linux/scripts/extract-cert.c
David Woodhouse 1329e8cc69 modsign: Extract signing cert from CONFIG_MODULE_SIG_KEY if needed
Where an external PEM file or PKCS#11 URI is given, we can get the cert
from it for ourselves instead of making the user drop signing_key.x509
in place for us.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2015-08-07 16:26:14 +01:00

133 lines
2.8 KiB
C

/* Extract X.509 certificate in DER form from PKCS#11 or PEM.
*
* Copyright © 2014 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 General Public Licence
* as published by the Free Software Foundation; either version
* 2 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 <getopt.h>
#include <err.h>
#include <arpa/inet.h>
#include <openssl/bio.h>
#include <openssl/evp.h>
#include <openssl/pem.h>
#include <openssl/pkcs7.h>
#include <openssl/err.h>
#include <openssl/engine.h>
#define PKEY_ID_PKCS7 2
static __attribute__((noreturn))
void format(void)
{
fprintf(stderr,
"Usage: scripts/extract-cert <source> <dest>\n");
exit(2);
}
static void display_openssl_errors(int l)
{
const char *file;
char buf[120];
int e, line;
if (ERR_peek_error() == 0)
return;
fprintf(stderr, "At main.c:%d:\n", l);
while ((e = ERR_get_error_line(&file, &line))) {
ERR_error_string(e, buf);
fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line);
}
}
static void drain_openssl_errors(void)
{
const char *file;
int line;
if (ERR_peek_error() == 0)
return;
while (ERR_get_error_line(&file, &line)) {}
}
#define ERR(cond, fmt, ...) \
do { \
bool __cond = (cond); \
display_openssl_errors(__LINE__); \
if (__cond) { \
err(1, fmt, ## __VA_ARGS__); \
} \
} while(0)
static const char *key_pass;
int main(int argc, char **argv)
{
char *cert_src, *cert_dst;
X509 *x509;
BIO *b;
OpenSSL_add_all_algorithms();
ERR_load_crypto_strings();
ERR_clear_error();
key_pass = getenv("KBUILD_SIGN_PIN");
if (argc != 3)
format();
cert_src = argv[1];
cert_dst = argv[2];
if (!strncmp(cert_src, "pkcs11:", 7)) {
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();
e = ENGINE_by_id("pkcs11");
ERR(!e, "Load PKCS#11 ENGINE");
if (ENGINE_init(e))
drain_openssl_errors();
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");
x509 = parms.cert;
} else {
b = BIO_new_file(cert_src, "rb");
ERR(!b, "%s", cert_src);
x509 = PEM_read_bio_X509(b, NULL, NULL, NULL);
ERR(!x509, "%s", cert_src);
BIO_free(b);
}
b = BIO_new_file(cert_dst, "wb");
ERR(!b, "%s", cert_dst);
ERR(!i2d_X509_bio(b, x509), cert_dst);
BIO_free(b);
return 0;
}