pp_check_addr + README

Makefile

@@ -3,6 +3,11 @@ LIBS=$(shell pkg-config --libs libobelisk libwallet)
 
 default: all
 
+pp_check_addr.o: pp_check_addr.cpp
+	$(CXX) -o $@ -c $< $(CXXFLAGS)
+pp_check_addr: pp_check_addr.o
+	$(CXX) -o $@ pp_check_addr.o $(LIBS)
+
 pp_unlock.o: pp_unlock.cpp
 	$(CXX) -o $@ -c $< $(CXXFLAGS)
 pp_unlock: pp_unlock.o aes256.o
@@ -26,9 +31,9 @@ pp_start.o: pp_start.cpp
 pp_start: pp_start.o aes256.o
 	$(CXX) -o $@ pp_start.o aes256.o $(LIBS)
 
-all: pp_start pp_prove pp_unlock pp_secrets
+all: pp_start pp_prove pp_unlock pp_secrets pp_check_addr
 
 clean:
-	rm -f pp_start pp_prove pp_unlock pp_secrets
+	rm -f pp_start pp_prove pp_unlock pp_secrets pp_check_addr 
 	rm -f *.o
 

README

@@ -0,0 +1,70 @@
+Provably fair information marketplace
+=====================================
+    Scheme by Peter Todd
+    Code by Amir Taaki
+
+I want to put out information and get $$$
+
+  $ pp_start TESTFILE 100
+  58 chunks created.
+  Choose a future block height, and announce it to the world.
+
+Announce the HEIGHT to the world.
+Make the _public_chunks/ directory publically available for download.
+
+  "At block HEIGHT 341000 (Expected Nov 11 2014), I will prove
+   possession of the files encrypted at this location:
+     <torrent:...>" -Leaker
+
+Once block hash becomes known:
+
+  $ pp_prove TESTFILE 100 0000000000000000251ed5ba6bc475c13e15550475e4049e153a06b78b5a8a50 10 > proof_file
+  $ cat proof_file
+  20 03e9fc6592798125ede112430e0b8beb30dacd9787f061883bf0bfa43e2ca8d378
+  34 036675c1d13a0112f28956e61475551c4bc53b8b5f6a8c0799fd9bb9f968cfc8ce
+  26 02267eeac444549d63836ff1d098de2b045d0f897849c50120645d6982463d0aa4
+  26 02267eeac444549d63836ff1d098de2b045d0f897849c50120645d6982463d0aa4
+  4 02096ec2b83982ddef77ce2e1628e90ff51ac04eaa9870326a38b3f15112577843
+  26 02267eeac444549d63836ff1d098de2b045d0f897849c50120645d6982463d0aa4
+  5 034633adfee376bed397acaa576196fff39fa8257080be0914e22cb92c2c90fe26
+  19 030c6624306007688c3f27e86b6add811c4a83f1bde2e728e62458c631f76359e5
+  21 028e3f035d4ec79e6afa3a8a90a95dda4f2ced04d1e5bb77321254bea3e5545ec5
+  33 03dd42d8d4134491aee30de991350547e87f100ac9d4e0a1ac6b94150cd2e2d2b8
+  39 023a9a24584ddd2788136128d2c9d84bf4fae9d8063fb691b16eaf62d55193d6b7
+  14 02c920dbd95487749ea8cd602ffe00c6f54f396e4e2a3c2cb0ee8507a761f7505f
+  5 034633adfee376bed397acaa576196fff39fa8257080be0914e22cb92c2c90fe26
+
+Reveal these to your audience by distributing proof_file. They can use this
+file to unlock chunks and verify their authenticity.
+
+  $ pp_unlock_all proof_file TESTFILE_public_chunks/ 0000000000000000251ed5ba6bc475c13e15550475e4049e153a06b78b5a8a50
+
+Which is just a bash script that repeatedly calls for each line in the
+proof_file:
+
+  $ pp_unlock TESTFILE_public_chunks/CHUNK.20 0000000000000000251ed5ba6bc475c13e15550475e4049e153a06b78b5a8a50 03e9fc6592798125ede112430e0b8beb30dacd9787f061883bf0bfa43e2ca8d378
+  // Creates CHUNK.20.decrypted
+
+The leaker can choose to reveal subsequent blocks by spending money send
+to the addresses in _public_chunks/ADDRS file.
+Spending money from those addresses, reveals the public key which is used
+to decrypt other chunks.
+
+To do that, the leaker simply needs to import these keys into his wallet
+and spend any funds at those addresses:
+
+  $ pp_secrets TESTFILE 100
+  L265LXaXqh5TX97voQjz4Wo7Qpyoj8aCxotZYoYsG1vA72oiRTRN
+  L4qJhBVQhHVWQDznzaUoiBkBBpZubJAoLuwhNGW1AdgUoLmXpZSC
+  L37xPybVaSmBKdL6s3SgKUzsmAuBDRsws6oUjXKzz8TgNiypcsvi
+  L2ob4c74UB6rbH7YPA1s6ATDLgrDHNtRB8rUhjL2xzqrXNztQzH6
+  KywiFkzENUKvuMrFGnbSN3PemGHM555QtXhRXAk3D8b1VJwRrc4X
+    ...
+
+To find the pubkeys for an ADDRESS, use the tool pp_check_addr:
+
+  $ ./pp_check_addr 1Ksv3HoCAn75uMfXtyWLgauUQv3gEa389A
+  Fetching de6528066e6f059f2ccd9cdca8bca273ea07fbf7f7017e26a6525f0694f14c09...
+  tx found. Searching...
+  02e1746dc1da27a5d4be9be4855016fc6fdd6f29b5a198239978dafdf7dd647656
+

pp_check_addr.cpp

@@ -0,0 +1,106 @@
+#include <atomic>
+#include <condition_variable>
+#include <thread>
+#include <bitcoin/bitcoin.hpp>
+#include <obelisk/obelisk.hpp>
+using namespace bc;
+
+bool stopped = false;
+payment_address payaddr;
+obelisk::fullnode_interface* node = nullptr;
+
+void tx_fetched(const std::error_code& ec, const transaction_type& tx)
+{
+    if (ec)
+    {
+        std::cerr << "pp_check_addr: Failed to fetch transaction: "
+            << ec.message() << std::endl;
+    }
+    else
+    {
+        std::cout << "tx found. Searching..." << std::endl;
+        for (const transaction_input_type& input: tx.inputs)
+        {
+            payment_address addr;
+            if (!extract(addr, input.script))
+                continue;
+            if (addr.encoded() != payaddr.encoded())
+                continue;
+            BITCOIN_ASSERT(input.script.type() ==
+                payment_type::pubkey_hash_sig);
+            const ec_point& pubkey = input.script.operations().back().data;
+            if (!verify_public_key(pubkey))
+            {
+                std::cerr << "pp_check_addr: problem with pubkey...";
+                stopped = true;
+                return;
+            }
+            std::cout << pubkey << std::endl;
+            stopped = true;
+            return;
+        }
+        BITCOIN_ASSERT(false);
+    }
+    stopped = true;
+}
+
+void history_fetched(
+    const std::error_code& ec, const blockchain::history_list& history)
+{
+    if (ec)
+    {
+        std::cerr << "pp_check_addr: Failed to fetch history: "
+            << ec.message() << std::endl;
+    }
+    else if (history.empty())
+    {
+        std::cerr << "pp_check_addr: No history yet at this address."
+            << std::endl;
+    }
+    else
+    {
+        for (const auto& row: history)
+        {
+            if (row.spend.hash != null_hash)
+            {
+                std::cout << "Fetching " << row.spend.hash
+                    << "..." << std::endl;
+                node->blockchain.fetch_transaction(row.spend.hash, tx_fetched);
+                return;
+            }
+        }
+        std::cerr << "pp_check_addr: No spends yet for this address. "
+            "Keep bidding." << std::endl;
+    }
+    stopped = true;
+}
+
+int main(int argc, char** argv)
+{
+    if (argc != 2)
+    {
+        std::cerr << "Usage: pp_check_addr ADDRESS" << std::endl;
+        return -1;
+    }
+    if (!payaddr.set_encoded(argv[1]))
+    {
+        std::cerr << "pp_check_addr: invalid Bitcoin address." << std::endl;
+        return -1;
+    }
+    threadpool pool(1);
+    obelisk::fullnode_interface fullnode(pool,
+        "tcp://obelisk.unsystem.net:9091");
+    fullnode.address.fetch_history(payaddr, history_fetched);
+    node = &fullnode;
+    // Try to find pubkey for address.
+    // Use the blockchain.
+    while (!stopped)
+    {
+        fullnode.update();
+        std::this_thread::sleep_for(std::chrono::milliseconds(100));
+    }
+    pool.stop();
+    pool.join();
+    return 0;
+}
+