/*

 * veritysetup - setup cryptographic volumes for dm-verity

 *

 * Copyright (C) 2012-2020 Red Hat, Inc. All rights reserved.

 * Copyright (C) 2012-2020 Milan Broz

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#include "cryptsetup.h"

#define PACKAGE_VERITY "veritysetup"

static int use_superblock = 1;

static const char *fec_device = NULL;

static int fec_roots = DEFAULT_VERITY_FEC_ROOTS;

static const char *hash_algorithm = NULL;

static int hash_type = 1;

static int data_block_size = DEFAULT_VERITY_DATA_BLOCK;

static int hash_block_size = DEFAULT_VERITY_HASH_BLOCK;

static uint64_t data_blocks = 0;

static const char *salt_string = NULL;

static uint64_t hash_offset = 0;

static uint64_t fec_offset = 0;

static const char *opt_uuid = NULL;

static int opt_restart_on_corruption = 0;

static int opt_ignore_corruption = 0;

static int opt_ignore_zero_blocks = 0;

static int opt_check_at_most_once = 0;

static const char *opt_root_hash_signature = NULL;

static const char **action_argv;

static int action_argc;

static int _prepare_format(struct crypt_params_verity *params,

			   const char *data_device,

			   uint32_t flags)

{

	char *salt = NULL;

	int len;

	params->hash_name = hash_algorithm ?: DEFAULT_VERITY_HASH;

	params->data_device = data_device;

	params->fec_device = fec_device;

	params->fec_roots = fec_roots;

	if (salt_string && !strcmp(salt_string, "-")) {

		params->salt_size = 0;

		params->salt = NULL;

	} else if (salt_string) {

		len = crypt_hex_to_bytes(salt_string, &salt, 0);

		if (len < 0) {

			log_err(_("Invalid salt string specified."));

			return -EINVAL;

		}

		params->salt_size = len;

		params->salt = salt;

	} else {

		params->salt_size = DEFAULT_VERITY_SALT_SIZE;

		params->salt = NULL;

	}

	params->data_block_size = data_block_size;

	params->hash_block_size = hash_block_size;

	params->data_size = data_blocks;

	params->hash_area_offset = hash_offset;

	params->fec_area_offset = fec_offset;

	params->hash_type = hash_type;

	params->flags = flags;

	return 0;

}

static int action_format(int arg)

{

	struct crypt_device *cd = NULL;

	struct crypt_params_verity params = {};

	uint32_t flags = CRYPT_VERITY_CREATE_HASH;

	int r;

	/* Try to create hash image if doesn't exist */

	r = open(action_argv[1], O_WRONLY | O_EXCL | O_CREAT, S_IRUSR | S_IWUSR);

	if (r < 0 && errno != EEXIST) {

		log_err(_("Cannot create hash image %s for writing."), action_argv[1]);

		return -EINVAL;

	} else if (r >= 0) {

		log_dbg("Created hash image %s.", action_argv[1]);

		close(r);

	}

	/* Try to create FEC image if doesn't exist */

	if (fec_device) {

		r = open(fec_device, O_WRONLY | O_EXCL | O_CREAT, S_IRUSR | S_IWUSR);

		if (r < 0 && errno != EEXIST) {

			log_err(_("Cannot create FEC image %s for writing."), fec_device);

			return -EINVAL;

		} else if (r >= 0) {

			log_dbg("Created FEC image %s.", fec_device);

			close(r);

		}

	}

	if ((r = crypt_init(&cd, action_argv[1])))

		goto out;

	if (!use_superblock)

		flags |= CRYPT_VERITY_NO_HEADER;

	r = _prepare_format(&params, action_argv[0], flags);

	if (r < 0)

		goto out;

	r = crypt_format(cd, CRYPT_VERITY, NULL, NULL, opt_uuid, NULL, 0, &params);

	if (!r)

		crypt_dump(cd);

out:

	crypt_free(cd);

	free(CONST_CAST(char*)params.salt);

	return r;

}

static int _activate(const char *dm_device,

		      const char *data_device,

		      const char *hash_device,

		      const char *root_hash,

		      uint32_t flags)

{

	struct crypt_device *cd = NULL;

	struct crypt_params_verity params = {};

	uint32_t activate_flags = CRYPT_ACTIVATE_READONLY;

	char *root_hash_bytes = NULL;

	ssize_t hash_size;

	struct stat st;

	char *signature = NULL;

	int signature_size = 0, r;

	if ((r = crypt_init_data_device(&cd, hash_device, data_device)))

		goto out;

	if (opt_ignore_corruption)

		activate_flags |= CRYPT_ACTIVATE_IGNORE_CORRUPTION;

	if (opt_restart_on_corruption)

		activate_flags |= CRYPT_ACTIVATE_RESTART_ON_CORRUPTION;

	if (opt_ignore_zero_blocks)

		activate_flags |= CRYPT_ACTIVATE_IGNORE_ZERO_BLOCKS;

	if (opt_check_at_most_once)

		activate_flags |= CRYPT_ACTIVATE_CHECK_AT_MOST_ONCE;

	if (use_superblock) {

		params.flags = flags;

		params.hash_area_offset = hash_offset;

		params.fec_area_offset = fec_offset;

		params.fec_device = fec_device;

		params.fec_roots = fec_roots;

		r = crypt_load(cd, CRYPT_VERITY, &params);

	} else {

		r = _prepare_format(&params, data_device, flags | CRYPT_VERITY_NO_HEADER);

		if (r < 0)

			goto out;

		r = crypt_format(cd, CRYPT_VERITY, NULL, NULL, NULL, NULL, 0, &params);

	}

	if (r < 0)

		goto out;

	hash_size = crypt_get_volume_key_size(cd);

	if (crypt_hex_to_bytes(root_hash, &root_hash_bytes, 0) != hash_size) {

		log_err(_("Invalid root hash string specified."));

		r = -EINVAL;

		goto out;

	}

	if (opt_root_hash_signature) {

		// FIXME: check max file size

		if (stat(opt_root_hash_signature, &st) || !S_ISREG(st.st_mode) || !st.st_size) {

			log_err(_("Invalid signature file %s."), opt_root_hash_signature);

			r = -EINVAL;

			goto out;

		}

		signature_size = st.st_size;

		r = tools_read_mk(opt_root_hash_signature, &signature, signature_size);

		if (r < 0) {

			log_err(_("Cannot read signature file %s."), opt_root_hash_signature);

			goto out;

		}

	}

	r = crypt_activate_by_signed_key(cd, dm_device,

					 root_hash_bytes,

					 hash_size,

					 signature, signature_size,

					 activate_flags);

out:

	crypt_safe_free(signature);

	crypt_free(cd);

	free(root_hash_bytes);

	free(CONST_CAST(char*)params.salt);

	return r;

}

static int action_open(int arg)

{

	return _activate(action_argv[1],

			 action_argv[0],

			 action_argv[2],

			 action_argv[3],

			 opt_root_hash_signature ? CRYPT_VERITY_ROOT_HASH_SIGNATURE : 0);

}

static int action_verify(int arg)

{

	return _activate(NULL,

			 action_argv[0],

			 action_argv[1],

			 action_argv[2],

			 CRYPT_VERITY_CHECK_HASH);

}

static int action_close(int arg)

{

	struct crypt_device *cd = NULL;

	int r;

	r = crypt_init_by_name(&cd, action_argv[0]);

	if (r == 0)

		r = crypt_deactivate(cd, action_argv[0]);

	crypt_free(cd);

	return r;

}

static int action_status(int arg)

{

	crypt_status_info ci;

	struct crypt_active_device cad;

	struct crypt_params_verity vp = {};

	struct crypt_device *cd = NULL;

	struct stat st;

	char *backing_file, *root_hash;

	size_t root_hash_size;

	unsigned i, path = 0;

	int r = 0;

	/* perhaps a path, not a dm device name */

	if (strchr(action_argv[0], '/') && !stat(action_argv[0], &st))

		path = 1;

	ci = crypt_status(NULL, action_argv[0]);

	switch (ci) {

	case CRYPT_INVALID:

		r = -EINVAL;

		break;

	case CRYPT_INACTIVE:

		if (path)

			log_std("%s is inactive.\n", action_argv[0]);

		else

			log_std("%s/%s is inactive.\n", crypt_get_dir(), action_argv[0]);

		r = -ENODEV;

		break;

	case CRYPT_ACTIVE:

	case CRYPT_BUSY:

		if (path)

			log_std("%s is active%s.\n", action_argv[0],

				ci == CRYPT_BUSY ? " and is in use" : "");

		else

			log_std("%s/%s is active%s.\n", crypt_get_dir(), action_argv[0],

				ci == CRYPT_BUSY ? " and is in use" : "");

		r = crypt_init_by_name_and_header(&cd, action_argv[0], NULL);

		if (r < 0)

			goto out;

		log_std("  type:        %s\n", crypt_get_type(cd) ?: "n/a");

		r = crypt_get_active_device(cd, action_argv[0], &cad;;

		if (r < 0)

			goto out;

		/* Print only VERITY type devices */

		r = crypt_get_verity_info(cd, &vp);

		if (r < 0)

			goto out;

		log_std("  status:      %s%s\n",

			cad.flags & CRYPT_ACTIVATE_CORRUPTED ? "corrupted" : "verified",

			vp.flags & CRYPT_VERITY_ROOT_HASH_SIGNATURE ? " (with signature)" : "");

		log_std("  hash type:   %u\n", vp.hash_type);

		log_std("  data block:  %u\n", vp.data_block_size);

		log_std("  hash block:  %u\n", vp.hash_block_size);

		log_std("  hash name:   %s\n", vp.hash_name);

		log_std("  salt:        ");

		if (vp.salt_size)

			for(i = 0; i < vp.salt_size; i++)

				log_std("%02hhx", (const char)vp.salt[i]);

		else

			log_std("-");

		log_std("\n");

		log_std("  data device: %s\n", vp.data_device);

		if ((backing_file = crypt_loop_backing_file(vp.data_device))) {

			log_std("  data loop:   %s\n", backing_file);

			free(backing_file);

		}

		log_std("  size:        %" PRIu64 " sectors\n", cad.size);

		log_std("  mode:        %s\n", cad.flags & CRYPT_ACTIVATE_READONLY ?

					   "readonly" : "read/write");

		log_std("  hash device: %s\n", vp.hash_device);

		if ((backing_file = crypt_loop_backing_file(vp.hash_device))) {

			log_std("  hash loop:   %s\n", backing_file);

			free(backing_file);

		}

		log_std("  hash offset: %" PRIu64 " sectors\n",

			vp.hash_area_offset * vp.hash_block_size / 512);

		if (vp.fec_device) {

			log_std("  FEC device:  %s\n", vp.fec_device);

			if ((backing_file = crypt_loop_backing_file(vp.fec_device))) {

				log_std("  FEC loop:    %s\n", backing_file);

				free(backing_file);

			}

			log_std("  FEC offset:  %" PRIu64 " sectors\n",

				vp.fec_area_offset * vp.hash_block_size / 512);

			log_std("  FEC roots:   %u\n", vp.fec_roots);

		}

		root_hash_size = crypt_get_volume_key_size(cd);

		if (root_hash_size > 0 && (root_hash = malloc(root_hash_size))) {

			r = crypt_volume_key_get(cd, CRYPT_ANY_SLOT, root_hash, &root_hash_size, NULL, 0);

			if (!r) {

				log_std("  root hash:   ");

				for (i = 0; i < root_hash_size; i++)

					log_std("%02hhx", (const char)root_hash[i]);

				log_std("\n");

			}

			free(root_hash);

		}

		if (cad.flags & (CRYPT_ACTIVATE_IGNORE_CORRUPTION|

				 CRYPT_ACTIVATE_RESTART_ON_CORRUPTION|

				 CRYPT_ACTIVATE_IGNORE_ZERO_BLOCKS|

				 CRYPT_ACTIVATE_CHECK_AT_MOST_ONCE))

			log_std("  flags:       %s%s%s%s\n",

				(cad.flags & CRYPT_ACTIVATE_IGNORE_CORRUPTION) ? "ignore_corruption " : "",

				(cad.flags & CRYPT_ACTIVATE_RESTART_ON_CORRUPTION) ? "restart_on_corruption " : "",

				(cad.flags & CRYPT_ACTIVATE_IGNORE_ZERO_BLOCKS) ? "ignore_zero_blocks " : "",

				(cad.flags & CRYPT_ACTIVATE_CHECK_AT_MOST_ONCE) ? "check_at_most_once" : "");

	}

out:

	crypt_free(cd);

	if (r == -ENOTSUP)

		r = 0;

	return r;

}

static int action_dump(int arg)

{

	struct crypt_device *cd = NULL;

	struct crypt_params_verity params = {};

	int r;

	if ((r = crypt_init(&cd, action_argv[0])))

		return r;

	params.hash_area_offset = hash_offset;

	params.fec_area_offset = fec_offset;

	r = crypt_load(cd, CRYPT_VERITY, &params);

	if (!r)

		crypt_dump(cd);

	crypt_free(cd);

	return r;

}

static struct action_type {

	const char *type;

	int (*handler)(int);

	int required_action_argc;

	const char *arg_desc;

	const char *desc;

} action_types[] = {

	{ "format",	action_format, 2, N_("<data_device> <hash_device>"),N_("format device") },

	{ "verify",	action_verify, 3, N_("<data_device> <hash_device> <root_hash>"),N_("verify device") },

	{ "open",	action_open,   4, N_("<data_device> <name> <hash_device> <root_hash>"),N_("open device as <name>") },

	{ "close",	action_close,  1, N_("<name>"),N_("close device (remove mapping)") },

	{ "status",	action_status, 1, N_("<name>"),N_("show active device status") },

	{ "dump",	action_dump,   1, N_("<hash_device>"),N_("show on-disk information") },

	{ NULL, NULL, 0, NULL, NULL }

};

static void help(poptContext popt_context,

		 enum poptCallbackReason reason __attribute__((unused)),

		 struct poptOption *key,

		 const char *arg __attribute__((unused)),

		 void *data __attribute__((unused)))

{

	struct action_type *action;

	if (key->shortName == '?') {

		log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);

		poptPrintHelp(popt_context, stdout, 0);

		log_std(_("\n"

			 "<action> is one of:\n"));

		for(action = action_types; action->type; action++)

			log_std("\t%s %s - %s\n", action->type, _(action->arg_desc), _(action->desc));

		log_std(_("\n"

			 "<name> is the device to create under %s\n"

			 "<data_device> is the data device\n"

			 "<hash_device> is the device containing verification data\n"

			 "<root_hash> hash of the root node on <hash_device>\n"),

			crypt_get_dir());

		log_std(_("\nDefault compiled-in dm-verity parameters:\n"

			 "\tHash: %s, Data block (bytes): %u, "

			 "Hash block (bytes): %u, Salt size: %u, Hash format: %u\n"),

			DEFAULT_VERITY_HASH, DEFAULT_VERITY_DATA_BLOCK,

			DEFAULT_VERITY_HASH_BLOCK, DEFAULT_VERITY_SALT_SIZE,

			1);

		poptFreeContext(popt_context);

		exit(EXIT_SUCCESS);

	} else if (key->shortName == 'V') {

		log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);

		poptFreeContext(popt_context);

		exit(EXIT_SUCCESS);

	} else

		usage(popt_context, EXIT_SUCCESS, NULL, NULL);

}

static int run_action(struct action_type *action)

{

	int r;

	log_dbg("Running command %s.", action->type);

	r = action->handler(0);

	show_status(r);

	return translate_errno(r);

}

int main(int argc, const char **argv)

{

	static char *popt_tmp;

	static const char *null_action_argv[] = {NULL};

	static struct poptOption popt_help_options[] = {

		{ NULL,    '\0', POPT_ARG_CALLBACK, help, 0, NULL,                         NULL },

		{ "help",  '?',  POPT_ARG_NONE,     NULL, 0, N_("Show this help message"), NULL },

		{ "usage", '\0', POPT_ARG_NONE,     NULL, 0, N_("Display brief usage"),    NULL },

		{ "version",'V', POPT_ARG_NONE,     NULL, 0, N_("Print package version"),  NULL },

		POPT_TABLEEND

	};

	static struct poptOption popt_options[] = {

		{ NULL,              '\0', POPT_ARG_INCLUDE_TABLE, popt_help_options, 0, N_("Help options:"), NULL },

		{ "verbose",         'v',  POPT_ARG_NONE, &opt_verbose,      0, N_("Shows more detailed error messages"), NULL },

		{ "debug",           '\0', POPT_ARG_NONE, &opt_debug,        0, N_("Show debug messages"), NULL },

		{ "no-superblock",   0,    POPT_ARG_VAL,  &use_superblock,   0, N_("Do not use verity superblock"), NULL },

		{ "format",          0,    POPT_ARG_INT,  &hash_type,        0, N_("Format type (1 - normal, 0 - original Chrome OS)"), N_("number") },

		{ "data-block-size", 0,    POPT_ARG_INT,  &data_block_size,  0, N_("Block size on the data device"), N_("bytes") },

		{ "hash-block-size", 0,    POPT_ARG_INT,  &hash_block_size,  0, N_("Block size on the hash device"), N_("bytes") },

		{ "fec-roots",       0,    POPT_ARG_INT,  &fec_roots,        0, N_("FEC parity bytes"), N_("bytes") },

		{ "data-blocks",     0,    POPT_ARG_STRING, &popt_tmp,       1, N_("The number of blocks in the data file"), N_("blocks") },

		{ "fec-device",      0,    POPT_ARG_STRING, &fec_device,     0, N_("Path to device with error correction data"), N_("path") },

		{ "hash-offset",     0,    POPT_ARG_STRING, &popt_tmp,       2, N_("Starting offset on the hash device"), N_("bytes") },

		{ "fec-offset",      0,    POPT_ARG_STRING, &popt_tmp,       3, N_("Starting offset on the FEC device"), N_("bytes") },

		{ "hash",            'h',  POPT_ARG_STRING, &hash_algorithm, 0, N_("Hash algorithm"), N_("string") },

		{ "salt",            's',  POPT_ARG_STRING, &salt_string,    0, N_("Salt"), N_("hex string") },

		{ "uuid",            '\0', POPT_ARG_STRING, &opt_uuid,       0, N_("UUID for device to use"), NULL },

		{ "root-hash-signature",'\0', POPT_ARG_STRING, &opt_root_hash_signature,  0, N_("Path to root hash signature file"), NULL },

		{ "restart-on-corruption", 0,POPT_ARG_NONE,&opt_restart_on_corruption, 0, N_("Restart kernel if corruption is detected"), NULL },

		{ "ignore-corruption", 0,  POPT_ARG_NONE, &opt_ignore_corruption,  0, N_("Ignore corruption, log it only"), NULL },

		{ "ignore-zero-blocks", 0, POPT_ARG_NONE, &opt_ignore_zero_blocks, 0, N_("Do not verify zeroed blocks"), NULL },

		{ "check-at-most-once", 0, POPT_ARG_NONE, &opt_check_at_most_once, 0, N_("Verify data block only the first time it is read"), NULL },

		POPT_TABLEEND

	};

	poptContext popt_context;

	struct action_type *action;

	const char *aname;

	int r;

	crypt_set_log_callback(NULL, tool_log, NULL);

	setlocale(LC_ALL, "");

	bindtextdomain(PACKAGE, LOCALEDIR);

	textdomain(PACKAGE);

	popt_context = poptGetContext("verity", argc, argv, popt_options, 0);

	poptSetOtherOptionHelp(popt_context,

	                       _("[OPTION...] <action> <action-specific>"));

	while((r = poptGetNextOpt(popt_context)) > 0) {

		unsigned long long ull_value;

		char *endp;

		errno = 0;

		ull_value = strtoull(popt_tmp, &endp, 10);

		if (*endp || !*popt_tmp || !isdigit(*popt_tmp) ||

		    (errno == ERANGE && ull_value == ULLONG_MAX) ||

		    (errno != 0 && ull_value == 0))

			r = POPT_ERROR_BADNUMBER;

		switch(r) {

			case 1:

				data_blocks = ull_value;

				break;

			case 2:

				hash_offset = ull_value;

				break;

			case 3:

				fec_offset = ull_value;

				break;

		}

		if (r < 0)

			break;

	}

	if (r < -1)

		usage(popt_context, EXIT_FAILURE, poptStrerror(r),

		      poptBadOption(popt_context, POPT_BADOPTION_NOALIAS));

	if (!(aname = poptGetArg(popt_context)))

		usage(popt_context, EXIT_FAILURE, _("Argument <action> missing."),

		      poptGetInvocationName(popt_context));

	action_argc = 0;

	action_argv = poptGetArgs(popt_context);

	/* Make return values of poptGetArgs more consistent in case of remaining argc = 0 */

	if(!action_argv)

		action_argv = null_action_argv;

	/* Count args, somewhat unnice, change? */

	while(action_argv[action_argc] != NULL)

		action_argc++;

	/* Handle aliases */

	if (!strcmp(aname, "create") && action_argc > 1) {

		/* create command had historically switched arguments */

		if (action_argv[0] && action_argv[1]) {

			const char *tmp = action_argv[0];

			action_argv[0] = action_argv[1];

			action_argv[1] = tmp;

		}

		aname = "open";

	} else if (!strcmp(aname, "remove")) {

		aname = "close";

	}

	for (action = action_types; action->type; action++)

		if (strcmp(action->type, aname) == 0)

			break;

	if (!action->type)

		usage(popt_context, EXIT_FAILURE, _("Unknown action."),

		      poptGetInvocationName(popt_context));

	if (action_argc < action->required_action_argc) {

		char buf[128];

		snprintf(buf, 128,_("%s: requires %s as arguments"), action->type, action->arg_desc);

		usage(popt_context, EXIT_FAILURE, buf,

		      poptGetInvocationName(popt_context));

	}

	if (data_block_size < 0 || hash_block_size < 0 || hash_type < 0) {

		usage(popt_context, EXIT_FAILURE,

		      _("Negative number for option not permitted."),

		      poptGetInvocationName(popt_context));

	}

	if ((opt_ignore_corruption || opt_restart_on_corruption || opt_ignore_zero_blocks) && strcmp(aname, "open"))

		usage(popt_context, EXIT_FAILURE,

		_("Option --ignore-corruption, --restart-on-corruption or --ignore-zero-blocks is allowed only for open operation."),

		poptGetInvocationName(popt_context));

	if (opt_root_hash_signature && strcmp(aname, "open"))

		usage(popt_context, EXIT_FAILURE,

		_("Option --root-hash-signature can be used only for open operation."),

		poptGetInvocationName(popt_context));

	if (opt_ignore_corruption && opt_restart_on_corruption)

		usage(popt_context, EXIT_FAILURE,

		_("Option --ignore-corruption and --restart-on-corruption cannot be used together."),

		poptGetInvocationName(popt_context));

	if (opt_debug) {

		opt_verbose = 1;

		crypt_set_debug_level(-1);

		dbg_version_and_cmd(argc, argv);

	}

	r = run_action(action);

	poptFreeContext(popt_context);

	return r;

}