/*
 * Copyright (C) 2011-2012 Free Software Foundation, Inc.
 * Author: Simon Josefsson
 *
 * This file is part of GnuTLS.
 *
 * The GnuTLS 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.
 *
 * This library 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 this program.  If not, see <https://www.gnu.org/licenses/>
 *
 */

/* Online Certificate Status Protocol - RFC 2560
 */

#include "gnutls_int.h"
#include "global.h"
#include "errors.h"
#include <libtasn1.h>
#include "pk.h"
#include "str.h"
#include "algorithms.h"

#include <gnutls/ocsp.h>

#define addf _gnutls_buffer_append_printf
#define adds _gnutls_buffer_append_str

static void print_req(gnutls_buffer_st *str, gnutls_ocsp_req_const_t req)
{
	int ret;
	unsigned indx;

	/* Version. */
	{
		int version = gnutls_ocsp_req_get_version(req);
		if (version < 0)
			addf(str, "error: get_version: %s\n",
			     gnutls_strerror(version));
		else
			addf(str, _("\tVersion: %d\n"), version);
	}

	/* XXX requestorName */

	/* requestList */
	addf(str, "\tRequest List:\n");
	for (indx = 0;; indx++) {
		gnutls_digest_algorithm_t digest;
		gnutls_datum_t in, ik, sn;

		ret = gnutls_ocsp_req_get_cert_id(req, indx, &digest, &in, &ik,
						  &sn);
		if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
			break;
		addf(str, "\t\tCertificate ID:\n");
		if (ret != GNUTLS_E_SUCCESS) {
			addf(str, "error: get_cert_id: %s\n",
			     gnutls_strerror(ret));
			continue;
		}
		addf(str, "\t\t\tHash Algorithm: %s\n",
		     _gnutls_digest_get_name(hash_to_entry(digest)));

		adds(str, "\t\t\tIssuer Name Hash: ");
		_gnutls_buffer_hexprint(str, in.data, in.size);
		adds(str, "\n");

		adds(str, "\t\t\tIssuer Key Hash: ");
		_gnutls_buffer_hexprint(str, ik.data, ik.size);
		adds(str, "\n");

		adds(str, "\t\t\tSerial Number: ");
		_gnutls_buffer_hexprint(str, sn.data, sn.size);
		adds(str, "\n");

		gnutls_free(in.data);
		gnutls_free(ik.data);
		gnutls_free(sn.data);

		/* XXX singleRequestExtensions */
	}

	for (indx = 0;; indx++) {
		gnutls_datum_t oid;
		unsigned int critical;
		gnutls_datum_t data;

		ret = gnutls_ocsp_req_get_extension(req, indx, &oid, &critical,
						    &data);
		if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
			break;
		else if (ret != GNUTLS_E_SUCCESS) {
			addf(str, "error: get_extension: %s\n",
			     gnutls_strerror(ret));
			continue;
		}
		if (indx == 0)
			adds(str, "\tExtensions:\n");

		if (oid.size == sizeof(GNUTLS_OCSP_NONCE) - 1 &&
		    memcmp(oid.data, GNUTLS_OCSP_NONCE, oid.size) == 0) {
			gnutls_datum_t nonce;
			unsigned int ncrit;

			ret = gnutls_ocsp_req_get_nonce(req, &ncrit, &nonce);
			if (ret != GNUTLS_E_SUCCESS) {
				addf(str, "error: get_nonce: %s\n",
				     gnutls_strerror(ret));
			} else {
				addf(str, "\t\tNonce%s: ",
				     ncrit ? " (critical)" : "");
				_gnutls_buffer_hexprint(str, nonce.data,
							nonce.size);
				adds(str, "\n");
				gnutls_free(nonce.data);
			}
		} else {
			addf(str, "\t\tUnknown extension %s (%s):\n", oid.data,
			     critical ? "critical" : "not critical");

			adds(str, _("\t\t\tASCII: "));
			_gnutls_buffer_asciiprint(str, (char *)data.data,
						  data.size);
			addf(str, "\n");

			adds(str, _("\t\t\tHexdump: "));
			_gnutls_buffer_hexprint(str, (char *)data.data,
						data.size);
			adds(str, "\n");
		}

		gnutls_free(oid.data);
		gnutls_free(data.data);
	}

	/* XXX Signature */
}

/**
 * gnutls_ocsp_req_print:
 * @req: The data to be printed
 * @format: Indicate the format to use
 * @out: Newly allocated datum with (0) terminated string.
 *
 * This function will pretty print a OCSP request, suitable for
 * display to a human.
 *
 * If the format is %GNUTLS_OCSP_PRINT_FULL then all fields of the
 * request will be output, on multiple lines.
 *
 * The output @out->data needs to be deallocate using gnutls_free().
 *
 * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
 *   negative error value.
 **/
int gnutls_ocsp_req_print(gnutls_ocsp_req_const_t req,
			  gnutls_ocsp_print_formats_t format,
			  gnutls_datum_t *out)
{
	gnutls_buffer_st str;
	int rc;

	if (format != GNUTLS_OCSP_PRINT_FULL) {
		gnutls_assert();
		return GNUTLS_E_INVALID_REQUEST;
	}

	_gnutls_buffer_init(&str);

	_gnutls_buffer_append_str(&str, _("OCSP Request Information:\n"));

	print_req(&str, req);

	rc = _gnutls_buffer_to_datum(&str, out, 1);
	if (rc != GNUTLS_E_SUCCESS) {
		gnutls_assert();
		return rc;
	}

	return GNUTLS_E_SUCCESS;
}

static void print_resp(gnutls_buffer_st *str, gnutls_ocsp_resp_const_t resp,
		       gnutls_ocsp_print_formats_t format)
{
	int ret;
	unsigned indx;

	ret = gnutls_ocsp_resp_get_status(resp);
	if (ret < 0) {
		addf(str, "error: ocsp_resp_get_status: %s\n",
		     gnutls_strerror(ret));
		return;
	}

	adds(str, "\tResponse Status: ");
	switch (ret) {
	case GNUTLS_OCSP_RESP_SUCCESSFUL:
		adds(str, "Successful\n");
		break;

	case GNUTLS_OCSP_RESP_MALFORMEDREQUEST:
		adds(str, "malformedRequest\n");
		return;

	case GNUTLS_OCSP_RESP_INTERNALERROR:
		adds(str, "internalError\n");
		return;

	case GNUTLS_OCSP_RESP_TRYLATER:
		adds(str, "tryLater\n");
		return;

	case GNUTLS_OCSP_RESP_SIGREQUIRED:
		adds(str, "sigRequired\n");
		return;

	case GNUTLS_OCSP_RESP_UNAUTHORIZED:
		adds(str, "unauthorized\n");
		return;

	default:
		adds(str, "unknown\n");
		return;
	}

	{
		gnutls_datum_t oid;

		ret = gnutls_ocsp_resp_get_response(resp, &oid, NULL);
		if (ret < 0) {
			addf(str, "error: get_response: %s\n",
			     gnutls_strerror(ret));
			return;
		}

		adds(str, "\tResponse Type: ");
#define OCSP_BASIC "1.3.6.1.5.5.7.48.1.1"

		if (oid.size == sizeof(OCSP_BASIC) - 1 &&
		    memcmp(oid.data, OCSP_BASIC, oid.size) == 0) {
			adds(str, "Basic OCSP Response\n");
			gnutls_free(oid.data);
		} else {
			addf(str, "Unknown response type (%.*s)\n", oid.size,
			     oid.data);
			gnutls_free(oid.data);
			return;
		}
	}

	/* Version. */
	{
		int version = gnutls_ocsp_resp_get_version(resp);
		if (version < 0)
			addf(str, "error: get_version: %s\n",
			     gnutls_strerror(version));
		else
			addf(str, _("\tVersion: %d\n"), version);
	}

	/* responderID */
	{
		gnutls_datum_t dn = { NULL, 0 };

		ret = gnutls_ocsp_resp_get_responder2(resp, &dn, 0);
		if (ret < 0) {
			if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
				ret = gnutls_ocsp_resp_get_responder_raw_id(
					resp, GNUTLS_OCSP_RESP_ID_KEY, &dn);

				if (ret >= 0) {
					addf(str, _("\tResponder Key ID: "));
					_gnutls_buffer_hexprint(str, dn.data,
								dn.size);
					adds(str, "\n");
				}
				gnutls_free(dn.data);
			} else {
				addf(str, "error: get_responder2: %s\n",
				     gnutls_strerror(ret));
			}
		} else {
			addf(str, _("\tResponder ID: %s\n"), dn.data);
			gnutls_free(dn.data);
		}
	}

	{
		char s[42];
		size_t max = sizeof(s);
		struct tm t;
		time_t tim = gnutls_ocsp_resp_get_produced(resp);

		if (tim == (time_t)-1)
			addf(str, "error: ocsp_resp_get_produced\n");
		else if (gmtime_r(&tim, &t) == NULL)
			addf(str, "error: gmtime_r (%ld)\n",
			     (unsigned long)tim);
		else if (strftime(s, max, "%a %b %d %H:%M:%S UTC %Y", &t) == 0)
			addf(str, "error: strftime (%ld)\n",
			     (unsigned long)tim);
		else
			addf(str, _("\tProduced At: %s\n"), s);
	}

	addf(str, "\tResponses:\n");
	for (indx = 0;; indx++) {
		gnutls_digest_algorithm_t digest;
		gnutls_datum_t in, ik, sn;
		unsigned int cert_status;
		time_t this_update;
		time_t next_update;
		time_t revocation_time;
		unsigned int revocation_reason;

		ret = gnutls_ocsp_resp_get_single(resp, indx, &digest, &in, &ik,
						  &sn, &cert_status,
						  &this_update, &next_update,
						  &revocation_time,
						  &revocation_reason);
		if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
			break;
		addf(str, "\t\tCertificate ID:\n");
		if (ret != GNUTLS_E_SUCCESS) {
			addf(str, "error: get_singleresponse: %s\n",
			     gnutls_strerror(ret));
			continue;
		}
		addf(str, "\t\t\tHash Algorithm: %s\n",
		     _gnutls_digest_get_name(hash_to_entry(digest)));

		adds(str, "\t\t\tIssuer Name Hash: ");
		_gnutls_buffer_hexprint(str, in.data, in.size);
		adds(str, "\n");

		adds(str, "\t\t\tIssuer Key Hash: ");
		_gnutls_buffer_hexprint(str, ik.data, ik.size);
		adds(str, "\n");

		adds(str, "\t\t\tSerial Number: ");
		_gnutls_buffer_hexprint(str, sn.data, sn.size);
		adds(str, "\n");

		gnutls_free(in.data);
		gnutls_free(ik.data);
		gnutls_free(sn.data);

		{
			const char *p = NULL;

			switch (cert_status) {
			case GNUTLS_OCSP_CERT_GOOD:
				p = "good";
				break;

			case GNUTLS_OCSP_CERT_REVOKED:
				p = "revoked";
				break;

			case GNUTLS_OCSP_CERT_UNKNOWN:
				p = "unknown";
				break;

			default:
				addf(str,
				     "\t\tCertificate Status: unexpected value %d\n",
				     cert_status);
				break;
			}

			if (p)
				addf(str, "\t\tCertificate Status: %s\n", p);
		}

		/* XXX revocation reason */

		if (cert_status == GNUTLS_OCSP_CERT_REVOKED) {
			char s[42];
			size_t max = sizeof(s);
			struct tm t;

			if (revocation_time == (time_t)-1)
				addf(str, "error: revocation_time\n");
			else if (gmtime_r(&revocation_time, &t) == NULL)
				addf(str, "error: gmtime_r (%ld)\n",
				     (unsigned long)revocation_time);
			else if (strftime(s, max, "%a %b %d %H:%M:%S UTC %Y",
					  &t) == 0)
				addf(str, "error: strftime (%ld)\n",
				     (unsigned long)revocation_time);
			else
				addf(str, _("\t\tRevocation time: %s\n"), s);
		}

		{
			char s[42];
			size_t max = sizeof(s);
			struct tm t;

			if (this_update == (time_t)-1)
				addf(str, "error: this_update\n");
			else if (gmtime_r(&this_update, &t) == NULL)
				addf(str, "error: gmtime_r (%ld)\n",
				     (unsigned long)this_update);
			else if (strftime(s, max, "%a %b %d %H:%M:%S UTC %Y",
					  &t) == 0)
				addf(str, "error: strftime (%ld)\n",
				     (unsigned long)this_update);
			else
				addf(str, _("\t\tThis Update: %s\n"), s);
		}

		{
			char s[42];
			size_t max = sizeof(s);
			struct tm t;

			if (next_update != (time_t)-1) {
				if (gmtime_r(&next_update, &t) == NULL)
					addf(str, "error: gmtime_r (%ld)\n",
					     (unsigned long)next_update);
				else if (strftime(s, max,
						  "%a %b %d %H:%M:%S UTC %Y",
						  &t) == 0)
					addf(str, "error: strftime (%ld)\n",
					     (unsigned long)next_update);
				else
					addf(str, _("\t\tNext Update: %s\n"),
					     s);
			}
		}

		/* XXX singleRequestExtensions */
	}

	adds(str, "\tExtensions:\n");
	for (indx = 0;; indx++) {
		gnutls_datum_t oid;
		unsigned int critical;
		gnutls_datum_t data;

		ret = gnutls_ocsp_resp_get_extension(resp, indx, &oid,
						     &critical, &data);
		if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
			break;
		else if (ret != GNUTLS_E_SUCCESS) {
			addf(str, "error: get_extension: %s\n",
			     gnutls_strerror(ret));
			continue;
		}

		if (oid.size == sizeof(GNUTLS_OCSP_NONCE) - 1 &&
		    memcmp(oid.data, GNUTLS_OCSP_NONCE, oid.size) == 0) {
			gnutls_datum_t nonce;
			unsigned int ncrit;

			ret = gnutls_ocsp_resp_get_nonce(resp, &ncrit, &nonce);
			if (ret != GNUTLS_E_SUCCESS) {
				addf(str, "error: get_nonce: %s\n",
				     gnutls_strerror(ret));
			} else {
				addf(str, "\t\tNonce%s: ",
				     ncrit ? " (critical)" : "");
				_gnutls_buffer_hexprint(str, nonce.data,
							nonce.size);
				adds(str, "\n");
				gnutls_free(nonce.data);
			}
		} else {
			addf(str, "\t\tUnknown extension %s (%s):\n", oid.data,
			     critical ? "critical" : "not critical");

			adds(str, _("\t\t\tASCII: "));
			_gnutls_buffer_asciiprint(str, (char *)data.data,
						  data.size);
			addf(str, "\n");

			adds(str, _("\t\t\tHexdump: "));
			_gnutls_buffer_hexprint(str, (char *)data.data,
						data.size);
			adds(str, "\n");
		}

		gnutls_free(oid.data);
		gnutls_free(data.data);
	}

	ret = gnutls_ocsp_resp_get_signature_algorithm(resp);
	if (ret < 0)
		addf(str, "error: get_signature_algorithm: %s\n",
		     gnutls_strerror(ret));
	else {
		const char *name = gnutls_sign_algorithm_get_name(ret);
		if (name == NULL)
			name = _("unknown");
		addf(str, _("\tSignature Algorithm: %s\n"), name);
	}
	if (ret != GNUTLS_SIGN_UNKNOWN && gnutls_sign_is_secure(ret) == 0) {
		adds(str, _("warning: signed using a broken signature "
			    "algorithm that can be forged.\n"));
	}

	if (format == GNUTLS_OCSP_PRINT_FULL) {
		gnutls_datum_t sig;
		gnutls_x509_crt_t *certs;
		size_t ncerts, i;
		gnutls_datum_t out;

		/* Signature. */
		ret = gnutls_ocsp_resp_get_signature(resp, &sig);
		if (ret < 0)
			addf(str, "error: get_signature: %s\n",
			     gnutls_strerror(ret));
		else {
			adds(str, _("\tSignature:\n"));
			_gnutls_buffer_hexdump(str, sig.data, sig.size, "\t\t");

			gnutls_free(sig.data);
		}

		/* certs */
		ret = gnutls_ocsp_resp_get_certs(resp, &certs, &ncerts);
		if (ret < 0)
			addf(str, "error: get_certs: %s\n",
			     gnutls_strerror(ret));
		else {
			if (ncerts > 0)
				addf(str, "\tAdditional certificates:\n");

			for (i = 0; i < ncerts; i++) {
				size_t s = 0;

				ret = gnutls_x509_crt_print(
					certs[i], GNUTLS_CRT_PRINT_FULL, &out);
				if (ret < 0)
					addf(str, "error: crt_print: %s\n",
					     gnutls_strerror(ret));
				else {
					addf(str, "%.*s", out.size, out.data);
					gnutls_free(out.data);
				}

				ret = gnutls_x509_crt_export(
					certs[i], GNUTLS_X509_FMT_PEM, NULL,
					&s);
				if (ret != GNUTLS_E_SHORT_MEMORY_BUFFER)
					addf(str, "error: crt_export: %s\n",
					     gnutls_strerror(ret));
				else {
					out.data = gnutls_malloc(s);
					if (out.data == NULL)
						addf(str, "error: malloc: %s\n",
						     gnutls_strerror(
							     GNUTLS_E_MEMORY_ERROR));
					else {
						ret = gnutls_x509_crt_export(
							certs[i],
							GNUTLS_X509_FMT_PEM,
							out.data, &s);
						if (ret < 0)
							addf(str,
							     "error: crt_export: %s\n",
							     gnutls_strerror(
								     ret));
						else {
							out.size = s;
							addf(str, "%.*s",
							     out.size,
							     out.data);
						}
						gnutls_free(out.data);
					}
				}

				gnutls_x509_crt_deinit(certs[i]);
			}
			gnutls_free(certs);
		}
	}
}

/**
 * gnutls_ocsp_resp_print:
 * @resp: The data to be printed
 * @format: Indicate the format to use
 * @out: Newly allocated datum with (0) terminated string.
 *
 * This function will pretty print a OCSP response, suitable for
 * display to a human.
 *
 * If the format is %GNUTLS_OCSP_PRINT_FULL then all fields of the
 * response will be output, on multiple lines.
 *
 * The output @out->data needs to be deallocate using gnutls_free().
 *
 * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
 *   negative error value.
 **/
int gnutls_ocsp_resp_print(gnutls_ocsp_resp_const_t resp,
			   gnutls_ocsp_print_formats_t format,
			   gnutls_datum_t *out)
{
	gnutls_buffer_st str;
	int rc;

	_gnutls_buffer_init(&str);

	_gnutls_buffer_append_str(&str, _("OCSP Response Information:\n"));

	print_resp(&str, resp, format);

	rc = _gnutls_buffer_to_datum(&str, out, 1);
	if (rc != GNUTLS_E_SUCCESS) {
		gnutls_assert();
		return rc;
	}

	return GNUTLS_E_SUCCESS;
}
