From 854b06f768794cd664886ec3ba3a5b1c58d42167 Mon Sep 17 00:00:00 2001 From: David Gstir Date: Wed, 28 Jun 2017 15:27:10 +0200 Subject: [PATCH] crypto: caam - properly set IV after {en,de}crypt MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Certain cipher modes like CTS expect the IV (req->info) of ablkcipher_request (or equivalently req->iv of skcipher_request) to contain the last ciphertext block when the {en,de}crypt operation is done. This is currently not the case for the CAAM driver which in turn breaks e.g. cts(cbc(aes)) when the CAAM driver is enabled. This patch fixes the CAAM driver to properly set the IV after the {en,de}crypt operation of ablkcipher finishes. This issue was revealed by the changes in the SW CTS mode in commit 0605c41cc53ca ("crypto: cts - Convert to skcipher") Cc: # 4.8+ Signed-off-by: David Gstir Reviewed-by: Horia Geantă Signed-off-by: Herbert Xu --- drivers/crypto/caam/caamalg.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c index fde399c88779..0488b7f81dcf 100644 --- a/drivers/crypto/caam/caamalg.c +++ b/drivers/crypto/caam/caamalg.c @@ -882,10 +882,10 @@ static void ablkcipher_encrypt_done(struct device *jrdev, u32 *desc, u32 err, { struct ablkcipher_request *req = context; struct ablkcipher_edesc *edesc; -#ifdef DEBUG struct crypto_ablkcipher *ablkcipher = crypto_ablkcipher_reqtfm(req); int ivsize = crypto_ablkcipher_ivsize(ablkcipher); +#ifdef DEBUG dev_err(jrdev, "%s %d: err 0x%x\n", __func__, __LINE__, err); #endif @@ -904,6 +904,14 @@ static void ablkcipher_encrypt_done(struct device *jrdev, u32 *desc, u32 err, #endif ablkcipher_unmap(jrdev, edesc, req); + + /* + * The crypto API expects us to set the IV (req->info) to the last + * ciphertext block. This is used e.g. by the CTS mode. + */ + scatterwalk_map_and_copy(req->info, req->dst, req->nbytes - ivsize, + ivsize, 0); + kfree(edesc); ablkcipher_request_complete(req, err); @@ -914,10 +922,10 @@ static void ablkcipher_decrypt_done(struct device *jrdev, u32 *desc, u32 err, { struct ablkcipher_request *req = context; struct ablkcipher_edesc *edesc; -#ifdef DEBUG struct crypto_ablkcipher *ablkcipher = crypto_ablkcipher_reqtfm(req); int ivsize = crypto_ablkcipher_ivsize(ablkcipher); +#ifdef DEBUG dev_err(jrdev, "%s %d: err 0x%x\n", __func__, __LINE__, err); #endif @@ -935,6 +943,14 @@ static void ablkcipher_decrypt_done(struct device *jrdev, u32 *desc, u32 err, #endif ablkcipher_unmap(jrdev, edesc, req); + + /* + * The crypto API expects us to set the IV (req->info) to the last + * ciphertext block. + */ + scatterwalk_map_and_copy(req->info, req->src, req->nbytes - ivsize, + ivsize, 0); + kfree(edesc); ablkcipher_request_complete(req, err);