, flags, ret); + if (r >= 0) + return r; + if (r == -EKEYREJECTED) + log_error_errno(r, "Incorrect passphrase, try again!"); + else if (r != -ENOKEY) { + log_error_errno(r, "Failed to decrypt image: %m"); + return r; + } + + if (--n < 0) { + log_error("Too many retries."); + return -EKEYREJECTED; + } + + z = strv_free(z); + + r = ask_password_auto("Please enter image passphrase!", NULL, "dissect", "dissect", USEC_INFINITY, 0, &z); + if (r < 0) + return log_error_errno(r, "Failed to query for passphrase: %m"); + + passphrase = z[0]; + } +} + +#ifdef HAVE_LIBCRYPTSETUP +static int deferred_remove(DecryptedPartition *p) { + + struct dm_ioctl dm = { + .version = { + DM_VERSION_MAJOR, + DM_VERSION_MINOR, + DM_VERSION_PATCHLEVEL + }, + .data_size = sizeof(dm), + .flags = DM_DEFERRED_REMOVE, + }; + + _cleanup_close_ int fd = -1; + + assert(p); + + /* Unfortunately, libcryptsetup doesn't provide a proper API for this, hence call the ioctl() directly. */ + + fd = open("/dev/mapper/control", O_RDWR|O_CLOEXEC); + if (fd < 0) + return -errno; + + strncpy(dm.name, p->name, sizeof(dm.name)); + + if (ioctl(fd, DM_DEV_REMOVE, &dm)) + return -errno; + + return 0; +} +#endif + +int decrypted_image_relinquish(DecryptedImage *d) { + +#ifdef HAVE_LIBCRYPTSETUP + size_t i; + int r; +#endif + + assert(d); + + /* Turns on automatic removal after the last use ended for all DM devices of this image, and sets a boolean so + * that we don't clean it up ourselves either anymore */ + +#ifdef HAVE_LIBCRYPTSETUP + for (i = 0; i < d->n_decrypted; i++) { + DecryptedPartition *p = d->decrypted + i; + + if (p->relinquished) + continue; + + r = deferred_remove(p); + if (r < 0) + return log_debug_errno(r, "Failed to mark %s for auto-removal: %m", p->name); + + p->relinquished = true; + } +#endif + + return 0; +} + +static const char *const partition_designator_table[] = { + [PARTITION_ROOT] = "root", + [PARTITION_ROOT_SECONDARY] = "root-secondary", + [PARTITION_HOME] = "home", + [PARTITION_SRV] = "srv", + [PARTITION_ESP] = "esp", + [PARTITION_SWAP] = "swap", + [PARTITION_ROOT_VERITY] = "root-verity", + [PARTITION_ROOT_SECONDARY_VERITY] = "root-secondary-verity", +}; + +DEFINE_STRING_TABLE_LOOKUP(partition_designator, int); |