From: Vitaly Chikunov <vt@altlinux.org>
To: Mimi Zohar <zohar@linux.vnet.ibm.com>,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
linux-integrity@vger.kernel.org
Subject: [PATCH v3 7/7] ima-evm-utils: Try to load digest by its alias
Date: Mon, 3 Dec 2018 06:35:25 +0300 [thread overview]
Message-ID: <20181203033525.20431-7-vt@altlinux.org> (raw)
In-Reply-To: <20181203033525.20431-1-vt@altlinux.org>
For compatibility with older OpenSSL try to load digest by its alias if
load by its proper name is failed.
This is configured in pkey_hash_algo by mentioning loadable alias first in the
comma separated list of algo names.
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
---
Changes since v1:
- New patch.
Changes since v2:
- No changes.
src/imaevm.h | 1 +
src/libimaevm.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++----
2 files changed, 52 insertions(+), 4 deletions(-)
diff --git a/src/imaevm.h b/src/imaevm.h
index c81bf21..795966a 100644
--- a/src/imaevm.h
+++ b/src/imaevm.h
@@ -75,6 +75,7 @@
#define DATA_SIZE 4096
#define SHA1_HASH_LEN 20
+#define MAX_DIGEST_NAME 32
#define MAX_DIGEST_SIZE 64
#define MAX_SIGNATURE_SIZE 1024
diff --git a/src/libimaevm.c b/src/libimaevm.c
index cb4721b..7501303 100644
--- a/src/libimaevm.c
+++ b/src/libimaevm.c
@@ -41,6 +41,7 @@
/* should we use logger instead for library? */
#define USE_FPRINTF
+#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
@@ -56,6 +57,7 @@
#include <openssl/pem.h>
#include <openssl/evp.h>
#include <openssl/x509.h>
+#include <openssl/engine.h>
#include <openssl/err.h>
#include "imaevm.h"
@@ -70,8 +72,8 @@ const char *const pkey_hash_algo[PKEY_HASH__LAST] = {
[PKEY_HASH_SHA384] = "sha384",
[PKEY_HASH_SHA512] = "sha512",
[PKEY_HASH_SHA224] = "sha224",
- [PKEY_HASH_STREEBOG_256] = "streebog256",
- [PKEY_HASH_STREEBOG_512] = "streebog512",
+ [PKEY_HASH_STREEBOG_256] = "md_gost12_256,streebog256",
+ [PKEY_HASH_STREEBOG_512] = "md_gost12_512,streebog512",
};
/*
@@ -284,6 +286,35 @@ static int add_dev_hash(struct stat *st, EVP_MD_CTX *ctx)
return !EVP_DigestUpdate(ctx, &dev, sizeof(dev));
}
+/* Call EVP_get_digestbyname with provided name and with alias,
+ * which is first name in the comma separated list of names
+ * in pkey_hash_algo.
+ */
+static const EVP_MD *get_digestbyname(const char *name)
+{
+ const EVP_MD *md;
+
+ md = EVP_get_digestbyname(params.hash_algo);
+ if (!md) {
+ char alias[MAX_DIGEST_NAME];
+ int len;
+ int algo_id;
+ const char *algo_alias;
+
+ /* try to get algo by its alias */
+ algo_id = get_hash_algo(params.hash_algo);
+ algo_alias = get_hash_algo_by_id(algo_id);
+ len = strchrnul(algo_alias, ',') - algo_alias;
+ if (len < sizeof(alias)) {
+ memcpy(alias, algo_alias, len);
+ alias[len] = '\0';
+ if (strcmp(params.hash_algo, alias))
+ md = EVP_get_digestbyname(alias);
+ }
+ }
+ return md;
+}
+
int ima_calc_hash(const char *file, uint8_t *hash)
{
const EVP_MD *md;
@@ -305,7 +336,7 @@ int ima_calc_hash(const char *file, uint8_t *hash)
return err;
}
- md = EVP_get_digestbyname(params.hash_algo);
+ md = get_digestbyname(params.hash_algo);
if (!md) {
log_err("EVP_get_digestbyname(%s) failed\n", params.hash_algo);
return 1;
@@ -561,6 +592,22 @@ static int algocmp(const char *a, const char *b)
return *a || *b;
}
+static int strmatch(const char *needle, const char *haystack)
+{
+ int len = strlen(needle);
+ const char *p = haystack;
+ const char *t;
+
+ for (t = strchrnul(p, ','); *p; p = t, t = strchrnul(p, ',')) {
+ if (t - p == len &&
+ !strncmp(needle, p, len))
+ return 0;
+ if (!*t++)
+ break;
+ }
+ return 1;
+}
+
int get_hash_algo(const char *algo)
{
int i;
@@ -568,7 +615,7 @@ int get_hash_algo(const char *algo)
/* first iterate over builtin algorithms */
for (i = 0; i < PKEY_HASH__LAST; i++)
if (pkey_hash_algo[i] &&
- !strcmp(algo, pkey_hash_algo[i]))
+ !strmatch(algo, pkey_hash_algo[i]))
return i;
/* iterate over algorithms provided by kernel-headers */
--
2.11.0
next prev parent reply other threads:[~2018-12-03 3:35 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-03 3:35 [PATCH v3 1/7] ima-evm-utils: Fix hash buffer overflow in verify_evm and hmac_evm Vitaly Chikunov
2018-12-03 3:35 ` [PATCH v3 2/7] ima-evm-utils: Define hash and sig buffer sizes and add asserts Vitaly Chikunov
2018-12-03 3:35 ` [PATCH v3 3/7] ima-evm-utils: Define the '--xattr-user' option for testing Vitaly Chikunov
2018-12-03 3:35 ` [PATCH v3 4/7] ima-evm-utils: Allow using Streebog hash function Vitaly Chikunov
2018-12-03 3:35 ` [PATCH v3 5/7] ima-evm-utils: Preload OpenSSL engine via '--engine' option Vitaly Chikunov
2018-12-03 3:35 ` [PATCH v3 6/7] ima-evm-utils: Extract digest algorithms from hash_info.h Vitaly Chikunov
2018-12-03 3:35 ` Vitaly Chikunov [this message]
2019-02-11 17:38 ` [PATCH v3 7/7] ima-evm-utils: Try to load digest by its alias Mimi Zohar
2019-02-11 17:52 ` Vitaly Chikunov
2019-02-11 17:59 ` Mimi Zohar
2019-02-11 18:13 ` Vitaly Chikunov
2019-02-11 18:21 ` Vitaly Chikunov
2019-02-11 19:26 ` Vitaly Chikunov
2019-02-11 20:21 ` Mimi Zohar
2019-02-11 20:37 ` Vitaly Chikunov
2019-02-12 15:41 ` Mimi Zohar
2019-02-12 17:07 ` Vitaly Chikunov
2018-12-03 13:03 ` [PATCH v3 1/7] ima-evm-utils: Fix hash buffer overflow in verify_evm and hmac_evm Mimi Zohar
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