82 lines
2.2 KiB
Go
82 lines
2.2 KiB
Go
package identity
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import (
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"errors"
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"fmt"
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"math/big"
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"testing"
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"github.com/ethereum/go-ethereum/crypto/secp256k1"
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)
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func ToColorID(pubkey string) (int64, error) {
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const colorPalletLength = 12
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pubkeyValue, ok := new(big.Int).SetString(pubkey, 0)
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if !ok {
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return 0, fmt.Errorf("invalid pubkey: %s", pubkey)
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}
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colorID := new(big.Int).Mod(pubkeyValue, new(big.Int).SetInt64(colorPalletLength-1)).Int64()
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return colorID, nil
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}
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func ToBigBase(value *big.Int, base uint64) (res [](uint64)) {
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toBigBaseImpl(value, base, &res)
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return
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}
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func toBigBaseImpl(value *big.Int, base uint64, res *[](uint64)) {
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bigBase := new(big.Int).SetUint64(base)
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quotient := new(big.Int).Div(value, bigBase)
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if quotient.Cmp(new(big.Int).SetUint64(0)) != 0 {
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toBigBaseImpl(quotient, base, res)
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}
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*res = append(*res, new(big.Int).Mod(value, bigBase).Uint64())
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}
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// compressedPubKey = |1.5 bytes chars cutoff|20 bytes emoji hash|10 bytes color hash|1.5 bytes chars cutoff|
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func Slices(compressedPubkey []byte) (res [4][]byte, err error) {
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if len(compressedPubkey) != 33 {
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return res, errors.New("incorrect compressed pubkey")
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}
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getSlice := func(low, high int, and string, rsh uint) []byte {
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sliceValue := new(big.Int).SetBytes(compressedPubkey[low:high])
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andValue, _ := new(big.Int).SetString(and, 0)
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andRes := new(big.Int).And(sliceValue, andValue)
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return new(big.Int).Rsh(andRes, rsh).Bytes()
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}
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res[0] = getSlice(0, 2, "0xFFF0", 4)
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res[1] = getSlice(1, 22, "0x0FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF0", 4)
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res[2] = getSlice(21, 32, "0x0FFFFFFFFFFFFFFFFFFFF0", 4)
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res[3] = getSlice(31, 33, "0x0FFF", 0)
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return res, nil
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}
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func ToCompressedKey(pubkey string) ([]byte, error) {
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pubkeyValue, ok := new(big.Int).SetString(pubkey, 0)
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if !ok {
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return nil, fmt.Errorf("invalid pubkey: %s", pubkey)
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}
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x, y := secp256k1.S256().Unmarshal(pubkeyValue.Bytes())
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if x == nil || !secp256k1.S256().IsOnCurve(x, y) {
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return nil, fmt.Errorf("invalid pubkey: %s", pubkey)
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}
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return secp256k1.CompressPubkey(x, y), nil
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}
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func ToBigInt(t *testing.T, str string) *big.Int {
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res, ok := new(big.Int).SetString(str, 0)
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if !ok {
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t.Errorf("invalid conversion to int from %s", str)
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}
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return res
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}
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