crypto: atmel-aes - Add blocksize constraint for ECB and CBC modes

NIST 800-38A requires for the ECB and CBC modes that the total number
of bits in the plaintext to be a multiple of the block cipher.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/atmel-aes.c b/drivers/crypto/atmel-aes.c
index b1d2860042958bb2ca103e33bf2d4d60041a557e..9c6d80d1d7a0ee9fbb656ec24b19522658d19127 100644 (file)
--- a/drivers/crypto/atmel-aes.c
+++ b/drivers/crypto/atmel-aes.c
@@ -1089,6 +1089,11 @@ static int atmel_aes_crypt(struct skcipher_request *req, unsigned long mode)
        struct atmel_aes_base_ctx *ctx = crypto_skcipher_ctx(skcipher);
        struct atmel_aes_reqctx *rctx;
        struct atmel_aes_dev *dd;
+       u32 opmode = mode & AES_FLAGS_OPMODE_MASK;
+
+       if ((opmode == AES_FLAGS_ECB || opmode == AES_FLAGS_CBC) &&
+           !IS_ALIGNED(req->cryptlen, crypto_skcipher_blocksize(skcipher)))
+               return -EINVAL;
 
        switch (mode & AES_FLAGS_OPMODE_MASK) {
        case AES_FLAGS_CFB8:
@@ -1120,7 +1125,7 @@ static int atmel_aes_crypt(struct skcipher_request *req, unsigned long mode)
        rctx = skcipher_request_ctx(req);
        rctx->mode = mode;
 
-       if ((mode & AES_FLAGS_OPMODE_MASK) != AES_FLAGS_ECB &&
+       if (opmode != AES_FLAGS_ECB &&
            !(mode & AES_FLAGS_ENCRYPT) && req->src == req->dst) {
                unsigned int ivsize = crypto_skcipher_ivsize(skcipher);