delphi.market/server/auth/lnauth.go

66 lines
1.6 KiB
Go

package auth
import (
"crypto/ecdsa"
"crypto/rand"
"encoding/hex"
"fmt"
"github.com/btcsuite/btcd/btcec/v2"
"github.com/btcsuite/btcutil/bech32"
"git.ekzyis.com/ekzyis/delphi.market/env"
)
type LNAuth struct {
K1 string
LNURL string
}
type LNAuthResponse struct {
K1 string `query:"k1"`
Sig string `query:"sig"`
Key string `query:"key"`
}
func NewLNAuth() (*LNAuth, error) {
k1 := make([]byte, 32)
_, err := rand.Read(k1)
if err != nil {
return nil, fmt.Errorf("rand.Read error: %w", err)
}
k1hex := hex.EncodeToString(k1)
url := []byte(fmt.Sprintf("https://%s/api/login/callback?tag=login&k1=%s&action=login", env.PublicURL, k1hex))
conv, err := bech32.ConvertBits(url, 8, 5, true)
if err != nil {
return nil, fmt.Errorf("bech32.ConvertBits error: %w", err)
}
lnurl, err := bech32.Encode("lnurl", conv)
if err != nil {
return nil, fmt.Errorf("bech32.Encode error: %w", err)
}
return &LNAuth{k1hex, lnurl}, nil
}
func VerifyLNAuth(r *LNAuthResponse) (bool, error) {
var k1Bytes, sigBytes, keyBytes []byte
k1Bytes, err := hex.DecodeString(r.K1)
if err != nil {
return false, fmt.Errorf("k1 decode error: %w", err)
}
sigBytes, err = hex.DecodeString(r.Sig)
if err != nil {
return false, fmt.Errorf("sig decode error: %w", err)
}
keyBytes, err = hex.DecodeString(r.Key)
if err != nil {
return false, fmt.Errorf("key decode error: %w", err)
}
key, err := btcec.ParsePubKey(keyBytes)
if err != nil {
return false, fmt.Errorf("key parse error: %w", err)
}
ecdsaKey := ecdsa.PublicKey{Curve: btcec.S256(), X: key.X(), Y: key.Y()}
return ecdsa.VerifyASN1(&ecdsaKey, k1Bytes, sigBytes), nil
}