Release v2.2.0

vendor/github.com/muun/libwallet/btcsuitew/chainhashw/chainhashw.go

@@ -0,0 +1,58 @@
+package chainhashw
+
+// This package adds some methods on top of chainhash. It's written to be both compatible and
+// similar in implementation, so it's easy to swap out in the future.
+
+import (
+	"bytes"
+	"crypto/sha256"
+
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+)
+
+var knownTagPrefix = map[string][]byte{}
+
+const (
+	TagTapLeaf    = "TapLeaf"
+	TagTapBranch  = "TapBranch"
+	TagTapTweak   = "TapTweak"
+	TagTapSighash = "TapSighash"
+)
+
+func init() {
+	knownTagPrefix[TagTapLeaf] = calcTagPrefix(TagTapLeaf)
+	knownTagPrefix[TagTapBranch] = calcTagPrefix(TagTapBranch)
+	knownTagPrefix[TagTapTweak] = calcTagPrefix(TagTapTweak)
+	knownTagPrefix[TagTapSighash] = calcTagPrefix(TagTapSighash)
+}
+
+func TagPrefix(tag string) []byte {
+	if prefix, ok := knownTagPrefix[tag]; ok {
+		return prefix
+	}
+
+	return calcTagPrefix(tag)
+}
+
+func TaggedHashB(tag string, data []byte) []byte {
+	// NOTE: BIP-340 suggests optimizations that we don't make
+	b := new(bytes.Buffer)
+	b.Write(TagPrefix(tag))
+	b.Write(data)
+
+	return chainhash.HashB(b.Bytes())
+}
+
+func TaggedHashH(tag string, data []byte) chainhash.Hash {
+	// NOTE: BIP-340 suggests optimizations that we don't make
+	b := new(bytes.Buffer)
+	b.Write(TagPrefix(tag))
+	b.Write(data)
+
+	return chainhash.HashH(b.Bytes())
+}
+
+func calcTagPrefix(tag string) []byte {
+	tagHash := sha256.Sum256([]byte(tag))
+	return append(tagHash[:], tagHash[:]...)
+}