/*	$Id: chngproc.c,v 1.11 2016/10/29 22:25:48 kristaps Exp $ */
/*
 * Copyright (c) 2016 Kristaps Dzonsons <kristaps@bsd.lv>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <assert.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "extern.h"

int
chngproc(int netsock, const char *root, const char *challenge)
{
	char		 *tok = NULL, *th = NULL, *fmt = NULL, 
			 *fmtbuf = NULL;
	char		**fs = NULL;
	size_t		  i, fsz = 0, sz;
	ssize_t		  ssz;
	int		  rc = 0, fd = -1, cc;
	long		  lval;
	enum chngop	  op;
	void		 *pp;

#ifdef WCMEDBGCHNGPROC
        doddbg ("(%d) %d %s %s", __LINE__, netsock, root, challenge);
#endif
	/* File-system and sandbox jailing. */

	if ( ! sandbox_before())
		goto out;
	else if ( ! dropfs(NULL != challenge ? PATH_VAR_EMPTY : root))
		goto out;
	else if ( ! sandbox_after(NULL != challenge))
		goto out;

	/*
	 * Loop while we wait to get a thumbprint and token.
	 * We'll get this for each SAN request.
	 */

	for (;;) {
#ifdef WCMEDBGCHNGPROC
                doddbg ("(%d)", __LINE__);
#endif
		op = CHNG__MAX;
		if (0 == (lval = readop(netsock, COMM_CHNG_OP)))
			op = CHNG_STOP;
		else if (CHNG_SYN == lval)
			op = lval;
#ifdef WCMEDBGCHNGPROC
                doddbg ("(%d) %d", __LINE__, op);
#endif

		if (CHNG__MAX == op) {
			warnx("unknown operation from netproc");
			goto out;
		} else if (CHNG_STOP == op)
			break;

		assert(CHNG_SYN == op);

		/*
		 * Read the thumbprint and token.
		 * The token is the filename, so store that in a vector
		 * of tokens that we'll later clean up.
		 */

		if (NULL == (th = readstr(netsock, COMM_THUMB)))
#ifndef WCMEDBGCHNGPROC
			goto out;
#else
               {
                        doddbg ("(%d)", __LINE__);
			goto out;
                }
#endif
		else if (NULL == (tok = readstr(netsock, COMM_TOK)))
			goto out;
#ifdef WCMEDBGCHNGPROC
                doddbg ("(%d)", __LINE__);
#endif

		/* Vector appending... */

		pp = realloc(fs, (fsz + 1) * sizeof(char *));
		if (NULL == pp) {
			warn("realloc");
			goto out;
		}
		fs = pp;
		fs[fsz] = tok;
		tok = NULL;
		fsz++;

		if (NULL != challenge) {
			/*
			 * If we have a specific challenge request, then
			 * we write the request and thumbprint to stdout
			 * and wait for a reply (which must be an echo
			 * of the output) to indicate that all's well.
			 */
			fmt = doasprintf("%s.%s\n", fs[fsz - 1], th);
			if (NULL == fmt) {
				warn("asprintf");
				goto out;
			} else if (NULL == (fmtbuf = strdup(fmt))) {
				warn("strdup");
				goto out;
			}

			sz = strlen(fmt);
			ssz = write(STDOUT_FILENO, fmt, sz);
			if (-1 == ssz) {
				warn("<stdout>");
				goto out;
			} else if ((size_t)ssz != sz) {
				warnx("<stdout>: short write");
				goto out;
			}
			doddbg("%s: challenge written", fs[fsz - 1]);
			ssz = read(STDIN_FILENO, fmt, sz);
			if (-1 == ssz) {
				warn("<stdin>");
				goto out;
			} else if ((size_t)ssz != sz) {
				warnx("<stdin>: short read");
				goto out;
			} else if (strcmp(fmt, fmtbuf)) {
				warnx("<stdin>: token mismatch");
				goto out;
			}
			doddbg("%s: challenge read", fs[fsz - 1]);
		} else { 
			/* 
			 * Create and write to our challenge file.
			 * Note: we use file descriptors instead of FILE
			 * because we want to minimise our pledges.
			 */
			fmt = doasprintf("%s.%s", fs[fsz - 1], th);
			if (NULL == fmt) {
				warn("asprintf");
				goto out;
			}
#ifndef WCMEIDIOM
			fd = open(fs[fsz - 1], 
				O_WRONLY|O_EXCL|O_CREAT, 0444);
#else
{
                        char  *sptr;
                        UtilSysPrv();
                        /* WCME confines to ODS-2 semantics */
			fd = open(sptr = UtilOds2FileName((char*)root,fs[fsz-1]),
                                  /* use 0777 to propagate protections */
                                  O_WRONLY|O_TRUNC|O_CREAT, 0777);
                        UtilMereMortal();
                        free (sptr);
#ifdef WCMEDBGCHNGPROC
                        doddbg ("(%d) %d %%X%08.08x %d %s", __LINE__,
                                fd, vaxc$errno, errno, strerror(errno));
#endif
}
#endif

			if (-1 == fd) {
				warn("%s", fs[fsz - 1]);
				goto out;
			} if (-1 == write(fd, fmt, strlen(fmt))) {
				warn("%s", fs[fsz - 1]);
				goto out;
			} else if (-1 == close(fd)) {
				warn("%s", fs[fsz - 1]);
				goto out;
			}
			fd = -1;
			dodbg("%s/%s: created", root, fs[fsz - 1]);
		}

		free(th);
		free(fmt);
		free(fmtbuf);
		th = fmt = fmtbuf = NULL;

		/*
		 * Write our acknowledgement.
		 * Ignore reader failure.
		 */

		cc = writeop(netsock, COMM_CHNG_ACK, CHNG_ACK);
		if (0 == cc)
			break;
		if (cc < 0)
			goto out;
	}

	rc = 1;

out:
#ifdef WCMEDBGCHNGPROC
        doddbg ("(%d) %d", __LINE__, rc);
#endif

	close(netsock);
	if (-1 != fd)
		close(fd);
	if (NULL == challenge) 
		for (i = 0; i < fsz; i++) {
#ifndef __VMS
			if (-1 == unlink(fs[i]) && ENOENT != errno)
				warn("%s", fs[i]);
#else
                        UtilSysPrv();
                        if (remove(fs[i]) && ENOENT != errno)
                           warn("%s", fs[i]);
                        else
                           /* all versions */
                           while (!remove (fs[i]));
                        UtilMereMortal();
#endif
			free(fs[i]);
		}
	free(fs);
	free(fmt);
	free(fmtbuf);
	free(th);
	free(tok);
	return(rc);
}