xref: /freebsd/lib/libsecureboot/readfile.c (revision 6829dae12bb055451fa467da4589c43bd03b1e64)
1 /*-
2  * Copyright (c) 2017-2018, Juniper Networks, Inc.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
14  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
15  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
16  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
17  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
18  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
19  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 #include <sys/cdefs.h>
26 __FBSDID("$FreeBSD$");
27 
28 #include <libsecureboot.h>
29 
30 unsigned char *
31 read_file(const char *path, size_t *len)
32 {
33 	int fd, m, n, x;
34 	struct stat st;
35 	unsigned char *buf;
36 
37 	if (len)
38 		*len = 0;
39 	if ((fd = open(path, O_RDONLY)) < 0)
40 		return (NULL);
41 	fstat(fd, &st);
42 	if (len)
43 		*len = st.st_size;
44 	buf = malloc(st.st_size + 1);
45 	for (x = 0, m = st.st_size; m > 0; ) {
46 		n = read(fd, &buf[x], m);
47 		if (n < 0)
48 			break;
49 		if (n > 0) {
50 			m -= n;
51 			x += n;
52 		}
53 	}
54 	close(fd);
55 	if (m == 0) {
56 		buf[st.st_size] = '\0';
57 		return (buf);
58 	}
59 	free(buf);
60 	return (NULL);
61 }
62