Currently, the gcm(aes-ni) driver open codes the scatterlist handling
that is encapsulated by the skcipher walk API. So let's switch to that
instead.
Also, move the handling at the end of gcmaes_crypt_by_sg() that is
dependent on whether we are encrypting or decrypting into the callers,
which always do one or the other.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
arch/x86/crypto/aesni-intel_glue.c | 139 ++++++++------------
1 file changed, 56 insertions(+), 83 deletions(-)
diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 26b012065701..d0b4fa7bd2d0 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -638,25 +638,18 @@ static int generic_gcmaes_set_authsize(struct crypto_aead *tfm,
static int gcmaes_crypt_by_sg(bool enc, struct aead_request *req,
unsigned int assoclen, u8 *hash_subkey,
- u8 *iv, void *aes_ctx)
+ u8 *iv, void *aes_ctx, u8 *auth_tag,
+ unsigned long auth_tag_len)
{
- struct crypto_aead *tfm = crypto_aead_reqtfm(req);
- unsigned long auth_tag_len = crypto_aead_authsize(tfm);
const struct aesni_gcm_tfm_s *gcm_tfm = aesni_gcm_tfm;
u8 databuf[sizeof(struct gcm_context_data) + (AESNI_ALIGN - 8)] __aligned(8);
struct gcm_context_data *data = PTR_ALIGN((void *)databuf, AESNI_ALIGN);
- struct scatter_walk dst_sg_walk = {};
unsigned long left = req->cryptlen;
- unsigned long len, srclen, dstlen;
struct scatter_walk assoc_sg_walk;
- struct scatter_walk src_sg_walk;
- struct scatterlist src_start[2];
- struct scatterlist dst_start[2];
- struct scatterlist *src_sg;
- struct scatterlist *dst_sg;
- u8 *src, *dst, *assoc;
+ struct skcipher_walk walk;
u8 *assocmem = NULL;
- u8 authTag[16];
+ u8 *assoc;
+ int err;
if (!enc)
left -= auth_tag_len;
@@ -683,61 +676,8 @@ static int gcmaes_crypt_by_sg(bool enc, struct aead_request *req,
scatterwalk_map_and_copy(assoc, req->src, 0, assoclen, 0);
}
- if (left) {
- src_sg = scatterwalk_ffwd(src_start, req->src, req->assoclen);
- scatterwalk_start(&src_sg_walk, src_sg);
- if (req->src != req->dst) {
- dst_sg = scatterwalk_ffwd(dst_start, req->dst,
- req->assoclen);
- scatterwalk_start(&dst_sg_walk, dst_sg);
- }
- }
-
kernel_fpu_begin();
gcm_tfm->init(aes_ctx, data, iv, hash_subkey, assoc, assoclen);
- if (req->src != req->dst) {
- while (left) {
- src = scatterwalk_map(&src_sg_walk);
- dst = scatterwalk_map(&dst_sg_walk);
- srclen = scatterwalk_clamp(&src_sg_walk, left);
- dstlen = scatterwalk_clamp(&dst_sg_walk, left);
- len = min(srclen, dstlen);
- if (len) {
- if (enc)
- gcm_tfm->enc_update(aes_ctx, data,
- dst, src, len);
- else
- gcm_tfm->dec_update(aes_ctx, data,
- dst, src, len);
- }
- left -= len;
-
- scatterwalk_unmap(src);
- scatterwalk_unmap(dst);
- scatterwalk_advance(&src_sg_walk, len);
- scatterwalk_advance(&dst_sg_walk, len);
- scatterwalk_done(&src_sg_walk, 0, left);
- scatterwalk_done(&dst_sg_walk, 1, left);
- }
- } else {
- while (left) {
- dst = src = scatterwalk_map(&src_sg_walk);
- len = scatterwalk_clamp(&src_sg_walk, left);
- if (len) {
- if (enc)
- gcm_tfm->enc_update(aes_ctx, data,
- src, src, len);
- else
- gcm_tfm->dec_update(aes_ctx, data,
- src, src, len);
- }
- left -= len;
- scatterwalk_unmap(src);
- scatterwalk_advance(&src_sg_walk, len);
- scatterwalk_done(&src_sg_walk, 1, left);
- }
- }
- gcm_tfm->finalize(aes_ctx, data, authTag, auth_tag_len);
kernel_fpu_end();
if (!assocmem)
@@ -745,24 +685,25 @@ static int gcmaes_crypt_by_sg(bool enc, struct aead_request *req,
else
kfree(assocmem);
- if (!enc) {
- u8 authTagMsg[16];
+ err = enc ? skcipher_walk_aead_encrypt(&walk, req, false)
+ : skcipher_walk_aead_decrypt(&walk, req, false);
- /* Copy out original authTag */
- scatterwalk_map_and_copy(authTagMsg, req->src,
- req->assoclen + req->cryptlen -
- auth_tag_len,
- auth_tag_len, 0);
+ while (walk.nbytes > 0) {
+ kernel_fpu_begin();
+ (enc ? gcm_tfm->enc_update
+ : gcm_tfm->dec_update)(aes_ctx, data, walk.dst.virt.addr,
+ walk.src.virt.addr, walk.nbytes);
+ kernel_fpu_end();
- /* Compare generated tag with passed in tag. */
- return crypto_memneq(authTagMsg, authTag, auth_tag_len) ?
- -EBADMSG : 0;
+ err = skcipher_walk_done(&walk, 0);
}
- /* Copy in the authTag */
- scatterwalk_map_and_copy(authTag, req->dst,
- req->assoclen + req->cryptlen,
- auth_tag_len, 1);
+ if (err)
+ return err;
+
+ kernel_fpu_begin();
+ gcm_tfm->finalize(aes_ctx, data, auth_tag, auth_tag_len);
+ kernel_fpu_end();
return 0;
}
@@ -770,15 +711,47 @@ static int gcmaes_crypt_by_sg(bool enc, struct aead_request *req,
static int gcmaes_encrypt(struct aead_request *req, unsigned int assoclen,
u8 *hash_subkey, u8 *iv, void *aes_ctx)
{
- return gcmaes_crypt_by_sg(true, req, assoclen, hash_subkey, iv,
- aes_ctx);
+ struct crypto_aead *tfm = crypto_aead_reqtfm(req);
+ unsigned long auth_tag_len = crypto_aead_authsize(tfm);
+ u8 auth_tag[16];
+ int err;
+
+ err = gcmaes_crypt_by_sg(true, req, assoclen, hash_subkey, iv, aes_ctx,
+ auth_tag, auth_tag_len);
+ if (err)
+ return err;
+
+ scatterwalk_map_and_copy(auth_tag, req->dst,
+ req->assoclen + req->cryptlen,
+ auth_tag_len, 1);
+ return 0;
}
static int gcmaes_decrypt(struct aead_request *req, unsigned int assoclen,
u8 *hash_subkey, u8 *iv, void *aes_ctx)
{
- return gcmaes_crypt_by_sg(false, req, assoclen, hash_subkey, iv,
- aes_ctx);
+ struct crypto_aead *tfm = crypto_aead_reqtfm(req);
+ unsigned long auth_tag_len = crypto_aead_authsize(tfm);
+ u8 auth_tag_msg[16];
+ u8 auth_tag[16];
+ int err;
+
+ err = gcmaes_crypt_by_sg(false, req, assoclen, hash_subkey, iv, aes_ctx,
+ auth_tag, auth_tag_len);
+ if (err)
+ return err;
+
+ /* Copy out original auth_tag */
+ scatterwalk_map_and_copy(auth_tag_msg, req->src,
+ req->assoclen + req->cryptlen - auth_tag_len,
+ auth_tag_len, 0);
+
+ /* Compare generated tag with passed in tag. */
+ if (crypto_memneq(auth_tag_msg, auth_tag, auth_tag_len)) {
+ memzero_explicit(auth_tag, sizeof(auth_tag));
+ return -EBADMSG;
+ }
+ return 0;
}
static int helper_rfc4106_encrypt(struct aead_request *req)
--
2.17.1
