package main import ( "bytes" "math/big" ) var b58Alphabet = []byte("123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz") // Base58Encode encodes a byte array to Base58 func Base58Encode(input []byte) []byte { var result []byte x := big.NewInt(0).SetBytes(input) base := big.NewInt(int64(len(b58Alphabet))) zero := big.NewInt(0) mod := &big.Int{} for x.Cmp(zero) != 0 { x.DivMod(x, base, mod) result = append(result, b58Alphabet[mod.Int64()]) } ReverseBytes(result) for b := range input { if b == 0x00 { result = append([]byte{b58Alphabet[0]}, result...) } else { break } } return result } // Base58Decode decodes Base58-encoded data func Base58Decode(input []byte) []byte { result := big.NewInt(0) zeroBytes := 0 for b := range input { if b == 0x00 { zeroBytes++ } } payload := input[zeroBytes:] for _, b := range payload { charIndex := bytes.IndexByte(b58Alphabet, b) result.Mul(result, big.NewInt(58)) result.Add(result, big.NewInt(int64(charIndex))) } decoded := result.Bytes() decoded = append(bytes.Repeat([]byte{byte(0x00)}, zeroBytes), decoded...) return decoded }