8c1fb9a70d66b8758cd8b3b89a4872debe588488
[releases.git] / extract-cert.c
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))
36 void format(void)
37 {
38         fprintf(stderr,
39                 "Usage: extract-cert <source> <dest>\n");
40         exit(2);
41 }
42
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
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 int kbuild_verbose;
82
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 (kbuild_verbose)
94                 fprintf(stderr, "Extracted cert: %s\n", buf);
95 }
96
97 int main(int argc, char **argv)
98 {
99         char *cert_src;
100
101         OpenSSL_add_all_algorithms();
102         ERR_load_crypto_strings();
103         ERR_clear_error();
104
105         kbuild_verbose = atoi(getenv("KBUILD_VERBOSE")?:"0");
106
107         key_pass = getenv("KBUILD_SIGN_PIN");
108
109         if (argc != 3)
110                 format();
111
112         cert_src = argv[1];
113         cert_dst = argv[2];
114
115         if (!cert_src[0]) {
116                 /* Invoked with no input; create empty file */
117                 FILE *f = fopen(cert_dst, "wb");
118                 ERR(!f, "%s", cert_dst);
119                 fclose(f);
120                 exit(0);
121         } else if (!strncmp(cert_src, "pkcs11:", 7)) {
122                 ENGINE *e;
123                 struct {
124                         const char *cert_id;
125                         X509 *cert;
126                 } parms;
127
128                 parms.cert_id = cert_src;
129                 parms.cert = NULL;
130
131                 ENGINE_load_builtin_engines();
132                 drain_openssl_errors();
133                 e = ENGINE_by_id("pkcs11");
134                 ERR(!e, "Load PKCS#11 ENGINE");
135                 if (ENGINE_init(e))
136                         drain_openssl_errors();
137                 else
138                         ERR(1, "ENGINE_init");
139                 if (key_pass)
140                         ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0), "Set PKCS#11 PIN");
141                 ENGINE_ctrl_cmd(e, "LOAD_CERT_CTRL", 0, &parms, NULL, 1);
142                 ERR(!parms.cert, "Get X.509 from PKCS#11");
143                 write_cert(parms.cert);
144         } else {
145                 BIO *b;
146                 X509 *x509;
147
148                 b = BIO_new_file(cert_src, "rb");
149                 ERR(!b, "%s", cert_src);
150
151                 while (1) {
152                         x509 = PEM_read_bio_X509(b, NULL, NULL, NULL);
153                         if (wb && !x509) {
154                                 unsigned long err = ERR_peek_last_error();
155                                 if (ERR_GET_LIB(err) == ERR_LIB_PEM &&
156                                     ERR_GET_REASON(err) == PEM_R_NO_START_LINE) {
157                                         ERR_clear_error();
158                                         break;
159                                 }
160                         }
161                         ERR(!x509, "%s", cert_src);
162                         write_cert(x509);
163                 }
164         }
165
166         BIO_free(wb);
167
168         return 0;
169 }