Add key-related functions

keys.go

@@ -0,0 +1,37 @@
+package nostr
+
+import (
+	"crypto/ecdsa"
+	"encoding/hex"
+
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/crypto/secp256k1"
+	"github.com/tyler-smith/go-bip39"
+)
+
+func PrivateKeyAsHex(key *ecdsa.PrivateKey) string {
+	skBytes := crypto.FromECDSA(key)
+	return hex.EncodeToString(skBytes)
+}
+
+func PrivateKeyAsMnemonic(key *ecdsa.PrivateKey) (string, error) {
+	skBytes := crypto.FromECDSA(key)
+	return bip39.NewMnemonic(skBytes)
+}
+
+func PublicKeyAsHex(key ecdsa.PublicKey) string {
+	return hex.EncodeToString(secp256k1.CompressPubkey(key.X, key.Y))
+}
+
+func GenerateKey() (*ecdsa.PrivateKey, error) {
+	return crypto.GenerateKey()
+}
+
+func PrivateKeyFromMnemonic(mnemonic string) (*ecdsa.PrivateKey, error) {
+	e, err := bip39.EntropyFromMnemonic(mnemonic)
+	if err != nil {
+		return &ecdsa.PrivateKey{}, err
+	}
+
+	return crypto.ToECDSA(e)
+}