The MD5 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 32 characters (33 in a C program). See Pre-dimensioning a string.
MD5_StringHexHash
MD5_BytesHexHash
MD5_BytesHash
MD5_FileHexHash
MD5_Init
MD5_AddBytes
MD5_AddString
MD5_HexDigest
MD5_Reset
MD5_Hmac
MD5_HmacHex