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authorHerbert Xu <herbert@gondor.apana.org.au>2016-11-22 15:08:19 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2016-11-28 16:23:18 +0300
commitf1c131b45410a202eb45cc55980a7a9e4e4b4f40 (patch)
tree7018499e4ee67d43eea6cab1689ca1d09495b2e9 /include/crypto/xts.h
parent700cb3f5fe755b1a2d0f5cf3ae89ad7ef69d321f (diff)
downloadlinux-f1c131b45410a202eb45cc55980a7a9e4e4b4f40.tar.xz
crypto: xts - Convert to skcipher
This patch converts xts over to the skcipher interface. It also optimises the implementation to be based on ECB instead of the underlying cipher. For compatibility the existing naming scheme of xts(aes) is maintained as opposed to the more obvious one of xts(ecb(aes)). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'include/crypto/xts.h')
-rw-r--r--include/crypto/xts.h26
1 files changed, 24 insertions, 2 deletions
diff --git a/include/crypto/xts.h b/include/crypto/xts.h
index ede6b97b24cc..77b630672b2c 100644
--- a/include/crypto/xts.h
+++ b/include/crypto/xts.h
@@ -2,8 +2,7 @@
#define _CRYPTO_XTS_H
#include <crypto/b128ops.h>
-#include <linux/crypto.h>
-#include <crypto/algapi.h>
+#include <crypto/internal/skcipher.h>
#include <linux/fips.h>
struct scatterlist;
@@ -51,4 +50,27 @@ static inline int xts_check_key(struct crypto_tfm *tfm,
return 0;
}
+static inline int xts_verify_key(struct crypto_skcipher *tfm,
+ const u8 *key, unsigned int keylen)
+{
+ /*
+ * key consists of keys of equal size concatenated, therefore
+ * the length must be even.
+ */
+ if (keylen % 2) {
+ crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+ return -EINVAL;
+ }
+
+ /* ensure that the AES and tweak key are not identical */
+ if ((fips_enabled || crypto_skcipher_get_flags(tfm) &
+ CRYPTO_TFM_REQ_WEAK_KEY) &&
+ !crypto_memneq(key, key + (keylen / 2), keylen / 2)) {
+ crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_WEAK_KEY);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
#endif /* _CRYPTO_XTS_H */