Limit bech32 addresses to segwitv0 (#2471)

* Limit bech32 addresses to segwitv0

* extend ScriptFactory, make check exhuastive

core-test/src/test/scala/org/bitcoins/core/protocol/Bech32Spec.scala

@@ -28,7 +28,7 @@ class Bech32Spec extends Properties("Bech32Spec") {
   }
 
   property("serialization symmetry") = {
-    Prop.forAll(ScriptGenerators.witnessScriptPubKey,
+    Prop.forAll(ScriptGenerators.witnessScriptPubKeyV0,
                 ChainParamsGenerator.networkParams) {
       case ((witSPK, _), network) =>
         val addr = Bech32Address(witSPK, network)

core-test/src/test/scala/org/bitcoins/core/protocol/Bech32Test.scala

@@ -240,4 +240,18 @@ class Bech32Test extends BitcoinSUnitTest {
         .checkDataValidity("bcrt1qq6w6pu6zq90az9krn53zlkvgyzkyeglzukyepf")
         .isFailure)
   }
+
+  it must "fail to read a segwitV1 bech32 address" in {
+    assert(
+      Bech32Address
+        .fromStringT(
+          "tb1prp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sl5k7")
+        .isFailure)
+
+    assert(
+      Bech32Address
+        .fromStringT(
+          "bc1prp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sl5k7")
+        .isFailure)
+  }
 }

core/src/main/scala/org/bitcoins/core/protocol/Address.scala

@@ -88,7 +88,7 @@ sealed abstract class Bech32Address extends BitcoinAddress {
 
   def checksum: Vector[UInt5] = Bech32Address.createChecksum(hrp, data)
 
-  override def scriptPubKey: WitnessScriptPubKey = {
+  override def scriptPubKey: WitnessScriptPubKeyV0 = {
     Bech32Address.fromStringToWitSPK(value).get
   }
 
@@ -99,9 +99,6 @@ sealed abstract class Bech32Address extends BitcoinAddress {
         Sha256Hash160Digest(byteVector)
       case _: P2WSHWitnessSPKV0 =>
         Sha256Digest(byteVector)
-      case _: UnassignedWitnessScriptPubKey =>
-        throw new IllegalArgumentException(
-          s"Cannot parse the hash of an unassigned witness scriptpubkey for bech32 address")
     }
   }
 
@@ -149,7 +146,7 @@ object Bech32Address extends AddressFactory[Bech32Address] {
   /** Tries to convert the given string a to a
     * [[org.bitcoins.core.protocol.script.WitnessScriptPubKey WitnessScriptPubKey]]
     */
-  def fromStringToWitSPK(string: String): Try[WitnessScriptPubKey] = {
+  def fromStringToWitSPK(string: String): Try[WitnessScriptPubKeyV0] = {
     val decoded = fromStringT(string)
     decoded.flatMap { bech32Addr =>
       val bytes = bech32Addr.data
@@ -161,7 +158,7 @@ object Bech32Address extends AddressFactory[Bech32Address] {
       witVersion match {
         case Some(v) =>
           val witSPK = Try(
-            WitnessScriptPubKey(
+            WitnessScriptPubKeyV0(
               List(v.version) ++ pushOp ++ List(ScriptConstant(progBytes))))
           witSPK match {
             case Success(spk) => Success(spk)

core/src/main/scala/org/bitcoins/core/protocol/script/ScriptPubKey.scala

@@ -1212,7 +1212,7 @@ sealed abstract class WitnessScriptPubKeyV0 extends WitnessScriptPubKey {
   override def witnessProgram: Seq[ScriptToken] = asm.tail.tail
 }
 
-object WitnessScriptPubKeyV0 {
+object WitnessScriptPubKeyV0 extends ScriptFactory[WitnessScriptPubKeyV0] {
 
   /**
     * Mimics the function to determine if a
@@ -1227,6 +1227,19 @@ object WitnessScriptPubKeyV0 {
     WitnessScriptPubKey.isWitnessScriptPubKey(asm) && asm.headOption.contains(
       OP_0)
   }
+
+  def apply(asm: Seq[ScriptToken]): WitnessScriptPubKeyV0 = fromAsm(asm)
+
+  override def fromAsm(asm: Seq[ScriptToken]): WitnessScriptPubKeyV0 =
+    asm match {
+      case _ if P2WPKHWitnessSPKV0.isValid(asm) =>
+        P2WPKHWitnessSPKV0.fromAsm(asm)
+      case _ if P2WSHWitnessSPKV0.isValid(asm) =>
+        P2WSHWitnessSPKV0.fromAsm(asm)
+      case _ =>
+        sys.error(
+          s"The given asm was not a valid WitnessScriptPubKeyV0, got asm=$asm")
+    }
 }
 
 /**

testkit/src/main/scala/org/bitcoins/testkit/core/gen/AddressGenerator.scala

@@ -24,9 +24,9 @@ sealed trait AddressGenerator {
 
   def bech32Address: Gen[Bech32Address] =
     for {
-      (witSPK, _) <- ScriptGenerators.assignedWitnessScriptPubKey
+      (witSPKV0, _) <- ScriptGenerators.witnessScriptPubKeyV0
       network <- ChainParamsGenerator.networkParams
-      addr = Bech32Address(witSPK, network)
+      addr = Bech32Address(witSPKV0, network)
     } yield addr
 
   def bitcoinAddress: Gen[BitcoinAddress] =