On Sun, May 19, 2019 at 03:42:01AM +0300, Stefan Strogin wrote:
Linux uses either PKCS #7 or CMS for signing modules (see
scripts/sign-file.c). CMS is not supported by LibreSSL or older OpenSSL,
so PKCS #7 is used on systems with these libcrypto providers.
CMS and PKCS #7 formats are very similar. CMS is newer but is as much as
possible backward compatible with PKCS #7 [1]. PKCS #7 is supported in
the latest OpenSSL as well as CMS. The fields used for signing kernel
modules are supported both in PKCS #7 and CMS.
For now modinfo uses CMS with no alternative requiring OpenSSL 1.1.0 or
newer.
Use PKCS #7 for parsing module signature information, so that modinfo
could be used both with OpenSSL and LibreSSL.
[1] https://tools.ietf.org/html/rfc5652#section-1.1
Changes v1->v2:
- Don't use ifdefs for keeping redundant CMS code, just use PKCS #7 both
with OpenSSL and LibreSSL.
Much better now, thanks!
Applied.
Lucas De Marchi
Signed-off-by: Stefan Strogin <steils@xxxxxxxxxx>
---
libkmod/libkmod-signature.c | 37 +++++++++++++++++++------------------
1 file changed, 19 insertions(+), 18 deletions(-)
diff --git a/libkmod/libkmod-signature.c b/libkmod/libkmod-signature.c
index 48d0145..4e8748c 100644
--- a/libkmod/libkmod-signature.c
+++ b/libkmod/libkmod-signature.c
@@ -20,7 +20,7 @@
#include <endian.h>
#include <inttypes.h>
#ifdef ENABLE_OPENSSL
-#include <openssl/cms.h>
+#include <openssl/pkcs7.h>
#include <openssl/ssl.h>
#endif
#include <stdio.h>
@@ -122,7 +122,7 @@ static bool fill_default(const char *mem, off_t size,
#ifdef ENABLE_OPENSSL
struct pkcs7_private {
- CMS_ContentInfo *cms;
+ PKCS7 *pkcs7;
unsigned char *key_id;
BIGNUM *sno;
};
@@ -132,7 +132,7 @@ static void pkcs7_free(void *s)
struct kmod_signature_info *si = s;
struct pkcs7_private *pvt = si->private;
- CMS_ContentInfo_free(pvt->cms);
+ PKCS7_free(pvt->pkcs7);
BN_free(pvt->sno);
free(pvt->key_id);
free(pvt);
@@ -197,11 +197,10 @@ static bool fill_pkcs7(const char *mem, off_t size,
struct kmod_signature_info *sig_info)
{
const char *pkcs7_raw;
- CMS_ContentInfo *cms;
- STACK_OF(CMS_SignerInfo) *sis;
- CMS_SignerInfo *si;
- int rc;
- ASN1_OCTET_STRING *key_id;
+ PKCS7 *pkcs7;
+ STACK_OF(PKCS7_SIGNER_INFO) *sis;
+ PKCS7_SIGNER_INFO *si;
+ PKCS7_ISSUER_AND_SERIAL *is;
X509_NAME *issuer;
ASN1_INTEGER *sno;
ASN1_OCTET_STRING *sig;
@@ -220,31 +219,33 @@ static bool fill_pkcs7(const char *mem, off_t size,
in = BIO_new_mem_buf(pkcs7_raw, sig_len);
- cms = d2i_CMS_bio(in, NULL);
- if (cms == NULL) {
+ pkcs7 = d2i_PKCS7_bio(in, NULL);
+ if (pkcs7 == NULL) {
BIO_free(in);
return false;
}
BIO_free(in);
- sis = CMS_get0_SignerInfos(cms);
+ sis = PKCS7_get_signer_info(pkcs7);
if (sis == NULL)
goto err;
- si = sk_CMS_SignerInfo_value(sis, 0);
+ si = sk_PKCS7_SIGNER_INFO_value(sis, 0);
if (si == NULL)
goto err;
- rc = CMS_SignerInfo_get0_signer_id(si, &key_id, &issuer, &sno);
- if (rc == 0)
+ is = si->issuer_and_serial;
+ if (is == NULL)
goto err;
+ issuer = is->issuer;
+ sno = is->serial;
- sig = CMS_SignerInfo_get0_signature(si);
+ sig = si->enc_digest;
if (sig == NULL)
goto err;
- CMS_SignerInfo_get0_algs(si, NULL, NULL, &dig_alg, &sig_alg);
+ PKCS7_SIGNER_INFO_get0_algs(si, NULL, &dig_alg, &sig_alg);
sig_info->sig = (const char *)ASN1_STRING_get0_data(sig);
sig_info->sig_len = ASN1_STRING_length(sig);
@@ -277,7 +278,7 @@ static bool fill_pkcs7(const char *mem, off_t size,
if (pvt == NULL)
goto err3;
- pvt->cms = cms;
+ pvt->pkcs7 = pkcs7;
pvt->key_id = key_id_str;
pvt->sno = sno_bn;
sig_info->private = pvt;
@@ -290,7 +291,7 @@ err3:
err2:
BN_free(sno_bn);
err:
- CMS_ContentInfo_free(cms);
+ PKCS7_free(pkcs7);
return false;
}
--
2.21.0
