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Test the exact order of CHECKMULTISIG sig/pubkey evaluation

Possible with STRICTENC
0.10
Peter Todd 10 years ago committed by Pieter Wuille
parent
commit
ca8158719b
  1. 6
      src/script/interpreter.cpp
  2. 19
      src/test/data/script_invalid.json
  3. 25
      src/test/data/script_valid.json

6
src/script/interpreter.cpp

@ -855,6 +855,9 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
valtype& vchSig = stacktop(-isig); valtype& vchSig = stacktop(-isig);
valtype& vchPubKey = stacktop(-ikey); valtype& vchPubKey = stacktop(-ikey);
// Note how this makes the exact order of pubkey/signature evaluation
// distinguishable by CHECKMULTISIG NOT if the STRICTENC flag is set.
// See the script_(in)valid tests for details.
if (!CheckSignatureEncoding(vchSig, flags, serror) || !CheckPubKeyEncoding(vchPubKey, flags, serror)) { if (!CheckSignatureEncoding(vchSig, flags, serror) || !CheckPubKeyEncoding(vchPubKey, flags, serror)) {
// serror is set // serror is set
return false; return false;
@ -871,7 +874,8 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, un
nKeysCount--; nKeysCount--;
// If there are more signatures left than keys left, // If there are more signatures left than keys left,
// then too many signatures have failed // then too many signatures have failed. Exit early,
// without checking any further signatures.
if (nSigsCount > nKeysCount) if (nSigsCount > nKeysCount)
fSuccess = false; fSuccess = false;
} }

19
src/test/data/script_invalid.json

@ -616,6 +616,25 @@ nSequences are max.
"STRICTENC", "STRICTENC",
"P2PK with undefined hashtype" "P2PK with undefined hashtype"
], ],
["
Order of CHECKMULTISIG evaluation tests, inverted by swapping the order of
pubkeys/signatures so they fail due to the STRICTENC rules on validly encoded
signatures and pubkeys.
"],
[
"0 0x47 0x3044022044dc17b0887c161bb67ba9635bf758735bdde503e4b0a0987f587f14a4e1143d022009a215772d49a85dae40d8ca03955af26ad3978a0ff965faa12915e9586249a501 0x47 0x3044022044dc17b0887c161bb67ba9635bf758735bdde503e4b0a0987f587f14a4e1143d022009a215772d49a85dae40d8ca03955af26ad3978a0ff965faa12915e9586249a501",
"2 0x21 0x02865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac0 0 2 CHECKMULTISIG NOT",
"STRICTENC",
"2-of-2 CHECKMULTISIG NOT with the first pubkey invalid, and both signatures validly encoded."
],
[
"0 0x47 0x3044022044dc17b0887c161bb67ba9635bf758735bdde503e4b0a0987f587f14a4e1143d022009a215772d49a85dae40d8ca03955af26ad3978a0ff965faa12915e9586249a501 0",
"2 0x21 0x02865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac0 0x21 0x02865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac0 2 CHECKMULTISIG NOT",
"STRICTENC",
"2-of-2 CHECKMULTISIG NOT with both pubkeys valid, but first signature invalid."
],
[ [
"0x47 0x30440220166848cd5b82a32b5944d90de3c35249354b43773c2ece1844ee8d1103e2f6c602203b6b046da4243c77adef80ada9201b27bbfdf7f9d5428f40434b060432afd62005", "0x47 0x30440220166848cd5b82a32b5944d90de3c35249354b43773c2ece1844ee8d1103e2f6c602203b6b046da4243c77adef80ada9201b27bbfdf7f9d5428f40434b060432afd62005",
"0x41 0x048282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f5150811f8a8098557dfe45e8256e830b60ace62d613ac2f7b17bed31b6eaff6e26caf CHECKSIG NOT", "0x41 0x048282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f5150811f8a8098557dfe45e8256e830b60ace62d613ac2f7b17bed31b6eaff6e26caf CHECKSIG NOT",

25
src/test/data/script_valid.json

@ -761,6 +761,31 @@ nSequences are max.
"STRICTENC", "STRICTENC",
"1-of-2 with the second 1 hybrid pubkey" "1-of-2 with the second 1 hybrid pubkey"
], ],
["
CHECKMULTISIG evaluation order tests. CHECKMULTISIG evaluates signatures and
pubkeys in a specific order, and will exit early if the number of signatures
left to check is greater than the number of keys left. As STRICTENC fails the
script when it reaches an invalidly encoded signature or pubkey, we can use it
to test the exact order in which signatures and pubkeys are evaluated by
distinguishing CHECKMULTISIG returning false on the stack and the script as a
whole failing.
See also the corresponding inverted versions of these tests in script_invalid.json
"],
[
"0 0x47 0x3044022044dc17b0887c161bb67ba9635bf758735bdde503e4b0a0987f587f14a4e1143d022009a215772d49a85dae40d8ca03955af26ad3978a0ff965faa12915e9586249a501 0x47 0x3044022044dc17b0887c161bb67ba9635bf758735bdde503e4b0a0987f587f14a4e1143d022009a215772d49a85dae40d8ca03955af26ad3978a0ff965faa12915e9586249a501",
"2 0 0x21 0x02865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac0 2 CHECKMULTISIG NOT",
"STRICTENC",
"2-of-2 CHECKMULTISIG NOT with the second pubkey invalid, and both signatures validly encoded. Valid pubkey fails, and CHECKMULTISIG exits early, prior to evaluation of second invalid pubkey."
],
[
"0 0 0x47 0x3044022044dc17b0887c161bb67ba9635bf758735bdde503e4b0a0987f587f14a4e1143d022009a215772d49a85dae40d8ca03955af26ad3978a0ff965faa12915e9586249a501",
"2 0x21 0x02865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac0 0x21 0x02865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac0 2 CHECKMULTISIG NOT",
"STRICTENC",
"2-of-2 CHECKMULTISIG NOT with both pubkeys valid, but second signature invalid. Valid pubkey fails, and CHECKMULTISIG exits early, prior to evaluation of second invalid signature."
],
[ [
"0x47 0x304402204649e9517ef0377a8f8270bd423053fd98ddff62d74ea553e9579558abbb75e4022044a2b2344469c12e35ed898987711272b634733dd0f5e051288eceb04bd4669e05", "0x47 0x304402204649e9517ef0377a8f8270bd423053fd98ddff62d74ea553e9579558abbb75e4022044a2b2344469c12e35ed898987711272b634733dd0f5e051288eceb04bd4669e05",
"0x41 0x048282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f5150811f8a8098557dfe45e8256e830b60ace62d613ac2f7b17bed31b6eaff6e26caf CHECKSIG", "0x41 0x048282263212c609d9ea2a6e3e172de238d8c39cabd5ac1ca10646e23fd5f5150811f8a8098557dfe45e8256e830b60ace62d613ac2f7b17bed31b6eaff6e26caf CHECKSIG",

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