NAME

       kcapi_kpp_setkey - set the private key of the DH / ECDH operation

SYNOPSIS

       int kcapi_kpp_setkey(struct kcapi_handle * handle, const uint8_t * key, uint32_t keylen);

ARGUMENTS

       handle
           [in] cipher handle

       key
           [in] key buffer

       keylen
           [in] length of key buffer

DESCRIPTION

       With this function, the caller sets the key for subsequent DH / ECDH public key generation or shared
       secret generation operations.

       If the key / keylen is zero, the kernel tries to generate the private key itself and retains it
       internally. This is useful if the DH / ECDH operation shall be performed on ephemeral keys where the
       caller is only interested in eventually obtain the shared secret.

       After the caller provided the key, the caller may securely destroy the key as it is now maintained by the
       kernel.

       Note, the key can only be set after the DH parameters or the ECC curve has been set.

       return in case of success a positive integer is returned that denominates the maximum output size of the
       cryptographic operation -- this value must be used as the size of the output buffer for one cryptographic
       operation); a negative errno-style error code if an error occurred -- the error -EOPNOTSUPP is returned
       in case a kernel-triggered private key generation is requested, but the underlying cipher implementation
       does not support this operation.

AUTHOR

       Stephan Mueller <smueller@chronox.de>
           Author.

COPYRIGHT

libkcapi Manual 1.5.0                              April 2024                                KCAPI_KPP_SETKEY(3)