1package mstypes 2 3import ( 4 "bufio" 5 "encoding/binary" 6 "fmt" 7 "io" 8) 9 10// Byte sizes of primitive types 11const ( 12 SizeBool = 1 13 SizeChar = 1 14 SizeUint8 = 1 15 SizeUint16 = 2 16 SizeUint32 = 4 17 SizeUint64 = 8 18 SizeEnum = 2 19 SizeSingle = 4 20 SizeDouble = 8 21 SizePtr = 4 22) 23 24// Reader reads simple byte stream data into a Go representations 25type Reader struct { 26 r *bufio.Reader // source of the data 27} 28 29// NewReader creates a new instance of a simple Reader. 30func NewReader(r io.Reader) *Reader { 31 reader := new(Reader) 32 reader.r = bufio.NewReader(r) 33 return reader 34} 35 36func (r *Reader) Read(p []byte) (n int, err error) { 37 return r.r.Read(p) 38} 39 40func (r *Reader) Uint8() (uint8, error) { 41 b, err := r.r.ReadByte() 42 if err != nil { 43 return uint8(0), err 44 } 45 return uint8(b), nil 46} 47 48func (r *Reader) Uint16() (uint16, error) { 49 b, err := r.ReadBytes(SizeUint16) 50 if err != nil { 51 return uint16(0), err 52 } 53 return binary.LittleEndian.Uint16(b), nil 54} 55 56func (r *Reader) Uint32() (uint32, error) { 57 b, err := r.ReadBytes(SizeUint32) 58 if err != nil { 59 return uint32(0), err 60 } 61 return binary.LittleEndian.Uint32(b), nil 62} 63 64func (r *Reader) Uint64() (uint64, error) { 65 b, err := r.ReadBytes(SizeUint64) 66 if err != nil { 67 return uint64(0), err 68 } 69 return binary.LittleEndian.Uint64(b), nil 70} 71 72func (r *Reader) FileTime() (f FileTime, err error) { 73 f.LowDateTime, err = r.Uint32() 74 if err != nil { 75 return 76 } 77 f.HighDateTime, err = r.Uint32() 78 if err != nil { 79 return 80 } 81 return 82} 83 84// UTF16String returns a string that is UTF16 encoded in a byte slice. n is the number of bytes representing the string 85func (r *Reader) UTF16String(n int) (str string, err error) { 86 //Length divided by 2 as each run is 16bits = 2bytes 87 s := make([]rune, n/2, n/2) 88 for i := 0; i < len(s); i++ { 89 var u uint16 90 u, err = r.Uint16() 91 if err != nil { 92 return 93 } 94 s[i] = rune(u) 95 } 96 str = string(s) 97 return 98} 99 100// readBytes returns a number of bytes from the NDR byte stream. 101func (r *Reader) ReadBytes(n int) ([]byte, error) { 102 //TODO make this take an int64 as input to allow for larger values on all systems? 103 b := make([]byte, n, n) 104 m, err := r.r.Read(b) 105 if err != nil || m != n { 106 return b, fmt.Errorf("error reading bytes from stream: %v", err) 107 } 108 return b, nil 109} 110