On 2/21/22 13:10, Nicolai Stange wrote:
Ephemeral key generation can be requested from any of the ffdheXYZ(dh) variants' common ->set_secret() by passing it an (encoded) struct dh with the key parameter being unset, i.e. with ->key_size == 0. As the whole purpose of the ffdheXYZ(dh) templates is to fill in the group parameters as appropriate, they expect ->p and ->g to be unset in any input struct dh as well. This means that a user would have to encode an all-zeroes struct dh instance via crypto_dh_encode_key() when requesting ephemeral key generation from a ffdheXYZ(dh) instance, which is kind of pointless. Make dh_safe_prime_set_secret() to decode a struct dh from the supplied buffer only if the latter is non-NULL and initialize it with all zeroes otherwise. That is, it is now possible to call crypto_kpp_set_secret(tfm, NULL, 0); on any ffdheXYZ(dh) tfm for requesting ephemeral key generation. Signed-off-by: Nicolai Stange <nstange@xxxxxxx> --- crypto/dh.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
Reviewed-by: Hannes Reinecke <hare@xxxxxxx> Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@xxxxxxx +49 911 74053 688 SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), GF: Felix Imendörffer
