xref: /freebsd/lib/libsecureboot/openpgp/dearmor.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * Copyright (c) 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 
26 #include <sys/cdefs.h>
27 #define NEED_BRSSL_H
28 #include <libsecureboot.h>
29 #include <brssl.h>
30 
31 #include "decode.h"
32 
33 /**
34  * @brief decode ascii armor
35  *
36  * once we get rid of the trailing checksum
37  * we can treat as PEM.
38  *
39  * @sa rfc4880:6.2
40  */
41 unsigned char *
42 dearmor(char *pem, size_t nbytes, size_t *len)
43 {
44 #ifdef USE_BEARSSL
45 	pem_object *po;
46 	size_t npo;
47 #else
48 	BIO *bp;
49 	char *name = NULL;
50 	char *header = NULL;
51 #endif
52 	unsigned char *data = NULL;
53 	char *cp;
54 	char *ep;
55 
56 	/* we need to remove the Armor tail */
57 	if ((cp = strstr((char *)pem, "\n=")) &&
58 	    (ep = strstr(cp, "\n---"))) {
59 		memmove(cp, ep, nbytes - (size_t)(ep - pem));
60 		nbytes -= (size_t)(ep - cp);
61 		pem[nbytes] = '\0';
62 	}
63 #ifdef USE_BEARSSL
64 	/* we also need to remove any headers */
65 	if ((cp = strstr((char *)pem, "---\n")) &&
66 	    (ep = strstr(cp, "\n\n"))) {
67 		cp += 4;
68 		ep += 2;
69 		memmove(cp, ep, nbytes - (size_t)(ep - pem));
70 		nbytes -= (size_t)(ep - cp);
71 		pem[nbytes] = '\0';
72 	}
73 	if ((po = decode_pem(pem, nbytes, &npo))) {
74 		data = po->data;
75 		*len = po->data_len;
76 	}
77 #else
78 	if ((bp = BIO_new_mem_buf(pem, (int)nbytes))) {
79 		long llen = (long)nbytes;
80 
81 		if (!PEM_read_bio(bp, &name, &header, &data, &llen))
82 			data = NULL;
83 		BIO_free(bp);
84 		*len = (size_t)llen;
85 	}
86 #endif
87 	return (data);
88 }
89 
90 #ifdef MAIN_DEARMOR
91 #include <unistd.h>
92 #include <fcntl.h>
93 #include <err.h>
94 
95 /*
96  * Mostly a unit test.
97  */
98 int
99 main(int argc, char *argv[])
100 {
101 	const char *infile, *outfile;
102 	unsigned char *data;
103 	size_t n, x;
104 	int fd;
105 	int o;
106 
107 	infile = outfile = NULL;
108 	while ((o = getopt(argc, argv, "i:o:")) != -1) {
109 		switch (o) {
110 		case 'i':
111 			infile = optarg;
112 			break;
113 		case 'o':
114 			outfile = optarg;
115 			break;
116 		default:
117 			errx(1, "unknown option: -%c", o);
118 		}
119 	}
120 	if (!infile)
121 		errx(1, "need -i infile");
122 	if (outfile) {
123 		if ((fd = open(outfile, O_WRONLY|O_CREAT|O_TRUNC)) < 0)
124 			err(1, "cannot open %s", outfile);
125 	} else {
126 		fd = 1;			/* stdout */
127 	}
128 	data = read_file(infile, &n);
129 	if (!(data[0] & OPENPGP_TAG_ISTAG))
130 		data = dearmor(data, n, &n);
131 	for (x = 0; x < n; ) {
132 		o = write(fd, &data[x], (n - x));
133 		if (o < 0)
134 			err(1, "cannot write");
135 		x += o;
136 	}
137 	if (fd != 1)
138 		close(fd);
139 	free(data);
140 	return (0);
141 }
142 #endif
143