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authorEric Biggers <ebiggers@google.com>2017-06-08 14:48:32 +0100
committerJames Morris <james.l.morris@oracle.com>2017-06-09 13:29:47 +1000
commit0f534e4a13496b02ae284f50fcb0263f6ea37007 (patch)
treea5200ddfa62a42340dd2ee2e918fb5b001240382 /security
parent64d107d3acca1565c39c044c459fd18f70943534 (diff)
downloadlinux-0f534e4a13496b02ae284f50fcb0263f6ea37007.tar.bz2
KEYS: encrypted: use constant-time HMAC comparison
MACs should, in general, be compared using crypto_memneq() to prevent timing attacks. Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Diffstat (limited to 'security')
-rw-r--r--security/keys/encrypted-keys/encrypted.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
index 702c80662069..5c98c2fe03f0 100644
--- a/security/keys/encrypted-keys/encrypted.c
+++ b/security/keys/encrypted-keys/encrypted.c
@@ -30,6 +30,7 @@
#include <linux/scatterlist.h>
#include <linux/ctype.h>
#include <crypto/aes.h>
+#include <crypto/algapi.h>
#include <crypto/hash.h>
#include <crypto/sha.h>
#include <crypto/skcipher.h>
@@ -534,8 +535,8 @@ static int datablob_hmac_verify(struct encrypted_key_payload *epayload,
ret = calc_hmac(digest, derived_key, sizeof derived_key, p, len);
if (ret < 0)
goto out;
- ret = memcmp(digest, epayload->format + epayload->datablob_len,
- sizeof digest);
+ ret = crypto_memneq(digest, epayload->format + epayload->datablob_len,
+ sizeof(digest));
if (ret) {
ret = -EINVAL;
dump_hmac("datablob",