1 /* Extract X.509 certificate in DER form from PKCS#11 or PEM.
2 *
3 * Copyright © 2014-2015 Red Hat, Inc. All Rights Reserved.
4 * Copyright © 2015 Intel Corporation.
5 *
6 * Authors: David Howells <dhowells@redhat.com>
7 * David Woodhouse <dwmw2@infradead.org>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public License
11 * as published by the Free Software Foundation; either version 2.1
12 * of the licence, or (at your option) any later version.
13 */
14 #define _GNU_SOURCE
15 #include <stdio.h>
16 #include <stdlib.h>
17 #include <stdint.h>
18 #include <stdbool.h>
19 #include <string.h>
20 #include <err.h>
21 #include <openssl/bio.h>
22 #include <openssl/pem.h>
23 #include <openssl/err.h>
24 #include <openssl/engine.h>
25
26 /*
27 * OpenSSL 3.0 deprecates the OpenSSL's ENGINE API.
28 *
29 * Remove this if/when that API is no longer used
30 */
31 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
32
33 #define PKEY_ID_PKCS7 2
34
35 static __attribute__((noreturn))
format(void)36 void format(void)
37 {
38 fprintf(stderr,
39 "Usage: extract-cert <source> <dest>\n");
40 exit(2);
41 }
42
display_openssl_errors(int l)43 static void display_openssl_errors(int l)
44 {
45 const char *file;
46 char buf[120];
47 int e, line;
48
49 if (ERR_peek_error() == 0)
50 return;
51 fprintf(stderr, "At main.c:%d:\n", l);
52
53 while ((e = ERR_get_error_line(&file, &line))) {
54 ERR_error_string(e, buf);
55 fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line);
56 }
57 }
58
drain_openssl_errors(void)59 static void drain_openssl_errors(void)
60 {
61 const char *file;
62 int line;
63
64 if (ERR_peek_error() == 0)
65 return;
66 while (ERR_get_error_line(&file, &line)) {}
67 }
68
69 #define ERR(cond, fmt, ...) \
70 do { \
71 bool __cond = (cond); \
72 display_openssl_errors(__LINE__); \
73 if (__cond) { \
74 err(1, fmt, ## __VA_ARGS__); \
75 } \
76 } while(0)
77
78 static const char *key_pass;
79 static BIO *wb;
80 static char *cert_dst;
81 static bool verbose;
82
write_cert(X509 * x509)83 static void write_cert(X509 *x509)
84 {
85 char buf[200];
86
87 if (!wb) {
88 wb = BIO_new_file(cert_dst, "wb");
89 ERR(!wb, "%s", cert_dst);
90 }
91 X509_NAME_oneline(X509_get_subject_name(x509), buf, sizeof(buf));
92 ERR(!i2d_X509_bio(wb, x509), "%s", cert_dst);
93 if (verbose)
94 fprintf(stderr, "Extracted cert: %s\n", buf);
95 }
96
main(int argc,char ** argv)97 int main(int argc, char **argv)
98 {
99 char *cert_src;
100 char *verbose_env;
101
102 OpenSSL_add_all_algorithms();
103 ERR_load_crypto_strings();
104 ERR_clear_error();
105
106 verbose_env = getenv("KBUILD_VERBOSE");
107 if (verbose_env && strchr(verbose_env, '1'))
108 verbose = true;
109
110 key_pass = getenv("KBUILD_SIGN_PIN");
111
112 if (argc != 3)
113 format();
114
115 cert_src = argv[1];
116 cert_dst = argv[2];
117
118 if (!cert_src[0]) {
119 /* Invoked with no input; create empty file */
120 FILE *f = fopen(cert_dst, "wb");
121 ERR(!f, "%s", cert_dst);
122 fclose(f);
123 exit(0);
124 } else if (!strncmp(cert_src, "pkcs11:", 7)) {
125 ENGINE *e;
126 struct {
127 const char *cert_id;
128 X509 *cert;
129 } parms;
130
131 parms.cert_id = cert_src;
132 parms.cert = NULL;
133
134 ENGINE_load_builtin_engines();
135 drain_openssl_errors();
136 e = ENGINE_by_id("pkcs11");
137 ERR(!e, "Load PKCS#11 ENGINE");
138 if (ENGINE_init(e))
139 drain_openssl_errors();
140 else
141 ERR(1, "ENGINE_init");
142 if (key_pass)
143 ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0), "Set PKCS#11 PIN");
144 ENGINE_ctrl_cmd(e, "LOAD_CERT_CTRL", 0, &parms, NULL, 1);
145 ERR(!parms.cert, "Get X.509 from PKCS#11");
146 write_cert(parms.cert);
147 } else {
148 BIO *b;
149 X509 *x509;
150
151 b = BIO_new_file(cert_src, "rb");
152 ERR(!b, "%s", cert_src);
153
154 while (1) {
155 x509 = PEM_read_bio_X509(b, NULL, NULL, NULL);
156 if (wb && !x509) {
157 unsigned long err = ERR_peek_last_error();
158 if (ERR_GET_LIB(err) == ERR_LIB_PEM &&
159 ERR_GET_REASON(err) == PEM_R_NO_START_LINE) {
160 ERR_clear_error();
161 break;
162 }
163 }
164 ERR(!x509, "%s", cert_src);
165 write_cert(x509);
166 }
167 }
168
169 BIO_free(wb);
170
171 return 0;
172 }
173