GlcoinCore/elements
1
0
Fork 0
mirror of https://github.com/ElementsProject/elements.git synced 2026-08-16 13:01:19 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

BlindOutputs: Move sum checker to end and always check

Browse source
This commit is contained in:
instagibbs 2016-11-03 14:43:12 -04:00 • committed by Gregory Sanders
parent 7501e0a1a0
commit 27bc93d754
1 changed files with 9 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

21
src/blind.cpp
View file

@ -96,24 +96,13 @@ bool BlindOutputs(const std::vector<uint256 >& input_blinding_factors, std::vect
}
}
static const unsigned char diff_zero[32] = {0};
if (nToBlind == 0) {
unsigned char diff[32];
// If there is no place to put a blinding factor anymore, the existing input blinding factors must equal the outputs
bool ret = secp256k1_pedersen_blind_sum(secp256k1_blind_context, diff, &blindptrs[0], nBlindsOut + nBlindsIn, nBlindsIn);
assert(ret);
if (memcmp(diff_zero, diff, 32)) {
return false;
}
}
//Running total of newly blinded outputs
static const unsigned char diff_zero[32] = {0};
int nBlinded = 0;
unsigned char blind[tx.vout.size()][32];
for (size_t nOut = 0; nOut < tx.vout.size(); nOut++) {
if (tx.vout[nOut].nValue.IsAmount() && output_pubkeys[nOut].IsValid()) {
assert(output_pubkeys[nOut].IsValid());
if (nBlinded + 1 == nToBlind) {
// Last to-be-blinded value: compute from all other blinding factors.
assert(secp256k1_pedersen_blind_sum(secp256k1_blind_context, &blind[nBlinded][0], &blindptrs[0], nBlindsOut + nBlindsIn, nBlindsIn));
@ -157,5 +146,13 @@ bool BlindOutputs(const std::vector<uint256 >& input_blinding_factors, std::vect
}
}
// Check resulting blinding, normal operation should pass
unsigned char diff[32];
bool ret = secp256k1_pedersen_blind_sum(secp256k1_blind_context, diff, &blindptrs[0], nBlindsOut + nBlindsIn, nBlindsIn);
assert(ret);
if (memcmp(diff_zero, diff, 32)) {
return false;
}
return true;
}