diff options
Diffstat (limited to 'internal/nostr/bech32.go')
| -rw-r--r-- | internal/nostr/bech32.go | 162 |
1 files changed, 0 insertions, 162 deletions
diff --git a/internal/nostr/bech32.go b/internal/nostr/bech32.go deleted file mode 100644 index c8b1293..0000000 --- a/internal/nostr/bech32.go +++ /dev/null | |||
| @@ -1,162 +0,0 @@ | |||
| 1 | package nostr | ||
| 2 | |||
| 3 | import ( | ||
| 4 | "fmt" | ||
| 5 | "strings" | ||
| 6 | ) | ||
| 7 | |||
| 8 | // Bech32 encoding/decoding for NIP-19 (npub, nsec, note, etc.) | ||
| 9 | // Implements BIP-173 bech32 encoding. | ||
| 10 | |||
| 11 | const bech32Alphabet = "qpzry9x8gf2tvdw0s3jn54khce6mua7l" | ||
| 12 | |||
| 13 | var bech32AlphabetMap [256]int8 | ||
| 14 | |||
| 15 | func init() { | ||
| 16 | for i := range bech32AlphabetMap { | ||
| 17 | bech32AlphabetMap[i] = -1 | ||
| 18 | } | ||
| 19 | for i, c := range bech32Alphabet { | ||
| 20 | bech32AlphabetMap[c] = int8(i) | ||
| 21 | } | ||
| 22 | } | ||
| 23 | |||
| 24 | // bech32Polymod computes the BCH checksum. | ||
| 25 | func bech32Polymod(values []int) int { | ||
| 26 | gen := []int{0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3} | ||
| 27 | chk := 1 | ||
| 28 | for _, v := range values { | ||
| 29 | top := chk >> 25 | ||
| 30 | chk = (chk&0x1ffffff)<<5 ^ v | ||
| 31 | for i := 0; i < 5; i++ { | ||
| 32 | if (top>>i)&1 == 1 { | ||
| 33 | chk ^= gen[i] | ||
| 34 | } | ||
| 35 | } | ||
| 36 | } | ||
| 37 | return chk | ||
| 38 | } | ||
| 39 | |||
| 40 | // bech32HRPExpand expands the human-readable part for checksum computation. | ||
| 41 | func bech32HRPExpand(hrp string) []int { | ||
| 42 | result := make([]int, len(hrp)*2+1) | ||
| 43 | for i, c := range hrp { | ||
| 44 | result[i] = int(c) >> 5 | ||
| 45 | result[i+len(hrp)+1] = int(c) & 31 | ||
| 46 | } | ||
| 47 | return result | ||
| 48 | } | ||
| 49 | |||
| 50 | // bech32CreateChecksum creates the 6-character checksum. | ||
| 51 | func bech32CreateChecksum(hrp string, data []int) []int { | ||
| 52 | values := append(bech32HRPExpand(hrp), data...) | ||
| 53 | values = append(values, []int{0, 0, 0, 0, 0, 0}...) | ||
| 54 | polymod := bech32Polymod(values) ^ 1 | ||
| 55 | checksum := make([]int, 6) | ||
| 56 | for i := 0; i < 6; i++ { | ||
| 57 | checksum[i] = (polymod >> (5 * (5 - i))) & 31 | ||
| 58 | } | ||
| 59 | return checksum | ||
| 60 | } | ||
| 61 | |||
| 62 | // bech32VerifyChecksum verifies the checksum of bech32 data. | ||
| 63 | func bech32VerifyChecksum(hrp string, data []int) bool { | ||
| 64 | return bech32Polymod(append(bech32HRPExpand(hrp), data...)) == 1 | ||
| 65 | } | ||
| 66 | |||
| 67 | // convertBits converts between bit groups. | ||
| 68 | func convertBits(data []byte, fromBits, toBits int, pad bool) ([]int, error) { | ||
| 69 | acc := 0 | ||
| 70 | bits := 0 | ||
| 71 | result := make([]int, 0, len(data)*fromBits/toBits+1) | ||
| 72 | maxv := (1 << toBits) - 1 | ||
| 73 | |||
| 74 | for _, value := range data { | ||
| 75 | acc = (acc << fromBits) | int(value) | ||
| 76 | bits += fromBits | ||
| 77 | for bits >= toBits { | ||
| 78 | bits -= toBits | ||
| 79 | result = append(result, (acc>>bits)&maxv) | ||
| 80 | } | ||
| 81 | } | ||
| 82 | |||
| 83 | if pad { | ||
| 84 | if bits > 0 { | ||
| 85 | result = append(result, (acc<<(toBits-bits))&maxv) | ||
| 86 | } | ||
| 87 | } else if bits >= fromBits || ((acc<<(toBits-bits))&maxv) != 0 { | ||
| 88 | return nil, fmt.Errorf("invalid padding") | ||
| 89 | } | ||
| 90 | |||
| 91 | return result, nil | ||
| 92 | } | ||
| 93 | |||
| 94 | // Bech32Encode encodes data with the given human-readable prefix. | ||
| 95 | func Bech32Encode(hrp string, data []byte) (string, error) { | ||
| 96 | values, err := convertBits(data, 8, 5, true) | ||
| 97 | if err != nil { | ||
| 98 | return "", err | ||
| 99 | } | ||
| 100 | |||
| 101 | checksum := bech32CreateChecksum(hrp, values) | ||
| 102 | combined := append(values, checksum...) | ||
| 103 | |||
| 104 | var result strings.Builder | ||
| 105 | result.WriteString(hrp) | ||
| 106 | result.WriteByte('1') | ||
| 107 | for _, v := range combined { | ||
| 108 | result.WriteByte(bech32Alphabet[v]) | ||
| 109 | } | ||
| 110 | |||
| 111 | return result.String(), nil | ||
| 112 | } | ||
| 113 | |||
| 114 | // Bech32Decode decodes a bech32 string, returning the HRP and data. | ||
| 115 | func Bech32Decode(s string) (string, []byte, error) { | ||
| 116 | s = strings.ToLower(s) | ||
| 117 | |||
| 118 | pos := strings.LastIndexByte(s, '1') | ||
| 119 | if pos < 1 || pos+7 > len(s) { | ||
| 120 | return "", nil, fmt.Errorf("invalid bech32 string") | ||
| 121 | } | ||
| 122 | |||
| 123 | hrp := s[:pos] | ||
| 124 | dataStr := s[pos+1:] | ||
| 125 | |||
| 126 | data := make([]int, len(dataStr)) | ||
| 127 | for i, c := range dataStr { | ||
| 128 | val := bech32AlphabetMap[c] | ||
| 129 | if val == -1 { | ||
| 130 | return "", nil, fmt.Errorf("invalid character: %c", c) | ||
| 131 | } | ||
| 132 | data[i] = int(val) | ||
| 133 | } | ||
| 134 | |||
| 135 | if !bech32VerifyChecksum(hrp, data) { | ||
| 136 | return "", nil, fmt.Errorf("invalid checksum") | ||
| 137 | } | ||
| 138 | |||
| 139 | // Remove checksum | ||
| 140 | data = data[:len(data)-6] | ||
| 141 | |||
| 142 | // Convert from 5-bit to 8-bit | ||
| 143 | result, err := convertBits(intSliceToBytes(data), 5, 8, false) | ||
| 144 | if err != nil { | ||
| 145 | return "", nil, err | ||
| 146 | } | ||
| 147 | |||
| 148 | bytes := make([]byte, len(result)) | ||
| 149 | for i, v := range result { | ||
| 150 | bytes[i] = byte(v) | ||
| 151 | } | ||
| 152 | |||
| 153 | return hrp, bytes, nil | ||
| 154 | } | ||
| 155 | |||
| 156 | func intSliceToBytes(data []int) []byte { | ||
| 157 | result := make([]byte, len(data)) | ||
| 158 | for i, v := range data { | ||
| 159 | result[i] = byte(v) | ||
| 160 | } | ||
| 161 | return result | ||
| 162 | } | ||
