SilcSKRStatus silc_skr_add_public_key_simple(SilcSKR skr,
                                                 SilcPublicKey public_key,
                                                 SilcSKRKeyUsage usage,
                                                 void *key_context,
                                                 SilcSKRKey *return_key);

    Same as silc_skr_add_public_key but adds only the public key, usage
    bits and key context.  The key cannot be found with any other search
    constraint except setting the public key, usage bits and/or key
    context as search constraint.  This function can be used to add the
    key with as little memory as possible to the repository, and makes
    it a good way to cheaply store large amounts of public keys.

    Returns an entry of the added public key in the repository to the
    `return_key' pointer, if it is non-NULL.  The returned entry remains
    valid as long as the public key is in the repository, however a
    reference may be taken with silc_skr_ref_public_key to assure the
    entry remains valid.

    Returns SILC_SKR_OK if the key was added successfully, and error
    status if key could not be added, or has been added already.