Sign JoinSplit transactions

src/pubkey.h

@@ -9,6 +9,7 @@
 #include "hash.h"
 #include "serialize.h"
 #include "uint256.h"
+#include "sodium.h"
 
 #include <stdexcept>
 #include <vector>
@@ -187,6 +188,81 @@ public:
     bool Derive(CPubKey& pubkeyChild, ChainCode &ccChild, unsigned int nChild, const ChainCode& cc) const;
 };
 
+class CCompressedPubKey {
+private:
+    CPubKey pubKey;
+public:
+
+    CCompressedPubKey()
+    {
+        // pubKey's 0-argument constructor invalidates it.
+    }
+
+    CCompressedPubKey(const CPubKey &pubKey)
+    {
+        this->pubKey = pubKey;
+        // TODO: check that it's compressed and valid and throw exception if
+        // not.
+    }
+
+    unsigned int GetSerializeSize(int nType, int nVersion) const
+    {
+        assert(pubKey.size() == 33);
+        return pubKey.size();
+    }
+
+    template <typename Stream>
+    void Serialize(Stream& s, int nType, int nVersion) const
+    {
+        unsigned int len = pubKey.size();
+        assert(len == 33);
+        s.write((char*)pubKey.begin(), len);
+    }
+
+    template <typename Stream>
+    void Unserialize(Stream& s, int nType, int nVersion)
+    {
+        unsigned int len = 33;
+        s.read((char*)pubKey.begin(), len);
+        // TODO: check that it's compressed and valid.
+    }
+
+    //! Get the 256-bit hash of this public key for the Zcash protocol.
+    uint256 GetZcashHash() const
+    {
+        // TODO: is the thing in vch actually the right thing to hash/encode?
+
+        const unsigned char personalization[crypto_generichash_blake2b_PERSONALBYTES]
+        = {'Z','c','a','s','h','E','C','D','S','A','P','u','b','K','e','y'};
+
+        uint256 hash;
+        assert(pubKey[0] == 2 || pubKey[0] == 3);
+        assert(pubKey.size() == 33);
+        if (crypto_generichash_blake2b_salt_personal(hash.begin(), 32,
+                                                    pubKey.begin(), pubKey.size(),
+                                                    NULL, 0, // No key.
+                                                    NULL,    // No salt.
+                                                    personalization
+                                                    ) != 0)
+        {
+            throw std::logic_error("hash function failure");
+        }
+
+        return hash;
+    }
+
+    // TODO: implement this to verify the shorter kind of signature
+    // TODO: make sure to check the s value thing etc.
+    // TODO: this used to have "const" at  the end, what does that mean??
+    bool Verify(const uint256& hash, const std::vector<unsigned char>& vchSig)
+    {
+        // TODO implement signature verification.
+        return false;
+    }
+
+};
+
+
 struct CExtPubKey {
     unsigned char nDepth;
     unsigned char vchFingerprint[4];