[PATCH v2 12/18] crypto: dh - introduce support for ephemeral key generation to qat driver

[Nicolai Stange <nstange@xxxxxxx>]

A previous patch made the dh-generic implementation's ->set_secret() to
generate an ephemeral key in case the input ->key_size is zero, just in
analogy with ecdh. Make the qat crypto driver's DH implementation to
behave consistently by doing the same.

Signed-off-by: Nicolai Stange <nstange@xxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
---
 drivers/crypto/qat/qat_common/qat_asym_algs.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/crypto/qat/qat_common/qat_asym_algs.c b/drivers/crypto/qat/qat_common/qat_asym_algs.c
index b0b78445418b..e0d3a70fa6b1 100644
--- a/drivers/crypto/qat/qat_common/qat_asym_algs.c
+++ b/drivers/crypto/qat/qat_common/qat_asym_algs.c
@@ -441,11 +441,20 @@ static int qat_dh_set_secret(struct crypto_kpp *tfm, const void *buf,
 	struct qat_dh_ctx *ctx = kpp_tfm_ctx(tfm);
 	struct device *dev = &GET_DEV(ctx->inst->accel_dev);
 	struct dh params;
+	char key[CRYPTO_DH_MAX_PRIVKEY_SIZE];
 	int ret;
 
 	if (crypto_dh_decode_key(buf, len, &params) < 0)
 		return -EINVAL;
 
+	if (!params.key_size) {
+		ret = crypto_dh_gen_privkey(params.group_id, key,
+					    &params.key_size);
+		if (ret)
+			return ret;
+		params.key = key;
+	}
+
 	/* Free old secret if any */
 	qat_dh_clear_ctx(dev, ctx);
 
-- 
2.26.2