From: Thiago Jung Bauermann <bauerman@linux.ibm.com>
To: linux-integrity@vger.kernel.org
Cc: linux-security-module@vger.kernel.org, keyrings@vger.kernel.org,
linux-crypto@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
Mimi Zohar <zohar@linux.ibm.com>,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
David Howells <dhowells@redhat.com>,
David Woodhouse <dwmw2@infradead.org>,
Jessica Yu <jeyu@kernel.org>,
Herbert Xu <herbert@gondor.apana.org.au>,
"David S. Miller" <davem@davemloft.net>,
Jonathan Corbet <corbet@lwn.net>,
"AKASHI, Takahiro" <takahiro.akashi@linaro.org>,
Thiago Jung Bauermann <bauerman@linux.ibm.com>
Subject: [PATCH v10 03/12] PKCS#7: Introduce pkcs7_get_digest()
Date: Thu, 18 Apr 2019 00:51:11 -0300 [thread overview]
Message-ID: <20190418035120.2354-4-bauerman@linux.ibm.com> (raw)
In-Reply-To: <20190418035120.2354-1-bauerman@linux.ibm.com>
IMA will need to access the digest of the PKCS7 message (as calculated by
the kernel) before the signature is verified, so introduce
pkcs7_get_digest() for that purpose.
Also, modify pkcs7_digest() to detect when the digest was already
calculated so that it doesn't have to do redundant work. Verifying that
sinfo->sig->digest isn't NULL is sufficient because both places which
allocate sinfo->sig (pkcs7_parse_message() and pkcs7_note_signed_info())
use kzalloc() so sig->digest is always initialized to zero.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
---
crypto/asymmetric_keys/pkcs7_verify.c | 33 +++++++++++++++++++++++++++
include/crypto/pkcs7.h | 4 ++++
2 files changed, 37 insertions(+)
diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c
index 97c77f66b20d..5c3de46b0b73 100644
--- a/crypto/asymmetric_keys/pkcs7_verify.c
+++ b/crypto/asymmetric_keys/pkcs7_verify.c
@@ -16,6 +16,7 @@
#include <linux/err.h>
#include <linux/asn1.h>
#include <crypto/hash.h>
+#include <crypto/hash_info.h>
#include <crypto/public_key.h>
#include "pkcs7_parser.h"
@@ -33,6 +34,10 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
kenter(",%u,%s", sinfo->index, sinfo->sig->hash_algo);
+ /* The digest was calculated already. */
+ if (sig->digest)
+ return 0;
+
if (!sinfo->sig->hash_algo)
return -ENOPKG;
@@ -122,6 +127,34 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
return ret;
}
+int pkcs7_get_digest(struct pkcs7_message *pkcs7, const u8 **buf, u32 *len,
+ enum hash_algo *hash_algo)
+{
+ struct pkcs7_signed_info *sinfo = pkcs7->signed_infos;
+ int i, ret;
+
+ /*
+ * This function doesn't support messages with more than one signature.
+ */
+ if (sinfo == NULL || sinfo->next != NULL)
+ return -EBADMSG;
+
+ ret = pkcs7_digest(pkcs7, sinfo);
+ if (ret)
+ return ret;
+
+ *buf = sinfo->sig->digest;
+ *len = sinfo->sig->digest_size;
+
+ for (i = 0; i < HASH_ALGO__LAST; i++)
+ if (!strcmp(hash_algo_name[i], sinfo->sig->hash_algo)) {
+ *hash_algo = i;
+ break;
+ }
+
+ return 0;
+}
+
/*
* Find the key (X.509 certificate) to use to verify a PKCS#7 message. PKCS#7
* uses the issuer's name and the issuing certificate serial number for
diff --git a/include/crypto/pkcs7.h b/include/crypto/pkcs7.h
index 583f199400a3..3bfe6829eaae 100644
--- a/include/crypto/pkcs7.h
+++ b/include/crypto/pkcs7.h
@@ -13,6 +13,7 @@
#define _CRYPTO_PKCS7_H
#include <linux/verification.h>
+#include <linux/hash_info.h>
#include <crypto/public_key.h>
struct key;
@@ -44,4 +45,7 @@ extern int pkcs7_verify(struct pkcs7_message *pkcs7,
extern int pkcs7_supply_detached_data(struct pkcs7_message *pkcs7,
const void *data, size_t datalen);
+extern int pkcs7_get_digest(struct pkcs7_message *pkcs7, const u8 **buf,
+ u32 *len, enum hash_algo *hash_algo);
+
#endif /* _CRYPTO_PKCS7_H */
next prev parent reply other threads:[~2019-04-18 3:52 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-18 3:51 [PATCH v10 00/12] Appended signatures support for IMA appraisal Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 01/12] MODSIGN: Export module signature definitions Thiago Jung Bauermann
2019-05-09 15:42 ` Mimi Zohar
2019-05-28 19:03 ` Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 02/12] PKCS#7: Refactor verify_pkcs7_signature() Thiago Jung Bauermann
2019-05-09 15:42 ` Mimi Zohar
2019-04-18 3:51 ` Thiago Jung Bauermann [this message]
2019-05-09 15:42 ` [PATCH v10 03/12] PKCS#7: Introduce pkcs7_get_digest() Mimi Zohar
2019-04-18 3:51 ` [PATCH v10 04/12] integrity: Introduce struct evm_xattr Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 05/12] integrity: Select CONFIG_KEYS instead of depending on it Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 06/12] ima: Use designated initializers for struct ima_event_data Thiago Jung Bauermann
2019-05-09 15:46 ` Mimi Zohar
2019-04-18 3:51 ` [PATCH v10 07/12] ima: Add modsig appraise_type option for module-style appended signatures Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 08/12] ima: Factor xattr_verify() out of ima_appraise_measurement() Thiago Jung Bauermann
2019-05-09 15:53 ` Mimi Zohar
2019-04-18 3:51 ` [PATCH v10 09/12] ima: Implement support for module-style appended signatures Thiago Jung Bauermann
2019-05-09 23:01 ` Mimi Zohar
2019-05-28 19:23 ` Thiago Jung Bauermann
2019-05-28 20:06 ` Mimi Zohar
2019-05-14 12:09 ` Mimi Zohar
2019-05-28 19:27 ` Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 10/12] ima: Collect modsig Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 11/12] ima: Define ima-modsig template Thiago Jung Bauermann
2019-05-09 23:01 ` Mimi Zohar
2019-05-28 19:09 ` Thiago Jung Bauermann
2019-04-18 3:51 ` [PATCH v10 12/12] ima: Store the measurement again when appraising a modsig Thiago Jung Bauermann
2019-05-28 14:09 ` Mimi Zohar
2019-05-28 19:14 ` Thiago Jung Bauermann
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