failed to parse Vkeywitness because its structure changed in babbage era

[hoangong]

This happens since version 1.35.4 where the default tx build is babbage-era

This is Vkeywitness from alonzo era:

./cardano-cli text-view decode-cbor --in-file txw.signed

82  # list(2)
   00  # int(0)
   82  # list(2)
      58 20 ad 19 59 d6 0a 5d 83 bf ff 8f d8 5a dc a4
      6a 8e 70 94 cb 57 d9 44 c1 20 4f 56 56 a9 0f 79
      a9 12  # bytes(32)
      58 40 d6 b9 ac 77 24 4c 78 b7 83 ce a7 f5 a6 a3
      2d d3 93 22 52 de e9 86 6a 8f 2f ea 8c 18 bb 0a
      89 09 43 e4 80 0f 57 40 73 a4 ea 80 21 65 47 b0
      53 f4 dd eb 68 6a bd 78 12 3a 6e ee e4 9e 36 55
      70 01  # bytes(64)

and this is from babbage era

./cardano-cli text-view decode-cbor --in-file txw.signed

82  # list(2)
   58 20 c0 c9 2e de cf d4 93 b3 6e 02 53 fe 8a da
   5f 3a 2a 05 67 31 8d 7f 9d c7 9c 40 0f 53 86 6e
   eb 94  # bytes(32)
   58 40 90 f4 b2 38 ff e5 10 19 9e 42 1e af 03 57
   5c a8 2a 03 b5 5f 8b 1f b8 e3 3f 80 b3 70 3e 51
   f3 8c b0 b7 f8 a6 68 d7 9c 32 8a d2 f9 8e 65 60
   0e f6 6b 4b 70 e1 66 40 24 75 07 67 3d 0d 5d 34
   a2 02  # bytes(64)

I could manually add two bytes 8200 prefix to the babbage era version to make it works. Is it something serializer should take into account?

[lisicky]

Hi @hoangong ! Could you provide more information about what you do and what you expect ? I looked at alonzo cddl and babbage cddl and didn't see any difference for vkeywitness

[hoangong]

Hi @lisicky From what I see, cardano-cli 1.35.4 generated tx witness differently (no 8200 prefix).

You can use these command to generate txw.signed file and compare the output.

./cardano-cli transaction build-raw \
--tx-in ... \
--tx-out ....\
--fee 300000 \
--out-file tx.raw \
--certificate-file pool-registration.cert \
--certificate-file stake.cert \
--certificate-file delegation.cert

./cardano-cli transaction witness \
--tx-body-file tx.raw \
--signing-key-file cold.skey \
--testnet-magic 1 \
--out-file txw.signed

The output from 1.35.4 has error when parse Vkeywitness. This is the code:

const txWitness = "825820c0c92edecfd493b36e0253fe8ada5f3a2a0567318d7f9dc79c400f53866eeb94584090f4b238ffe510199e421eaf03575ca82a03b55f8b1fb8e33f80b3703e51f38cb0b7f8a668d79c328ad2f98e65600ef66b4b70e16640247507673d0d5d34a202"; // this is cbor from txw.signed from cli 1.35.4
const witness = cbor.encode(cbor.decodeAllSync(txWitness)[0][1]);
const encodedWitness = ada.Vkeywitness.from_bytes(witness); // this line throw error "Deserialization failed in Vkeywitness because: Invalid cbor: not the right type, expected `Array' byte received `Bytes'."

If I put "8200" prefix to txWitness, it works fine. what I expect is ada.Vkeywitness.from_bytes can read txWitness that is generated from cardano-cli 1.35.4

[lisicky]

@hoangong Could you tell me what you are doing by that line ? Does it work before ?

const witness = cbor.encode(cbor.decodeAllSync(txWitness)[0][1]);

I have checked deserialization with your cbor and it works. You can use from_hex like in an example below.

Vkeywitness::from_hex("825820c0c92edecfd493b36e0253fe8ada5f3a2a0567318d7f9dc79c400f53866eeb94584090f4b238ffe510199e421eaf03575ca82a03b55f8b1fb8e33f80b3703e51f38cb0b7f8a668d79c328ad2f98e65600ef66b4b70e16640247507673d0d5d34a202");

[hoangong]

@lisicky Thank for quick reply. from_hex works with output from cli 1.35.4

Vkeywitness::from_hex("825820c0c92edecfd493b36e0253fe8ada5f3a2a0567318d7f9dc79c400f53866eeb94584090f4b238ffe510199e421eaf03575ca82a03b55f8b1fb8e33f80b3703e51f38cb0b7f8a668d79c328ad2f98e65600ef66b4b70e16640247507673d0d5d34a202");

but not with output from cli 1.35.3

Vkeywitness::from_hex("8200825820c0c92edecfd493b36e0253fe8ada5f3a2a0567318d7f9dc79c400f53866eeb94584090f4b238ffe510199e421eaf03575ca82a03b55f8b1fb8e33f80b3703e51f38cb0b7f8a668d79c328ad2f98e65600ef66b4b70e16640247507673d0d5d34a202"); // Deserialization failed in Vkeywitness.vkey because: Invalid cbor: not the right type, expected `Bytes' byte received `UnsignedInteger'.

[lisicky]

@hoangong Seems cli 1.35.3 gives cbor in not from cddl format. CSL supports cbor in format that is described in the Alonzo and babbage cddl.