From d0794efb1e0442fda01ea24c411ccc18335e0be2 Mon Sep 17 00:00:00 2001 From: Gulliver Date: Thu, 20 Apr 2023 22:52:56 +0200 Subject: [PATCH] added test_crypto.cpp with first code for rsa blinding --- CMakeLists.txt | 7 +- test/test_crypto.cpp | 163 +++++++++++++++++++++++++++ test/{test.cpp => test_json_s8n.cpp} | 2 +- 3 files changed, 170 insertions(+), 2 deletions(-) create mode 100644 test/test_crypto.cpp rename test/{test.cpp => test_json_s8n.cpp} (99%) diff --git a/CMakeLists.txt b/CMakeLists.txt index 55994e3..c283ef5 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -16,6 +16,8 @@ endif() project(oc-issuer VERSION 0.0.2 LANGUAGES CXX) +set(CMAKE_EXPORT_COMPILE_COMMANDS ON) + include(FetchContent) # @@ -96,7 +98,10 @@ add_executable(${PROJECT_NAME} src/main.cpp) target_link_libraries(${PROJECT_NAME} PRIVATE oc-mint-lib INTERFACE tl::expected::expected) ## these are unittests that can be run on any platform -add_executable(tests test/test_big_int.cpp test/test.cpp) +add_executable(tests test/test_big_int.cpp + test/test_json_s8n.cpp + test/test_crypto.cpp) + target_link_libraries(tests oc-mint-lib Catch2::Catch2WithMain) diff --git a/test/test_crypto.cpp b/test/test_crypto.cpp new file mode 100644 index 0000000..6789ea6 --- /dev/null +++ b/test/test_crypto.cpp @@ -0,0 +1,163 @@ + +#include + +#include "cryptlib.h" +#include "integer.h" +#include "nbtheory.h" +#include "osrng.h" +#include "rsa.h" +#include "sha.h" + +#include +#include + + +CryptoPP::Integer blind_signature(unsigned char *msg, + size_t msg_len, + + const CryptoPP::RSA::PublicKey& pub_key, + const CryptoPP::RSA::PrivateKey& priv_key) { + using namespace CryptoPP; + using std::cout; + using std::endl; + AutoSeededRandomPool prng; + + // Convenience + const Integer &n = pub_key.GetModulus(); + const Integer &e = pub_key.GetPublicExponent(); + const Integer &d = priv_key.GetPrivateExponent(); + +// For sizing the hashed message buffer. This should be SHA256 size. + const size_t sig_size = UnsignedMin(SHA256::BLOCKSIZE, n.ByteCount()); +// Scratch + SecByteBlock buff_1, buff_2, buff_3; + + SecByteBlock orig(msg, msg_len); + Integer m(orig.data(), orig.size()); + cout << "Message: " << std::hex << m << endl; + + // Hash message per Rabin (1979) + buff_1.resize(sig_size); + SHA256 hash_1; + hash_1.CalculateTruncatedDigest(buff_1, buff_1.size(), orig, orig.size()); + + // H(m) as Integer + Integer hm(buff_1.data(), buff_1.size()); + cout << "H(m): " << std::hex << hm << endl; + + // Alice blinding + Integer r; + do { + r.Randomize(prng, Integer::One(), n - Integer::One()); + } while (!RelativelyPrime(r, n)); + + // Blinding factor + Integer b = a_exp_b_mod_c(r, e, n); + cout << "Random: " << std::hex << b << endl; + + // Alice blinded message + Integer mm = a_times_b_mod_c(hm, b, n); + cout << "Blind msg: " << std::hex << mm << endl; + + // Bob sign + Integer ss = priv_key.CalculateInverse(prng, mm); + cout << "Blind sign: " << ss << endl; + + return ss; +} + +TEST_CASE("cryptopp", "[crypto]") { + using namespace CryptoPP; + using std::cout; + using std::endl; + using std::runtime_error; + + // Bob artificially small key pair + AutoSeededRandomPool prng; + RSA::PrivateKey priv_key; + + priv_key.GenerateRandomWithKeySize(prng, 64U); + RSA::PublicKey pub_key(priv_key); + + // Convenience + const Integer &n = pub_key.GetModulus(); + const Integer &e = pub_key.GetPublicExponent(); + const Integer &d = priv_key.GetPrivateExponent(); + + // Print params + cout << "Pub mod: " << std::hex << pub_key.GetModulus() << endl; + cout << "Pub exp: " << std::hex << e << endl; + cout << "Priv mod: " << std::hex << priv_key.GetModulus() << endl; + cout << "Priv exp: " << std::hex << d << endl; + + // For sizing the hashed message buffer. This should be SHA256 size. + const size_t sig_size = UnsignedMin(SHA256::BLOCKSIZE, n.ByteCount()); + + // Scratch + SecByteBlock buff_1, buff_2, buff_3; + + // Alice original message to be signed by Bob + SecByteBlock orig((const byte *)"secret", 6U); + Integer m(orig.data(), orig.size()); + cout << "Message: " << std::hex << m << endl; + + // Hash message per Rabin (1979) + buff_1.resize(sig_size); + SHA256 hash_1; + hash_1.CalculateTruncatedDigest(buff_1, buff_1.size(), orig, orig.size()); + + // H(m) as Integer + Integer hm(buff_1.data(), buff_1.size()); + cout << "H(m): " << std::hex << hm << endl; + + // Alice blinding + Integer r; + do { + r.Randomize(prng, Integer::One(), n - Integer::One()); + } while (!RelativelyPrime(r, n)); + + // Blinding factor + Integer b = a_exp_b_mod_c(r, e, n); + cout << "Random: " << std::hex << b << endl; + + // Alice blinded message + Integer mm = a_times_b_mod_c(hm, b, n); + cout << "Blind msg: " << std::hex << mm << endl; + + // Bob sign + Integer ss = priv_key.CalculateInverse(prng, mm); + cout << "Blind sign: " << ss << endl; + + // Alice checks s(s'(x)) = x. This is from Chaum's paper + Integer c = pub_key.ApplyFunction(ss); + cout << "Check sign: " << c << endl; + if (c != mm) { + throw runtime_error("Alice cross-check failed"); + } + // Alice remove blinding + Integer s = a_times_b_mod_c(ss, r.InverseMod(n), n); + cout << "Unblind sign: " << s << endl; + + // Eve verifies + Integer v = pub_key.ApplyFunction(s); + cout << "Verify: " << std::hex << v << endl; + + // Convert to a string + size_t req = v.MinEncodedSize(); + buff_2.resize(req); + v.Encode(&buff_2[0], buff_2.size()); + + // Hash message per Rabin (1979) + buff_3.resize(sig_size); + SHA256 hash_2; + hash_2.CalculateTruncatedDigest(buff_3, buff_3.size(), orig, orig.size()); + + // Constant time compare + bool equal = buff_2.size() == buff_3.size() && + VerifyBufsEqual(buff_2.data(), buff_3.data(), buff_3.size()); + + if (!equal) { + throw runtime_error("Eve verified failed"); + } + cout << "Verified signature" << endl; +} diff --git a/test/test.cpp b/test/test_json_s8n.cpp similarity index 99% rename from test/test.cpp rename to test/test_json_s8n.cpp index 5045313..a5f46a1 100644 --- a/test/test.cpp +++ b/test/test_json_s8n.cpp @@ -12,7 +12,7 @@ TEST_CASE( "PublicKey::to_json", "[to_json]" ) { REQUIRE( json["modulus"].dump() == "\"" + k.modulus.to_string() + "\"" ); REQUIRE( json["public_exponent"].dump() == "\"" + k.public_exponent.to_string()+"\"" ); REQUIRE( json["type"].dump() == "\"rsa public key\"" ); - REQUIRE( json.keys().size() == 3 ); + REQUIRE( json.keys().size() == 3U ); } TEST_CASE("RequestCDDCSerial::from_string", "[from_string]") {