kcapi_kdf_ctr - Counter Mode Key Derivation Function

handle
           [in] cipher handle allocated by caller. This cipher handle must be allocated with kcapi_md_init. If
           the caller is interested in a KDF using a keyed message digest, the caller should also call
           kcapi_md_setkey before invoking this function.

       src
           [in] Input data that should be transformed into a key (see below).

       slen
           [in] Length of the src input data.

       dst
           [out] Buffer to store the generated key in,

       dlen
           [in] Length of the dst buffer. This value defines the number of bytes generated by the KDF.

StephanMueller <smueller@chronox.de>
           Author.

libkcapi Manual 1.5.0                              April 2024                                   KCAPI_KDF_CTR(3)

       This function is an implementation of the KDF in counter mode according to SP800-108 section 5.1 as well
       as SP800-56A section 5.8.1 (Single-step KDF).

       SP800-108: The caller must provide Label || 0x00 || Context in src. This src pointer may also be NULL if
       the caller wishes not to provide anything.

       SP800-56A: If a keyed MAC is used, the key shall NOT be the shared secret from the DH operation, but an
       independently generated key. The src pointer is defined as Z || other info where Z is the shared secret
       from DH and other info is an arbitrary string (see SP800-56A section 5.8.1.2).

       return 0 upon success; a negative errno-style error code if an error occurred

       kcapi_kdf_ctr - Counter Mode Key Derivation Function

ssize_tkcapi_kdf_ctr(structkcapi_handle*handle,constuint8_t*src,size_tslen,uint8_t*dst,size_tdlen);