add vanity address generator toy

Makefile

@@ -13,7 +13,7 @@ OBJECTS = $(SOURCES:.cpp=.o)
 I2PD_LIB = libi2pd.a
 
 
-all: keygen keyinfo famtool routerinfo regaddr
+all: keygen keyinfo famtool routerinfo regaddr vain
 
 routerinfo: $(OBJECTS)
 	$(CXX) -o routerinfo routerinfo.o $(LDFLAGS) $(LIBS)
@@ -30,6 +30,9 @@ famtool: $(OBJECTS)
 regaddr: $(OBJECTS)
 	$(CXX) -o regaddr regaddr.o $(LDFLAGS) $(LIBS)
 
+vain: $(OBJECTS)
+	$(CXX) -o vain vanitygen.o $(LDFLAGS) $(LIBS)
+
 $(OBJECTS): libi2pd.a
 
 .SUFFIXES:

vanitygen.cpp

@@ -0,0 +1,58 @@
+#include <iostream>
+#include <fstream>
+#include <stdlib.h>
+#include <openssl/rand.h>
+#include "Crypto.h"
+#include "Identity.h"
+#include "common/key.hpp"
+
+// XXX: make this faster
+static bool check_keys(const std::string & prefix, i2p::data::PrivateKeys & key)
+{
+  return key.GetPublic()->GetIdentHash().ToBase32().substr(0, prefix.length()) == prefix;
+}
+
+// XXX: make this faster
+static void mutate_keys(uint8_t * buf, i2p::data::PrivateKeys & key)
+{
+  uint8_t * ptr = key.GetPadding();
+  // TODO: do not hard code for ed25519
+  RAND_bytes(ptr, 96);
+  key.RecalculateIdentHash(buf);
+}
+
+int main (int argc, char * argv[])
+{
+	if (argc < 2)
+	{
+		std::cout << "Usage: " << argv[0] << " filename prefix" << std::endl;
+		return -1;
+	}
+  uint8_t buf[1024] = {0};
+  std::string prefix(argv[2]);
+	i2p::crypto::InitCrypto (false);
+  // default to ed 25519 keys
+	i2p::data::SigningKeyType type = i2p::data::SIGNING_KEY_TYPE_EDDSA_SHA512_ED25519;
+	auto keys = i2p::data::PrivateKeys::CreateRandomKeys (type);
+
+  // TODO: multi threading
+  while(!check_keys(prefix, keys))
+    mutate_keys(buf, keys);
+
+	std::ofstream f (argv[1], std::ofstream::binary | std::ofstream::out);
+	if (f)
+	{
+		size_t len = keys.GetFullLen ();
+		uint8_t * buf = new uint8_t[len];
+		len = keys.ToBuffer (buf, len);
+		f.write ((char *)buf, len);
+		delete[] buf;
+		std::cout << "Destination " << keys.GetPublic ()->GetIdentHash ().ToBase32 () << " created" << std::endl;
+	}
+	else
+		std::cout << "Can't create file " << argv[1] << std::endl;
+
+	i2p::crypto::TerminateCrypto ();
+
+	return 0;
+}