~graywolf/acme-client-portable

ref: openbsd acme-client-portable/fileproc.c -rw-r--r-- 4.7 KiB
d43c6d31Wolf Update from openbsd (2021-07-25 16:17:33 UTC) 11 days ago
                                                                                
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
/*	$Id: fileproc.c,v 1.18 2021/07/12 15:09:20 beck 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 <sys/stat.h>

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

#include "extern.h"

static int
serialise(const char *real, const char *v, size_t vsz, const char *v2, size_t v2sz)
{
	int	  fd;
	char	 *tmp;

	/* create backup hardlink */
	if (asprintf(&tmp, "%s.1", real) == -1) {
		warn("asprintf");
		return 0;
	}
	(void) unlink(tmp);
	if (link(real, tmp) == -1 && errno != ENOENT) {
		warn("link");
		free(tmp);
		return 0;
	}
	free(tmp);

	/*
	 * Write into backup location, overwriting.
	 * Then atomically do the rename.
	 */

	if (asprintf(&tmp, "%s.XXXXXXXXXX", real) == -1) {
		warn("asprintf");
		return 0;
	}
	if ((fd = mkstemp(tmp)) == -1) {
		warn("mkstemp");
		goto out;
	}
	if (fchmod(fd, 0444) == -1) {
		warn("fchmod");
		goto out;
	}
	if ((ssize_t)vsz != write(fd, v, vsz)) {
		warnx("write");
		goto out;
	}
	if (v2 != NULL && write(fd, v2, v2sz) != (ssize_t)v2sz) {
		warnx("write");
		goto out;
	}
	if (close(fd) == -1)
		goto out;
	if (rename(tmp, real) == -1) {
		warn("%s", real);
		goto out;
	}

	free(tmp);
	return 1;
out:
	if (fd != -1)
		close(fd);
	(void) unlink(tmp);
	free(tmp);
	return 0;
}

int
fileproc(int certsock, const char *certdir, const char *certfile, const char
    *chainfile, const char *fullchainfile)
{
	char		*csr = NULL, *ch = NULL;
	size_t		 chsz, csz;
	int		 rc = 0;
	long		 lval;
	enum fileop	 op;

	if (unveil(certdir, "rwc") == -1) {
		warn("unveil %s", certdir);
		goto out;
	}

	/*
	 * rpath and cpath for rename, wpath and cpath for
	 * writing to the temporary. fattr for fchmod.
	 */
	if (pledge("stdio cpath wpath rpath fattr", NULL) == -1) {
		warn("pledge");
		goto out;
	}

	/* Read our operation. */

	op = FILE__MAX;
	if ((lval = readop(certsock, COMM_CHAIN_OP)) == 0)
		op = FILE_STOP;
	else if (lval == FILE_CREATE || lval == FILE_REMOVE)
		op = lval;

	if (FILE_STOP == op) {
		rc = 1;
		goto out;
	} else if (FILE__MAX == op) {
		warnx("unknown operation from certproc");
		goto out;
	}

	/*
	 * If revoking certificates, just unlink the files.
	 * We return the special error code of 2 to indicate that the
	 * certificates were removed.
	 */

	if (FILE_REMOVE == op) {
		if (certfile) {
			if (unlink(certfile) == -1 && errno != ENOENT) {
				warn("%s", certfile);
				goto out;
			} else
				dodbg("%s: unlinked", certfile);
		}

		if (chainfile) {
			if (unlink(chainfile) == -1 && errno != ENOENT) {
				warn("%s", chainfile);
				goto out;
			} else
				dodbg("%s: unlinked", chainfile);
		}

		if (fullchainfile) {
			if (unlink(fullchainfile) == -1 && errno != ENOENT) {
				warn("%s", fullchainfile);
				goto out;
			} else
				dodbg("%s: unlinked", fullchainfile);
		}

		rc = 2;
		goto out;
	}

	/*
	 * Start by downloading the chain PEM as a buffer.
	 * This is not NUL-terminated, but we're just going to guess
	 * that it's well-formed and not actually touch the data.
	 */
	if ((ch = readbuf(certsock, COMM_CHAIN, &chsz)) == NULL)
		goto out;

	if (chainfile) {
		if (!serialise(chainfile, ch, chsz, NULL, 0))
			goto out;

		dodbg("%s: created", chainfile);
	}

	/*
	 * Next, wait until we receive the DER encoded (signed)
	 * certificate from the network process.
	 * This comes as a stream of bytes: we don't know how many, so
	 * just keep downloading.
	 */

	if ((csr = readbuf(certsock, COMM_CSR, &csz)) == NULL)
		goto out;

	if (certfile) {
		if (!serialise(certfile, csr, csz, NULL, 0))
			goto out;

		dodbg("%s: created", certfile);
	}

	/*
	 * Finally, create the full-chain file.
	 * This is just the concatenation of the certificate and chain.
	 * We return the special error code 2 to indicate that the
	 * on-file certificates were changed.
	 */
	if (fullchainfile) {
		if (!serialise(fullchainfile, csr, csz, ch,
		    chsz))
			goto out;

		dodbg("%s: created", fullchainfile);
	}

	rc = 2;
out:
	close(certsock);
	free(csr);
	free(ch);
	return rc;
}