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/* $Id: chngproc.c,v 1.7 2016/09/13 17:13:37 deraadt 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.
*/
#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, int remote)
{
char *tok = NULL, *th = NULL, *fmt = NULL, **fs = NULL;
size_t i, fsz = 0;
int rc = 0, fd = -1, cc;
long lval;
enum chngop op;
void *pp;
if (chroot(root) == -1) {
warn("chroot");
goto out;
}
if (chdir("/") == -1) {
warn("chdir");
goto out;
}
if (pledge("stdio cpath wpath", NULL) == -1) {
warn("pledge");
goto out;
}
/*
* Loop while we wait to get a thumbprint and token.
* We'll get this for each SAN request.
*/
for (;;) {
op = CHNG__MAX;
if (0 == (lval = readop(netsock, COMM_CHNG_OP)))
op = CHNG_STOP;
else if (CHNG_SYN == lval)
op = lval;
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)))
goto out;
else if (NULL == (tok = readstr(netsock, COMM_TOK)))
goto out;
/* Vector appending... */
pp = reallocarray(fs, (fsz + 1), sizeof(char *));
if (NULL == pp) {
warn("realloc");
goto out;
}
fs = pp;
fs[fsz] = tok;
tok = NULL;
fsz++;
if (-1 == asprintf(&fmt, "%s.%s", fs[fsz - 1], th)) {
warn("asprintf");
goto out;
}
/*
* I use this for testing when letskencrypt is being run
* on machines apart from where I'm hosting the
* challenge directory.
* DON'T DEPEND ON THIS FEATURE.
*/
if (remote) {
puts("RUN THIS IN THE CHALLENGE DIRECTORY");
puts("YOU HAVE 20 SECONDS...");
printf("doas sh -c \"echo %s > %s\"\n",
fmt, fs[fsz - 1]);
sleep(20);
puts("TIME'S UP.");
} else {
/*
* Create and write to our challenge file.
* Note: we use file descriptors instead of FILE
* because we want to minimise our pledges.
*/
fd = open(fs[fsz - 1], O_WRONLY|O_EXCL|O_CREAT, 0444);
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;
}
free(th);
free(fmt);
th = fmt = NULL;
dodbg("%s/%s: created", root, fs[fsz - 1]);
/*
* 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:
close(netsock);
if (-1 != fd)
close(fd);
for (i = 0; i < fsz; i++) {
if (-1 == unlink(fs[i]) && ENOENT != errno)
warn("%s", fs[i]);
free(fs[i]);
}
free(fs);
free(fmt);
free(th);
free(tok);
return(rc);
}
|
