2021-07-20 08:59:28

by Tudor Ambarus

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Subject: [PATCH 6/9] crypto: atmel-tdes: Add FIPS81's zero length cryptlen constraint

FIPS81 requires for the ECB, CBC, CFB, and OFB modes that the
plaintext and ciphertext to have a positive integer length.
Add this constraint and just return 0 for a zero length cryptlen.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/crypto/atmel-tdes.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/crypto/atmel-tdes.c b/drivers/crypto/atmel-tdes.c
index abbf1b7a75ab..8380e0ab149a 100644
--- a/drivers/crypto/atmel-tdes.c
+++ b/drivers/crypto/atmel-tdes.c
@@ -682,6 +682,9 @@ static int atmel_tdes_crypt(struct skcipher_request *req, unsigned long mode)
struct atmel_tdes_reqctx *rctx = skcipher_request_ctx(req);
struct device *dev = ctx->dd->dev;

+ if (!req->cryptlen)
+ return 0;
+
switch (mode & TDES_FLAGS_OPMODE_MASK) {
case TDES_FLAGS_CFB8:
if (!IS_ALIGNED(req->cryptlen, CFB8_BLOCK_SIZE)) {
--
2.25.1