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authorEric Biggers <ebiggers@google.com>2017-11-22 11:51:36 -0800
committerHerbert Xu <herbert@gondor.apana.org.au>2017-11-29 17:33:32 +1100
commitdbd872a123fab81d0fa235a265c39e5ccdf735b3 (patch)
tree5c69967a0c96c4ae9504d4ee7b6d2c0ddea1373c
parentecf3220d882ae84844909ed6323032aac47aff93 (diff)
crypto: chacha20 - Use unaligned access macros when loading key and IV
The generic ChaCha20 implementation has a cra_alignmask of 3, which ensures that the key passed into crypto_chacha20_setkey() and the IV passed into crypto_chacha20_init() are 4-byte aligned. However, these functions are also called from the ARM and ARM64 implementations of ChaCha20, which intentionally do not have a cra_alignmask set. This is broken because 32-bit words are being loaded from potentially-unaligned buffers without the unaligned access macros. Fix it by using the unaligned access macros when loading the key and IV. Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--crypto/chacha20_generic.c16
1 files changed, 6 insertions, 10 deletions
diff --git a/crypto/chacha20_generic.c b/crypto/chacha20_generic.c
index ec84e7837aac..b5a10ebf1b82 100644
--- a/crypto/chacha20_generic.c
+++ b/crypto/chacha20_generic.c
@@ -9,16 +9,12 @@
* (at your option) any later version.
*/
+#include <asm/unaligned.h>
#include <crypto/algapi.h>
#include <crypto/chacha20.h>
#include <crypto/internal/skcipher.h>
#include <linux/module.h>
-static inline u32 le32_to_cpuvp(const void *p)
-{
- return le32_to_cpup(p);
-}
-
static void chacha20_docrypt(u32 *state, u8 *dst, const u8 *src,
unsigned int bytes)
{
@@ -53,10 +49,10 @@ void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv)
state[9] = ctx->key[5];
state[10] = ctx->key[6];
state[11] = ctx->key[7];
- state[12] = le32_to_cpuvp(iv + 0);
- state[13] = le32_to_cpuvp(iv + 4);
- state[14] = le32_to_cpuvp(iv + 8);
- state[15] = le32_to_cpuvp(iv + 12);
+ state[12] = get_unaligned_le32(iv + 0);
+ state[13] = get_unaligned_le32(iv + 4);
+ state[14] = get_unaligned_le32(iv + 8);
+ state[15] = get_unaligned_le32(iv + 12);
}
EXPORT_SYMBOL_GPL(crypto_chacha20_init);
@@ -70,7 +66,7 @@ int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
return -EINVAL;
for (i = 0; i < ARRAY_SIZE(ctx->key); i++)
- ctx->key[i] = le32_to_cpuvp(key + i * sizeof(u32));
+ ctx->key[i] = get_unaligned_le32(key + i * sizeof(u32));
return 0;
}