The SHA-256 functions are identical in syntax and usage to their SHA-1 equivalents, except the string to receive the message digest must be set to a minimum of 64 characters (65 in a C program). See Pre-dimensioning a string.
SHA2_StringHexHash
SHA2_BytesHexHash
SHA2_BytesHash
SHA2_FileHexHash
SHA2_Init
SHA2_AddBytes
SHA2_AddString
SHA2_HexDigest
SHA2_Reset
SHA2_Hmac
SHA2_HmacHex