From 61345ae70320f2242e83181c799eb044e6af3461 Mon Sep 17 00:00:00 2001
From: Simon <simon@bitcartel.com>
Date: Thu, 7 Dec 2017 10:11:43 -0800
Subject: [PATCH] Closes #2746. Payment disclosure blobs now use 'zpd:' prefix.

---
 qa/rpc-tests/paymentdisclosure.py    | 11 +++++++++++
 src/gtest/test_paymentdisclosure.cpp |  4 +++-
 src/paymentdisclosure.h              |  2 ++
 src/wallet/rpcdisclosure.cpp         | 18 ++++++++++++------
 4 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/qa/rpc-tests/paymentdisclosure.py b/qa/rpc-tests/paymentdisclosure.py
index 60d6f188f..bc873897a 100755
--- a/qa/rpc-tests/paymentdisclosure.py
+++ b/qa/rpc-tests/paymentdisclosure.py
@@ -175,6 +175,17 @@ class PaymentDisclosureTest (BitcoinTestFramework):
         assert_equal(result["message"], message)
         assert_equal(result["value"], output_value_sum)
 
+        # Confirm that payment disclosure begins with prefix zpd:
+        assert(pd.startswith("zpd:"))
+
+        # Confirm that payment disclosure without prefix zpd: fails validation
+        try:
+            self.nodes[1].z_validatepaymentdisclosure(pd[4:])
+            assert(False)
+        except JSONRPCException as e:
+            errorString = e.error['message']
+            assert("payment disclosure prefix not found" in errorString)
+
         # Check that total value of output index 0 and index 1 should equal shielding amount of 40 less standard fee.
         pd = self.nodes[0].z_getpaymentdisclosure(txid, 0, 1)
         result = self.nodes[0].z_validatepaymentdisclosure(pd)
diff --git a/src/gtest/test_paymentdisclosure.cpp b/src/gtest/test_paymentdisclosure.cpp
index e87c89297..ddab3c7e6 100644
--- a/src/gtest/test_paymentdisclosure.cpp
+++ b/src/gtest/test_paymentdisclosure.cpp
@@ -87,7 +87,9 @@ public:
 
 // This test creates random payment disclosure blobs and checks that they can be
 // 1. inserted and retrieved from a database
-// 2. serialized and deserialized without corruption 
+// 2. serialized and deserialized without corruption
+// Note that the zpd: prefix is not part of the payment disclosure blob itself.  It is only
+// used as convention to improve the user experience when sharing payment disclosure blobs.
 TEST(paymentdisclosure, mainnet) {
     ECC_Start();
     SelectParams(CBaseChainParams::MAIN);
diff --git a/src/paymentdisclosure.h b/src/paymentdisclosure.h
index b4f56eb45..e6a995ab4 100644
--- a/src/paymentdisclosure.h
+++ b/src/paymentdisclosure.h
@@ -28,6 +28,8 @@
 
 #define PAYMENT_DISCLOSURE_VERSION_EXPERIMENTAL 0
 
+#define PAYMENT_DISCLOSURE_BLOB_STRING_PREFIX    "zpd:"
+
 typedef JSOutPoint PaymentDisclosureKey;
 
 struct PaymentDisclosureInfo {
diff --git a/src/wallet/rpcdisclosure.cpp b/src/wallet/rpcdisclosure.cpp
index c1c8cb87c..539cf4b2a 100644
--- a/src/wallet/rpcdisclosure.cpp
+++ b/src/wallet/rpcdisclosure.cpp
@@ -59,7 +59,7 @@ UniValue z_getpaymentdisclosure(const UniValue& params, bool fHelp)
             "3. \"output_index\"    (string, required) \n"
             "4. \"message\"         (string, optional) \n"
             "\nResult:\n"
-            "\"paymentblob\"        (string) Hex string of payment blob\n"
+            "\"paymentdisclosure\"  (string) Hex data string, with \"zpd:\" prefix.\n"
             "\nExamples:\n"
             + HelpExampleCli("z_getpaymentdisclosure", "96f12882450429324d5f3b48630e3168220e49ab7b0f066e5c2935a6b88bb0f2 0 0 \"refund\"")
             + HelpExampleRpc("z_getpaymentdisclosure", "\"96f12882450429324d5f3b48630e3168220e49ab7b0f066e5c2935a6b88bb0f2\", 0, 0, \"refund\"")
@@ -134,7 +134,7 @@ UniValue z_getpaymentdisclosure(const UniValue& params, bool fHelp)
     CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
     ss << pd;
     string strHex = HexStr(ss.begin(), ss.end());
-    return strHex;
+    return PAYMENT_DISCLOSURE_BLOB_STRING_PREFIX + strHex;
 }
 
 
@@ -160,10 +160,10 @@ UniValue z_validatepaymentdisclosure(const UniValue& params, bool fHelp)
             "\nEXPERIMENTAL FEATURE\n"
             + strPaymentDisclosureDisabledMsg +
             "\nArguments:\n"
-            "1. \"paymentdisclosure\"     (string, required) Hex data string\n"
+            "1. \"paymentdisclosure\"     (string, required) Hex data string, with \"zpd:\" prefix.\n"
             "\nExamples:\n"
-            + HelpExampleCli("z_validatepaymentdisclosure", "\"hexblob\"")
-            + HelpExampleRpc("z_validatepaymentdisclosure", "\"hexblob\"")
+            + HelpExampleCli("z_validatepaymentdisclosure", "\"zpd:706462ff004c561a0447ba2ec51184e6c204...\"")
+            + HelpExampleRpc("z_validatepaymentdisclosure", "\"zpd:706462ff004c561a0447ba2ec51184e6c204...\"")
         );
 
     if (!fEnablePaymentDisclosure) {
@@ -174,7 +174,13 @@ UniValue z_validatepaymentdisclosure(const UniValue& params, bool fHelp)
 
     EnsureWalletIsUnlocked();
 
-    string hexInput = params[0].get_str();
+    // Verify the payment disclosure input begins with "zpd:" prefix.
+    string strInput = params[0].get_str();
+    size_t pos = strInput.find(PAYMENT_DISCLOSURE_BLOB_STRING_PREFIX);
+    if (pos != 0) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, payment disclosure prefix not found.");
+    }
+    string hexInput = strInput.substr(strlen(PAYMENT_DISCLOSURE_BLOB_STRING_PREFIX));
     if (!IsHex(hexInput))
     {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, expected payment disclosure data in hexadecimal format.");