Skip to content

Commit

Permalink
scripts/sign-file.c: Add support for signing with a raw signature
Browse files Browse the repository at this point in the history 
This patch adds support for signing a kernel module with a raw
detached PKCS#7 signature/message.

The signature is not converted and is simply appended to the module so
it needs to be in the right format. Using openssl, a valid signature can
be generated like this:
  $ openssl smime -sign -nocerts -noattr -binary -in <module> -inkey \
    <key> -signer <x509> -outform der -out <raw sig>

The resulting raw signature from the above command is (more or less)
identical to the raw signature that sign-file itself can produce like
this:
  $ scripts/sign-file -d <hash algo> <key> <x509> <module>

Signed-off-by: Juerg Haefliger <juerg.haefliger@hpe.com>
Signed-off-by: David Howells <dhowells@redhat.com>
  • Loading branch information
Juerg Haefliger authored and David Howells committed Feb 18, 2016
1 parent a1f2bdf commit e5a2e3c
Showing 1 changed file with 146 additions and 90 deletions.
236 changes: 146 additions & 90 deletions scripts/sign-file.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2,9 +2,11 @@
*
* 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
Expand Down Expand Up @@ -67,6 +69,8 @@ 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);
}

Expand Down Expand Up @@ -126,26 +130,84 @@ static int pem_pw_cb(char *buf, int len, int w, void *v)
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, *x509_name, *module_name, *dest_name;
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;
CMS_ContentInfo *cms = NULL;
unsigned int use_keyid = 0;
#else
PKCS7 *pkcs7;
PKCS7 *pkcs7 = NULL;
#endif
X509 *x509;
BIO *b, *bd = NULL, *bm;
BIO *bd, *bm;
int opt, n;
OpenSSL_add_all_algorithms();
ERR_load_crypto_strings();
Expand All @@ -160,8 +222,9 @@ int main(int argc, char **argv)
#endif

do {
opt = getopt(argc, argv, "dpk");
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
Expand All @@ -177,8 +240,13 @@ int main(int argc, char **argv)
if (argc < 4 || argc > 5)
format();

hash_algo = argv[0];
private_key_name = argv[1];
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) {
Expand All @@ -198,116 +266,104 @@ int main(int argc, char **argv)
}
#endif

/* Read the private key and the X.509 cert the PKCS#7 message
* will point to.
*/
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 {
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);
}

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);

/* Open the destination file now so that we can shovel the module data
* across as we read it.
*/
if (!sign_only) {
bd = BIO_new_file(dest_name, "wb");
ERR(!bd, "%s", dest_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");

/* 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");
/* 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");
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;
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);
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);
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);
ERR(i2d_PKCS7_bio(b, pkcs7) < 0,
"%s", sig_file_name);
#endif
BIO_free(b);
BIO_free(b);
}

if (sign_only) {
BIO_free(bm);
return 0;
}
}

if (sign_only)
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);
ERR(i2d_CMS_bio_stream(bd, cms, NULL, 0) < 0, "%s", dest_name);
#else
ERR(i2d_PKCS7_bio(bd, pkcs7) < 0, "%s", dest_name);
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);
Expand Down

0 comments on commit e5a2e3c

Please sign in to comment.