Signed-off-by: Maxim Levitsky <mlevi...@redhat.com>
---
crypto/block-luks.c | 374 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 373 insertions(+), 1 deletion(-)
diff --git a/crypto/block-luks.c b/crypto/block-luks.c
index 1997e92fe1..2c33643b52 100644
--- a/crypto/block-luks.c
+++ b/crypto/block-luks.c
@@ -72,6 +72,8 @@ typedef struct QCryptoBlockLUKSKeySlot
QCryptoBlockLUKSKeySlot;
#define QCRYPTO_BLOCK_LUKS_DEFAULT_ITER_TIME 2000
+#define QCRYPTO_BLOCK_LUKS_ERASE_ITERATIONS 40
+
static const char qcrypto_block_luks_magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN] = {
'L', 'U', 'K', 'S', 0xBA, 0xBE
};
@@ -221,6 +223,9 @@ struct QCryptoBlockLUKS {
/* Hash algorithm used in pbkdf2 function */
QCryptoHashAlgorithm hash_alg;
+
+ /* Name of the secret that was used to open the image */
+ char *secret;
};
@@ -1121,6 +1126,194 @@ qcrypto_block_luks_find_key(QCryptoBlock *block,
}
+
+/*
+ * Returns true if a slot i is marked as containing as active
+ * (contains encrypted copy of the master key)
+ */
+
+static bool
+qcrypto_block_luks_slot_active(QCryptoBlockLUKS *luks, int slot_idx)
+{
+ uint32_t val = luks->header.key_slots[slot_idx].active;
+ return val == QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED;
+}
+
+/*
+ * Returns the number of slots that are marked as active
+ * (contains encrypted copy of the master key)
+ */
+
+static int
+qcrypto_block_luks_count_active_slots(QCryptoBlockLUKS *luks)
+{
+ int i, ret = 0;
+
+ for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
+ if (qcrypto_block_luks_slot_active(luks, i)) {
+ ret++;
+ }
+ }
+ return ret;
+}
+
+
+/*
+ * Finds first key slot which is not active
+ * Returns the key slot index, or -1 if doesn't exist
+ */
+
+static int
+qcrypto_block_luks_find_free_keyslot(QCryptoBlockLUKS *luks)
+{
+ uint i;
+
+ for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
+ if (!qcrypto_block_luks_slot_active(luks, i)) {
+ return i;
+ }
+ }
+ return -1;
+
+}
+
+/*
+ * Erases an keyslot given its index
+ *
+ * Returns:
+ * 0 if the keyslot was erased successfully
+ * -1 if a error occurred while erasing the keyslot
+ *
+ */
+
+static int
+qcrypto_block_luks_erase_key(QCryptoBlock *block,
+ uint slot_idx,
+ QCryptoBlockWriteFunc writefunc,
+ void *opaque,
+ Error **errp)
+{
+ QCryptoBlockLUKS *luks = block->opaque;
+ QCryptoBlockLUKSKeySlot *slot = &luks->header.key_slots[slot_idx];
+ uint8_t *garbagekey = NULL;
+ size_t splitkeylen = masterkeylen(luks) * slot->stripes;
+ int i;
+ int ret = -1;
+
+ assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
+ assert(splitkeylen > 0);
+
+ garbagekey = g_malloc0(splitkeylen);
+
+ /* Reset the key slot header */
+ memset(slot->salt, 0, QCRYPTO_BLOCK_LUKS_SALT_LEN);
+ slot->iterations = 0;
+ slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED;
+
+ qcrypto_block_luks_store_header(block, writefunc, opaque, errp);
+
+ /*
+ * Now try to erase the key material, even if the header
+ * update failed
+ */
+
+ for (i = 0 ; i < QCRYPTO_BLOCK_LUKS_ERASE_ITERATIONS ; i++) {
+ if (qcrypto_random_bytes(garbagekey, splitkeylen, errp) < 0) {
+
+ /*
+ * If we failed to get the random data, still write
+ * *something* to the key slot at least once
+ */
+
+ if (i > 0) {
+ goto cleanup;
+ }
+ }
+
+ if (writefunc(block, slot->key_offset * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
+ garbagekey,
+ splitkeylen,
+ opaque,
+ errp) != splitkeylen) {
+ goto cleanup;
+ }
+ }
+
+ ret = 0;
+cleanup:
+ g_free(garbagekey);
+ return ret;
+}
+
+
+/*
+ * Erase all the keys that match the given password
+ * Will stop when only one keyslot is remaining
+ * Returns 0 is some keys were erased or -1 on failure
+ */
+
+static int
+qcrypto_block_luks_erase_matching_keys(QCryptoBlock *block,
+ const char *password,
+ QCryptoBlockReadFunc readfunc,
+ QCryptoBlockWriteFunc writefunc,
+ void *opaque,
+ bool force,
+ Error **errp)
+{
+ QCryptoBlockLUKS *luks = block->opaque;
+ uint i;
+ int rv, ret = -1;
+ uint8_t *masterkey;
+ uint erased_count = 0;
+ uint active_slot_count = qcrypto_block_luks_count_active_slots(luks);
+
+ masterkey = g_new0(uint8_t, masterkeylen(luks));
+
+ for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
+
+ /* refuse to erase last key if not forced */
+ if (!force && active_slot_count == 1) {
+ break;
+ }
+
+ rv = qcrypto_block_luks_load_key(block,
+ i,
+ password,
+ masterkey,
+ readfunc,
+ opaque,
+ errp);
+ if (rv < 0) {
+ goto cleanup;
+ }
+ if (rv == 0) {
+ continue;
+ }
+
+ rv = qcrypto_block_luks_erase_key(block, i, writefunc, opaque, errp);
+ if (rv < 0) {
+ goto cleanup;
+ }
+
+ erased_count++;
+ active_slot_count--;
+ }
+
+ if (!erased_count) {
+ error_setg(errp, "Didn't erase a keyslot, because no keyslots "
+ "match the given password");
+ goto cleanup;
+ }
+
+ ret = 0;
+cleanup:
+ memset(masterkey, 0, masterkeylen(luks));
+ g_free(masterkey);
+ return ret;
+}
+
+
static int
qcrypto_block_luks_open(QCryptoBlock *block,
QCryptoBlockOpenOptions *options,
@@ -1151,6 +1344,7 @@ qcrypto_block_luks_open(QCryptoBlock *block,
luks = g_new0(QCryptoBlockLUKS, 1);
block->opaque = luks;
+ luks->secret = g_strdup(options->u.luks.key_secret);
ret = qcrypto_block_luks_load_header(block, readfunc, opaque, errp);
if (ret) {
@@ -1320,6 +1514,8 @@ qcrypto_block_luks_create(QCryptoBlock *block,
optprefix ? optprefix : "");
return -1;
}
+ luks->secret = options->u.luks.key_secret;
+
password = qcrypto_secret_lookup_as_utf8(luks_opts.key_secret, errp);
if (!password) {
return -1;
@@ -1605,7 +1801,9 @@ static int qcrypto_block_luks_get_info(QCryptoBlock
*block,
static void qcrypto_block_luks_cleanup(QCryptoBlock *block)
{
- g_free(block->opaque);
+ QCryptoBlockLUKS *luks = block->opaque;
+ g_free(luks->secret);
+ g_free(luks);
}
@@ -1638,6 +1836,179 @@ qcrypto_block_luks_encrypt(QCryptoBlock *block,
offset, buf, len, errp);
}
+static int
+qcrypto_block_luks_setup_encryption(QCryptoBlock *block,
+ QCryptoBlockReadFunc readfunc,
+ QCryptoBlockWriteFunc writefunc,
+ void *opaque,
+ enum BlkSetupEncryptionAction action,
+ QCryptoEncryptionSetupOptions *options,
+ bool force,
+ Error **errp)
+{
+ QCryptoBlockLUKS *luks = block->opaque;
+ char *old_password = NULL;
+ char *password = NULL;
+ const char *old_secret = luks->secret;
+ uint8_t *masterkey = NULL;
+ int slot = -1;
+ int ret = -1;
+ int64_t iter_time = QCRYPTO_BLOCK_LUKS_DEFAULT_ITER_TIME;
+
+ /* Read given slot and check it */
+ if (options->has_slot) {
+ slot = options->slot;
+ if (slot < 0 || slot >= QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS) {
+ error_setg(errp,
+ "Given key slot %i is not supported by LUKS", slot);
+ goto cleanup;
+ }
+ }
+
+ if (options->has_iter_time) {
+ iter_time = options->iter_time;
+ }
+
+ switch (action) {
+
+ case BLK_UPDATE_ENCRYPTION:
+
+ /* Check that we are not overwriting an active slot */
+ if (!force && slot != -1 &&
+ qcrypto_block_luks_slot_active(luks, slot)) {
+
+ error_setg(errp, "Can't update an active key slot %i",
+ slot);
+ goto cleanup;
+ }
+
+ /* check that we have the passwords*/
+ if (!options->has_key_secret) {
+ error_setg(errp, "Can't add a key slot without a password");
+ goto cleanup;
+ }
+
+ if (options->has_old_key_secret) {
+ old_secret = options->old_key_secret;
+ }
+
+ /* Read the old password */
+ old_password = qcrypto_secret_lookup_as_utf8(old_secret, errp);
+ if (!old_password) {
+ goto cleanup;
+ }
+
+ masterkey = g_new0(uint8_t, masterkeylen(luks));
+
+ /* Retrieve the master key*/
+ if (qcrypto_block_luks_find_key(block, old_password, masterkey,
+ readfunc, opaque, errp) < 0) {
+ error_append_hint(errp,
+ "Old password that was given doesn't unlock the image");
+ goto cleanup;
+ }
+
+ /* Read the new password*/
+ password = qcrypto_secret_lookup_as_utf8(options->key_secret, errp);
+ if (!password) {
+ goto cleanup;
+ }
+
+ /* Find the new slot to write to */
+ if (slot == -1) {
+ slot = qcrypto_block_luks_find_free_keyslot(luks);
+
+ if (slot == -1) {
+ error_setg(errp,
+ "Can't add a keyslot - all key slots are in use");
+ goto cleanup;
+
+ }
+ }
+
+ /* Store the master key to the new slot */
+ if (qcrypto_block_luks_store_key(block, slot, password,
+ masterkey, iter_time,
+ writefunc, opaque, errp)) {
+
+ error_append_hint(errp, "Failed to store the keyslot %i", slot);
+ goto cleanup;
+ }
+ break;
+
+ case BLK_ERASE_ENCRYPTION:
+
+ /* Check that we are not erasing last key slot */
+ if (qcrypto_block_luks_count_active_slots(luks) <= 1) {
+
+ if (!force) {
+ error_setg(errp, "Only one slot active - can't erase");
+ goto cleanup;
+ }
+ }
+
+ if (slot != -1) {
+ /* Check that we are not erasing an inactive slot */
+ if (!qcrypto_block_luks_slot_active(luks, options->slot)) {
+ if (!force) {
+ error_setg(errp, "Can't erase an inactive key slot %i",
+ slot);
+ goto cleanup;
+ }
+ }
+
+ /* Erase the given slot */
+ if (qcrypto_block_luks_erase_key(block, slot,
+ writefunc, opaque, errp)) {
+ goto cleanup;
+ }
+
+ } else {
+ if (!options->has_key_secret) {
+ error_setg(errp,
+ "To erase a keyslot you have to specify either the"
+ "slot index or a password "
+ "(to erase all slots that match it)");
+ goto cleanup;
+ }
+
+ password = qcrypto_secret_lookup_as_utf8(options->key_secret,
errp);
+ if (!password) {
+ goto cleanup;
+ }
+
+ if (qcrypto_block_luks_erase_matching_keys(block, password,
+ readfunc, writefunc,
+ opaque, force, errp)) {
+ goto cleanup;
+ }
+ }
+ break;
+
+ default:
+ goto cleanup;
+ }
+
+ ret = 0;
+cleanup:
+
+ if (old_password) {
+ memset(old_password, 0, strlen(old_password));
+ g_free(old_password);
+ }
+
+ if (password) {
+ memset(password, 0, strlen(password));
+ g_free(password);
+ }
+
+ if (masterkey) {
+ memset(masterkey, 0, masterkeylen(luks));
+ g_free(masterkey);
+ }
+ return ret;
+}
+
const QCryptoBlockDriver qcrypto_block_driver_luks = {
.open = qcrypto_block_luks_open,
@@ -1647,4 +2018,5 @@ const QCryptoBlockDriver qcrypto_block_driver_luks = {
.decrypt = qcrypto_block_luks_decrypt,
.encrypt = qcrypto_block_luks_encrypt,
.has_format = qcrypto_block_luks_has_format,
+ .setup_encryption = qcrypto_block_luks_setup_encryption,
};
--
2.17.2
