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 1/2] ima-evm-utils: Do not allow fallback and unknown hash algos
Date: Thu, 25 Jul 2019 09:13:05 +0300 [thread overview]
Message-ID: <20190725061306.30515-1-vt@altlinux.org> (raw)
Falling back and permissiveness could have security implications.
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
---
src/evmctl.c | 4 ++++
src/libimaevm.c | 7 +++++--
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/src/evmctl.c b/src/evmctl.c
index 3289061..3766343 100644
--- a/src/evmctl.c
+++ b/src/evmctl.c
@@ -584,6 +584,10 @@ static int hash_ima(const char *file)
int len, err, offset;
int algo = get_hash_algo(params.hash_algo);
+ if (algo < 0) {
+ log_err("Unknown hash algo: %s\n", params.hash_algo);
+ return -1;
+ }
if (algo > PKEY_HASH_SHA1) {
hash[0] = IMA_XATTR_DIGEST_NG;
hash[1] = algo;
diff --git a/src/libimaevm.c b/src/libimaevm.c
index 2d99570..86c5784 100644
--- a/src/libimaevm.c
+++ b/src/libimaevm.c
@@ -571,8 +571,7 @@ int get_hash_algo(const char *algo)
!strcmp(algo, hash_algo_name[i]))
return i;
- log_info("digest %s not found, fall back to sha1\n", algo);
- return PKEY_HASH_SHA1;
+ return -1;
}
static int get_hash_algo_from_sig(unsigned char *sig)
@@ -920,6 +919,10 @@ int sign_hash_v2(const char *algo, const unsigned char *hash, int size, const ch
hdr->version = (uint8_t) DIGSIG_VERSION_2;
hdr->hash_algo = get_hash_algo(algo);
+ if (hdr->hash_algo == -1) {
+ log_err("sign_hash_v2: hash algo is unknown: %s\n", algo);
+ return -1;
+ }
calc_keyid_v2(&keyid, name, pkey);
hdr->keyid = keyid;
--
2.11.0
next reply other threads:[~2019-07-25 6:13 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-25 6:13 Vitaly Chikunov [this message]
2019-07-25 6:13 ` [PATCH 2/2] ima-evm-utils: Show used hash algo in verbose mode Vitaly Chikunov
2019-07-25 13:49 ` Mimi Zohar
2019-07-25 13:44 ` [PATCH 1/2] ima-evm-utils: Do not allow fallback and unknown hash algos Mimi Zohar
2019-07-25 14:08 ` Vitaly Chikunov
2019-07-25 14:29 ` Mimi Zohar
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