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Add PAK proof validation function

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This commit is contained in:
Gregory Sanders 2019-01-17 14:48:35 -05:00
parent 378e594617
commit 43424cbf71
2 changed files with 98 additions and 9 deletions
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99
src/primitives/pak.cpp
View file

@ -3,18 +3,19 @@
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <primitives/pak.h>
#include <pubkey.h>
namespace {
static secp256k1_context *secp256k1_ctx;
static secp256k1_context *secp256k1_ctx_pak;
class CSecp256k1Init {
public:
CSecp256k1Init() {
secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY);
secp256k1_ctx_pak = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY);
}
~CSecp256k1Init() {
secp256k1_context_destroy(secp256k1_ctx);
secp256k1_context_destroy(secp256k1_ctx_pak);
}
};
static CSecp256k1Init instance_of_csecp256k1;
@ -42,10 +43,10 @@ std::vector<CScript> CPAKList::GenerateCoinbasePAKCommitments() const
CScript scriptCommitment(scriptPubKey);
unsigned char pubkey[33];
size_t outputlen = 33;
secp256k1_ec_pubkey_serialize(secp256k1_ctx, pubkey, &outputlen, &m_offline_keys[i], SECP256K1_EC_COMPRESSED);
secp256k1_ec_pubkey_serialize(secp256k1_ctx_pak, pubkey, &outputlen, &m_offline_keys[i], SECP256K1_EC_COMPRESSED);
assert(outputlen == 33);
scriptCommitment << std::vector<unsigned char>(pubkey, pubkey+outputlen);
secp256k1_ec_pubkey_serialize(secp256k1_ctx, pubkey, &outputlen, &m_online_keys[i], SECP256K1_EC_COMPRESSED);
secp256k1_ec_pubkey_serialize(secp256k1_ctx_pak, pubkey, &outputlen, &m_online_keys[i], SECP256K1_EC_COMPRESSED);
assert(outputlen == 33);
scriptCommitment << std::vector<unsigned char>(pubkey, pubkey+outputlen);
commitments.push_back(scriptCommitment);
@ -111,8 +112,8 @@ bool CPAKList::FromBytes(CPAKList &paklist, std::vector<std::vector<unsigned cha
for (unsigned int i = 0; i < offline_keys_bytes.size(); i++) {
secp256k1_pubkey pubkey1;
secp256k1_pubkey pubkey2;
int ret1 = secp256k1_ec_pubkey_parse(secp256k1_ctx, &pubkey1, &offline_keys_bytes[i][0], offline_keys_bytes[i].size());
int ret2 = secp256k1_ec_pubkey_parse(secp256k1_ctx, &pubkey2, &online_keys_bytes[i][0], online_keys_bytes[i].size());
int ret1 = secp256k1_ec_pubkey_parse(secp256k1_ctx_pak, &pubkey1, &offline_keys_bytes[i][0], offline_keys_bytes[i].size());
int ret2 = secp256k1_ec_pubkey_parse(secp256k1_ctx_pak, &pubkey2, &online_keys_bytes[i][0], online_keys_bytes[i].size());
if (ret1 != 1 || ret2 != 1) {
return false;
@ -133,12 +134,92 @@ void CPAKList::ToBytes(std::vector<std::vector<unsigned char> >& offline_keys, s
for (unsigned int i = 0; i < m_offline_keys.size(); i++) {
unsigned char pubkey[33];
size_t outputlen = 33;
secp256k1_ec_pubkey_serialize(secp256k1_ctx, pubkey, &outputlen, &m_offline_keys[i], SECP256K1_EC_COMPRESSED);
secp256k1_ec_pubkey_serialize(secp256k1_ctx_pak, pubkey, &outputlen, &m_offline_keys[i], SECP256K1_EC_COMPRESSED);
offline_keys.push_back(std::vector<unsigned char>(pubkey, pubkey+outputlen));
secp256k1_ec_pubkey_serialize(secp256k1_ctx, pubkey, &outputlen, &m_online_keys[i], SECP256K1_EC_COMPRESSED);
secp256k1_ec_pubkey_serialize(secp256k1_ctx_pak, pubkey, &outputlen, &m_online_keys[i], SECP256K1_EC_COMPRESSED);
online_keys.push_back(std::vector<unsigned char>(pubkey, pubkey+outputlen));
}
is_reject = reject;
}
// Proof follows the OP_RETURN <genesis_block_hash> <destination_scriptpubkey>
// in multiple pushes: <full_pubkey> <proof>
bool ScriptHasValidPAKProof(const CScript& script, const uint256& genesis_hash)
{
assert(script.IsPegoutScript(genesis_hash));
CPAKList paklist;
if (g_paklist_config) {
paklist = *g_paklist_config;
} else {
paklist = g_paklist_blockchain;
}
if (paklist.IsReject() || paklist.IsEmpty()) {
return false;
}
CScript::const_iterator pc = script.begin();
std::vector<unsigned char> data;
opcodetype opcode;
script.GetOp(pc, opcode, data);
script.GetOp(pc, opcode, data);
script.GetOp(pc, opcode, data);
CScript destination(data.begin(), data.end());
// Only accept p2pkh
if (!destination.IsPayToPubkeyHash()) {
return false;
}
// Grab pubkey hash within the extracted sub-script
CScript::const_iterator pc2 = destination.begin();
std::vector<unsigned char> data2;
opcodetype opcode2;
if (!destination.GetOp(pc2, opcode2, data2) || !destination.GetOp(pc2, opcode2, data2) ||!destination.GetOp(pc2, opcode2, data2)) {
return false;
}
// Follow-up with full pubkey
if (!script.GetOp(pc, opcode, data) || opcode != 33 || data.size() != 33) {
return false;
}
CPubKey cpubkey(data.begin(), data.end());
//Ensure the chaindest p2pkh matches the included pubkey
if (cpubkey.GetID() != uint160(data2)) {
return false;
}
// Parse pubkey
secp256k1_pubkey pubkey;
if (secp256k1_ec_pubkey_parse(secp256k1_ctx_pak, &pubkey, &data[0], data.size()) != 1) {
return false;
}
if (!script.GetOp(pc, opcode, data) || opcode > OP_PUSHDATA4 || data.size() == 0) {
return false;
}
// Parse whitelist proof
secp256k1_whitelist_signature sig;
if (secp256k1_whitelist_signature_parse(secp256k1_ctx_pak, &sig, &data[0], data.size()) != 1)
return false;
if (secp256k1_whitelist_signature_n_keys(&sig) != paklist.size()) {
return false;
}
if (secp256k1_whitelist_verify(secp256k1_ctx_pak, &sig, &paklist.OnlineKeys()[0], &paklist.OfflineKeys()[0], paklist.size(), &pubkey) != 1) {
return false;
}
//No more pushes allowed
if (script.GetOp(pc, opcode, data)) {
return false;
}
return true;
}

8
src/primitives/pak.h
View file

@ -67,4 +67,12 @@ public:
void ToBytes(std::vector<std::vector<unsigned char> >& offline_keys, std::vector<std::vector<unsigned char> >& online_keys, bool &is_reject) const;
};
/**
** Returns true if the script includes valid pegout proof
** given the PAK list loaded. Two pushes after regular pegout script:
** <full_pubkey> <proof>
**/
bool ScriptHasValidPAKProof(const CScript& script, const uint256& genesis_hash);
#endif // BITCOIN_PRIMITIVES_PAK_H