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Patch "crypto: caam - properly set IV after {en,de}crypt" has been added to the 4.12-stable tree

PATCH [email protected] 1 participant 1 message Jul 19, 2017

Subsystems (3)
Stable branch Crypto API Freescale CAAM (Cryptographic Acceleration and Assurance Module) driver
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This is a note to let you know that I've just added the patch titled

crypto: caam - properly set IV after {en,de}crypt

to the 4.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
crypto-caam-properly-set-iv-after-en-de-crypt.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 854b06f768794cd664886ec3ba3a5b1c58d42167 Mon Sep 17 00:00:00 2001

From: David Gstir <[email protected]>
Date: Wed, 28 Jun 2017 15:27:10 +0200
Subject: crypto: caam - properly set IV after {en,de}crypt
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From: David Gstir <[email protected]>

commit 854b06f768794cd664886ec3ba3a5b1c58d42167 upstream.

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")

Signed-off-by David Gstir <[email protected]>
Reviewed-by Horia Geantă <[email protected]>
Signed-off-by Herbert Xu <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/crypto/caam/caamalg.c |   20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)
drivers/crypto/caam/caamalg.c +18 -2
@@ -882,10 +882,10 @@ static void ablkcipher_encrypt_done(stru
 {
 	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(stru
 #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(stru
 {
 	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(stru
 #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);

Patches currently in stable-queue which might be from [email protected] are

queue-4.12/crypto-caam-properly-set-iv-after-en-de-crypt.patch