Merge pull request #4219

9137ad2c blockchain: add a testnet v9 a day after v8 (moneromooo-monero)
ac4f71c2 wallet2: bump testnet rollback to account for coming reorg (moneromooo-monero)
8f418a6d bulletproofs: #include <openssl/bn.h> (moneromooo-monero)
2bf63650 bulletproofs: speed up the latest changes a bit (moneromooo-monero)
044dff5a bulletproofs: scale points by 8 to ensure subgroup validity (moneromooo-monero)
c83012c4 bulletproofs: match aggregated verification to sarang's latest prototype (moneromooo-monero)
ce0c7432 performance_tests: add padded bulletproof construction (moneromooo-monero)
1224e53b core_tests: add a test for 4-aggregated BP verification (moneromooo-monero)
0e6ed559 fuzz_tests: add a bulletproof fuzz test (moneromooo-monero)
463434d1 more comprehensive test for ge_p3 comparison to identity/point at infinity (moneromooo-monero)
d0a0565f unit_tests: add a few more multiexp unit tests (moneromooo-monero)
6526d87f core_tests: add a test for a tx with empty bulletproof (moneromooo-monero)
a129bbd9 multiexp: fix maxscalar off by one (moneromooo-monero)
7ed496cc ringct: error out when hashToPoint* returns the point at infinity (moneromooo-monero)
d1591853 cryptonote_basic: check output type before using it (moneromooo-monero)
61632dc1 ringct: prevent a potential very large allocation (moneromooo-monero)
a4317e61 crypto: some paranoid checks in generate_signature/check_signature (moneromooo-monero)
7434df1c crypto: never return zero in random32_unbiased (moneromooo-monero)
0825e974 multiexp: fix wrong Bos-Coster result for 1 non trivial input (moneromooo-monero)
a1359ad4 Check inputs to addKeys are in range (moneromooo-monero)
fe0fa3b9 bulletproofs: reject x, y, z, or w[i] being zero (moneromooo-monero)
5ffb2ff9 v8: per byte fee, pad bulletproofs, fixed 11 ring size (moneromooo-monero)
869b3bf8 bulletproofs: a few fixes from the Kudelski review (moneromooo-monero)
c4291762 bulletproofs: reject points not in the main subgroup (moneromooo-monero)
15697177 bulletproofs: speed up a few multiplies using existing Hi cache (moneromooo-monero)
0b05a0fa Add Pippenger cache and limit Straus cache size (moneromooo-monero)
51eb3bdc add pippenger unit tests (moneromooo-monero)
b17b8db3 performance_tests: add stats and loop count multiplier options (moneromooo-monero)
7314d919 perf_timer: split timer class into a base one and a logging one (moneromooo-monero)
d126a02b performance_tests: add aggregated bulletproof tx verification (moneromooo-monero)
263431c4 Pippenger multiexp (moneromooo-monero)
1ed0ed4d multiexp: cut down on memory allocations (moneromooo-monero)
1b867e7f precalc the ge_p3 representation of H (moneromooo-monero)
ef56529f performance_tests: document the tested bulletproof layouts (moneromooo-monero)
30111780 unit_tests: a couple more bulletproof unit tests for gamma (moneromooo-monero)
c444b1b2 require canonical multi output bulletproof layout (moneromooo-monero)
7e67c52f Add a define for the max number of bulletproof multi-outputs (moneromooo-monero)
2a8fcb42 Bulletproof aggregated verification and tests (moneromooo-monero)
126196b0 multiexp: some speedups (moneromooo-monero)
71d67bda aligned: aligned memory alloc/realloc/free (moneromooo-monero)
cb9ecab1 performance_tests: add signature generation/verification (moneromooo-monero)
bacf0a1e bulletproofs: add aggregated verification (moneromooo-monero)
e895c3de make straus cached mode thread safe, and add tests for it (moneromooo-monero)
7f48bf05 multiexp: bos coster now works for just one point (moneromooo-monero)
9ce9f8ca bulletproofs: add multi output bulletproofs to rct (moneromooo-monero)
f34e2e20 performance_tests: add tx checking tests with more than 2 outputs (moneromooo-monero)
0793184b performance_tests: add a --verbose flag, and default to terse (moneromooo-monero)
939bc223 add Straus multiexp (moneromooo-monero)
9ff6e6a0 ringct: add bos coster multiexp (moneromooo-monero)
e9164bb3 bulletproofs: misc optimizations (moneromooo-monero)
112f32f0 performance_tests: add crypto ops (moneromooo-monero)
f5d7b993 performance_tests: add bulletproofs (moneromooo-monero)
8f4ce989 performance_tests: add RingCT MLSAG gen/ver tests (moneromooo-monero)
1aa10c43 performance_tests: add (Borromean) range proofs (moneromooo-monero)
aacfd6e3 bulletproofs: multi-output bulletproofs (moneromooo-monero)
cb1cc757 performance_tests: don't override log level to 0 (moneromooo-monero)

1 files changed, 32 insertions, 3 deletions

diff --git a/src/ringct/rctOps.cpp b/src/ringct/rctOps.cpp
index 50693bad7..6c3c4500e 100644
--- a/src/ringct/rctOps.cpp
+++ b/src/ringct/rctOps.cpp
@@ -60,6 +60,17 @@ namespace rct {
 
     //Various key generation functions
 
+    bool toPointCheckOrder(ge_p3 *P, const unsigned char *data)
+    {
+        if (ge_frombytes_vartime(P, data))
+            return false;
+        ge_p2 R;
+        ge_scalarmult(&R, curveOrder().bytes, P);
+        key tmp;
+        ge_tobytes(tmp.bytes, &R);
+        return tmp == identity();
+    }
+
     //generates a random scalar which can be used as a secret key or mask
     void skGen(key &sk) {
         random32_unbiased(sk.bytes);
@@ -193,15 +204,33 @@ namespace rct {
 
     //Computes aH where H= toPoint(cn_fast_hash(G)), G the basepoint
     key scalarmultH(const key & a) {
-        ge_p3 A;
         ge_p2 R;
-        CHECK_AND_ASSERT_THROW_MES_L1(ge_frombytes_vartime(&A, H.bytes) == 0, "ge_frombytes_vartime failed at "+boost::lexical_cast<std::string>(__LINE__));
-        ge_scalarmult(&R, a.bytes, &A);
+        ge_scalarmult(&R, a.bytes, &ge_p3_H);
         key aP;
         ge_tobytes(aP.bytes, &R);
         return aP;
     }
 
+    //Computes 8P
+    key scalarmult8(const key & P) {
+        ge_p3 p3;
+        CHECK_AND_ASSERT_THROW_MES_L1(ge_frombytes_vartime(&p3, P.bytes) == 0, "ge_frombytes_vartime failed at "+boost::lexical_cast<std::string>(__LINE__));
+        ge_p2 p2;
+        ge_p3_to_p2(&p2, &p3);
+        ge_p1p1 p1;
+        ge_mul8(&p1, &p2);
+        ge_p1p1_to_p2(&p2, &p1);
+        rct::key res;
+        ge_tobytes(res.bytes, &p2);
+        return res;
+    }
+
+    //Computes aL where L is the curve order
+    bool isInMainSubgroup(const key & a) {
+        ge_p3 p3;
+        return toPointCheckOrder(&p3, a.bytes);
+    }
+
     //Curve addition / subtractions
 
     //for curve points: AB = A + B