From 781a08d9740afa73357f1a60d45d7c93d7cca2dd Mon Sep 17 00:00:00 2001 From: Tudor Ambarus Date: Thu, 5 Dec 2019 09:54:01 +0000 Subject: crypto: atmel-aes - Fix counter overflow in CTR mode 32 bit counter is not supported by neither of our AES IPs, all implement a 16 bit block counter. Drop the 32 bit block counter logic. Fixes: fcac83656a3e ("crypto: atmel-aes - fix the counter overflow in CTR mode") Signed-off-by: Tudor Ambarus Signed-off-by: Herbert Xu --- drivers/crypto/atmel-aes.c | 37 ++++++++++++------------------------- 1 file changed, 12 insertions(+), 25 deletions(-) (limited to 'drivers/crypto/atmel-aes.c') diff --git a/drivers/crypto/atmel-aes.c b/drivers/crypto/atmel-aes.c index f25dd0e1d52b..6af9ad075a8e 100644 --- a/drivers/crypto/atmel-aes.c +++ b/drivers/crypto/atmel-aes.c @@ -88,7 +88,6 @@ struct atmel_aes_caps { bool has_dualbuff; bool has_cfb64; - bool has_ctr32; bool has_gcm; bool has_xts; bool has_authenc; @@ -1018,8 +1017,9 @@ static int atmel_aes_ctr_transfer(struct atmel_aes_dev *dd) struct atmel_aes_ctr_ctx *ctx = atmel_aes_ctr_ctx_cast(dd->ctx); struct skcipher_request *req = skcipher_request_cast(dd->areq); struct scatterlist *src, *dst; - u32 ctr, blocks; size_t datalen; + u32 ctr; + u16 blocks, start, end; bool use_dma, fragmented = false; /* Check for transfer completion. */ @@ -1031,27 +1031,17 @@ static int atmel_aes_ctr_transfer(struct atmel_aes_dev *dd) datalen = req->cryptlen - ctx->offset; blocks = DIV_ROUND_UP(datalen, AES_BLOCK_SIZE); ctr = be32_to_cpu(ctx->iv[3]); - if (dd->caps.has_ctr32) { - /* Check 32bit counter overflow. */ - u32 start = ctr; - u32 end = start + blocks - 1; - - if (end < start) { - ctr |= 0xffffffff; - datalen = AES_BLOCK_SIZE * -start; - fragmented = true; - } - } else { - /* Check 16bit counter overflow. */ - u16 start = ctr & 0xffff; - u16 end = start + (u16)blocks - 1; - - if (blocks >> 16 || end < start) { - ctr |= 0xffff; - datalen = AES_BLOCK_SIZE * (0x10000-start); - fragmented = true; - } + + /* Check 16bit counter overflow. */ + start = ctr & 0xffff; + end = start + blocks - 1; + + if (blocks >> 16 || end < start) { + ctr |= 0xffff; + datalen = AES_BLOCK_SIZE * (0x10000 - start); + fragmented = true; } + use_dma = (datalen >= ATMEL_AES_DMA_THRESHOLD); /* Jump to offset. */ @@ -2521,7 +2511,6 @@ static void atmel_aes_get_cap(struct atmel_aes_dev *dd) { dd->caps.has_dualbuff = 0; dd->caps.has_cfb64 = 0; - dd->caps.has_ctr32 = 0; dd->caps.has_gcm = 0; dd->caps.has_xts = 0; dd->caps.has_authenc = 0; @@ -2532,7 +2521,6 @@ static void atmel_aes_get_cap(struct atmel_aes_dev *dd) case 0x500: dd->caps.has_dualbuff = 1; dd->caps.has_cfb64 = 1; - dd->caps.has_ctr32 = 1; dd->caps.has_gcm = 1; dd->caps.has_xts = 1; dd->caps.has_authenc = 1; @@ -2541,7 +2529,6 @@ static void atmel_aes_get_cap(struct atmel_aes_dev *dd) case 0x200: dd->caps.has_dualbuff = 1; dd->caps.has_cfb64 = 1; - dd->caps.has_ctr32 = 1; dd->caps.has_gcm = 1; dd->caps.max_burst_size = 4; break; -- cgit v1.2.3-59-g8ed1b