stellar-strkey 0.0.13

Encode and decode strkeys for Stellar.
Documentation
package main

import (
	"encoding/base32"
	"encoding/csv"
	"os"
)

func main() {
	recs := [][]string{
		{
			"Test case",
			"Strkey",
		},
		{
			"Valid Liquidity Pool",
			encode(11<<3|0, []byte{
				0x36, 0x3e, 0xaa, 0x38, 0x67, 0x84, 0x1f, 0xba, 0xd0, 0xf4, 0xed, 0x88, 0xc7, 0x79,
				0xe4, 0xfe, 0x66, 0xe5, 0x6a, 0x24, 0x70, 0xdc, 0x98, 0xc0, 0xec, 0x9c, 0x07, 0x3d,
				0x05, 0xc7, 0xb1, 0x03,
			}),
		},
		{
			"Valid Liquidity Pool",
			encode(11<<3|0, []byte{
				0x3f, 0x0c, 0x34, 0xbf, 0x93, 0xad, 0x0d, 0x99, 0x71, 0xd0, 0x4c, 0xcc, 0x90, 0xf7,
				0x05, 0x51, 0x1c, 0x83, 0x8a, 0xad, 0x97, 0x34, 0xa4, 0xa2, 0xfb, 0x0d, 0x7a, 0x03,
				0xfc, 0x7f, 0xe8, 0x9a,
			}),
		},
		{
			"Invalid length (Liquidity pool should be 32 bytes, not 5).",
			encode(11<<3|0, []byte{
				0x00, 0x00, 0x00, 0x00, 0x00,
			}),
		},
		{
			"Invalid length (congruent to 1 mod 8).",
			encode(11<<3|0, []byte{
				0x3f, 0x0c, 0x34, 0xbf, 0x93, 0xad, 0x0d, 0x99, 0x71, 0xd0, 0x4c, 0xcc, 0x90, 0xf7,
				0x05, 0x51, 0x1c, 0x83, 0x8a, 0xad, 0x97, 0x34, 0xa4, 0xa2, 0xfb, 0x0d, 0x7a, 0x03,
				0xfc, 0x7f, 0xe8, 0x9a,
			}) + "A",
		},
		{
			"Invalid length (base-32 decoding should yield 35 bytes, not 36).",
			encode(11<<3|0, []byte{
				0x3f, 0x0c, 0x34, 0xbf, 0x93, 0xad, 0x0d, 0x99, 0x71, 0xd0, 0x4c, 0xcc, 0x90, 0xf7,
				0x05, 0x51, 0x1c, 0x83, 0x8a, 0xad, 0x97, 0x34, 0xa4, 0xa2, 0xfb, 0x0d, 0x7a, 0x03,
				0xfc, 0x7f, 0xe8, 0x9a, 0x00,
			}),
		},
		{
			"Invalid algorithm (low 3 bits of version byte are 7).",
			encode(11<<3|7, []byte{
				0x3f, 0x0c, 0x34, 0xbf, 0x93, 0xad, 0x0d, 0x99, 0x71, 0xd0, 0x4c, 0xcc, 0x90, 0xf7,
				0x05, 0x51, 0x1c, 0x83, 0x8a, 0xad, 0x97, 0x34, 0xa4, 0xa2, 0xfb, 0x0d, 0x7a, 0x03,
				0xfc, 0x7f, 0xe8, 0x9a,
			}),
		},
		{
			"Valid Claimable Balance",
			encode(1<<3|0, []byte{
				0x00, // V0
				0x3f, 0x0c, 0x34, 0xbf, 0x93, 0xad, 0x0d, 0x99, 0x71, 0xd0, 0x4c, 0xcc, 0x90, 0xf7,
				0x05, 0x51, 0x1c, 0x83, 0x8a, 0xad, 0x97, 0x34, 0xa4, 0xa2, 0xfb, 0x0d, 0x7a, 0x03,
				0xfc, 0x7f, 0xe8, 0x9a,
			}),
		},
		{
			"Invalid length (Claimable balance should be 32+1 bytes, not 5+1).",
			encode(1<<3|0, []byte{
				0x00, // V0
				0x00, 0x00, 0x00, 0x00, 0x00,
			}),
		},
		{
			"Invalid length (congruent to 1 mod 8).",
			encode(1<<3|0, []byte{
				0x00, // V0
				0x3f, 0x0c, 0x34, 0xbf, 0x93, 0xad, 0x0d, 0x99, 0x71, 0xd0, 0x4c, 0xcc, 0x90, 0xf7,
				0x05, 0x51, 0x1c, 0x83, 0x8a, 0xad, 0x97, 0x34, 0xa4, 0xa2, 0xfb, 0x0d, 0x7a, 0x03,
				0xfc, 0x7f, 0xe8, 0x9a,
			}) + "A",
		},
		{
			"Invalid length (base-32 decoding should yield 35 bytes, not 36).",
			encode(1<<3|0, []byte{
				0x3f, 0x0c, 0x34, 0xbf, 0x93, 0xad, 0x0d, 0x99, 0x71, 0xd0, 0x4c, 0xcc, 0x90, 0xf7,
				0x05, 0x51, 0x1c, 0x83, 0x8a, 0xad, 0x97, 0x34, 0xa4, 0xa2, 0xfb, 0x0d, 0x7a, 0x03,
				0xfc, 0x7f, 0xe8, 0x9a, 0x00,
			}),
		},
		{
			"Invalid algorithm (low 3 bits of version byte are 7).",
			encode(1<<3|7, []byte{
				0x3f, 0x0c, 0x34, 0xbf, 0x93, 0xad, 0x0d, 0x99, 0x71, 0xd0, 0x4c, 0xcc, 0x90, 0xf7,
				0x05, 0x51, 0x1c, 0x83, 0x8a, 0xad, 0x97, 0x34, 0xa4, 0xa2, 0xfb, 0x0d, 0x7a, 0x03,
				0xfc, 0x7f, 0xe8, 0x9a,
			}),
		},
		{
			"Invalid sub type",
			encode(1<<3|0, []byte{
				0x01, // ??
				0x3f, 0x0c, 0x34, 0xbf, 0x93, 0xad, 0x0d, 0x99, 0x71, 0xd0, 0x4c, 0xcc, 0x90, 0xf7,
				0x05, 0x51, 0x1c, 0x83, 0x8a, 0xad, 0x97, 0x34, 0xa4, 0xa2, 0xfb, 0x0d, 0x7a, 0x03,
				0xfc, 0x7f, 0xe8, 0x9a,
			}),
		},
	}
	csvw := csv.NewWriter(os.Stdout)
	err := csvw.WriteAll(recs)
	if err != nil {
		panic(err)
	}
}

func encode(version byte, payload []byte) string {
	// Create a buffer for version + payload + checksum
	combined := make([]byte, len(payload)+3)
	combined[0] = version
	copy(combined[1:], payload)

	// Calculate checksum
	checksum := crc16(combined[:len(combined)-2])

	// Add checksum bytes in little-endian order
	combined[len(combined)-2] = byte(checksum & 0xff)
	combined[len(combined)-1] = byte(checksum >> 8)

	// Use standard base32 encoder but with custom alphabet
	encoding := base32.NewEncoding("ABCDEFGHIJKLMNOPQRSTUVWXYZ234567").WithPadding(base32.NoPadding)
	return encoding.EncodeToString(combined)
}

// crc16 calculates CRC16 XModem checksum and returns it in little-endian byte order
func crc16(payload []byte) uint16 {
	crc := uint16(0x0000)
	for _, b := range payload {
		crc = (crc << 8) ^ crc16Table[byte(crc>>8)^b]
	}
	return crc
}

// crc16Table is the XMODEM CRC16 lookup table
var crc16Table = [256]uint16{
	0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
	0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
	0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
	0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
	0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
	0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
	0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
	0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
	0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
	0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
	0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
	0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
	0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
	0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
	0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
	0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
	0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
	0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
	0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
	0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
	0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
	0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
	0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
	0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
	0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
	0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
	0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
	0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
	0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
	0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
	0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
	0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0,
}