Merge #17156: psbt: check that various indexes and amounts are within bounds

deaa6dd144f5650b385658a0c4f9a014aff8dde2 psbt: check output index is within bounds before accessing (Andrew Chow)
f1ef7f0aa46338f4cd8de79696027a1bf868f359 Don't calculate tx fees for PSBTs with invalid money values (Andrew Chow)

Pull request description:

  Fixes #17149

  Two classes of issues were found by the psbt fuzzer: values out of range and causing overflows, and prevout indexes being out of range. This PR fixes both.

  When accessing a specific output using the index given in the tx, check that it is actually a possible output before trying to access the output.

  When summing and checking amounts for `decodepsbt` and `analyzepsbt`, make sure that the values are actually valid money values.. Otherwise, stop summing and don't show the fee. For `analyzepsbt`, return that the next role is the Creator since the Creator needs to remake the transaction to be valid.

ACKs for top commit:
  practicalswift:
    ACK deaa6dd144f5650b385658a0c4f9a014aff8dde2 -- only change since last ACK was the addition of tests
  gwillen:
    tested ACK deaa6dd, would also like to see this merged!

Tree-SHA512: 06c36720bbb5a7ab1c29f7d15878bf9f0d3e5760c06bff479d412e1bf07bb3e0e9ab6cca820a4bfedaab71bfd7af813807e87cbcdf0af25cc3f66a53a06dbcfd

1 files changed, 15 insertions, 0 deletions

diff --git a/test/functional/rpc_psbt.py b/test/functional/rpc_psbt.py
index 2cc9650cb2..33af819d34 100755
--- a/test/functional/rpc_psbt.py
+++ b/test/functional/rpc_psbt.py
@@ -422,5 +422,20 @@ class PSBTTest(BitcoinTestFramework):
         assert_equal(analysis['next'], 'creator')
         assert_equal(analysis['error'], 'PSBT is not valid. Input 0 spends unspendable output')
 
+        self.log.info("PSBT with invalid values should have error message and Creator as next")
+        analysis = self.nodes[0].analyzepsbt('cHNidP8BAHECAAAAAfA00BFgAm6tp86RowwH6BMImQNL5zXUcTT97XoLGz0BAAAAAAD/////AgD5ApUAAAAAFgAUKNw0x8HRctAgmvoevm4u1SbN7XL87QKVAAAAABYAFPck4gF7iL4NL4wtfRAKgQbghiTUAAAAAAABAR8AgIFq49AHABYAFJUDtxf2PHo641HEOBOAIvFMNTr2AAAA')
+        assert_equal(analysis['next'], 'creator')
+        assert_equal(analysis['error'], 'PSBT is not valid. Input 0 has invalid value')
+
+        analysis = self.nodes[0].analyzepsbt('cHNidP8BAHECAAAAAfA00BFgAm6tp86RowwH6BMImQNL5zXUcTT97XoLGz0BAAAAAAD/////AgCAgWrj0AcAFgAUKNw0x8HRctAgmvoevm4u1SbN7XL87QKVAAAAABYAFPck4gF7iL4NL4wtfRAKgQbghiTUAAAAAAABAR8A8gUqAQAAABYAFJUDtxf2PHo641HEOBOAIvFMNTr2AAAA')
+        assert_equal(analysis['next'], 'creator')
+        assert_equal(analysis['error'], 'PSBT is not valid. Output amount invalid')
+
+        analysis = self.nodes[0].analyzepsbt('cHNidP8BAJoCAAAAAkvEW8NnDtdNtDpsmze+Ht2LH35IJcKv00jKAlUs21RrAwAAAAD/////S8Rbw2cO1020OmybN74e3Ysffkglwq/TSMoCVSzbVGsBAAAAAP7///8CwLYClQAAAAAWABSNJKzjaUb3uOxixsvh1GGE3fW7zQD5ApUAAAAAFgAUKNw0x8HRctAgmvoevm4u1SbN7XIAAAAAAAEAnQIAAAACczMa321tVHuN4GKWKRncycI22aX3uXgwSFUKM2orjRsBAAAAAP7///9zMxrfbW1Ue43gYpYpGdzJwjbZpfe5eDBIVQozaiuNGwAAAAAA/v///wIA+QKVAAAAABl2qRT9zXUVA8Ls5iVqynLHe5/vSe1XyYisQM0ClQAAAAAWABRmWQUcjSjghQ8/uH4Bn/zkakwLtAAAAAAAAQEfQM0ClQAAAAAWABRmWQUcjSjghQ8/uH4Bn/zkakwLtAAAAA==')
+        assert_equal(analysis['next'], 'creator')
+        assert_equal(analysis['error'], 'PSBT is not valid. Input 0 specifies invalid prevout')
+
+        assert_raises_rpc_error(-25, 'Missing inputs', self.nodes[0].walletprocesspsbt, 'cHNidP8BAJoCAAAAAkvEW8NnDtdNtDpsmze+Ht2LH35IJcKv00jKAlUs21RrAwAAAAD/////S8Rbw2cO1020OmybN74e3Ysffkglwq/TSMoCVSzbVGsBAAAAAP7///8CwLYClQAAAAAWABSNJKzjaUb3uOxixsvh1GGE3fW7zQD5ApUAAAAAFgAUKNw0x8HRctAgmvoevm4u1SbN7XIAAAAAAAEAnQIAAAACczMa321tVHuN4GKWKRncycI22aX3uXgwSFUKM2orjRsBAAAAAP7///9zMxrfbW1Ue43gYpYpGdzJwjbZpfe5eDBIVQozaiuNGwAAAAAA/v///wIA+QKVAAAAABl2qRT9zXUVA8Ls5iVqynLHe5/vSe1XyYisQM0ClQAAAAAWABRmWQUcjSjghQ8/uH4Bn/zkakwLtAAAAAAAAQEfQM0ClQAAAAAWABRmWQUcjSjghQ8/uH4Bn/zkakwLtAAAAA==')
+
 if __name__ == '__main__':
     PSBTTest().main()