diff options
| -rw-r--r-- | crypto/cts.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/crypto/cts.c b/crypto/cts.c index 4e28d83ae37d..9441da797bb9 100644 --- a/crypto/cts.c +++ b/crypto/cts.c @@ -152,12 +152,14 @@ static int crypto_cts_encrypt(struct skcipher_request *req) struct skcipher_request *subreq = &rctx->subreq; int bsize = crypto_skcipher_blocksize(tfm); unsigned int nbytes = req->cryptlen; - int cbc_blocks = (nbytes + bsize - 1) / bsize - 1; unsigned int offset; skcipher_request_set_tfm(subreq, ctx->child); - if (cbc_blocks <= 0) { + if (nbytes < bsize) + return -EINVAL; + + if (nbytes == bsize) { skcipher_request_set_callback(subreq, req->base.flags, req->base.complete, req->base.data); @@ -166,7 +168,7 @@ static int crypto_cts_encrypt(struct skcipher_request *req) return crypto_skcipher_encrypt(subreq); } - offset = cbc_blocks * bsize; + offset = rounddown(nbytes - 1, bsize); rctx->offset = offset; skcipher_request_set_callback(subreq, req->base.flags, @@ -244,13 +246,15 @@ static int crypto_cts_decrypt(struct skcipher_request *req) struct skcipher_request *subreq = &rctx->subreq; int bsize = crypto_skcipher_blocksize(tfm); unsigned int nbytes = req->cryptlen; - int cbc_blocks = (nbytes + bsize - 1) / bsize - 1; unsigned int offset; u8 *space; skcipher_request_set_tfm(subreq, ctx->child); - if (cbc_blocks <= 0) { + if (nbytes < bsize) + return -EINVAL; + + if (nbytes == bsize) { skcipher_request_set_callback(subreq, req->base.flags, req->base.complete, req->base.data); @@ -264,10 +268,10 @@ static int crypto_cts_decrypt(struct skcipher_request *req) space = crypto_cts_reqctx_space(req); - offset = cbc_blocks * bsize; + offset = rounddown(nbytes - 1, bsize); rctx->offset = offset; - if (cbc_blocks <= 1) + if (offset <= bsize) memcpy(space, req->iv, bsize); else scatterwalk_map_and_copy(space, req->src, offset - 2 * bsize, |