[RPC] Add utility getsignaturehash #11653

NicolasDorier · 2017-11-10T10:01:06Z

Add an utility to get the signature hash in a generic way.
signrawtransaction can't create a signature for an arbitrary scriptCode, as it is using ProduceSignature internally. This make it impossible to create complex scripts without a library.

laanwj · 2017-11-10T10:03:03Z

src/rpc/misc.cpp

+    if (!request.params[5].isNull()) {
+        RPCTypeCheckArgument(request.params[5], UniValue::VSTR);
+        static std::map<std::string, int> mapSigHashValues = {
+            { std::string("ALL"), int(SIGHASH_ALL) },


This table is duplicated with signrawtransaction, which makes it harder to change later. Please factor it out.

NicolasDorier · 2017-11-10T10:14:36Z

Just refactored.

maflcko · 2017-11-10T15:48:13Z

test/functional/getsignaturehash.py

+        self.setup_clean_chain = True
+
+    def run_test(self):
+        assert_equal("64e049981a10cf597406a175d7443c8499d308168915377637e3f706ce186137", self.nodes[0].getsignaturehash( 


No trailing white space, please.

promag

Some comments.

Missing tests for all sighashtype values and missing test for sigversion = WITNESS_V0?

promag · 2017-11-10T16:26:34Z

src/rpc/server.cpp

@@ -131,6 +131,25 @@ uint256 ParseHashV(const UniValue& v, std::string strName)
    result.SetHex(strHex);
    return result;
 }
+
+int ParseSigHash(std::string strHashType)


const std::string& hash_type

promag · 2017-11-10T16:27:23Z

src/rpc/server.cpp

+        { std::string("SINGLE|ANYONECANPAY"), int(SIGHASH_SINGLE | SIGHASH_ANYONECANPAY) },
+    };
+    if (mapSigHashValues.count(strHashType))
+        nHashType = mapSigHashValues[strHashType];


Avoid 2nd lookup by using map::find.

promag · 2017-11-10T16:28:18Z

src/rpc/server.cpp

+    if (mapSigHashValues.count(strHashType))
+        nHashType = mapSigHashValues[strHashType];
+    else
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid sighash param");


For getsignaturehash the parameter name is sighashtype.

promag · 2017-11-10T16:30:40Z

test/functional/getsignaturehash.py

+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import *
+
+


Nit, remove 2nd empty line.

promag · 2017-11-10T16:31:53Z

test/functional/getsignaturehash.py

+        # optional
+        assert_equal("64e049981a10cf597406a175d7443c8499d308168915377637e3f706ce186137", self.nodes[0].getsignaturehash( 
+            # tx
+            "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",


Declare tx only once, and at the same time these 2 asserts will be more readable.

promag · 2017-11-10T16:32:07Z

test/functional/getsignaturehash.py

+            0
+        ))
+
+


Remove 2nd empty line.

promag · 2017-11-10T16:35:26Z

src/rpc/server.cpp

+int ParseSigHash(std::string strHashType)
+{
+    int nHashType = 0;
+    static std::map<std::string, int> mapSigHashValues = {


Should ANYONECANPAY|SINGLE be possible?

Currently it's not.

promag · 2017-11-10T16:36:31Z

src/rpc/misc.cpp

+        UniValue::VSTR, // amount
+        UniValue::VSTR, // sigVersion
+        UniValue::VNUM // inputIndex
+    },


Wrong indentation?

promag · 2017-11-10T16:38:44Z

src/rpc/misc.cpp

+        false);
+
+    CMutableTransaction mtx;
+    if (!DecodeHexTx(mtx, request.params[0].get_str(), true))


Nit, there are a couple of {} missing, as per developer notes.

promag · 2017-11-10T16:41:32Z

src/rpc/misc.cpp

+            "\nCreate the hash to sign for the given input\n"
+
+            "\nArguments:\n"
+            "1. \"tx\"     (string, required) The transaction hex string\n"


Please align the descriptions.

luke-jr · 2017-11-10T16:43:12Z

src/rpc/misc.cpp

+    std::vector<unsigned char> scriptCodeData(ParseHexV(request.params[1], "scriptCode"));
+    CScript scriptCode(scriptCodeData.begin(), scriptCodeData.end());
+
+    auto amount = AmountFromValue(request.params[2].get_str());


New RPCs should use satoshis, especially for low-level stuff.

luke-jr · 2017-11-10T16:43:57Z

src/rpc/misc.cpp

+
+            "\nArguments:\n"
+            "1. \"tx\"     (string, required) The transaction hex string\n"
+            "2. \"scriptcode\"     (string, required) The scriptCode to sign\n"


This doesn't explain what it is.

the scriptCode is difficult to explain, it depends on OP_CODESEPARATOR and whether you are using Segwit/P2SH/Segwit-P2SH/Normal script. It will never fit in one line.

luke-jr · 2017-11-10T16:47:03Z

(Light concept NACK because utilities should be in libraries, not RPC.)

promag · 2017-11-10T21:20:13Z

@luke-jr I understand that but there is no harm in having these utilities:

they don't block, just spend a thread handling the request;
make the source stronger by using core code and having test coverage;
always updated response, libraries can have bugs or be outdated.

That said, most *rawtransactions are also utilities, and they are supported.

NicolasDorier · 2017-11-11T01:43:45Z

@luke-jr When you start doing services which span multiple blockchain (cross chain swap), then library can't possibly know how to sign each and every of them. While if each expose getsignaturehash it becomes possible. I bumped into the need of that as I was trying to do a cross chain swap between bitcoin and elements.

sipa · 2017-11-11T01:45:54Z

@NicolasDorier I don't see how that is related. You need some code specific for each chain anyway, no?

NicolasDorier · 2017-11-11T01:48:09Z

@sipa, not really. By using using decoderawtransaction, decodescript, createrawtransaction and all of those utilities, I can create transaction on two chains even if their binary representation of a transaction is completely different.
Basically, this is one of the piece missing to have a generic code for all crypto forked from Bitcoin, which does not rely on a library knowing the details.

sipa · 2017-11-11T02:00:22Z

@NicolasDorier I don't understand, you can't just paste signature hashes into any other RPC, so it can't be a 'missing piece'. You still need to know what the chain's signatures look like (ECDSA, sighash flags, scripting system, ...) to use that information for anything. I expect that if not already, between any two interesting chains those things will differ significantly.

A more useful thing would be an RPC which you give an unsigned transaction, a key and/or an output being spent, possibly a scriptCode, and a sighash flag, and it gives you a piece of scriptSig/witness containing a valid signature for it. You'd still be responsible for combining it with other script elements. Even that isn't a missing piece IMHO, but it wouldn't need intricate knowledge of the digital signature system in your application.

NicolasDorier · 2017-11-11T02:09:31Z

@sipa there is indeed the creation of script that the library need. But the scripts are most likely similar accross all chains.
Good point for the ECDSA. I thought they were not different, but they are: Bitcoin Cash is using another sighash. I agree, having a RPC method gettransactionsignature where you pass the private key be more generic. Will work on another PR for this as well.

NicolasDorier · 2017-11-11T03:14:50Z

I addressed the nits, I keep this open while working on an alternative gettransactionsignature which accept a private key as well and returns the signature.

Github-Pull: bitcoin#11653 Rebased-From: 0a688c4

NicolasDorier · 2017-11-12T05:10:03Z

Alternative signinput: #11666

NicolasDorier · 2018-03-06T17:04:38Z

supersede by #11666

fanquake added the RPC/REST/ZMQ label Nov 10, 2017

laanwj reviewed Nov 10, 2017

View reviewed changes

NicolasDorier force-pushed the getsignaturehash branch from 8875b95 to 3f98c3c Compare November 10, 2017 10:13

maflcko reviewed Nov 10, 2017

View reviewed changes

promag reviewed Nov 10, 2017

View reviewed changes

luke-jr reviewed Nov 10, 2017

View reviewed changes

NicolasDorier force-pushed the getsignaturehash branch from 3f98c3c to b899e24 Compare November 11, 2017 02:19

[RPC] Add utility getsignaturehash

0a688c4

NicolasDorier force-pushed the getsignaturehash branch from b899e24 to 0a688c4 Compare November 11, 2017 03:14

luke-jr pushed a commit to bitcoinknots/bitcoin that referenced this pull request Nov 11, 2017

[RPC] Add utility getsignaturehash

4ac2c48

Github-Pull: bitcoin#11653 Rebased-From: 0a688c4

NicolasDorier mentioned this pull request Nov 12, 2017

[RPC] Add utility signinput #11666

Closed

ajtowns mentioned this pull request Dec 10, 2017

Add Travis check for unused Python imports #11835

Merged

NicolasDorier closed this Mar 6, 2018

bitcoin locked as resolved and limited conversation to collaborators Sep 8, 2021

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

[RPC] Add utility getsignaturehash #11653

[RPC] Add utility getsignaturehash #11653

NicolasDorier commented Nov 10, 2017 •

edited

laanwj Nov 10, 2017

NicolasDorier commented Nov 10, 2017

maflcko Nov 10, 2017

promag left a comment

promag Nov 10, 2017

promag Nov 10, 2017

promag Nov 10, 2017

promag Nov 10, 2017

promag Nov 10, 2017

promag Nov 10, 2017

promag Nov 10, 2017

NicolasDorier Nov 11, 2017

promag Nov 11, 2017

promag Nov 10, 2017

promag Nov 10, 2017

promag Nov 10, 2017

luke-jr Nov 10, 2017

luke-jr Nov 10, 2017

NicolasDorier Nov 11, 2017 •

edited

luke-jr commented Nov 10, 2017

promag commented Nov 10, 2017

NicolasDorier commented Nov 11, 2017 •

edited

sipa commented Nov 11, 2017

NicolasDorier commented Nov 11, 2017 •

edited

sipa commented Nov 11, 2017 •

edited

NicolasDorier commented Nov 11, 2017 •

edited

NicolasDorier commented Nov 11, 2017

NicolasDorier commented Nov 12, 2017 •

edited

NicolasDorier commented Mar 6, 2018

		from test_framework.test_framework import BitcoinTestFramework
		from test_framework.util import *

[RPC] Add utility getsignaturehash #11653

[RPC] Add utility getsignaturehash #11653

Conversation

NicolasDorier commented Nov 10, 2017 • edited

Choose a reason for hiding this comment

NicolasDorier commented Nov 10, 2017

Choose a reason for hiding this comment

promag left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

NicolasDorier Nov 11, 2017 • edited

Choose a reason for hiding this comment

luke-jr commented Nov 10, 2017

promag commented Nov 10, 2017

NicolasDorier commented Nov 11, 2017 • edited

sipa commented Nov 11, 2017

NicolasDorier commented Nov 11, 2017 • edited

sipa commented Nov 11, 2017 • edited

NicolasDorier commented Nov 11, 2017 • edited

NicolasDorier commented Nov 11, 2017

NicolasDorier commented Nov 12, 2017 • edited

NicolasDorier commented Mar 6, 2018

NicolasDorier commented Nov 10, 2017 •

edited

NicolasDorier Nov 11, 2017 •

edited

NicolasDorier commented Nov 11, 2017 •

edited

NicolasDorier commented Nov 11, 2017 •

edited

sipa commented Nov 11, 2017 •

edited

NicolasDorier commented Nov 11, 2017 •

edited

NicolasDorier commented Nov 12, 2017 •

edited