bech32: add new set of constants/versions to be used for bech32m

bech32/version.go

@@ -0,0 +1,43 @@
+package bech32
+
+// ChecksumConst is a type that represents the currently defined bech32
+// checksum constants.
+type ChecksumConst int
+
+const (
+	// Version0Const is the original constant used in the checksum
+	// verification for bech32.
+	Version0Const ChecksumConst = 1
+
+	// VersionMConst is the new constant used for bech32m checksum
+	// verification.
+	VersionMConst ChecksumConst = 0x2bc830a3
+)
+
+// Version defines the current set of bech32 versions.
+type Version uint8
+
+const (
+	// Version0 defines the original bech version.
+	Version0 Version = iota
+
+	// VersionM is the new bech32 version defined in BIP-350, also known as
+	// bech32m.
+	VersionM
+
+	// VersionUnknown denotes an unknown bech version.
+	VersionUnknown
+)
+
+// VersionToConsts maps bech32 versions to the checksum constant to be used
+// when encoding, and asserting a particular version when decoding.
+var VersionToConsts = map[Version]ChecksumConst{
+	Version0: Version0Const,
+	VersionM: VersionMConst,
+}
+
+// ConstsToVersion maps a bech32 constant to the version it's associated with.
+var ConstsToVersion = map[ChecksumConst]Version{
+	Version0Const: Version0,
+	VersionMConst: VersionM,
+}