TxBuilder: add support for RSBuffer type keyPairs and .publicKey

Author: dcousens

src/transaction_builder.js

@@ -680,7 +680,7 @@ TransactionBuilder.prototype.sign = function (vin, keyPair, redeemScript, hashTy
     throw new Error('Inconsistent redeemScript')
   }
 
-  var kpPubKey = keyPair.getPublicKeyBuffer()
+  var kpPubKey = keyPair.publicKey || keyPair.getPublicKeyBuffer()
   if (!canSign(input)) {
     if (witnessValue !== undefined) {
       if (input.value !== undefined && input.value !== witnessValue) throw new Error('Input didn\'t match witnessValue')
@@ -699,14 +699,18 @@ TransactionBuilder.prototype.sign = function (vin, keyPair, redeemScript, hashTy
   } else {
     signatureHash = this.tx.hashForSignature(vin, input.signScript, hashType)
   }
+
   // enforce in order signing of public keys
   var signed = input.pubKeys.some(function (pubKey, i) {
     if (!kpPubKey.equals(pubKey)) return false
     if (input.signatures[i]) throw new Error('Signature already exists')
-    if (!keyPair.compressed &&
+    if (kpPubKey.length !== 33 &&
       input.signType === scriptTypes.P2WPKH) throw new Error('BIP143 rejects uncompressed public keys in P2WPKH or P2WSH')
 
-    input.signatures[i] = keyPair.sign(signatureHash).toScriptSignature(hashType)
+    var signature = keyPair.sign(signatureHash)
+    if (Buffer.isBuffer(signature)) signature = ECSignature.fromRSBuffer(signature)
+
+    input.signatures[i] = signature.toScriptSignature(hashType)
     return true
   })