bulletproofs: reject points not in the main subgroup

3 files changed, 64 insertions, 0 deletions

diff --git a/tests/performance_tests/crypto_ops.h b/tests/performance_tests/crypto_ops.h
index 852a6670d..f52faa708 100644
--- a/tests/performance_tests/crypto_ops.h
+++ b/tests/performance_tests/crypto_ops.h
@@ -51,6 +51,7 @@ enum test_op
   op_addKeys2,
   op_addKeys3,
   op_addKeys3_2,
+  op_isInMainSubgroup,
 };
 
 template<test_op op>
@@ -102,6 +103,7 @@ public:
       case op_addKeys2: rct::addKeys2(key, scalar0, scalar1, point0); break;
       case op_addKeys3: rct::addKeys3(key, scalar0, point0, scalar1, precomp1); break;
       case op_addKeys3_2: rct::addKeys3(key, scalar0, precomp0, scalar1, precomp1); break;
+      case op_isInMainSubgroup: rct::isInMainSubgroup(point0); break;
       default: return false;
     }
     return true;
diff --git a/tests/performance_tests/main.cpp b/tests/performance_tests/main.cpp
index 142e544dd..19c2cb5e5 100644
--- a/tests/performance_tests/main.cpp
+++ b/tests/performance_tests/main.cpp
@@ -237,6 +237,7 @@ int main(int argc, char** argv)
   TEST_PERFORMANCE1(filter, p, test_crypto_ops, op_addKeys2);
   TEST_PERFORMANCE1(filter, p, test_crypto_ops, op_addKeys3);
   TEST_PERFORMANCE1(filter, p, test_crypto_ops, op_addKeys3_2);
+  TEST_PERFORMANCE1(filter, p, test_crypto_ops, op_isInMainSubgroup);
 
   TEST_PERFORMANCE2(filter, p, test_multiexp, multiexp_bos_coster, 2);
   TEST_PERFORMANCE2(filter, p, test_multiexp, multiexp_bos_coster, 4);
diff --git a/tests/unit_tests/bulletproofs.cpp b/tests/unit_tests/bulletproofs.cpp
index f163f7a20..2358aa27a 100644
--- a/tests/unit_tests/bulletproofs.cpp
+++ b/tests/unit_tests/bulletproofs.cpp
@@ -30,6 +30,7 @@
 
 #include "gtest/gtest.h"
 
+#include "string_tools.h"
 #include "ringct/rctOps.h"
 #include "ringct/rctSigs.h"
 #include "ringct/bulletproofs.h"
@@ -193,3 +194,63 @@ TEST(bulletproofs, invalid_gamma_ff)
   rct::Bulletproof proof = bulletproof_PROVE(invalid_amount, gamma);
   ASSERT_FALSE(rct::bulletproof_VERIFY(proof));
 }
+
+static const char * const torsion_elements[] =
+{
+  "c7176a703d4dd84fba3c0b760d10670f2a2053fa2c39ccc64ec7fd7792ac03fa",
+  "0000000000000000000000000000000000000000000000000000000000000000",
+  "26e8958fc2b227b045c3f489f2ef98f0d5dfac05d3c63339b13802886d53fc85",
+  "ecffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff7f",
+  "26e8958fc2b227b045c3f489f2ef98f0d5dfac05d3c63339b13802886d53fc05",
+  "0000000000000000000000000000000000000000000000000000000000000080",
+  "c7176a703d4dd84fba3c0b760d10670f2a2053fa2c39ccc64ec7fd7792ac037a",
+};
+
+TEST(bulletproofs, invalid_torsion)
+{
+  rct::Bulletproof proof = bulletproof_PROVE(7329838943733, rct::skGen());
+  ASSERT_TRUE(rct::bulletproof_VERIFY(proof));
+  for (const auto &xs: torsion_elements)
+  {
+    rct::key x;
+    ASSERT_TRUE(epee::string_tools::hex_to_pod(xs, x));
+    ASSERT_FALSE(rct::isInMainSubgroup(x));
+    for (auto &k: proof.V)
+    {
+      const rct::key org_k = k;
+      rct::addKeys(k, org_k, x);
+      ASSERT_FALSE(rct::bulletproof_VERIFY(proof));
+      k = org_k;
+    }
+    for (auto &k: proof.L)
+    {
+      const rct::key org_k = k;
+      rct::addKeys(k, org_k, x);
+      ASSERT_FALSE(rct::bulletproof_VERIFY(proof));
+      k = org_k;
+    }
+    for (auto &k: proof.R)
+    {
+      const rct::key org_k = k;
+      rct::addKeys(k, org_k, x);
+      ASSERT_FALSE(rct::bulletproof_VERIFY(proof));
+      k = org_k;
+    }
+    const rct::key org_A = proof.A;
+    rct::addKeys(proof.A, org_A, x);
+    ASSERT_FALSE(rct::bulletproof_VERIFY(proof));
+    proof.A = org_A;
+    const rct::key org_S = proof.S;
+    rct::addKeys(proof.S, org_S, x);
+    ASSERT_FALSE(rct::bulletproof_VERIFY(proof));
+    proof.S = org_S;
+    const rct::key org_T1 = proof.T1;
+    rct::addKeys(proof.T1, org_T1, x);
+    ASSERT_FALSE(rct::bulletproof_VERIFY(proof));
+    proof.T1 = org_T1;
+    const rct::key org_T2 = proof.T2;
+    rct::addKeys(proof.T2, org_T2, x);
+    ASSERT_FALSE(rct::bulletproof_VERIFY(proof));
+    proof.T2 = org_T2;
+  }
+}