From 990f0f8da92a2d11828a7c05ca93bf0520b2a95e Mon Sep 17 00:00:00 2001 From: Pieter Wuille Date: Thu, 6 Jul 2023 14:19:29 -0400 Subject: [PATCH] Add BIP324Cipher, encapsulating key agreement, derivation, and stream/AEAD ciphers Co-authored-by: dhruv <856960+dhruv@users.noreply.github.com> --- src/Makefile.am | 2 + src/Makefile.test.include | 2 + src/bip324.cpp | 110 +++++++++++++++++ src/bip324.h | 90 ++++++++++++++ src/pubkey.h | 3 + src/test/bip324_tests.cpp | 242 ++++++++++++++++++++++++++++++++++++++ src/test/fuzz/bip324.cpp | 137 +++++++++++++++++++++ 7 files changed, 586 insertions(+) create mode 100644 src/bip324.cpp create mode 100644 src/bip324.h create mode 100644 src/test/bip324_tests.cpp create mode 100644 src/test/fuzz/bip324.cpp diff --git a/src/Makefile.am b/src/Makefile.am index b6fe2563350..fecf86498f7 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -124,6 +124,7 @@ BITCOIN_CORE_H = \ banman.h \ base58.h \ bech32.h \ + bip324.h \ blockencodings.h \ blockfilter.h \ chain.h \ @@ -376,6 +377,7 @@ libbitcoin_node_a_SOURCES = \ addrdb.cpp \ addrman.cpp \ banman.cpp \ + bip324.cpp \ blockencodings.cpp \ blockfilter.cpp \ chain.cpp \ diff --git a/src/Makefile.test.include b/src/Makefile.test.include index d3d2464ce67..37de6237eca 100644 --- a/src/Makefile.test.include +++ b/src/Makefile.test.include @@ -74,6 +74,7 @@ BITCOIN_TESTS =\ test/base64_tests.cpp \ test/bech32_tests.cpp \ test/bip32_tests.cpp \ + test/bip324_tests.cpp \ test/blockchain_tests.cpp \ test/blockencodings_tests.cpp \ test/blockfilter_index_tests.cpp \ @@ -246,6 +247,7 @@ test_fuzz_fuzz_SOURCES = \ test/fuzz/banman.cpp \ test/fuzz/base_encode_decode.cpp \ test/fuzz/bech32.cpp \ + test/fuzz/bip324.cpp \ test/fuzz/bitdeque.cpp \ test/fuzz/block.cpp \ test/fuzz/block_header.cpp \ diff --git a/src/bip324.cpp b/src/bip324.cpp new file mode 100644 index 00000000000..eb223f1f048 --- /dev/null +++ b/src/bip324.cpp @@ -0,0 +1,110 @@ +// Copyright (c) 2023 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#include + +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +BIP324Cipher::BIP324Cipher() noexcept +{ + m_key.MakeNewKey(true); + uint256 entropy = GetRandHash(); + m_our_pubkey = m_key.EllSwiftCreate(MakeByteSpan(entropy)); +} + +BIP324Cipher::BIP324Cipher(const CKey& key, Span ent32) noexcept : + m_key(key) +{ + m_our_pubkey = m_key.EllSwiftCreate(ent32); +} + +BIP324Cipher::BIP324Cipher(const CKey& key, const EllSwiftPubKey& pubkey) noexcept : + m_key(key), m_our_pubkey(pubkey) {} + +void BIP324Cipher::Initialize(const EllSwiftPubKey& their_pubkey, bool initiator) noexcept +{ + // Determine salt (fixed string + network magic bytes) + const auto& message_header = Params().MessageStart(); + std::string salt = std::string{"bitcoin_v2_shared_secret"} + std::string(std::begin(message_header), std::end(message_header)); + + // Perform ECDH to derive shared secret. + ECDHSecret ecdh_secret = m_key.ComputeBIP324ECDHSecret(their_pubkey, m_our_pubkey, initiator); + + // Derive encryption keys from shared secret, and initialize stream ciphers and AEADs. + CHKDF_HMAC_SHA256_L32 hkdf(UCharCast(ecdh_secret.data()), ecdh_secret.size(), salt); + std::array hkdf_32_okm; + hkdf.Expand32("initiator_L", UCharCast(hkdf_32_okm.data())); + (initiator ? m_send_l_cipher : m_recv_l_cipher).emplace(hkdf_32_okm, REKEY_INTERVAL); + hkdf.Expand32("initiator_P", UCharCast(hkdf_32_okm.data())); + (initiator ? m_send_p_cipher : m_recv_p_cipher).emplace(hkdf_32_okm, REKEY_INTERVAL); + hkdf.Expand32("responder_L", UCharCast(hkdf_32_okm.data())); + (initiator ? m_recv_l_cipher : m_send_l_cipher).emplace(hkdf_32_okm, REKEY_INTERVAL); + hkdf.Expand32("responder_P", UCharCast(hkdf_32_okm.data())); + (initiator ? m_recv_p_cipher : m_send_p_cipher).emplace(hkdf_32_okm, REKEY_INTERVAL); + + // Derive garbage terminators from shared secret. + hkdf.Expand32("garbage_terminators", UCharCast(hkdf_32_okm.data())); + std::copy(std::begin(hkdf_32_okm), std::begin(hkdf_32_okm) + GARBAGE_TERMINATOR_LEN, + (initiator ? m_send_garbage_terminator : m_recv_garbage_terminator).begin()); + std::copy(std::end(hkdf_32_okm) - GARBAGE_TERMINATOR_LEN, std::end(hkdf_32_okm), + (initiator ? m_recv_garbage_terminator : m_send_garbage_terminator).begin()); + + // Derive session id from shared secret. + hkdf.Expand32("session_id", UCharCast(m_session_id.data())); + + // Wipe all variables that contain information which could be used to re-derive encryption keys. + memory_cleanse(ecdh_secret.data(), ecdh_secret.size()); + memory_cleanse(hkdf_32_okm.data(), sizeof(hkdf_32_okm)); + memory_cleanse(&hkdf, sizeof(hkdf)); + m_key = CKey(); +} + +void BIP324Cipher::Encrypt(Span contents, Span aad, bool ignore, Span output) noexcept +{ + assert(output.size() == contents.size() + EXPANSION); + + // Encrypt length. + std::byte len[LENGTH_LEN]; + len[0] = std::byte{(uint8_t)(contents.size() & 0xFF)}; + len[1] = std::byte{(uint8_t)((contents.size() >> 8) & 0xFF)}; + len[2] = std::byte{(uint8_t)((contents.size() >> 16) & 0xFF)}; + m_send_l_cipher->Crypt(len, output.first(LENGTH_LEN)); + + // Encrypt plaintext. + std::byte header[HEADER_LEN] = {ignore ? IGNORE_BIT : std::byte{0}}; + m_send_p_cipher->Encrypt(header, contents, aad, output.subspan(LENGTH_LEN)); +} + +uint32_t BIP324Cipher::DecryptLength(Span input) noexcept +{ + assert(input.size() == LENGTH_LEN); + + std::byte buf[LENGTH_LEN]; + // Decrypt length + m_recv_l_cipher->Crypt(input, buf); + // Convert to number. + return uint32_t(buf[0]) + (uint32_t(buf[1]) << 8) + (uint32_t(buf[2]) << 16); +} + +bool BIP324Cipher::Decrypt(Span input, Span aad, bool& ignore, Span contents) noexcept +{ + assert(input.size() + LENGTH_LEN == contents.size() + EXPANSION); + + std::byte header[HEADER_LEN]; + if (!m_recv_p_cipher->Decrypt(input, aad, header, contents)) return false; + + ignore = (header[0] & IGNORE_BIT) == IGNORE_BIT; + return true; +} diff --git a/src/bip324.h b/src/bip324.h new file mode 100644 index 00000000000..1738356ee51 --- /dev/null +++ b/src/bip324.h @@ -0,0 +1,90 @@ +// Copyright (c) 2023 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#ifndef BITCOIN_BIP324_H +#define BITCOIN_BIP324_H + +#include +#include + +#include +#include +#include +#include +#include + +/** The BIP324 packet cipher, encapsulating its key derivation, stream cipher, and AEAD. */ +class BIP324Cipher +{ +public: + static constexpr unsigned SESSION_ID_LEN{32}; + static constexpr unsigned GARBAGE_TERMINATOR_LEN{16}; + static constexpr unsigned REKEY_INTERVAL{224}; + static constexpr unsigned LENGTH_LEN{3}; + static constexpr unsigned HEADER_LEN{1}; + static constexpr unsigned EXPANSION = LENGTH_LEN + HEADER_LEN + FSChaCha20Poly1305::EXPANSION; + static constexpr std::byte IGNORE_BIT{0x80}; + +private: + std::optional m_send_l_cipher; + std::optional m_recv_l_cipher; + std::optional m_send_p_cipher; + std::optional m_recv_p_cipher; + + CKey m_key; + EllSwiftPubKey m_our_pubkey; + + std::array m_session_id; + std::array m_send_garbage_terminator; + std::array m_recv_garbage_terminator; + +public: + /** Initialize a BIP324 cipher with securely generated random keys. */ + BIP324Cipher() noexcept; + + /** Initialize a BIP324 cipher with specified key and encoding entropy (testing only). */ + BIP324Cipher(const CKey& key, Span ent32) noexcept; + + /** Initialize a BIP324 cipher with specified key (testing only). */ + BIP324Cipher(const CKey& key, const EllSwiftPubKey& pubkey) noexcept; + + /** Retrieve our public key. */ + const EllSwiftPubKey& GetOurPubKey() const noexcept { return m_our_pubkey; } + + /** Initialize when the other side's public key is received. Can only be called once. */ + void Initialize(const EllSwiftPubKey& their_pubkey, bool initiator) noexcept; + + /** Determine whether this cipher is fully initialized. */ + explicit operator bool() const noexcept { return m_send_l_cipher.has_value(); } + + /** Encrypt a packet. Only after Initialize(). + * + * It must hold that output.size() == contents.size() + EXPANSION. + */ + void Encrypt(Span contents, Span aad, bool ignore, Span output) noexcept; + + /** Decrypt the length of a packet. Only after Initialize(). + * + * It must hold that input.size() == LENGTH_LEN. + */ + unsigned DecryptLength(Span input) noexcept; + + /** Decrypt a packet. Only after Initialize(). + * + * It must hold that input.size() + LENGTH_LEN == contents.size() + EXPANSION. + * Contents.size() must equal the length returned by DecryptLength. + */ + bool Decrypt(Span input, Span aad, bool& ignore, Span contents) noexcept; + + /** Get the Session ID. Only after Initialize(). */ + Span GetSessionID() const noexcept { return m_session_id; } + + /** Get the Garbage Terminator to send. Only after Initialize(). */ + Span GetSendGarbageTerminator() const noexcept { return m_send_garbage_terminator; } + + /** Get the expected Garbage Terminator to receive. Only after Initialize(). */ + Span GetReceiveGarbageTerminator() const noexcept { return m_recv_garbage_terminator; } +}; + +#endif // BITCOIN_BIP324_H diff --git a/src/pubkey.h b/src/pubkey.h index 7d37504b012..00defa25a01 100644 --- a/src/pubkey.h +++ b/src/pubkey.h @@ -299,6 +299,9 @@ private: std::array m_pubkey; public: + /** Default constructor creates all-zero pubkey (which is valid). */ + EllSwiftPubKey() noexcept = default; + /** Construct a new ellswift public key from a given serialization. */ EllSwiftPubKey(const std::array& ellswift) : m_pubkey(ellswift) {} diff --git a/src/test/bip324_tests.cpp b/src/test/bip324_tests.cpp new file mode 100644 index 00000000000..3b0ec8513e8 --- /dev/null +++ b/src/test/bip324_tests.cpp @@ -0,0 +1,242 @@ +// Copyright (c) 2023 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include + +namespace { + +void TestBIP324PacketVector( + uint32_t in_idx, + const std::string& in_priv_ours_hex, + const std::string& in_ellswift_ours_hex, + const std::string& in_ellswift_theirs_hex, + bool in_initiating, + const std::string& in_contents_hex, + uint32_t in_multiply, + const std::string& in_aad_hex, + bool in_ignore, + const std::string& mid_send_garbage_hex, + const std::string& mid_recv_garbage_hex, + const std::string& out_session_id_hex, + const std::string& out_ciphertext_hex, + const std::string& out_ciphertext_endswith_hex) +{ + // Convert input from hex to char/byte vectors/arrays. + const auto in_priv_ours = ParseHex(in_priv_ours_hex); + const auto in_ellswift_ours_vec = ParseHex(in_ellswift_ours_hex); + assert(in_ellswift_ours_vec.size() == 64); + std::array in_ellswift_ours; + std::copy(in_ellswift_ours_vec.begin(), in_ellswift_ours_vec.end(), in_ellswift_ours.begin()); + const auto in_ellswift_theirs_vec = ParseHex(in_ellswift_theirs_hex); + assert(in_ellswift_theirs_vec.size() == 64); + std::array in_ellswift_theirs; + std::copy(in_ellswift_theirs_vec.begin(), in_ellswift_theirs_vec.end(), in_ellswift_theirs.begin()); + const auto in_contents = ParseHex(in_contents_hex); + const auto in_aad = ParseHex(in_aad_hex); + const auto mid_send_garbage = ParseHex(mid_send_garbage_hex); + const auto mid_recv_garbage = ParseHex(mid_recv_garbage_hex); + const auto out_session_id = ParseHex(out_session_id_hex); + const auto out_ciphertext = ParseHex(out_ciphertext_hex); + const auto out_ciphertext_endswith = ParseHex(out_ciphertext_endswith_hex); + + // Load keys + CKey key; + key.Set(in_priv_ours.begin(), in_priv_ours.end(), true); + EllSwiftPubKey ellswift_ours(in_ellswift_ours); + EllSwiftPubKey ellswift_theirs(in_ellswift_theirs); + + // Instantiate encryption BIP324 cipher. + BIP324Cipher cipher(key, ellswift_ours); + BOOST_CHECK(!cipher); + BOOST_CHECK(cipher.GetOurPubKey() == ellswift_ours); + cipher.Initialize(ellswift_theirs, in_initiating); + BOOST_CHECK(cipher); + + // Compare session variables. + BOOST_CHECK(Span{out_session_id} == cipher.GetSessionID()); + BOOST_CHECK(Span{mid_send_garbage} == cipher.GetSendGarbageTerminator()); + BOOST_CHECK(Span{mid_recv_garbage} == cipher.GetReceiveGarbageTerminator()); + + // Seek to the numbered packet. + for (uint32_t i = 0; i < in_idx; ++i) { + std::vector dummy(cipher.EXPANSION); + cipher.Encrypt({}, {}, false, dummy); + } + + // Construct contents and encrypt it. + std::vector contents; + for (uint32_t i = 0; i < in_multiply; ++i) { + contents.insert(contents.end(), in_contents.begin(), in_contents.end()); + } + std::vector ciphertext(contents.size() + cipher.EXPANSION); + cipher.Encrypt(contents, in_aad, in_ignore, ciphertext); + + // Verify ciphertext. Note that the test vectors specify either out_ciphertext (for short + // messages) or out_ciphertext_endswith (for long messages), so only check the relevant one. + if (!out_ciphertext.empty()) { + BOOST_CHECK(out_ciphertext == ciphertext); + } else { + BOOST_CHECK(ciphertext.size() >= out_ciphertext_endswith.size()); + BOOST_CHECK(Span{out_ciphertext_endswith} == Span{ciphertext}.last(out_ciphertext_endswith.size())); + } + + // Note that we don't test decryption here, as the test vectors don't provide the other party's + // private key, so we cannot act like them. See the bip324_cipher_roundtrip fuzz test for a test + // that does cover decryption. +} + +} // namespace + +BOOST_FIXTURE_TEST_SUITE(bip324_tests, BasicTestingSetup) + +BOOST_AUTO_TEST_CASE(packet_test_vectors) { + // BIP324 key derivation uses network magic in the HKDF process. We use mainnet params here + // as that is what the test vectors are written for. + SelectParams(ChainType::MAIN); + + // The test vectors are converted using the following Python code in the BIP bip-0324/ directory: + // + // import sys + // import csv + // with open('packet_encoding_test_vectors.csv', newline='', encoding='utf-8') as csvfile: + // reader = csv.DictReader(csvfile) + // quote = lambda x: "\"" + x + "\"" + // for row in reader: + // args = [ + // row['in_idx'], + // quote(row['in_priv_ours']), + // quote(row['in_ellswift_ours']), + // quote(row['in_ellswift_theirs']), + // "true" if int(row['in_initiating']) else "false", + // quote(row['in_contents']), + // row['in_multiply'], + // quote(row['in_aad']), + // "true" if int(row['in_ignore']) else "false", + // quote(row['mid_send_garbage_terminator']), + // quote(row['mid_recv_garbage_terminator']), + // quote(row['out_session_id']), + // quote(row['out_ciphertext']), + // quote(row['out_ciphertext_endswith']) + // ] + // print(" TestBIP324PacketVector(\n " + ",\n ".join(args) + ");") + TestBIP324PacketVector( + 1, + "61062ea5071d800bbfd59e2e8b53d47d194b095ae5a4df04936b49772ef0d4d7", + "ec0adff257bbfe500c188c80b4fdd640f6b45a482bbc15fc7cef5931deff0aa186f6eb9bba7b85dc4dcc28b28722de1e3d9108b985e2967045668f66098e475b", + "a4a94dfce69b4a2a0a099313d10f9f7e7d649d60501c9e1d274c300e0d89aafaffffffffffffffffffffffffffffffffffffffffffffffffffffffff8faf88d5", + true, + "8e", + 1, + "", + false, + "faef555dfcdb936425d84aba524758f3", + "02cb8ff24307a6e27de3b4e7ea3fa65b", + "ce72dffb015da62b0d0f5474cab8bc72605225b0cee3f62312ec680ec5f41ba5", + "7530d2a18720162ac09c25329a60d75adf36eda3c3", + ""); + TestBIP324PacketVector( + 999, + "1f9c581b35231838f0f17cf0c979835baccb7f3abbbb96ffcc318ab71e6e126f", + "a1855e10e94e00baa23041d916e259f7044e491da6171269694763f018c7e63693d29575dcb464ac816baa1be353ba12e3876cba7628bd0bd8e755e721eb0140", + "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f0000000000000000000000000000000000000000000000000000000000000000", + false, + "3eb1d4e98035cfd8eeb29bac969ed3824a", + 1, + "", + false, + "efb64fd80acd3825ac9bc2a67216535a", + "b3cb553453bceb002897e751ff7588bf", + "9267c54560607de73f18c563b76a2442718879c52dd39852885d4a3c9912c9ea", + "1da1bcf589f9b61872f45b7fa5371dd3f8bdf5d515b0c5f9fe9f0044afb8dc0aa1cd39a8c4", + ""); + TestBIP324PacketVector( + 0, + "0286c41cd30913db0fdff7a64ebda5c8e3e7cef10f2aebc00a7650443cf4c60d", + "d1ee8a93a01130cbf299249a258f94feb5f469e7d0f2f28f69ee5e9aa8f9b54a60f2c3ff2d023634ec7f4127a96cc11662e402894cf1f694fb9a7eaa5f1d9244", + "ffffffffffffffffffffffffffffffffffffffffffffffffffffffff22d5e441524d571a52b3def126189d3f416890a99d4da6ede2b0cde1760ce2c3f98457ae", + true, + "054290a6c6ba8d80478172e89d32bf690913ae9835de6dcf206ff1f4d652286fe0ddf74deba41d55de3edc77c42a32af79bbea2c00bae7492264c60866ae5a", + 1, + "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", + false, + "d4e3f18ac2e2095edb5c3b94236118ad", + "4faa6c4233d9fd53d170ede4172142a8", + "23f154ac43cfc59c4243e9fc68aeec8f19ad3942d74108e833b36f0dd3dcd357", + "8da7de6ea7bf2a81a396a42880ba1f5756734c4821309ac9aeffa2a26ce86873b9dc4935a772de6ec5162c6d075b14536800fb174841153511bfb597e992e2fe8a450c4bce102cc550bb37fd564c4d60bf884e", + ""); + TestBIP324PacketVector( + 223, + "6c77432d1fda31e9f942f8af44607e10f3ad38a65f8a4bddae823e5eff90dc38", + "d2685070c1e6376e633e825296634fd461fa9e5bdf2109bcebd735e5a91f3e587c5cb782abb797fbf6bb5074fd1542a474f2a45b673763ec2db7fb99b737bbb9", + "56bd0c06f10352c3a1a9f4b4c92f6fa2b26df124b57878353c1fc691c51abea77c8817daeeb9fa546b77c8daf79d89b22b0e1b87574ece42371f00237aa9d83a", + false, + "7e0e78eb6990b059e6cf0ded66ea93ef82e72aa2f18ac24f2fc6ebab561ae557420729da103f64cecfa20527e15f9fb669a49bbbf274ef0389b3e43c8c44e5f60bf2ac38e2b55e7ec4273dba15ba41d21f8f5b3ee1688b3c29951218caf847a97fb50d75a86515d445699497d968164bf740012679b8962de573be941c62b7ef", + 1, + "", + true, + "cf2e25f23501399f30738d7eee652b90", + "225a477a28a54ea7671d2b217a9c29db", + "7ec02fea8c1484e3d0875f978c5f36d63545e2e4acf56311394422f4b66af612", + "", + "729847a3e9eba7a5bff454b5de3b393431ee360736b6c030d7a5bd01d1203d2e98f528543fd2bf886ccaa1ada5e215a730a36b3f4abfc4e252c89eb01d9512f94916dae8a76bf16e4da28986ffe159090fe5267ee3394300b7ccf4dfad389a26321b3a3423e4594a82ccfbad16d6561ecb8772b0cb040280ff999a29e3d9d4fd"); + TestBIP324PacketVector( + 448, + "a6ec25127ca1aa4cf16b20084ba1e6516baae4d32422288e9b36d8bddd2de35a", + "ffffffffffffffffffffffffffffffffffffffffffffffffffffffff053d7ecca53e33e185a8b9be4e7699a97c6ff4c795522e5918ab7cd6b6884f67e683f3dc", + "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffa7730be30000000000000000000000000000000000000000000000000000000000000000", + true, + "00cf68f8f7ac49ffaa02c4864fdf6dfe7bbf2c740b88d98c50ebafe32c92f3427f57601ffcb21a3435979287db8fee6c302926741f9d5e464c647eeb9b7acaeda46e00abd7506fc9a719847e9a7328215801e96198dac141a15c7c2f68e0690dd1176292a0dded04d1f548aad88f1aebdc0a8f87da4bb22df32dd7c160c225b843e83f6525d6d484f502f16d923124fc538794e21da2eb689d18d87406ecced5b9f92137239ed1d37bcfa7836641a83cf5e0a1cf63f51b06f158e499a459ede41c", + 1, + "", + false, + "fead69be77825a23daec377c362aa560", + "511d4980526c5e64aa7187462faeafdd", + "acb8f084ea763ddd1b92ac4ed23bf44de20b84ab677d4e4e6666a6090d40353d", + "", + "77b4656934a82de1a593d8481f020194ddafd8cac441f9d72aeb8721e6a14f49698ca6d9b2b6d59d07a01aa552fd4d5b68d0d1617574c77dea10bfadbaa31b83885b7ceac2fd45e3e4a331c51a74e7b1698d81b64c87c73c5b9258b4d83297f9debc2e9aa07f8572ff434dc792b83ecf07b3197de8dc9cf7be56acb59c66cff5"); + TestBIP324PacketVector( + 673, + "0af952659ed76f80f585966b95ab6e6fd68654672827878684c8b547b1b94f5a", + "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffc81017fd92fd31637c26c906b42092e11cc0d3afae8d9019d2578af22735ce7bc469c72d", + "9652d78baefc028cd37a6a92625b8b8f85fde1e4c944ad3f20e198bef8c02f19fffffffffffffffffffffffffffffffffffffffffffffffffffffffff2e91870", + false, + "5c6272ee55da855bbbf7b1246d9885aa7aa601a715ab86fa46c50da533badf82b97597c968293ae04e", + 97561, + "", + false, + "5e2375ac629b8df1e4ff3617c6255a70", + "70bcbffcb62e4d29d2605d30bceef137", + "7332e92a3f9d2792c4d444fac5ed888c39a073043a65eefb626318fd649328f8", + "", + "657a4a19711ce593c3844cb391b224f60124aba7e04266233bc50cafb971e26c7716b76e98376448f7d214dd11e629ef9a974d60e3770a695810a61c4ba66d78b936ee7892b98f0b48ddae9fcd8b599dca1c9b43e9b95e0226cf8d4459b8a7c2c4e6db80f1d58c7b20dd7208fa5c1057fb78734223ee801dbd851db601fee61e"); + TestBIP324PacketVector( + 1024, + "f90e080c64b05824c5a24b2501d5aeaf08af3872ee860aa80bdcd430f7b63494", + "ffffffffffffffffffffffffffffffffffffffffffffffffffffffff115173765dc202cf029ad3f15479735d57697af12b0131dd21430d5772e4ef11474d58b9", + "12a50f3fafea7c1eeada4cf8d33777704b77361453afc83bda91eef349ae044d20126c6200547ea5a6911776c05dee2a7f1a9ba7dfbabbbd273c3ef29ef46e46", + true, + "5f67d15d22ca9b2804eeab0a66f7f8e3a10fa5de5809a046084348cbc5304e843ef96f59a59c7d7fdfe5946489f3ea297d941bac326225df316a25fc90f0e65b0d31a9c497e960fdbf8c482516bc8a9c1c77b7f6d0e1143810c737f76f9224e6f2c9af5186b4f7259c7e8d165b6e4fe3d38a60bdbdd4d06ecdcaaf62086070dbb68686b802d53dfd7db14b18743832605f5461ad81e2af4b7e8ff0eff0867a25b93cec7becf15c43131895fed09a83bf1ee4a87d44dd0f02a837bf5a1232e201cb882734eb9643dc2dc4d4e8b5690840766212c7ac8f38ad8a9ec47c7a9b3e022ae3eb6a32522128b518bd0d0085dd81c5", + 69615, + "", + true, + "b709dea25e0be287c50e3603482c2e98", + "1f677e9d7392ebe3633fd82c9efb0f16", + "889f339285564fd868401fac8380bb9887925122ec8f31c8ae51ce067def103b", + "", + "7c4b9e1e6c1ce69da7b01513cdc4588fd93b04dafefaf87f31561763d906c672bac3dfceb751ebd126728ac017d4d580e931b8e5c7d5dfe0123be4dc9b2d2238b655c8a7fadaf8082c31e310909b5b731efc12f0a56e849eae6bfeedcc86dd27ef9b91d159256aa8e8d2b71a311f73350863d70f18d0d7302cf551e4303c7733"); +} + +BOOST_AUTO_TEST_SUITE_END() diff --git a/src/test/fuzz/bip324.cpp b/src/test/fuzz/bip324.cpp new file mode 100644 index 00000000000..359de6c66a3 --- /dev/null +++ b/src/test/fuzz/bip324.cpp @@ -0,0 +1,137 @@ +// Copyright (c) 2023 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +namespace { + +void Initialize() +{ + ECC_Start(); + SelectParams(ChainType::MAIN); +} + +} // namespace + +FUZZ_TARGET(bip324_cipher_roundtrip, .init=Initialize) +{ + // Test that BIP324Cipher's encryption and decryption agree. + + // Load keys from fuzzer. + FuzzedDataProvider provider(buffer.data(), buffer.size()); + // Initiator key + auto init_key_data = provider.ConsumeBytes(32); + init_key_data.resize(32); + CKey init_key; + init_key.Set(init_key_data.begin(), init_key_data.end(), true); + if (!init_key.IsValid()) return; + // Initiator entropy + auto init_ent = provider.ConsumeBytes(32); + init_ent.resize(32); + // Responder key + auto resp_key_data = provider.ConsumeBytes(32); + resp_key_data.resize(32); + CKey resp_key; + resp_key.Set(resp_key_data.begin(), resp_key_data.end(), true); + if (!resp_key.IsValid()) return; + // Responder entropy + auto resp_ent = provider.ConsumeBytes(32); + resp_ent.resize(32); + + // Initialize ciphers by exchanging public keys. + BIP324Cipher initiator(init_key, init_ent); + assert(!initiator); + BIP324Cipher responder(resp_key, resp_ent); + assert(!responder); + initiator.Initialize(responder.GetOurPubKey(), true); + assert(initiator); + responder.Initialize(initiator.GetOurPubKey(), false); + assert(responder); + + // Initialize RNG deterministically, to generate contents and AAD. We assume that there are no + // (potentially buggy) edge cases triggered by specific values of contents/AAD, so we can avoid + // reading the actual data for those from the fuzzer input (which would need large amounts of + // data). + XoRoShiRo128PlusPlus rng(provider.ConsumeIntegral()); + + // Compare session IDs and garbage terminators. + assert(initiator.GetSessionID() == responder.GetSessionID()); + assert(initiator.GetSendGarbageTerminator() == responder.GetReceiveGarbageTerminator()); + assert(initiator.GetReceiveGarbageTerminator() == responder.GetSendGarbageTerminator()); + + LIMITED_WHILE(provider.remaining_bytes(), 1000) { + // Mode: + // - Bit 0: whether the ignore bit is set in message + // - Bit 1: whether the responder (0) or initiator (1) sends + // - Bit 2: whether this ciphertext will be corrupted (making it the last sent one) + // - Bit 3-4: controls the maximum aad length (max 511 bytes) + // - Bit 5-7: controls the maximum content length (max 16383 bytes, for performance reasons) + unsigned mode = provider.ConsumeIntegral(); + bool ignore = mode & 1; + bool from_init = mode & 2; + bool damage = mode & 4; + unsigned aad_length_bits = 3 * ((mode >> 3) & 3); + unsigned aad_length = provider.ConsumeIntegralInRange(0, (1 << aad_length_bits) - 1); + unsigned length_bits = 2 * ((mode >> 5) & 7); + unsigned length = provider.ConsumeIntegralInRange(0, (1 << length_bits) - 1); + // Generate aad and content. + std::vector aad(aad_length); + for (auto& val : aad) val = std::byte{(uint8_t)rng()}; + std::vector contents(length); + for (auto& val : contents) val = std::byte{(uint8_t)rng()}; + + // Pick sides. + auto& sender{from_init ? initiator : responder}; + auto& receiver{from_init ? responder : initiator}; + + // Encrypt + std::vector ciphertext(length + initiator.EXPANSION); + sender.Encrypt(contents, aad, ignore, ciphertext); + + // Optionally damage 1 bit in either the ciphertext (corresponding to a change in transit) + // or the aad (to make sure that decryption will fail if the AAD mismatches). + if (damage) { + unsigned damage_bit = provider.ConsumeIntegralInRange(0, + (ciphertext.size() + aad.size()) * 8U - 1U); + unsigned damage_pos = damage_bit >> 3; + std::byte damage_val{(uint8_t)(1U << (damage_bit & 3))}; + if (damage_pos >= ciphertext.size()) { + aad[damage_pos - ciphertext.size()] ^= damage_val; + } else { + ciphertext[damage_pos] ^= damage_val; + } + } + + // Decrypt length + uint32_t dec_length = receiver.DecryptLength(Span{ciphertext}.first(initiator.LENGTH_LEN)); + if (!damage) { + assert(dec_length == length); + } else { + // For performance reasons, don't try to decode if length got increased too much. + if (dec_length > 16384 + length) break; + // Otherwise, just append zeros if dec_length > length. + ciphertext.resize(dec_length + initiator.EXPANSION); + } + + // Decrypt + std::vector decrypt(dec_length); + bool dec_ignore{false}; + bool ok = receiver.Decrypt(Span{ciphertext}.subspan(initiator.LENGTH_LEN), aad, dec_ignore, decrypt); + // Decryption *must* fail if the packet was damaged, and succeed if it wasn't. + assert(!ok == damage); + if (!ok) break; + assert(ignore == dec_ignore); + assert(decrypt == contents); + } +}