The patch adds data fetching from the PKCS#7 certificate using
openssl library (which is used by scripts/sign-file.c in the linux
kernel to sign modules).
In general the certificate can contain many signatures, but since
kmod (modinfo) supports only one signature at the moment,
With the current sign-file.c certificate doesn't contain signer
key's fingerprint, so "serial number" is used for the key id.
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@xxxxxxxxxx>
---
Makefile.am | 4 +-
configure.ac | 11 ++
libkmod/libkmod-internal.h | 3 +
libkmod/libkmod-module.c | 3 +
libkmod/libkmod-signature.c | 195 +++++++++++++++++++++++++++++++++++-
5 files changed, 211 insertions(+), 5 deletions(-)
diff --git a/Makefile.am b/Makefile.am
index 194e1115ae70..5ab7fc0b4750 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -35,6 +35,8 @@ SED_PROCESS = \
-e 's,@liblzma_LIBS\@,${liblzma_LIBS},g' \
-e 's,@zlib_CFLAGS\@,${zlib_CFLAGS},g' \
-e 's,@zlib_LIBS\@,${zlib_LIBS},g' \
+ -e 's,@openssl_CFLAGS\@,${openssl_CFLAGS},g' \
+ -e 's,@openssl_LIBS\@,${openssl_LIBS},g' \
< $< > $@ || rm $@
%.pc: %.pc.in Makefile
@@ -87,7 +89,7 @@ libkmod_libkmod_la_DEPENDENCIES = \
${top_srcdir}/libkmod/libkmod.sym
libkmod_libkmod_la_LIBADD = \
shared/libshared.la \
- ${liblzma_LIBS} ${zlib_LIBS}
+ ${liblzma_LIBS} ${zlib_LIBS} ${openssl_LIBS}
noinst_LTLIBRARIES += libkmod/libkmod-internal.la
libkmod_libkmod_internal_la_SOURCES = $(libkmod_libkmod_la_SOURCES)
diff --git a/configure.ac b/configure.ac
index fbc7391b2d1b..2e33380a0cc2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -106,6 +106,17 @@ AS_IF([test "x$with_zlib" != "xno"], [
])
CC_FEATURE_APPEND([with_features], [with_zlib], [ZLIB])
+AC_ARG_WITH([openssl],
+ AS_HELP_STRING([--with-openssl], [handle PKCS7 signatures @<:@default=disabled@:>@]),
+ [], [with_openssl=no])
+AS_IF([test "x$with_openssl" != "xno"], [
+ PKG_CHECK_MODULES([openssl], [openssl])
+ AC_DEFINE([ENABLE_OPENSSL], [1], [Enable openssl for modinfo.])
+], [
+ AC_MSG_NOTICE([openssl support not requested])
+])
+CC_FEATURE_APPEND([with_features], [with_openssl], [OPENSSL])
+
AC_ARG_WITH([bashcompletiondir],
AS_HELP_STRING([--with-bashcompletiondir=DIR], [Bash completions directory]),
[],
diff --git a/libkmod/libkmod-internal.h b/libkmod/libkmod-internal.h
index 346579c71aab..a65ddd156f18 100644
--- a/libkmod/libkmod-internal.h
+++ b/libkmod/libkmod-internal.h
@@ -188,5 +188,8 @@ struct kmod_signature_info {
const char *algo, *hash_algo, *id_type;
const char *sig;
size_t sig_len;
+ void (*free)(void *);
+ void *private;
};
bool kmod_module_signature_info(const struct kmod_file *file, struct kmod_signature_info *sig_info) _must_check_ __attribute__((nonnull(1, 2)));
+void kmod_module_signature_info_free(struct kmod_signature_info *sig_info) __attribute__((nonnull));
diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
index 889f26479a98..bffe715cdef4 100644
--- a/libkmod/libkmod-module.c
+++ b/libkmod/libkmod-module.c
@@ -2357,6 +2357,9 @@ KMOD_EXPORT int kmod_module_get_info(const struct kmod_module *mod, struct kmod_
ret = count;
list_error:
+ /* aux structures freed in normal case also */
+ kmod_module_signature_info_free(&sig_info);
+
if (ret < 0) {
kmod_module_info_free_list(*list);
*list = NULL;
diff --git a/libkmod/libkmod-signature.c b/libkmod/libkmod-signature.c
index 429ffbd8a957..4b44c3701d28 100644
--- a/libkmod/libkmod-signature.c
+++ b/libkmod/libkmod-signature.c
@@ -19,6 +19,10 @@
#include <endian.h>
#include <inttypes.h>
+#ifdef ENABLE_OPENSSL
+#include <openssl/cms.h>
+#include <openssl/ssl.h>
+#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -115,15 +119,192 @@ static bool fill_default(const char *mem, off_t size,
return true;
}
-static bool fill_unknown(const char *mem, off_t size,
- const struct module_signature *modsig, size_t sig_len,
- struct kmod_signature_info *sig_info)
+#ifdef ENABLE_OPENSSL
+
+struct pkcs7_private {
+ CMS_ContentInfo *cms;
+ unsigned char *key_id;
+ BIGNUM *sno;
+};
+
+static void pkcs7_free(void *s)
+{
+ struct kmod_signature_info *si = s;
+ struct pkcs7_private *pvt = si->private;
+
+ CMS_ContentInfo_free(pvt->cms);
+ BN_free(pvt->sno);
+ free(pvt->key_id);
+ free(pvt);
+ si->private = NULL;
+}
+
+static int obj_to_hash_algo(const ASN1_OBJECT *o)
+{
+ int nid;
+
+ nid = OBJ_obj2nid(o);
+ switch (nid) {
+ case NID_md4:
+ return PKEY_HASH_MD4;
+ case NID_md5:
+ return PKEY_HASH_MD5;
+ case NID_sha1:
+ return PKEY_HASH_SHA1;
+ case NID_ripemd160:
+ return PKEY_HASH_RIPE_MD_160;
+ case NID_sha256:
+ return PKEY_HASH_SHA256;
+ case NID_sha384:
+ return PKEY_HASH_SHA384;
+ case NID_sha512:
+ return PKEY_HASH_SHA512;
+ case NID_sha224:
+ return PKEY_HASH_SHA224;
+ default:
+ return -1;
+ }
+ return -1;
+}
+
+static const char *x509_name_to_str(X509_NAME *name)
+{
+ int i;
+ X509_NAME_ENTRY *e;
+ ASN1_STRING *d;
+ ASN1_OBJECT *o;
+ int nid = -1;
+ const char *str;
+
+ for (i = 0; i < X509_NAME_entry_count(name); i++) {
+ e = X509_NAME_get_entry(name, i);
+ o = X509_NAME_ENTRY_get_object(e);
+ nid = OBJ_obj2nid(o);
+ if (nid == NID_commonName)
+ break;
+ }
+ if (nid == -1)
+ return NULL;
+
+ d = X509_NAME_ENTRY_get_data(e);
+ str = (const char *)ASN1_STRING_get0_data(d);
+
+ return str;
+}
+
+static bool fill_pkcs7(const char *mem, off_t size,
+ const struct module_signature *modsig, size_t sig_len,
+ 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;
+ X509_NAME *issuer;
+ ASN1_INTEGER *sno;
+ ASN1_OCTET_STRING *sig;
+ BIGNUM *sno_bn;
+ X509_ALGOR *dig_alg;
+ X509_ALGOR *sig_alg;
+ const ASN1_OBJECT *o;
+ BIO *in;
+ int len;
+ unsigned char *key_id_str;
+ struct pkcs7_private *pvt;
+ const char *issuer_str;
+
+ size -= sig_len;
+ pkcs7_raw = mem + size;
+
+ in = BIO_new_mem_buf(pkcs7_raw, sig_len);
+
+ cms = d2i_CMS_bio(in, NULL);
+ if (cms == NULL) {
+ BIO_free(in);
+ return false;
+ }
+
+ BIO_free(in);
+
+ sis = CMS_get0_SignerInfos(cms);
+ if (sis == NULL)
+ goto err;
+
+ si = sk_CMS_SignerInfo_value(sis, 0);
+ if (si == NULL)
+ goto err;
+
+ rc = CMS_SignerInfo_get0_signer_id(si, &key_id, &issuer, &sno);
+ if (rc == 0)
+ goto err;
+
+ sig = CMS_SignerInfo_get0_signature(si);
+ if (sig == NULL)
+ goto err;
+
+ CMS_SignerInfo_get0_algs(si, NULL, NULL, &dig_alg, &sig_alg);
+
+ sig_info->sig = (const char *)ASN1_STRING_get0_data(sig);
+ sig_info->sig_len = ASN1_STRING_length(sig);
+
+
+ sno_bn = ASN1_INTEGER_to_BN(sno, NULL);
+ if (sno_bn == NULL)
+ goto err;
+
+ len = BN_num_bytes(sno_bn);
+ key_id_str = malloc(len);
+ BN_bn2bin(sno_bn, key_id_str);
+
+ sig_info->key_id = (const char *)key_id_str;
+ sig_info->key_id_len = len;
+
+ issuer_str = x509_name_to_str(issuer);
+ if (issuer_str != NULL) {
+ sig_info->signer = issuer_str;
+ sig_info->signer_len = strlen(issuer_str);
+ }
+
+ sig_info->algo = NULL;
+
+ X509_ALGOR_get0(&o, NULL, NULL, dig_alg);
+
+ sig_info->hash_algo = pkey_hash_algo[obj_to_hash_algo(o)];
+ sig_info->id_type = pkey_id_type[modsig->id_type];
+
+ pvt = malloc(sizeof(*pvt));
+ if (pvt == NULL)
+ goto err;
+
+ pvt->cms = cms;
+ pvt->key_id = key_id_str;
+ pvt->sno = sno_bn;
+ sig_info->private = pvt;
+
+ sig_info->free = pkcs7_free;
+
+ return true;
+
+err:
+ CMS_ContentInfo_free(cms);
+ return false;
+}
+
+#else /* ENABLE OPENSSL */
+
+static bool fill_pkcs7(const char *mem, off_t size,
+ const struct module_signature *modsig, size_t sig_len,
+ struct kmod_signature_info *sig_info)
{
sig_info->hash_algo = "unknown";
sig_info->id_type = pkey_id_type[modsig->id_type];
return true;
}
+#endif /* ENABLE OPENSSL */
+
#define SIG_MAGIC "~Module signature appended~\n"
/*
@@ -167,8 +348,14 @@ bool kmod_module_signature_info(const struct kmod_file *file, struct kmod_signat
switch (modsig->id_type) {
case PKEY_ID_PKCS7:
- return fill_unknown(mem, size, modsig, sig_len, sig_info);
+ return fill_pkcs7(mem, size, modsig, sig_len, sig_info);
default:
return fill_default(mem, size, modsig, sig_len, sig_info);
}
}
+
+void kmod_module_signature_info_free(struct kmod_signature_info *sig_info)
+{
+ if (sig_info->free)
+ sig_info->free(sig_info);
+}
--
2.19.1
