linux/certs/extract-cert.c

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/* Extract X.509 certificate in DER form from PKCS#11 or PEM.
*
* Copyright © 2014-2015 Red Hat, Inc. All Rights Reserved.
* Copyright © 2015 Intel Corporation.
*
* Authors: David Howells <dhowells@redhat.com>
* David Woodhouse <dwmw2@infradead.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* of the licence, or (at your option) any later version.
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <err.h>
#include <openssl/bio.h>
#include <openssl/pem.h>
#include <openssl/err.h>
#if OPENSSL_VERSION_MAJOR >= 3
# define USE_PKCS11_PROVIDER
# include <openssl/provider.h>
# include <openssl/store.h>
#else
# if !defined(OPENSSL_NO_ENGINE) && !defined(OPENSSL_NO_DEPRECATED_3_0)
# define USE_PKCS11_ENGINE
# include <openssl/engine.h>
# endif
#endif
#include "ssl-common.h"
#define PKEY_ID_PKCS7 2
static __attribute__((noreturn))
void format(void)
{
fprintf(stderr,
"Usage: extract-cert <source> <dest>\n");
exit(2);
}
static const char *key_pass;
static BIO *wb;
static char *cert_dst;
static bool verbose;
static void write_cert(X509 *x509)
{
char buf[200];
if (!wb) {
wb = BIO_new_file(cert_dst, "wb");
ERR(!wb, "%s", cert_dst);
}
X509_NAME_oneline(X509_get_subject_name(x509), buf, sizeof(buf));
ERR(!i2d_X509_bio(wb, x509), "%s", cert_dst);
if (verbose)
fprintf(stderr, "Extracted cert: %s\n", buf);
}
static X509 *load_cert_pkcs11(const char *cert_src)
{
X509 *cert = NULL;
#ifdef USE_PKCS11_PROVIDER
OSSL_STORE_CTX *store;
if (!OSSL_PROVIDER_try_load(NULL, "pkcs11", true))
ERR(1, "OSSL_PROVIDER_try_load(pkcs11)");
if (!OSSL_PROVIDER_try_load(NULL, "default", true))
ERR(1, "OSSL_PROVIDER_try_load(default)");
store = OSSL_STORE_open(cert_src, NULL, NULL, NULL, NULL);
ERR(!store, "OSSL_STORE_open");
while (!OSSL_STORE_eof(store)) {
OSSL_STORE_INFO *info = OSSL_STORE_load(store);
if (!info) {
drain_openssl_errors(__LINE__, 0);
continue;
}
if (OSSL_STORE_INFO_get_type(info) == OSSL_STORE_INFO_CERT) {
cert = OSSL_STORE_INFO_get1_CERT(info);
ERR(!cert, "OSSL_STORE_INFO_get1_CERT");
}
OSSL_STORE_INFO_free(info);
if (cert)
break;
}
OSSL_STORE_close(store);
#elif defined(USE_PKCS11_ENGINE)
ENGINE *e;
struct {
const char *cert_id;
X509 *cert;
} parms;
parms.cert_id = cert_src;
parms.cert = NULL;
ENGINE_load_builtin_engines();
drain_openssl_errors(__LINE__, 1);
e = ENGINE_by_id("pkcs11");
ERR(!e, "Load PKCS#11 ENGINE");
if (ENGINE_init(e))
drain_openssl_errors(__LINE__, 1);
else
ERR(1, "ENGINE_init");
if (key_pass)
ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0), "Set PKCS#11 PIN");
ENGINE_ctrl_cmd(e, "LOAD_CERT_CTRL", 0, &parms, NULL, 1);
ERR(!parms.cert, "Get X.509 from PKCS#11");
cert = parms.cert;
#else
fprintf(stderr, "no pkcs11 engine/provider available\n");
exit(1);
#endif
return cert;
}
int main(int argc, char **argv)
{
char *cert_src;
char *verbose_env;
OpenSSL_add_all_algorithms();
ERR_load_crypto_strings();
ERR_clear_error();
verbose_env = getenv("KBUILD_VERBOSE");
if (verbose_env && strchr(verbose_env, '1'))
verbose = true;
key_pass = getenv("KBUILD_SIGN_PIN");
if (argc != 3)
format();
cert_src = argv[1];
cert_dst = argv[2];
if (!cert_src[0]) {
/* Invoked with no input; create empty file */
FILE *f = fopen(cert_dst, "wb");
ERR(!f, "%s", cert_dst);
fclose(f);
exit(0);
} else if (!strncmp(cert_src, "pkcs11:", 7)) {
X509 *cert = load_cert_pkcs11(cert_src);
ERR(!cert, "load_cert_pkcs11 failed");
write_cert(cert);
} else {
BIO *b;
X509 *x509;
b = BIO_new_file(cert_src, "rb");
ERR(!b, "%s", cert_src);
while (1) {
x509 = PEM_read_bio_X509(b, NULL, NULL, NULL);
if (wb && !x509) {
unsigned long err = ERR_peek_last_error();
if (ERR_GET_LIB(err) == ERR_LIB_PEM &&
ERR_GET_REASON(err) == PEM_R_NO_START_LINE) {
ERR_clear_error();
break;
}
}
ERR(!x509, "%s", cert_src);
write_cert(x509);
}
}
BIO_free(wb);
return 0;
}