keychain: add single key wrapper implementations

keychain/signer.go

@@ -0,0 +1,56 @@
+package keychain
+
+import "github.com/btcsuite/btcd/btcec"
+
+func NewPubKeyDigestSigner(keyDesc KeyDescriptor,
+	signer DigestSignerRing) *PubKeyDigestSigner {
+
+	return &PubKeyDigestSigner{
+		keyDesc:      keyDesc,
+		digestSigner: signer,
+	}
+}
+
+type PubKeyDigestSigner struct {
+	keyDesc      KeyDescriptor
+	digestSigner DigestSignerRing
+}
+
+func (p *PubKeyDigestSigner) PubKey() *btcec.PublicKey {
+	return p.keyDesc.PubKey
+}
+
+func (p *PubKeyDigestSigner) SignDigest(digest [32]byte) (*btcec.Signature,
+	error) {
+
+	return p.digestSigner.SignDigest(p.keyDesc, digest)
+}
+
+func (p *PubKeyDigestSigner) SignDigestCompact(digest [32]byte) ([]byte,
+	error) {
+
+	return p.digestSigner.SignDigestCompact(p.keyDesc, digest)
+}
+
+type PrivKeyDigestSigner struct {
+	PrivKey *btcec.PrivateKey
+}
+
+func (p *PrivKeyDigestSigner) PubKey() *btcec.PublicKey {
+	return p.PrivKey.PubKey()
+}
+
+func (p *PrivKeyDigestSigner) SignDigest(digest [32]byte) (*btcec.Signature,
+	error) {
+
+	return p.PrivKey.Sign(digest[:])
+}
+
+func (p *PrivKeyDigestSigner) SignDigestCompact(digest [32]byte) ([]byte,
+	error) {
+
+	return btcec.SignCompact(btcec.S256(), p.PrivKey, digest[:], true)
+}
+
+var _ SingleKeyDigestSigner = (*PubKeyDigestSigner)(nil)
+var _ SingleKeyDigestSigner = (*PrivKeyDigestSigner)(nil)