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#if OPENSSL_VERSION_MAJOR >= 3
 25# define USE_PKCS11_PROVIDER
 26# include <openssl/provider.h>
 27# include <openssl/store.h>
 28#else
 29# if !defined(OPENSSL_NO_ENGINE) && !defined(OPENSSL_NO_DEPRECATED_3_0)
 30#  define USE_PKCS11_ENGINE
 31#  include <openssl/engine.h>
 32# endif
 33#endif
 34#include "ssl-common.h"
 35
 36#define PKEY_ID_PKCS7 2
 37
 38static __attribute__((noreturn))
 39void format(void)
 40{
 41	fprintf(stderr,
 42		"Usage: extract-cert <source> <dest>\n");
 43	exit(2);
 44}
 45
 46static const char *key_pass;
 47static BIO *wb;
 48static char *cert_dst;
 49static bool verbose;
 50
 51static void write_cert(X509 *x509)
 52{
 53	char buf[200];
 54
 55	if (!wb) {
 56		wb = BIO_new_file(cert_dst, "wb");
 57		ERR(!wb, "%s", cert_dst);
 58	}
 59	X509_NAME_oneline(X509_get_subject_name(x509), buf, sizeof(buf));
 60	ERR(!i2d_X509_bio(wb, x509), "%s", cert_dst);
 61	if (verbose)
 62		fprintf(stderr, "Extracted cert: %s\n", buf);
 63}
 64
 65static X509 *load_cert_pkcs11(const char *cert_src)
 66{
 67	X509 *cert = NULL;
 68#ifdef USE_PKCS11_PROVIDER
 69	OSSL_STORE_CTX *store;
 70
 71	if (!OSSL_PROVIDER_try_load(NULL, "pkcs11", true))
 72		ERR(1, "OSSL_PROVIDER_try_load(pkcs11)");
 73	if (!OSSL_PROVIDER_try_load(NULL, "default", true))
 74		ERR(1, "OSSL_PROVIDER_try_load(default)");
 75
 76	store = OSSL_STORE_open(cert_src, NULL, NULL, NULL, NULL);
 77	ERR(!store, "OSSL_STORE_open");
 78
 79	while (!OSSL_STORE_eof(store)) {
 80		OSSL_STORE_INFO *info = OSSL_STORE_load(store);
 81
 82		if (!info) {
 83			drain_openssl_errors(__LINE__, 0);
 84			continue;
 85		}
 86		if (OSSL_STORE_INFO_get_type(info) == OSSL_STORE_INFO_CERT) {
 87			cert = OSSL_STORE_INFO_get1_CERT(info);
 88			ERR(!cert, "OSSL_STORE_INFO_get1_CERT");
 89		}
 90		OSSL_STORE_INFO_free(info);
 91		if (cert)
 92			break;
 93	}
 94	OSSL_STORE_close(store);
 95#elif defined(USE_PKCS11_ENGINE)
 96		ENGINE *e;
 97		struct {
 98			const char *cert_id;
 99			X509 *cert;
100		} parms;
101
102		parms.cert_id = cert_src;
103		parms.cert = NULL;
104
105		ENGINE_load_builtin_engines();
106		drain_openssl_errors(__LINE__, 1);
107		e = ENGINE_by_id("pkcs11");
108		ERR(!e, "Load PKCS#11 ENGINE");
109		if (ENGINE_init(e))
110			drain_openssl_errors(__LINE__, 1);
111		else
112			ERR(1, "ENGINE_init");
113		if (key_pass)
114			ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0), "Set PKCS#11 PIN");
115		ENGINE_ctrl_cmd(e, "LOAD_CERT_CTRL", 0, &parms, NULL, 1);
116		ERR(!parms.cert, "Get X.509 from PKCS#11");
117		cert = parms.cert;
118#else
119		fprintf(stderr, "no pkcs11 engine/provider available\n");
120		exit(1);
121#endif
122	return cert;
123}
124
125int main(int argc, char **argv)
126{
127	char *cert_src;
128	char *verbose_env;
129
130	OpenSSL_add_all_algorithms();
131	ERR_load_crypto_strings();
132	ERR_clear_error();
133
134	verbose_env = getenv("KBUILD_VERBOSE");
135	if (verbose_env && strchr(verbose_env, '1'))
136		verbose = true;
137
138        key_pass = getenv("KBUILD_SIGN_PIN");
139
140	if (argc != 3)
141		format();
142
143	cert_src = argv[1];
144	cert_dst = argv[2];
145
146	if (!cert_src[0]) {
147		/* Invoked with no input; create empty file */
148		FILE *f = fopen(cert_dst, "wb");
149		ERR(!f, "%s", cert_dst);
150		fclose(f);
151		exit(0);
152	} else if (!strncmp(cert_src, "pkcs11:", 7)) {
153		X509 *cert = load_cert_pkcs11(cert_src);
154
155		ERR(!cert, "load_cert_pkcs11 failed");
156		write_cert(cert);
157	} else {
158		BIO *b;
159		X509 *x509;
160
161		b = BIO_new_file(cert_src, "rb");
162		ERR(!b, "%s", cert_src);
163
164		while (1) {
165			x509 = PEM_read_bio_X509(b, NULL, NULL, NULL);
166			if (wb && !x509) {
167				unsigned long err = ERR_peek_last_error();
168				if (ERR_GET_LIB(err) == ERR_LIB_PEM &&
169				    ERR_GET_REASON(err) == PEM_R_NO_START_LINE) {
170					ERR_clear_error();
171					break;
172				}
173			}
174			ERR(!x509, "%s", cert_src);
175			write_cert(x509);
176		}
177	}
178
179	BIO_free(wb);
180
181	return 0;
182}