56 lines
1.2 KiB
Go
56 lines
1.2 KiB
Go
package multibase
|
|
|
|
import (
|
|
"fmt"
|
|
"math"
|
|
"strconv"
|
|
)
|
|
|
|
// binaryEncodeToString takes an array of bytes and returns
|
|
// multibase binary representation
|
|
func binaryEncodeToString(src []byte) string {
|
|
dst := make([]byte, len(src)*8)
|
|
encodeBinary(dst, src)
|
|
return string(dst)
|
|
}
|
|
|
|
// encodeBinary takes the src and dst bytes and converts each
|
|
// byte to their binary rep using power reduction method
|
|
func encodeBinary(dst []byte, src []byte) {
|
|
for i := 0; i < len(src); i++ {
|
|
t := src[i]
|
|
for j := i * 8; j < (i*8)+8; j++ {
|
|
higherPower := math.Pow(2, float64(7-(j%8)))
|
|
if float64(t) >= higherPower {
|
|
dst[j] = '1'
|
|
t = t - byte(higherPower)
|
|
} else {
|
|
dst[j] = '0'
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// decodeBinaryString takes multibase binary representation
|
|
// and returns a byte array
|
|
func decodeBinaryString(s string) ([]byte, error) {
|
|
if len(s)%8 != 0 {
|
|
return nil, fmt.Errorf("cannot decode multibase: %s",
|
|
"length should be a multiple of 4")
|
|
}
|
|
|
|
data := make([]byte, len(s)/8)
|
|
|
|
for i, dstIndex := 0, 0; i < len(s); i = i + 8 {
|
|
value, err := strconv.ParseInt(s[i:i+8], 2, 0)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("error while conversion: %s", err)
|
|
}
|
|
|
|
data[dstIndex] = byte(value)
|
|
dstIndex++
|
|
}
|
|
|
|
return data, nil
|
|
}
|