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, 12 insertions, 2 deletions

diff --git a/src/crypto/crypto.cpp b/src/crypto/crypto.cpp
index 4243c71fd..ad7721cf0 100644
--- a/src/crypto/crypto.cpp
+++ b/src/crypto/crypto.cpp
@@ -116,7 +116,7 @@ namespace crypto {
     do
     {
       generate_random_bytes_thread_safe(32, bytes);
-    } while (!less32(bytes, limit)); // should be good about 15/16 of the time
+    } while (!sc_isnonzero(bytes) && !less32(bytes, limit)); // should be good about 15/16 of the time
     sc_reduce32(bytes);
   }
   /* generate a random 32-byte (256-bit) integer and copy it to res */
@@ -274,11 +274,18 @@ namespace crypto {
 #endif
     buf.h = prefix_hash;
     buf.key = pub;
+  try_again:
     random_scalar(k);
+    if (((const uint32_t*)(&k))[7] == 0) // we don't want tiny numbers here
+      goto try_again;
     ge_scalarmult_base(&tmp3, &k);
     ge_p3_tobytes(&buf.comm, &tmp3);
     hash_to_scalar(&buf, sizeof(s_comm), sig.c);
+    if (!sc_isnonzero((const unsigned char*)sig.c.data))
+      goto try_again;
     sc_mulsub(&sig.r, &sig.c, &unwrap(sec), &k);
+    if (!sc_isnonzero((const unsigned char*)sig.r.data))
+      goto try_again;
   }
 
   bool crypto_ops::check_signature(const hash &prefix_hash, const public_key &pub, const signature &sig) {
@@ -292,11 +299,14 @@ namespace crypto {
     if (ge_frombytes_vartime(&tmp3, &pub) != 0) {
       return false;
     }
-    if (sc_check(&sig.c) != 0 || sc_check(&sig.r) != 0) {
+    if (sc_check(&sig.c) != 0 || sc_check(&sig.r) != 0 || !sc_isnonzero(&sig.c)) {
       return false;
     }
     ge_double_scalarmult_base_vartime(&tmp2, &sig.c, &tmp3, &sig.r);
     ge_tobytes(&buf.comm, &tmp2);
+    static const ec_point infinity = {{ 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}};
+    if (memcmp(&buf.comm, &infinity, 32) == 0)
+      return false;
     hash_to_scalar(&buf, sizeof(s_comm), c);
     sc_sub(&c, &c, &sig.c);
     return sc_isnonzero(&c) == 0;