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#define PKEY_ID_PKCS7 2
27
28static __attribute__((noreturn))
29void format(void)
30{
31	fprintf(stderr,
32		"Usage: scripts/extract-cert <source> <dest>\n");
33	exit(2);
34}
35
36static void display_openssl_errors(int l)
37{
38	const char *file;
39	char buf[120];
40	int e, line;
41
42	if (ERR_peek_error() == 0)
43		return;
44	fprintf(stderr, "At main.c:%d:\n", l);
45
46	while ((e = ERR_get_error_line(&file, &line))) {
47		ERR_error_string(e, buf);
48		fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line);
49	}
50}
51
52static void drain_openssl_errors(void)
53{
54	const char *file;
55	int line;
56
57	if (ERR_peek_error() == 0)
58		return;
59	while (ERR_get_error_line(&file, &line)) {}
60}
61
62#define ERR(cond, fmt, ...)				\
63	do {						\
64		bool __cond = (cond);			\
65		display_openssl_errors(__LINE__);	\
66		if (__cond) {				\
67			err(1, fmt, ## __VA_ARGS__);	\
68		}					\
69	} while(0)
70
71static const char *key_pass;
72static BIO *wb;
73static char *cert_dst;
74int kbuild_verbose;
75
76static void write_cert(X509 *x509)
77{
78	char buf[200];
79
80	if (!wb) {
81		wb = BIO_new_file(cert_dst, "wb");
82		ERR(!wb, "%s", cert_dst);
83	}
84	X509_NAME_oneline(X509_get_subject_name(x509), buf, sizeof(buf));
85	ERR(!i2d_X509_bio(wb, x509), "%s", cert_dst);
86	if (kbuild_verbose)
87		fprintf(stderr, "Extracted cert: %s\n", buf);
88}
89
90int main(int argc, char **argv)
91{
92	char *cert_src;
93
94	OpenSSL_add_all_algorithms();
95	ERR_load_crypto_strings();
96	ERR_clear_error();
97
98	kbuild_verbose = atoi(getenv("KBUILD_VERBOSE")?:"0");
99
100        key_pass = getenv("KBUILD_SIGN_PIN");
101
102	if (argc != 3)
103		format();
104
105	cert_src = argv[1];
106	cert_dst = argv[2];
107
108	if (!cert_src[0]) {
109		/* Invoked with no input; create empty file */
110		FILE *f = fopen(cert_dst, "wb");
111		ERR(!f, "%s", cert_dst);
112		fclose(f);
113		exit(0);
114	} else if (!strncmp(cert_src, "pkcs11:", 7)) {
115		ENGINE *e;
116		struct {
117			const char *cert_id;
118			X509 *cert;
119		} parms;
120
121		parms.cert_id = cert_src;
122		parms.cert = NULL;
123
124		ENGINE_load_builtin_engines();
125		drain_openssl_errors();
126		e = ENGINE_by_id("pkcs11");
127		ERR(!e, "Load PKCS#11 ENGINE");
128		if (ENGINE_init(e))
129			drain_openssl_errors();
130		else
131			ERR(1, "ENGINE_init");
132		if (key_pass)
133			ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0), "Set PKCS#11 PIN");
134		ENGINE_ctrl_cmd(e, "LOAD_CERT_CTRL", 0, &parms, NULL, 1);
135		ERR(!parms.cert, "Get X.509 from PKCS#11");
136		write_cert(parms.cert);
137	} else {
138		BIO *b;
139		X509 *x509;
140
141		b = BIO_new_file(cert_src, "rb");
142		ERR(!b, "%s", cert_src);
143
144		while (1) {
145			x509 = PEM_read_bio_X509(b, NULL, NULL, NULL);
146			if (wb && !x509) {
147				unsigned long err = ERR_peek_last_error();
148				if (ERR_GET_LIB(err) == ERR_LIB_PEM &&
149				    ERR_GET_REASON(err) == PEM_R_NO_START_LINE) {
150					ERR_clear_error();
151					break;
152				}
153			}
154			ERR(!x509, "%s", cert_src);
155			write_cert(x509);
156		}
157	}
158
159	BIO_free(wb);
160
161	return 0;
162}
163