Bech32 address improvements (#2571)

* Bech32 address improvements

* Respond to review

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

@@ -29,6 +29,15 @@ class Bech32Test extends BitcoinSUnitTest {
     }
   }
 
+  it must "properly read an uppercase bech32 address" in {
+    val addrStr = "bcrt1qq6w6pu6zq90az9krn53zlkvgyzkyeglzukyepf"
+    val addrT = Address.fromStringT(addrStr.toUpperCase)
+    addrT match {
+      case Success(addr: Bech32Address) => assert(addr.value == addrStr)
+      case _                            => fail()
+    }
+  }
+
   it must "follow the example in BIP173" in {
     //https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki#examples
     val key = ECPublicKey(

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

@@ -105,6 +105,10 @@ sealed abstract class Bech32Address extends BitcoinAddress {
   def expandHrp: Vector[UInt5] = {
     hrp.expand
   }
+
+  def verifyChecksum: Boolean = {
+    Bech32.verifyChecksum(hrp.expand, data ++ checksum)
+  }
 }
 
 object Bech32Address extends AddressFactory[Bech32Address] {
@@ -113,7 +117,7 @@ object Bech32Address extends AddressFactory[Bech32Address] {
       networkParameters: NetworkParameters,
       data: Vector[UInt5])
       extends Bech32Address {
-    //require(verifyChecksum(hrp, data), "checksum did not pass")
+    require(verifyChecksum, s"checksum did not pass $checksum")
   }
 
   def empty(network: NetworkParameters = MainNet): Bech32Address =
@@ -192,7 +196,7 @@ object Bech32Address extends AddressFactory[Bech32Address] {
       spk: ScriptPubKey,
       np: NetworkParameters): Try[Bech32Address] =
     spk match {
-      case witSPK: WitnessScriptPubKey =>
+      case witSPK: WitnessScriptPubKeyV0 =>
         Success(Bech32Address(witSPK, np))
       case x @ (_: P2PKScriptPubKey | _: P2PKHScriptPubKey |
           _: P2PKWithTimeoutScriptPubKey | _: MultiSignatureScriptPubKey |
@@ -386,9 +390,9 @@ object BitcoinAddress extends AddressFactory[BitcoinAddress] {
       spk: ScriptPubKey,
       np: NetworkParameters): Try[BitcoinAddress] =
     spk match {
-      case p2pkh: P2PKHScriptPubKey    => Success(P2PKHAddress(p2pkh, np))
+      case p2pkh: P2PKHScriptPubKey      => Success(P2PKHAddress(p2pkh, np))
-      case p2sh: P2SHScriptPubKey      => Success(P2SHAddress(p2sh, np))
+      case p2sh: P2SHScriptPubKey        => Success(P2SHAddress(p2sh, np))
-      case witSPK: WitnessScriptPubKey => Success(Bech32Address(witSPK, np))
+      case witSPK: WitnessScriptPubKeyV0 => Success(Bech32Address(witSPK, np))
       case x @ (_: P2PKScriptPubKey | _: P2PKWithTimeoutScriptPubKey |
           _: MultiSignatureScriptPubKey | _: LockTimeScriptPubKey |
           _: ConditionalScriptPubKey | _: NonStandardScriptPubKey |

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

@@ -39,7 +39,7 @@ object BtcHumanReadablePart extends StringFactory[BtcHumanReadablePart] {
   }
 
   override def fromString(str: String): BtcHumanReadablePart =
-    str match {
+    str.toLowerCase match {
       case "bc"   => bc
       case "tb"   => tb
       case "bcrt" => bcrt // Bitcoin Core specific

core/src/main/scala/org/bitcoins/core/util/Bech32.scala

@@ -135,20 +135,20 @@ sealed abstract class Bech32 {
       remaining match {
         case Nil => Success(accum.reverse)
         case h :: t =>
-          if (!Bech32.charset.contains(h.toLower)) {
+          if ((h.isUpper && hasLower) || (h.isLower && hasUpper)) {
             Failure(
               new IllegalArgumentException(
-                "Invalid character in data of bech32 address, got: " + h))
+                "Cannot have mixed case for bech32 address"))
           } else {
-            if ((h.isUpper && hasLower) || (h.isLower && hasUpper)) {
+            val value = Bech32.charsetReversed(h.toInt)
+
+            if (value == -1) {
               Failure(
                 new IllegalArgumentException(
-                  "Cannot have mixed case for bech32 address"))
+                  "Invalid character in data of bech32 address, got: " + h))
             } else {
-              val byte = Bech32.charset.indexOf(h.toLower).toByte
-
               loop(remaining = t,
-                   accum = UInt5.fromByte(byte) +: accum,
+                   accum = UInt5.fromByte(value.toByte) +: accum,
                    hasUpper = h.isUpper || hasUpper,
                    hasLower = h.isLower || hasLower)
             }
@@ -305,6 +305,19 @@ object Bech32 extends Bech32 {
   val charset: Vector[Char] = Vector('q', 'p', 'z', 'r', 'y', '9', 'x', '8',
     'g', 'f', '2', 't', 'v', 'd', 'w', '0', 's', '3', 'j', 'n', '5', '4', 'k',
     'h', 'c', 'e', '6', 'm', 'u', 'a', '7', 'l')
+
+  /** The Bech32 character set for decoding.
+    * @see https://github.com/sipa/bech32/blob/master/ref/c%2B%2B/bech32.cpp#L33
+    */
+  val charsetReversed: Vector[Int] = Vector(
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 15, -1, 10, 17, 21, 20, 26, 30, 7,
+    5, -1, -1, -1, -1, -1, -1, -1, 29, -1, 24, 13, 25, 9, 8, 23, -1, 18, 22, 31,
+    27, 19, -1, 1, 0, 3, 16, 11, 28, 12, 14, 6, 4, 2, -1, -1, -1, -1, -1, -1,
+    29, -1, 24, 13, 25, 9, 8, 23, -1, 18, 22, 31, 27, 19, -1, 1, 0, 3, 16, 11,
+    28, 12, 14, 6, 4, 2, -1, -1, -1, -1, -1
+  )
 }
 
 abstract class Bech32HumanReadablePart {