xref: /freebsd/usr.sbin/pkg/rsa.c (revision 2e065d74a5b0ea32db7d4f6e3f78eaa17ee7685e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2012-2014 Baptiste Daroussin <bapt@FreeBSD.org>
5  * Copyright (c) 2013 Bryan Drewery <bdrewery@FreeBSD.org>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/param.h>
31 #include <sys/types.h>
32 
33 #include <err.h>
34 #include <stdbool.h>
35 
36 #include <openssl/err.h>
37 #include <openssl/ssl.h>
38 
39 #include "pkg.h"
40 
41 #include "config.h"
42 #include "hash.h"
43 
44 static EVP_PKEY *
45 load_public_key_file(const char *file)
46 {
47 	EVP_PKEY *pkey;
48 	BIO *bp;
49 	char errbuf[1024];
50 
51 	bp = BIO_new_file(file, "r");
52 	if (!bp)
53 		errx(EXIT_FAILURE, "Unable to read %s", file);
54 
55 	if ((pkey = PEM_read_bio_PUBKEY(bp, NULL, NULL, NULL)) == NULL)
56 		warnx("ici: %s", ERR_error_string(ERR_get_error(), errbuf));
57 
58 	BIO_free(bp);
59 
60 	return (pkey);
61 }
62 
63 static EVP_PKEY *
64 load_public_key_buf(const unsigned char *cert, int certlen)
65 {
66 	EVP_PKEY *pkey;
67 	BIO *bp;
68 	char errbuf[1024];
69 
70 	bp = BIO_new_mem_buf(__DECONST(void *, cert), certlen);
71 
72 	if ((pkey = PEM_read_bio_PUBKEY(bp, NULL, NULL, NULL)) == NULL)
73 		warnx("%s", ERR_error_string(ERR_get_error(), errbuf));
74 
75 	BIO_free(bp);
76 
77 	return (pkey);
78 }
79 
80 static bool
81 rsa_verify_data(const struct pkgsign_ctx *ctx __unused,
82     const char *data, size_t datasz, const char *sigfile,
83     const unsigned char *key, int keylen, unsigned char *sig, int siglen)
84 {
85 	EVP_MD_CTX *mdctx;
86 	EVP_PKEY *pkey;
87 	char errbuf[1024];
88 	bool ret;
89 
90 	pkey = NULL;
91 	mdctx = NULL;
92 	ret = false;
93 	SSL_load_error_strings();
94 
95 	if (sigfile != NULL) {
96 		if ((pkey = load_public_key_file(sigfile)) == NULL) {
97 			warnx("Error reading public key");
98 			goto cleanup;
99 		}
100 	} else {
101 		if ((pkey = load_public_key_buf(key, keylen)) == NULL) {
102 			warnx("Error reading public key");
103 			goto cleanup;
104 		}
105 	}
106 
107 	/* Verify signature of the SHA256(pkg) is valid. */
108 	if ((mdctx = EVP_MD_CTX_create()) == NULL) {
109 		warnx("%s", ERR_error_string(ERR_get_error(), errbuf));
110 		goto error;
111 	}
112 
113 	if (EVP_DigestVerifyInit(mdctx, NULL, EVP_sha256(), NULL, pkey) != 1) {
114 		warnx("%s", ERR_error_string(ERR_get_error(), errbuf));
115 		goto error;
116 	}
117 	if (EVP_DigestVerifyUpdate(mdctx, data, datasz) != 1) {
118 		warnx("%s", ERR_error_string(ERR_get_error(), errbuf));
119 		goto error;
120 	}
121 
122 	if (EVP_DigestVerifyFinal(mdctx, sig, siglen) != 1) {
123 		warnx("%s", ERR_error_string(ERR_get_error(), errbuf));
124 		goto error;
125 	}
126 
127 	ret = true;
128 	printf("done\n");
129 	goto cleanup;
130 
131 error:
132 	printf("failed\n");
133 
134 cleanup:
135 	if (pkey)
136 		EVP_PKEY_free(pkey);
137 	if (mdctx)
138 		EVP_MD_CTX_destroy(mdctx);
139 	ERR_free_strings();
140 
141 	return (ret);
142 }
143 
144 static bool
145 rsa_verify_cert(const struct pkgsign_ctx *ctx __unused, int fd,
146     const char *sigfile, const unsigned char *key, int keylen,
147     unsigned char *sig, int siglen)
148 {
149 	char *sha256;
150 	bool ret;
151 
152 	sha256 = NULL;
153 
154 	/* Compute SHA256 of the package. */
155 	if (lseek(fd, 0, 0) == -1) {
156 		warn("lseek");
157 		return (false);
158 	}
159 	if ((sha256 = sha256_fd(fd)) == NULL) {
160 		warnx("Error creating SHA256 hash for package");
161 		return (false);
162 	}
163 
164 	ret = rsa_verify_data(ctx, sha256, strlen(sha256), sigfile, key, keylen,
165 	    sig, siglen);
166 	free(sha256);
167 
168 	return (ret);
169 }
170 
171 const struct pkgsign_ops pkgsign_rsa = {
172 	.pkgsign_verify_cert = rsa_verify_cert,
173 	.pkgsign_verify_data = rsa_verify_data,
174 };
175