Add support for spending keys to the basic key store

src/Makefile.gtest.include

@@ -8,6 +8,7 @@ zcash_gtest_SOURCES = \
 	gtest/test_checktransaction.cpp \
 	gtest/test_equihash.cpp \
 	gtest/test_joinsplit.cpp \
+	gtest/test_keystore.cpp \
 	gtest/test_noteencryption.cpp \
 	gtest/test_merkletree.cpp \
 	gtest/test_circuit.cpp \

src/gtest/test_keystore.cpp

@@ -0,0 +1,26 @@
+#include <gtest/gtest.h>
+
+#include "keystore.h"
+#include "zcash/Address.hpp"
+
+TEST(keystore_tests, store_and_retrieve_spending_key) {
+    CBasicKeyStore keyStore;
+
+    std::set<libzcash::PaymentAddress> addrs;
+    keyStore.GetPaymentAddresses(addrs);
+    ASSERT_EQ(0, addrs.size());
+
+    auto sk = libzcash::SpendingKey::random();
+    keyStore.AddSpendingKey(sk);
+
+    auto addr = sk.address();
+    ASSERT_TRUE(keyStore.HaveSpendingKey(addr));
+
+    libzcash::SpendingKey keyOut;
+    keyStore.GetSpendingKey(addr, keyOut);
+    ASSERT_EQ(sk, keyOut);
+
+    keyStore.GetPaymentAddresses(addrs);
+    ASSERT_EQ(1, addrs.size());
+    ASSERT_EQ(1, addrs.count(addr));
+}

src/keystore.cpp

@@ -23,6 +23,10 @@ bool CKeyStore::AddKey(const CKey &key) {
     return AddKeyPubKey(key, key.GetPubKey());
 }
 
+bool CKeyStore::AddSpendingKey(const libzcash::SpendingKey &key) {
+    return AddSpendingKeyPaymentAddress(key, key.address());
+}
+
 bool CBasicKeyStore::AddKeyPubKey(const CKey& key, const CPubKey &pubkey)
 {
     LOCK(cs_KeyStore);
@@ -83,3 +87,10 @@ bool CBasicKeyStore::HaveWatchOnly() const
     LOCK(cs_KeyStore);
     return (!setWatchOnly.empty());
 }
+
+bool CBasicKeyStore::AddSpendingKeyPaymentAddress(const libzcash::SpendingKey& key, const libzcash::PaymentAddress &address)
+{
+    LOCK(cs_KeyStore);
+    mapSpendingKeys[address] = key;
+    return true;
+}

src/keystore.h

@@ -11,6 +11,7 @@
 #include "script/script.h"
 #include "script/standard.h"
 #include "sync.h"
+#include "zcash/Address.hpp"
 
 #include <boost/signals2/signal.hpp>
 #include <boost/variant.hpp>
@@ -44,11 +45,21 @@ public:
     virtual bool RemoveWatchOnly(const CScript &dest) =0;
     virtual bool HaveWatchOnly(const CScript &dest) const =0;
     virtual bool HaveWatchOnly() const =0;
+
+    //! Add a spending key to the store.
+    virtual bool AddSpendingKeyPaymentAddress(const libzcash::SpendingKey &key, const libzcash::PaymentAddress &address) =0;
+    virtual bool AddSpendingKey(const libzcash::SpendingKey &key);
+
+    //! Check whether a spending key corresponding to a given payment address is present in the store.
+    virtual bool HaveSpendingKey(const libzcash::PaymentAddress &address) const =0;
+    virtual bool GetSpendingKey(const libzcash::PaymentAddress &address, libzcash::SpendingKey& keyOut) const =0;
+    virtual void GetPaymentAddresses(std::set<libzcash::PaymentAddress> &setAddress) const =0;
 };
 
 typedef std::map<CKeyID, CKey> KeyMap;
 typedef std::map<CScriptID, CScript > ScriptMap;
 typedef std::set<CScript> WatchOnlySet;
+typedef std::map<libzcash::PaymentAddress, libzcash::SpendingKey> SpendingKeyMap;
 
 /** Basic key store, that keeps keys in an address->secret map */
 class CBasicKeyStore : public CKeyStore
@@ -57,6 +68,7 @@ protected:
     KeyMap mapKeys;
     ScriptMap mapScripts;
     WatchOnlySet setWatchOnly;
+    SpendingKeyMap mapSpendingKeys;
 
 public:
     bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey);
@@ -103,6 +115,43 @@ public:
     virtual bool RemoveWatchOnly(const CScript &dest);
     virtual bool HaveWatchOnly(const CScript &dest) const;
     virtual bool HaveWatchOnly() const;
+
+    bool AddSpendingKeyPaymentAddress(const libzcash::SpendingKey &key, const libzcash::PaymentAddress &address);
+    bool HaveSpendingKey(const libzcash::PaymentAddress &address) const
+    {
+        bool result;
+        {
+            LOCK(cs_KeyStore);
+            result = (mapSpendingKeys.count(address) > 0);
+        }
+        return result;
+    }
+    bool GetSpendingKey(const libzcash::PaymentAddress &address, libzcash::SpendingKey &keyOut) const
+    {
+        {
+            LOCK(cs_KeyStore);
+            SpendingKeyMap::const_iterator mi = mapSpendingKeys.find(address);
+            if (mi != mapSpendingKeys.end())
+            {
+                keyOut = mi->second;
+                return true;
+            }
+        }
+        return false;
+    }
+    void GetPaymentAddresses(std::set<libzcash::PaymentAddress> &setAddress) const
+    {
+        setAddress.clear();
+        {
+            LOCK(cs_KeyStore);
+            SpendingKeyMap::const_iterator mi = mapSpendingKeys.begin();
+            while (mi != mapSpendingKeys.end())
+            {
+                setAddress.insert((*mi).first);
+                mi++;
+            }
+        }
+    }
 };
 
 typedef std::vector<unsigned char, secure_allocator<unsigned char> > CKeyingMaterial;

src/uint252.h

@@ -43,6 +43,8 @@ public:
     uint256 inner() const {
         return contents;
     }
+
+    friend inline bool operator==(const uint252& a, const uint252& b) { return a.contents == b.contents; }
 };
 
 #endif

src/zcash/Address.cpp

@@ -8,7 +8,7 @@ uint256 ViewingKey::pk_enc() {
     return ZCNoteEncryption::generate_pubkey(*this);
 }
 
-ViewingKey SpendingKey::viewing_key() {
+ViewingKey SpendingKey::viewing_key() const {
     return ViewingKey(ZCNoteEncryption::generate_privkey(*this));
 }
 
@@ -16,8 +16,8 @@ SpendingKey SpendingKey::random() {
     return SpendingKey(random_uint252());
 }
 
-PaymentAddress SpendingKey::address() {
+PaymentAddress SpendingKey::address() const {
     return PaymentAddress(PRF_addr_a_pk(*this), viewing_key().pk_enc());
 }
 
-}
+}

src/zcash/Address.hpp

@@ -22,6 +22,8 @@ public:
         READWRITE(a_pk);
         READWRITE(pk_enc);
     }
+
+    friend inline bool operator<(const PaymentAddress& a, const PaymentAddress& b) { return a.a_pk < b.a_pk; }
 };
 
 class ViewingKey : public uint256 {
@@ -38,8 +40,8 @@ public:
 
     static SpendingKey random();
 
-    ViewingKey viewing_key();
-    PaymentAddress address();
+    ViewingKey viewing_key() const;
+    PaymentAddress address() const;
 };
 
 }