From a4f2779ecf2f42b0997fedef6fd20a931c40a3e3 Mon Sep 17 00:00:00 2001
From: Harald Freudenberger <freude@linux.vnet.ibm.com>
Date: Thu, 15 Dec 2016 14:58:08 +0100
Subject: [PATCH] s390/crypto: Extend key length check for AES-XTS in fips
mode.
In fips mode only xts keys with 128 bit or 125 bit are allowed.
This fix extends the xts_aes_set_key function to check for these
valid key lengths in fips mode.
Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
arch/s390/crypto/aes_s390.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c
index 303d28eb03a2f..591cbdf615af0 100644
--- a/arch/s390/crypto/aes_s390.c
+++ b/arch/s390/crypto/aes_s390.c
@@ -28,6 +28,7 @@
#include <linux/cpufeature.h>
#include <linux/init.h>
#include <linux/spinlock.h>
+#include <linux/fips.h>
#include <crypto/xts.h>
#include <asm/cpacf.h>
@@ -501,6 +502,12 @@ static int xts_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
if (err)
return err;
+ /* In fips mode only 128 bit or 256 bit keys are valid */
+ if (fips_enabled && key_len != 32 && key_len != 64) {
+ tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
+ return -EINVAL;
+ }
+
/* Pick the correct function code based on the key length */
fc = (key_len == 32) ? CPACF_KM_XTS_128 :
(key_len == 64) ? CPACF_KM_XTS_256 : 0;
--
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