linux/scripts/sign-file.c
Marc-Antoine Perennou 41693d1c03 sign-file: fix build with CMS support disabled
Some versions of openssl might have the CMS feature disabled
LibreSSL disables this feature too
If the feature is disabled, fallback to PKCS7

In file included from scripts/sign-file.c:46:0:
/usr/x86_64-pc-linux-gnu/include/openssl/cms.h:62:2: error: #error CMS is disabled.
 #error CMS is disabled.

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2016-03-03 10:50:46 +00:00

380 lines
9.3 KiB
C
Executable File

/* Sign a module file using the given key.
*
* Copyright © 2014-2015 Red Hat, Inc. All Rights Reserved.
* Copyright © 2015 Intel Corporation.
* Copyright © 2016 Hewlett Packard Enterprise Development LP
*
* Authors: David Howells <dhowells@redhat.com>
* David Woodhouse <dwmw2@infradead.org>
* Juerg Haefliger <juerg.haefliger@hpe.com>
*
* 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 <getopt.h>
#include <err.h>
#include <arpa/inet.h>
#include <openssl/opensslv.h>
#include <openssl/bio.h>
#include <openssl/evp.h>
#include <openssl/pem.h>
#include <openssl/err.h>
#include <openssl/engine.h>
/*
* Use CMS if we have openssl-1.0.0 or newer available - otherwise we have to
* assume that it's not available and its header file is missing and that we
* should use PKCS#7 instead. Switching to the older PKCS#7 format restricts
* the options we have on specifying the X.509 certificate we want.
*
* Further, older versions of OpenSSL don't support manually adding signers to
* the PKCS#7 message so have to accept that we get a certificate included in
* the signature message. Nor do such older versions of OpenSSL support
* signing with anything other than SHA1 - so we're stuck with that if such is
* the case.
*/
#if OPENSSL_VERSION_NUMBER < 0x10000000L || defined(OPENSSL_NO_CMS)
#define USE_PKCS7
#endif
#ifndef USE_PKCS7
#include <openssl/cms.h>
#else
#include <openssl/pkcs7.h>
#endif
struct module_signature {
uint8_t algo; /* Public-key crypto algorithm [0] */
uint8_t hash; /* Digest algorithm [0] */
uint8_t id_type; /* Key identifier type [PKEY_ID_PKCS7] */
uint8_t signer_len; /* Length of signer's name [0] */
uint8_t key_id_len; /* Length of key identifier [0] */
uint8_t __pad[3];
uint32_t sig_len; /* Length of signature data */
};
#define PKEY_ID_PKCS7 2
static char magic_number[] = "~Module signature appended~\n";
static __attribute__((noreturn))
void format(void)
{
fprintf(stderr,
"Usage: scripts/sign-file [-dp] <hash algo> <key> <x509> <module> [<dest>]\n");
fprintf(stderr,
" scripts/sign-file -s <raw sig> <hash algo> <x509> <module> [<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;
static int pem_pw_cb(char *buf, int len, int w, void *v)
{
int pwlen;
if (!key_pass)
return -1;
pwlen = strlen(key_pass);
if (pwlen >= len)
return -1;
strcpy(buf, key_pass);
/* If it's wrong, don't keep trying it. */
key_pass = NULL;
return pwlen;
}
static EVP_PKEY *read_private_key(const char *private_key_name)
{
EVP_PKEY *private_key;
if (!strncmp(private_key_name, "pkcs11:", 7)) {
ENGINE *e;
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");
private_key = ENGINE_load_private_key(e, private_key_name,
NULL, NULL);
ERR(!private_key, "%s", private_key_name);
} else {
BIO *b;
b = BIO_new_file(private_key_name, "rb");
ERR(!b, "%s", private_key_name);
private_key = PEM_read_bio_PrivateKey(b, NULL, pem_pw_cb,
NULL);
ERR(!private_key, "%s", private_key_name);
BIO_free(b);
}
return private_key;
}
static X509 *read_x509(const char *x509_name)
{
X509 *x509;
BIO *b;
b = BIO_new_file(x509_name, "rb");
ERR(!b, "%s", x509_name);
x509 = d2i_X509_bio(b, NULL); /* Binary encoded X.509 */
if (!x509) {
ERR(BIO_reset(b) != 1, "%s", x509_name);
x509 = PEM_read_bio_X509(b, NULL, NULL,
NULL); /* PEM encoded X.509 */
if (x509)
drain_openssl_errors();
}
BIO_free(b);
ERR(!x509, "%s", x509_name);
return x509;
}
int main(int argc, char **argv)
{
struct module_signature sig_info = { .id_type = PKEY_ID_PKCS7 };
char *hash_algo = NULL;
char *private_key_name = NULL, *raw_sig_name = NULL;
char *x509_name, *module_name, *dest_name;
bool save_sig = false, replace_orig;
bool sign_only = false;
bool raw_sig = false;
unsigned char buf[4096];
unsigned long module_size, sig_size;
unsigned int use_signed_attrs;
const EVP_MD *digest_algo;
EVP_PKEY *private_key;
#ifndef USE_PKCS7
CMS_ContentInfo *cms = NULL;
unsigned int use_keyid = 0;
#else
PKCS7 *pkcs7 = NULL;
#endif
X509 *x509;
BIO *bd, *bm;
int opt, n;
OpenSSL_add_all_algorithms();
ERR_load_crypto_strings();
ERR_clear_error();
key_pass = getenv("KBUILD_SIGN_PIN");
#ifndef USE_PKCS7
use_signed_attrs = CMS_NOATTR;
#else
use_signed_attrs = PKCS7_NOATTR;
#endif
do {
opt = getopt(argc, argv, "sdpk");
switch (opt) {
case 's': raw_sig = true; break;
case 'p': save_sig = true; break;
case 'd': sign_only = true; save_sig = true; break;
#ifndef USE_PKCS7
case 'k': use_keyid = CMS_USE_KEYID; break;
#endif
case -1: break;
default: format();
}
} while (opt != -1);
argc -= optind;
argv += optind;
if (argc < 4 || argc > 5)
format();
if (raw_sig) {
raw_sig_name = argv[0];
hash_algo = argv[1];
} else {
hash_algo = argv[0];
private_key_name = argv[1];
}
x509_name = argv[2];
module_name = argv[3];
if (argc == 5) {
dest_name = argv[4];
replace_orig = false;
} else {
ERR(asprintf(&dest_name, "%s.~signed~", module_name) < 0,
"asprintf");
replace_orig = true;
}
#ifdef USE_PKCS7
if (strcmp(hash_algo, "sha1") != 0) {
fprintf(stderr, "sign-file: %s only supports SHA1 signing\n",
OPENSSL_VERSION_TEXT);
exit(3);
}
#endif
/* Open the module file */
bm = BIO_new_file(module_name, "rb");
ERR(!bm, "%s", module_name);
if (!raw_sig) {
/* Read the private key and the X.509 cert the PKCS#7 message
* will point to.
*/
private_key = read_private_key(private_key_name);
x509 = read_x509(x509_name);
/* Digest the module data. */
OpenSSL_add_all_digests();
display_openssl_errors(__LINE__);
digest_algo = EVP_get_digestbyname(hash_algo);
ERR(!digest_algo, "EVP_get_digestbyname");
#ifndef USE_PKCS7
/* Load the signature message from the digest buffer. */
cms = CMS_sign(NULL, NULL, NULL, NULL,
CMS_NOCERTS | CMS_PARTIAL | CMS_BINARY |
CMS_DETACHED | CMS_STREAM);
ERR(!cms, "CMS_sign");
ERR(!CMS_add1_signer(cms, x509, private_key, digest_algo,
CMS_NOCERTS | CMS_BINARY |
CMS_NOSMIMECAP | use_keyid |
use_signed_attrs),
"CMS_add1_signer");
ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY) < 0,
"CMS_final");
#else
pkcs7 = PKCS7_sign(x509, private_key, NULL, bm,
PKCS7_NOCERTS | PKCS7_BINARY |
PKCS7_DETACHED | use_signed_attrs);
ERR(!pkcs7, "PKCS7_sign");
#endif
if (save_sig) {
char *sig_file_name;
BIO *b;
ERR(asprintf(&sig_file_name, "%s.p7s", module_name) < 0,
"asprintf");
b = BIO_new_file(sig_file_name, "wb");
ERR(!b, "%s", sig_file_name);
#ifndef USE_PKCS7
ERR(i2d_CMS_bio_stream(b, cms, NULL, 0) < 0,
"%s", sig_file_name);
#else
ERR(i2d_PKCS7_bio(b, pkcs7) < 0,
"%s", sig_file_name);
#endif
BIO_free(b);
}
if (sign_only) {
BIO_free(bm);
return 0;
}
}
/* Open the destination file now so that we can shovel the module data
* across as we read it.
*/
bd = BIO_new_file(dest_name, "wb");
ERR(!bd, "%s", dest_name);
/* Append the marker and the PKCS#7 message to the destination file */
ERR(BIO_reset(bm) < 0, "%s", module_name);
while ((n = BIO_read(bm, buf, sizeof(buf))),
n > 0) {
ERR(BIO_write(bd, buf, n) < 0, "%s", dest_name);
}
BIO_free(bm);
ERR(n < 0, "%s", module_name);
module_size = BIO_number_written(bd);
if (!raw_sig) {
#ifndef USE_PKCS7
ERR(i2d_CMS_bio_stream(bd, cms, NULL, 0) < 0, "%s", dest_name);
#else
ERR(i2d_PKCS7_bio(bd, pkcs7) < 0, "%s", dest_name);
#endif
} else {
BIO *b;
/* Read the raw signature file and write the data to the
* destination file
*/
b = BIO_new_file(raw_sig_name, "rb");
ERR(!b, "%s", raw_sig_name);
while ((n = BIO_read(b, buf, sizeof(buf))), n > 0)
ERR(BIO_write(bd, buf, n) < 0, "%s", dest_name);
BIO_free(b);
}
sig_size = BIO_number_written(bd) - module_size;
sig_info.sig_len = htonl(sig_size);
ERR(BIO_write(bd, &sig_info, sizeof(sig_info)) < 0, "%s", dest_name);
ERR(BIO_write(bd, magic_number, sizeof(magic_number) - 1) < 0, "%s", dest_name);
ERR(BIO_free(bd) < 0, "%s", dest_name);
/* Finally, if we're signing in place, replace the original. */
if (replace_orig)
ERR(rename(dest_name, module_name) < 0, "%s", dest_name);
return 0;
}