Merge c67ef29 into merged_master (Elements PR ElementsProject#600)

Also uncommented a bunch of PSBT functional tests (had to add a fee output
to one transaction, update `find_output` to skip CT outputs, and change two
constant checks at the end of the commented-out section).

Author: apoelstra

src/core_io.h

@@ -37,6 +37,7 @@ bool DecodeHexBlockHeader(CBlockHeader&, const std::string& hex_header);
  */
 bool ParseHashStr(const std::string& strHex, uint256& result);
 std::vector<unsigned char> ParseHexUV(const UniValue& v, const std::string& strName);
+
 int ParseSighashString(const UniValue& sighash);
 
 // core_write.cpp

src/core_write.cpp

@@ -9,6 +9,7 @@
 #include <issuance.h>
 #include <key_io.h>
 #include <script/script.h>
+#include <script/sign.h>
 #include <script/standard.h>
 #include <serialize.h>
 #include <streams.h>
@@ -326,15 +327,21 @@ void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry,
             uint64_t minv;
             uint64_t maxv;
             const CTxOutWitness* ptxoutwit = tx.witness.vtxoutwit.size() <= i? NULL: &tx.witness.vtxoutwit[i];
-            if (ptxoutwit && secp256k1_rangeproof_info(secp256k1_blind_context, &exp, &mantissa, &minv, &maxv, &ptxoutwit->vchRangeproof[0], ptxoutwit->vchRangeproof.size())) {
-                if (exp == -1) {
-                    out.pushKV("value", ValueFromAmount((CAmount)minv));
-                } else {
-                    out.pushKV("value-minimum", ValueFromAmount((CAmount)minv));
-                    out.pushKV("value-maximum", ValueFromAmount((CAmount)maxv));
+            if (ptxoutwit) {
+                if (ptxoutwit->vchRangeproof.size() && secp256k1_rangeproof_info(secp256k1_blind_context, &exp, &mantissa, &minv, &maxv, &ptxoutwit->vchRangeproof[0], ptxoutwit->vchRangeproof.size())) {
+                    if (exp == -1) {
+                        out.pushKV("value", ValueFromAmount((CAmount)minv));
+                    } else {
+                        out.pushKV("value-minimum", ValueFromAmount((CAmount)minv));
+                        out.pushKV("value-maximum", ValueFromAmount((CAmount)maxv));
+                    }
+                    out.pushKV("ct-exponent", exp);
+                    out.pushKV("ct-bits", mantissa);
+                }
+
+                if (ptxoutwit->vchSurjectionproof.size()) {
+                    out.pushKV("surjectionproof", HexStr(ptxoutwit->vchSurjectionproof));
                 }
-                out.pushKV("ct-exponent", exp);
-                out.pushKV("ct-bits", mantissa);
             }
             out.pushKV("valuecommitment", txout.nValue.GetHex());
         }

src/psbt.cpp

@@ -4,6 +4,7 @@
 
 #include <psbt.h>
 #include <util/strencodings.h>
+#include <confidential_validation.h>
 
 #include <numeric>
 
@@ -154,6 +155,11 @@ void PSBTInput::Merge(const PSBTInput& input)
     if (witness_script.empty() && !input.witness_script.empty()) witness_script = input.witness_script;
     if (final_script_sig.empty() && !input.final_script_sig.empty()) final_script_sig = input.final_script_sig;
     if (final_script_witness.IsNull() && !input.final_script_witness.IsNull()) final_script_witness = input.final_script_witness;
+
+    if (!value && input.value) value = input.value;
+    if (value_blinding_factor.IsNull() && !input.value_blinding_factor.IsNull()) value_blinding_factor = input.value_blinding_factor;
+    if (asset.IsNull() && !input.asset.IsNull()) asset = input.asset;
+    if (asset_blinding_factor.IsNull() && !input.asset_blinding_factor.IsNull()) asset_blinding_factor = input.asset_blinding_factor;
 }
 
 bool PSBTInput::IsSane() const
@@ -206,6 +212,15 @@ void PSBTOutput::Merge(const PSBTOutput& output)
 
     if (redeem_script.empty() && !output.redeem_script.empty()) redeem_script = output.redeem_script;
     if (witness_script.empty() && !output.witness_script.empty()) witness_script = output.witness_script;
+
+    if (!blinding_pubkey.IsValid() && output.blinding_pubkey.IsValid()) blinding_pubkey = output.blinding_pubkey;
+    if (value_commitment.IsNull() && !output.value_commitment.IsNull()) value_commitment = output.value_commitment;
+    if (value_blinding_factor.IsNull() && !output.value_blinding_factor.IsNull()) value_blinding_factor = output.value_blinding_factor;
+    if (asset_commitment.IsNull() && !output.asset_commitment.IsNull()) asset_commitment = output.asset_commitment;
+    if (asset_blinding_factor.IsNull() && !output.asset_blinding_factor.IsNull()) asset_blinding_factor = output.asset_blinding_factor;
+    if (nonce_commitment.IsNull() && !output.nonce_commitment.IsNull()) nonce_commitment = output.nonce_commitment;
+    if (range_proof.empty() && !output.range_proof.empty()) range_proof = output.range_proof;
+    if (surjection_proof.empty() && !output.surjection_proof.empty()) surjection_proof = output.surjection_proof;
 }
 bool PSBTInputSigned(const PSBTInput& input)
 {
@@ -244,7 +259,7 @@ bool SignPSBTInput(const SigningProvider& provider, PartiallySignedTransaction&
     SignatureData sigdata;
     input.FillSignatureData(sigdata);
 
-    // Get UTXO
+    // Get UTXO for this input
     bool require_witness_sig = false;
     CTxOut utxo;
 
@@ -323,10 +338,35 @@ bool FinalizeAndExtractPSBT(PartiallySignedTransaction& psbtx, CMutableTransacti
     }
 
     result = *psbtx.tx;
+    result.witness.vtxinwit.resize(result.vin.size());
     for (unsigned int i = 0; i < result.vin.size(); ++i) {
         result.vin[i].scriptSig = psbtx.inputs[i].final_script_sig;
         result.witness.vtxinwit[i].scriptWitness = psbtx.inputs[i].final_script_witness;
     }
+
+    result.witness.vtxoutwit.resize(result.vout.size());
+    for (unsigned int i = 0; i < result.vout.size(); ++i) {
+        PSBTOutput& output = psbtx.outputs.at(i);
+        CTxOut& out = result.vout[i];
+        CTxOutWitness& outwit = result.witness.vtxoutwit[i];
+
+        if (!output.value_commitment.IsNull()) {
+            out.nValue = output.value_commitment;
+        }
+        if (!output.asset_commitment.IsNull()) {
+            out.nAsset = output.asset_commitment;
+        }
+        if (!output.nonce_commitment.IsNull()) {
+            out.nNonce = output.nonce_commitment;
+        }
+        if (!output.range_proof.empty()) {
+            outwit.vchRangeproof = output.range_proof;
+        }
+        if (!output.surjection_proof.empty()) {
+            outwit.vchSurjectionproof = output.surjection_proof;
+        }
+    }
+
     return true;
 }
 
@@ -358,6 +398,14 @@ std::string PSBTRoleName(PSBTRole role) {
     assert(false);
 }
 
+std::string EncodePSBT(const PartiallySignedTransaction& psbt)
+{
+    CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
+    ssTx << psbt;
+    return EncodeBase64((unsigned char*)ssTx.data(), ssTx.size());
+}
+
+
 bool DecodeBase64PSBT(PartiallySignedTransaction& psbt, const std::string& base64_tx, std::string& error)
 {
     bool invalid;