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authorJames Bottomley <James.Bottomley@HansenPartnership.com>2018-03-01 14:37:42 -0800
committerHerbert Xu <herbert@gondor.apana.org.au>2018-03-09 22:45:49 +0800
commit6e4fb0e6d4aea3be9d50f79dbb504da344180f1c (patch)
tree58a3f5e6d342a501a3b128fc74dc1195270904fc
parentdf5fcebba63e72ce808d19765a398d4e174aad1d (diff)
downloadlinux-crypto-6e4fb0e6d4aea3be9d50f79dbb504da344180f1c.tar.gz
linux-crypto-6e4fb0e6d4aea3be9d50f79dbb504da344180f1c.zip
crypto: ecdh - fix to allow multi segment scatterlists
Apparently the ecdh use case was in bluetooth which always has single element scatterlists, so the ecdh module was hard coded to expect them. Now we're using this in TPM, we need multi-element scatterlists, so remove this limitation. Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--crypto/ecdh.c23
1 files changed, 17 insertions, 6 deletions
diff --git a/crypto/ecdh.c b/crypto/ecdh.c
index 3aca0933..d2ec33f0 100644
--- a/crypto/ecdh.c
+++ b/crypto/ecdh.c
@@ -89,12 +89,19 @@ static int ecdh_compute_value(struct kpp_request *req)
if (!shared_secret)
goto free_pubkey;
- copied = sg_copy_to_buffer(req->src, 1, public_key,
- public_key_sz);
- if (copied != public_key_sz) {
- ret = -EINVAL;
+ /* from here on it's invalid parameters */
+ ret = -EINVAL;
+
+ /* must have exactly two points to be on the curve */
+ if (public_key_sz != req->src_len)
+ goto free_all;
+
+ copied = sg_copy_to_buffer(req->src,
+ sg_nents_for_len(req->src,
+ public_key_sz),
+ public_key, public_key_sz);
+ if (copied != public_key_sz)
goto free_all;
- }
ret = crypto_ecdh_shared_secret(ctx->curve_id, ctx->ndigits,
ctx->private_key, public_key,
@@ -111,7 +118,11 @@ static int ecdh_compute_value(struct kpp_request *req)
if (ret < 0)
goto free_all;
- copied = sg_copy_from_buffer(req->dst, 1, buf, nbytes);
+ /* might want less than we've got */
+ nbytes = min_t(size_t, nbytes, req->dst_len);
+ copied = sg_copy_from_buffer(req->dst, sg_nents_for_len(req->dst,
+ nbytes),
+ buf, nbytes);
if (copied != nbytes)
ret = -EINVAL;