/*
 * Copyright (C) 2012 Free Software Foundation, Inc.
 *
 * This file is part of GnuTLS.
 *
 * GnuTLS 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 3 of the License, or
 * (at your option) any later version.
 *
 * GnuTLS 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, see
 * <http://www.gnu.org/licenses/>.
 */

#include <config.h>

#include <gnutls/gnutls.h>
#include <gnutls/x509.h>
#include <gnutls/openpgp.h>
#include <gnutls/pkcs12.h>
#include <gnutls/pkcs11.h>
#include <gnutls/abstract.h>
#include <gnutls/crypto.h>

#ifdef HAVE_DANE
#include <gnutls/dane.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <time.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

/* Gnulib portability files. */
#include <read-file.h>

#include <common.h>
#include "danetool-args.h"
#include "certtool-common.h"

static void cmd_parser(int argc, char **argv);
static void dane_info(const char *host, const char *proto,
		      unsigned int port, unsigned int ca,
		      unsigned int domain, common_info_st * cinfo);

static void dane_check(const char *host, const char *proto,
		       unsigned int port, common_info_st * cinfo);

FILE *outfile;
static gnutls_digest_algorithm_t default_dig;

/* non interactive operation if set
 */
int batch = 0;
int ask_pass = 0;


static void tls_log_func(int level, const char *str)
{
	fprintf(stderr, "|<%d>| %s", level, str);
}

int main(int argc, char **argv)
{
	cmd_parser(argc, argv);

	return 0;
}


static void cmd_parser(int argc, char **argv)
{
	int ret, privkey_op = 0;
	common_info_st cinfo;
	const char *proto = "tcp";
	unsigned int port = 443;

	optionProcess(&danetoolOptions, argc, argv);

	if (HAVE_OPT(OUTFILE)) {
		outfile = safe_open_rw(OPT_ARG(OUTFILE), privkey_op);
		if (outfile == NULL) {
			fprintf(stderr, "%s", OPT_ARG(OUTFILE));
			exit(1);
		}
	} else
		outfile = stdout;

	default_dig = GNUTLS_DIG_UNKNOWN;
	if (HAVE_OPT(HASH)) {
		if (strcasecmp(OPT_ARG(HASH), "md5") == 0) {
			fprintf(stderr,
				"Warning: MD5 is broken, and should not be used any more for digital signatures.\n");
			default_dig = GNUTLS_DIG_MD5;
		} else if (strcasecmp(OPT_ARG(HASH), "sha1") == 0)
			default_dig = GNUTLS_DIG_SHA1;
		else if (strcasecmp(OPT_ARG(HASH), "sha256") == 0)
			default_dig = GNUTLS_DIG_SHA256;
		else if (strcasecmp(OPT_ARG(HASH), "sha224") == 0)
			default_dig = GNUTLS_DIG_SHA224;
		else if (strcasecmp(OPT_ARG(HASH), "sha384") == 0)
			default_dig = GNUTLS_DIG_SHA384;
		else if (strcasecmp(OPT_ARG(HASH), "sha512") == 0)
			default_dig = GNUTLS_DIG_SHA512;
		else if (strcasecmp(OPT_ARG(HASH), "rmd160") == 0)
			default_dig = GNUTLS_DIG_RMD160;
		else {
			fprintf(stderr, "invalid hash: %s", OPT_ARG(HASH));
			exit(1);
		}
	}

	gnutls_global_set_log_function(tls_log_func);

	if (HAVE_OPT(DEBUG)) {
		gnutls_global_set_log_level(OPT_VALUE_DEBUG);
		printf("Setting log level to %d\n", (int) OPT_VALUE_DEBUG);
	}

	if ((ret = gnutls_global_init()) < 0) {
		fprintf(stderr, "global_init: %s", gnutls_strerror(ret));
		exit(1);
	}
#ifdef ENABLE_PKCS11
	pkcs11_common();
#endif

	memset(&cinfo, 0, sizeof(cinfo));

	if (HAVE_OPT(INDER) || HAVE_OPT(INRAW))
		cinfo.incert_format = GNUTLS_X509_FMT_DER;
	else
		cinfo.incert_format = GNUTLS_X509_FMT_PEM;

	if (HAVE_OPT(VERBOSE))
		cinfo.verbose = 1;

	if (HAVE_OPT(LOAD_PUBKEY))
		cinfo.pubkey = OPT_ARG(LOAD_PUBKEY);

	if (HAVE_OPT(LOAD_CERTIFICATE))
		cinfo.cert = OPT_ARG(LOAD_CERTIFICATE);

	if (HAVE_OPT(PORT))
		port = OPT_VALUE_PORT;
	if (HAVE_OPT(PROTO))
		proto = OPT_ARG(PROTO);

	if (HAVE_OPT(TLSA_RR))
		dane_info(OPT_ARG(HOST), proto, port,
			  HAVE_OPT(CA), ENABLED_OPT(DOMAIN), &cinfo);
	else if (HAVE_OPT(CHECK))
		dane_check(OPT_ARG(CHECK), proto, port, &cinfo);
	else
		USAGE(1);

	fclose(outfile);

#ifdef ENABLE_PKCS11
	gnutls_pkcs11_deinit();
#endif
	gnutls_global_deinit();
}

static void dane_check(const char *host, const char *proto,
		       unsigned int port, common_info_st * cinfo)
{
#ifdef HAVE_DANE
	dane_state_t s;
	dane_query_t q;
	int ret, retcode = 0;
	unsigned entries;
	unsigned int flags = DANE_F_IGNORE_LOCAL_RESOLVER, i;
	unsigned int usage, type, match;
	gnutls_datum_t data, file;
	size_t size;
	unsigned vflags = DANE_VFLAG_FAIL_IF_NOT_CHECKED;

	if (ENABLED_OPT(LOCAL_DNS))
		flags = 0;

	if (HAVE_OPT(INSECURE))
		flags |= DANE_F_INSECURE;

	if (HAVE_OPT(CHECK_EE))
		vflags |= DANE_VFLAG_ONLY_CHECK_EE_USAGE;

	if (HAVE_OPT(CHECK_CA))
		vflags |= DANE_VFLAG_ONLY_CHECK_CA_USAGE;

	printf("Querying %s (%s:%d)...\n", host, proto, port);
	ret = dane_state_init(&s, flags);
	if (ret < 0) {
		fprintf(stderr, "dane_state_init: %s\n",
			dane_strerror(ret));
		exit(1);
	}

	if (HAVE_OPT(DLV)) {
		ret = dane_state_set_dlv_file(s, OPT_ARG(DLV));
		if (ret < 0) {
			fprintf(stderr, "dane_state_set_dlv_file: %s\n",
				dane_strerror(ret));
			exit(1);
		}
	}

	ret = dane_query_tlsa(s, &q, host, proto, port);
	if (ret < 0) {
		fprintf(stderr, "dane_query_tlsa: %s\n",
			dane_strerror(ret));
		exit(1);
	}

	entries = dane_query_entries(q);
	for (i = 0; i < entries; i++) {
		ret = dane_query_data(q, i, &usage, &type, &match, &data);
		if (ret < 0) {
			fprintf(stderr, "dane_query_data: %s\n",
				dane_strerror(ret));
			exit(1);
		}


		size = buffer_size;
		ret = gnutls_hex_encode(&data, (void *) buffer, &size);
		if (ret < 0) {
			fprintf(stderr, "gnutls_hex_encode: %s\n",
				dane_strerror(ret));
			exit(1);
		}

		if (entries > 1)
			printf("\nEntry %d:\n", i + 1);

		fprintf(outfile,
			"_%u._%s.%s. IN TLSA ( %.2x %.2x %.2x %s )\n",
			port, proto, host, usage, type, match, buffer);
		printf("Certificate usage: %s (%.2x)\n",
		       dane_cert_usage_name(usage), usage);
		printf("Certificate type:  %s (%.2x)\n",
		       dane_cert_type_name(type), type);
		printf("Contents:          %s (%.2x)\n",
		       dane_match_type_name(match), match);
		printf("Data:              %s\n", buffer);

		/* Verify the DANE data */
		if (cinfo->cert) {
			gnutls_x509_crt_t *clist;
			unsigned int clist_size, status;

			ret = gnutls_load_file(cinfo->cert, &file);
			if (ret < 0) {
				fprintf(stderr, "gnutls_load_file: %s\n",
					gnutls_strerror(ret));
				exit(1);
			}

			ret =
			    gnutls_x509_crt_list_import2(&clist,
							 &clist_size,
							 &file,
							 cinfo->
							 incert_format, 0);
			if (ret < 0) {
				fprintf(stderr,
					"gnutls_x509_crt_list_import2: %s\n",
					gnutls_strerror(ret));
				exit(1);
			}

			if (clist_size > 0) {
				gnutls_datum_t certs[clist_size];
				gnutls_datum_t out;
				unsigned int i;

				for (i = 0; i < clist_size; i++) {
					ret =
					    gnutls_x509_crt_export2(clist
								    [i],
								    GNUTLS_X509_FMT_DER,
								    &certs
								    [i]);
					if (ret < 0) {
						fprintf(stderr,
							"gnutls_x509_crt_export2: %s\n",
							gnutls_strerror
							(ret));
						exit(1);
					}
				}

				ret =
				    dane_verify_crt(s, certs, clist_size,
						    GNUTLS_CRT_X509, host,
						    proto, port, 0, vflags,
						    &status);
				if (ret < 0) {
					fprintf(stderr,
						"dane_verify_crt: %s\n",
						dane_strerror(ret));
					exit(1);
				}

				ret =
				    dane_verification_status_print(status,
								   &out,
								   0);
				if (ret < 0) {
					fprintf(stderr,
						"dane_verification_status_print: %s\n",
						dane_strerror(ret));
					exit(1);
				}

				printf("\nVerification: %s\n", out.data);
				gnutls_free(out.data);

				if (status != 0)
					retcode = 1;

				for (i = 0; i < clist_size; i++) {
					gnutls_free(certs[i].data);
					gnutls_x509_crt_deinit(clist[i]);
				}
				gnutls_free(clist);
			}
		} else {
			fprintf(stderr,
				"\nCertificate was not verified. Use --load-certificate.\n");
		}
	}


	dane_query_deinit(q);
	dane_state_deinit(s);

	exit(retcode);
#else
	fprintf(stderr,
		"This functionality was disabled (GnuTLS was not compiled with support for DANE).\n");
	return;
#endif
}

static void dane_info(const char *host, const char *proto,
		      unsigned int port, unsigned int ca,
		      unsigned int domain, common_info_st * cinfo)
{
	gnutls_pubkey_t pubkey;
	gnutls_x509_crt_t crt;
	unsigned char digest[64];
	gnutls_datum_t t;
	int ret;
	unsigned int usage, selector, type;
	size_t size;

	if (proto == NULL)
		proto = "tcp";
	if (port == 0)
		port = 443;

	crt = load_cert(0, cinfo);
	if (crt != NULL && HAVE_OPT(X509)) {
		selector = 0;	/* X.509 */

		size = buffer_size;
		ret =
		    gnutls_x509_crt_export(crt, GNUTLS_X509_FMT_DER,
					   buffer, &size);
		if (ret < 0) {
			fprintf(stderr, "export error: %s\n",
				gnutls_strerror(ret));
			exit(1);
		}

		gnutls_x509_crt_deinit(crt);
	} else {		/* use public key only */

		selector = 1;

		ret = gnutls_pubkey_init(&pubkey);
		if (ret < 0) {
			fprintf(stderr, "pubkey_init: %s\n",
				gnutls_strerror(ret));
			exit(1);
		}

		if (crt != NULL) {

			ret = gnutls_pubkey_import_x509(pubkey, crt, 0);
			if (ret < 0) {
				fprintf(stderr, "pubkey_import_x509: %s\n",
					gnutls_strerror(ret));
				exit(1);
			}

			size = buffer_size;
			ret =
			    gnutls_pubkey_export(pubkey,
						 GNUTLS_X509_FMT_DER,
						 buffer, &size);
			if (ret < 0) {
				fprintf(stderr, "pubkey_export: %s\n",
					gnutls_strerror(ret));
				exit(1);
			}

			gnutls_x509_crt_deinit(crt);
		} else {
			pubkey = load_pubkey(1, cinfo);

			size = buffer_size;
			ret =
			    gnutls_pubkey_export(pubkey,
						 GNUTLS_X509_FMT_DER,
						 buffer, &size);
			if (ret < 0) {
				fprintf(stderr, "export error: %s\n",
					gnutls_strerror(ret));
				exit(1);
			}
		}

		gnutls_pubkey_deinit(pubkey);
	}

	if (default_dig != GNUTLS_DIG_SHA256
	    && default_dig != GNUTLS_DIG_SHA512) {
		if (default_dig != GNUTLS_DIG_UNKNOWN)
			fprintf(stderr,
				"Unsupported digest. Assuming SHA256.\n");
		default_dig = GNUTLS_DIG_SHA256;
	}

	ret = gnutls_hash_fast(default_dig, buffer, size, digest);
	if (ret < 0) {
		fprintf(stderr, "hash error: %s\n", gnutls_strerror(ret));
		exit(1);
	}

	if (default_dig == GNUTLS_DIG_SHA256)
		type = 1;
	else
		type = 2;

	/* DANE certificate classification crap */
	if (domain == 0) {
		if (ca)
			usage = 0;
		else
			usage = 1;
	} else {
		if (ca)
			usage = 2;
		else
			usage = 3;
	}

	t.data = digest;
	t.size = gnutls_hash_get_len(default_dig);

	size = buffer_size;
	ret = gnutls_hex_encode(&t, (void *) buffer, &size);
	if (ret < 0) {
		fprintf(stderr, "hex encode error: %s\n",
			gnutls_strerror(ret));
		exit(1);
	}

	fprintf(outfile, "_%u._%s.%s. IN TLSA ( %.2x %.2x %.2x %s )\n",
		port, proto, host, usage, selector, type, buffer);

}