Files
nostrlib/signature.go
2025-04-15 17:13:57 -03:00

59 lines
1.3 KiB
Go

//go:build !libsecp256k1
package nostr
import (
"crypto/sha256"
"github.com/btcsuite/btcd/btcec/v2"
"github.com/btcsuite/btcd/btcec/v2/schnorr"
)
// Verify checks if the event signature is valid for the given event.
// It won't look at the ID field, instead it will recompute the id from the entire event body.
// Returns true if the signature is valid, false otherwise.
func (evt Event) VerifySignature() bool {
// read and check pubkey
pubkey, err := schnorr.ParsePubKey(evt.PubKey[:])
if err != nil {
return false
}
// read signature
sig, err := schnorr.ParseSignature(evt.Sig[:])
if err != nil {
return false
}
// check signature
hash := sha256.Sum256(evt.Serialize())
return sig.Verify(hash[:], pubkey)
}
// Sign signs an event with a given privateKey.
//
// It sets the event's ID, PubKey, and Sig fields.
//
// Returns an error if the private key is invalid or if signing fails.
func (evt *Event) Sign(secretKey [32]byte) error {
if evt.Tags == nil {
evt.Tags = make(Tags, 0)
}
sk, pk := btcec.PrivKeyFromBytes(secretKey[:])
pkBytes := pk.SerializeCompressed()[1:]
evt.PubKey = [32]byte(pkBytes)
h := sha256.Sum256(evt.Serialize())
sig, err := schnorr.Sign(sk, h[:], schnorr.FastSign())
if err != nil {
return err
}
evt.ID = h
sigb := sig.Serialize()
evt.Sig = [64]byte(sigb)
return nil
}