From 7ff9036a62053995ff4bc7048dc176bdf9135d96 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 2 Oct 2018 22:22:15 -0700 Subject: [PATCH] crypto: arm64/aes - fix handling sub-block CTS-CBC inputs In the new arm64 CTS-CBC implementation, return an error code rather than crashing on inputs shorter than AES_BLOCK_SIZE bytes. Also set cra_blocksize to AES_BLOCK_SIZE (like is done in the cts template) to indicate the minimum input size. Fixes: dd597fb33ff0 ("crypto: arm64/aes-blk - add support for CTS-CBC mode") Signed-off-by: Eric Biggers Reviewed-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- arch/arm64/crypto/aes-glue.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/arch/arm64/crypto/aes-glue.c b/arch/arm64/crypto/aes-glue.c index 26d2b0263ba6..1e676625ef33 100644 --- a/arch/arm64/crypto/aes-glue.c +++ b/arch/arm64/crypto/aes-glue.c @@ -243,8 +243,11 @@ static int cts_cbc_encrypt(struct skcipher_request *req) skcipher_request_set_tfm(&rctx->subreq, tfm); - if (req->cryptlen == AES_BLOCK_SIZE) + if (req->cryptlen <= AES_BLOCK_SIZE) { + if (req->cryptlen < AES_BLOCK_SIZE) + return -EINVAL; cbc_blocks = 1; + } if (cbc_blocks > 0) { unsigned int blocks; @@ -305,8 +308,11 @@ static int cts_cbc_decrypt(struct skcipher_request *req) skcipher_request_set_tfm(&rctx->subreq, tfm); - if (req->cryptlen == AES_BLOCK_SIZE) + if (req->cryptlen <= AES_BLOCK_SIZE) { + if (req->cryptlen < AES_BLOCK_SIZE) + return -EINVAL; cbc_blocks = 1; + } if (cbc_blocks > 0) { unsigned int blocks; @@ -486,14 +492,13 @@ static struct skcipher_alg aes_algs[] = { { .cra_driver_name = "__cts-cbc-aes-" MODE, .cra_priority = PRIO, .cra_flags = CRYPTO_ALG_INTERNAL, - .cra_blocksize = 1, + .cra_blocksize = AES_BLOCK_SIZE, .cra_ctxsize = sizeof(struct crypto_aes_ctx), .cra_module = THIS_MODULE, }, .min_keysize = AES_MIN_KEY_SIZE, .max_keysize = AES_MAX_KEY_SIZE, .ivsize = AES_BLOCK_SIZE, - .chunksize = AES_BLOCK_SIZE, .walksize = 2 * AES_BLOCK_SIZE, .setkey = skcipher_aes_setkey, .encrypt = cts_cbc_encrypt,