The key for DES is always 8 bytes long; the block length is 8 bytes. There is no need to specify the key length when calling the DES functions, because you must provide exactly 8 bytes. The parity bits in the key are ignored.
DES_Hex
DES_HexMode
DES_Bytes
DES_BytesMode
DES_B64Mode
DES_File
DES_FileHex
DES_Init
DES_InitHex
DES_InitError
DES_Update
DES_UpdateHex
DES_Final
DES_CheckKey
DES_CheckKeyHex