func FrequencyAttack(chars []string, charset, cipher string) (guesses []string, err error) {
//
for _, commonChar := range frequency.Top3 {
for _, char := range chars {
pos := strings.Index(charset, char)
if pos == -1 {
return nil, errorsutil.Errorf("Character `%c` is not present in charset: `%s`", char, charset)
}
commonCharPos := strings.Index(charset, commonChar)
if commonCharPos == -1 {
return nil, errorsutil.Errorf("Character `%c` is not present in charset: `%s`", commonChar, charset)
}
unwindBy := commonCharPos - pos
unciphered, err := broken.Caesar(charset, cipher, unwindBy)
if err != nil {
return nil, err
}
guesses = append(guesses, unciphered)
}
}
return guesses, nil
}
// Returns a unit struct initiated with the raw codes
func NewUnit(baseRawCode, customRawCode string) (unit *Unit, err error) {
if temp.IsRawCode(baseRawCode) == false {
return nil, errorsutil.Errorf("Invalid base unit rawcode: %s - must be upper or lowercase alpha numeric and 4 characters long", baseRawCode)
} else if temp.IsRawCode(customRawCode) == false {
return nil, errorsutil.Errorf("Invalid custom unit rawcode: %s - must be upper or lowercase alpha numeric and 4 characters long", customRawCode)
}
return &Unit{BaseRawCode: baseRawCode, CustomRawCode: customRawCode}, nil
}
// Caesar shifts each character in the message some fixed number of
// positions down the charset.
func Caesar(charset, message string, shiftBy int) (cipher string, err error) {
// When shift overflows the slice index we use the modulo of the
// charset length to simulate rotation.
// Example:
// When Y + 2 becomes A; (24 + 2) % 26 = 0 -> charset[0] = 'a'
// Or when A - 1 becomes Z; (26 - 1) % 26 = 25 -> charset[25] = 'z'
csLen := len(charset)
// For each character in message
// Get it's position in the charset
// The new character is it's position in the charset + shiftBy
// Simulate rotation with modulo and subtraction.
for _, mChar := range message {
pos := strings.IndexRune(charset, mChar)
if pos == -1 {
return "", errorsutil.Errorf("Character `%c` is not present in charset: `%s`", mChar, charset)
}
posShift := pos + shiftBy
if posShift < 0 {
// Example:
// 26 + (-1) = 25; charset[25] = 'z'
posShift = csLen + posShift
}
// Concatenate the final cipher string
cipher += string(charset[posShift%csLen])
}
return cipher, nil
}
func GetRawCode(buffer *bytes.Buffer) (rawCode string, err error) {
rawCode = string(buffer.Next(4))
if !temp.IsRawCode(rawCode) {
return "", errorsutil.Errorf("Illegal raw code: [% X]", rawCode)
}
return rawCode, nil
}
// Adds a new field to the unit
func (unit *Unit) AddField(fieldRawCode string, value interface{}) (err error) {
if temp.IsRawCode(fieldRawCode) == false {
return errorsutil.Errorf("Invalid field rawcode: %s - must be upper or lowercase alpha numeric and 4 characters long", fieldRawCode)
}
unit.Fields = append(unit.Fields, field.Field{Name: fieldRawCode, Value: value})
return nil
}
func FromBuf(byteNum []byte) (b Binary, err error) {
// buf := bytes.NewBuffer([]byte{0x18, 0x2d, 0x44, 0x54, 0xfb, 0x21, 0x09, 0x40})
if len(byteNum)%8 != 1 {
for {
if len(byteNum)%8 == 0 {
break
}
byteNum = append(byteNum, 0x00)
}
}
buf := bytes.NewBuffer(byteNum)
err = binary.Read(buf, binary.LittleEndian, &b)
if err != nil {
return 0, errorsutil.Errorf("FromBuf: %s - % x", err, byteNum)
}
return b, nil
}
func Open(fileName string) (w3 *W3u, err error) {
w3 = New()
// Read w3u file
file, err := os.Open(fileName)
if err != nil {
return nil, err
}
// Read all bytes from the file pointer
buf, err := ioutil.ReadAll(file)
if err != nil {
return nil, err
}
// Make the bytes into a Buffer
buffer := bytes.NewBuffer(buf)
// Check header
w3.Header = buffer.Next(8)
if !w3.IsHeader() {
return nil, errorsutil.Errorf("Invalid w3u header! Correct header: % X, your header: % X", Header, w3.Header)
}
// Number of units
numUnits := uint(buffer.Next(1)[0])
if numUnits < 0 {
return nil, errorsutil.Errorf("Invalid number of units: %d\n", numUnits)
}
// Skip seperator
buffer.Next(3)
for i := 0; i < int(numUnits); i++ {
// Base unit rawcode
baseUnit, err := GetRawCode(buffer)
if err != nil {
return nil, err
}
// Custom unit rawcode
customUnit, err := GetRawCode(buffer)
if err != nil {
return nil, err
}
u, err := unit.NewUnit(baseUnit, customUnit)
if err != nil {
return nil, err
}
// Number of fields
numFields := uint(buffer.Next(1)[0])
if numFields < 0 {
return nil, errorsutil.Errorf("Invalid number of fields: %d\n", numFields)
}
// Skip seperator
buffer.Next(3)
for j := 0; j < int(numFields); j++ {
f := new(field.Field)
// Field name in raw data
fieldName, err := GetRawCode(buffer)
if err != nil {
return nil, err
}
f.Name = fieldName
// Type of field, 0:int(and bool), 1:fixed decimal point, 2:float, 3:string
fieldType := int(buffer.Next(1)[0])
// 0, 1, 2, 3 are valid field types
if fieldType < 0 || fieldType > 3 {
return nil, errorsutil.Errorf("Invalid field type: %d\n", fieldType)
}
// Skip seperator
buffer.Next(3)
// ###Add fixed
switch fieldType {
case 0:
f.Value, err = temp.FromBuf(buffer.Next(3))
if err != nil {
return nil, err
}
// f.Value = temp.BigToLittle(buffer.Next(3))
case 2:
// Float value
f.Value = buffer.Next(3)
case 3:
// Get next seperator, that's were the string ends
strLen := bytes.Index(buffer.Bytes(), []byte{00, 00, 00})
// String value
f.Value = string(buffer.Next(strLen))
}
// Skip field seperator
buffer.Next(5)
u.Fields = append(u.Fields, *f)
}
w3.Units = append(w3.Units, *u)
}
return w3, nil
}