Remove the limitation of single element scatterlists. ECDH with
multi-element scatterlists is needed by TPM.
Similar to 'commit 95ec01ba1ef0 ("crypto: ecdh - fix to allow multi
segment scatterlists")'.
Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
---
drivers/crypto/atmel-ecc.c | 31 ++++++++++++++++++++++---------
1 file changed, 22 insertions(+), 9 deletions(-)
diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
index e66f18a0..a25772e 100644
--- a/drivers/crypto/atmel-ecc.c
+++ b/drivers/crypto/atmel-ecc.c
@@ -186,7 +186,10 @@ static int atmel_ecc_init_ecdh_cmd(struct atmel_ecc_cmd *cmd,
* always be the same. Use a macro for the key size to avoid unnecessary
* computations.
*/
- copied = sg_copy_to_buffer(pubkey, 1, cmd->data, ATMEL_ECC_PUBKEY_SIZE);
+ copied = sg_copy_to_buffer(pubkey,
+ sg_nents_for_len(pubkey,
+ ATMEL_ECC_PUBKEY_SIZE),
+ cmd->data, ATMEL_ECC_PUBKEY_SIZE);
if (copied != ATMEL_ECC_PUBKEY_SIZE)
return -EINVAL;
@@ -268,15 +271,17 @@ static void atmel_ecdh_done(struct atmel_ecc_work_data *work_data, void *areq,
struct kpp_request *req = areq;
struct atmel_ecdh_ctx *ctx = work_data->ctx;
struct atmel_ecc_cmd *cmd = &work_data->cmd;
- size_t copied;
- size_t n_sz = ctx->n_sz;
+ size_t copied, n_sz;
if (status)
goto free_work_data;
+ /* might want less than we've got */
+ n_sz = min_t(size_t, ctx->n_sz, req->dst_len);
+
/* copy the shared secret */
- copied = sg_copy_from_buffer(req->dst, 1, &cmd->data[RSP_DATA_IDX],
- n_sz);
+ copied = sg_copy_from_buffer(req->dst, sg_nents_for_len(req->dst, n_sz),
+ &cmd->data[RSP_DATA_IDX], n_sz);
if (copied != n_sz)
status = -EINVAL;
@@ -440,7 +445,7 @@ static int atmel_ecdh_generate_public_key(struct kpp_request *req)
{
struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
- size_t copied;
+ size_t copied, nbytes;
int ret = 0;
if (ctx->do_fallback) {
@@ -448,10 +453,14 @@ static int atmel_ecdh_generate_public_key(struct kpp_request *req)
return crypto_kpp_generate_public_key(req);
}
+ /* might want less than we've got */
+ nbytes = min_t(size_t, ATMEL_ECC_PUBKEY_SIZE, req->dst_len);
+
/* public key was saved at private key generation */
- copied = sg_copy_from_buffer(req->dst, 1, ctx->public_key,
- ATMEL_ECC_PUBKEY_SIZE);
- if (copied != ATMEL_ECC_PUBKEY_SIZE)
+ copied = sg_copy_from_buffer(req->dst,
+ sg_nents_for_len(req->dst, nbytes),
+ ctx->public_key, nbytes);
+ if (copied != nbytes)
ret = -EINVAL;
return ret;
@@ -470,6 +479,10 @@ static int atmel_ecdh_compute_shared_secret(struct kpp_request *req)
return crypto_kpp_compute_shared_secret(req);
}
+ /* must have exactly two points to be on the curve */
+ if (req->src_len != ATMEL_ECC_PUBKEY_SIZE)
+ return -EINVAL;
+
gfp = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? GFP_KERNEL :
GFP_ATOMIC;
--
2.9.4
