Error: Unexpected data: 0x44

[iamgabrielsoft]

Why getting this error while
`

decodeFirst`

Please somebody respond to this....

[hildjj]

Can you give me more information, please? I think your report got its formatting confused a little.

[iamgabrielsoft]

yeah sure...

I was using the cbor package to decode a message but ran into this error ----> Error: Unexpected data: 0x44

[iamgabrielsoft]

return cbor.decodeFirst(payload)
.then((obj) => {
let type = options.defaultType ? options.defaultType : this.Signtag;
if (obj instanceof Tagged) {
if (obj.tag !== this.Signtag && obj.tag !== this.Sign1Tag) {
throw new Error('Unexpected cbor tag, '' + obj.tag + ''');
}
type = obj.tag;
obj = obj.value;
}

});``

[hildjj]

Your payload includes multiple cbor data items.

const result = await cbor.decodeFirst('014401020304')

where the first byte (01) is a complete CBOR data item, and decodeFirst by default throws an error in that situation. Try this:

const extendedResult = await cbor.decodeFirst('0144', {extendedResults: true})
// { value: 1, bytes: <Buffer 01>, length: 1, unused: <Buffer 44> }
const result = extendedResult.value

Alternately, it is more efficient to treat the decoder as a stream:

const d = new cbor.Decoder()
d.on('data', value => console.log(value))
d.write(payload)

[hildjj]

cbor.Decoder is a class. cbor.decodeFirst is a function, which is also available as cbor.Decoder.decodeFirst.

[iamgabrielsoft]

Error: Unexpected data: 0x44. Sorry but till getting the error

[hildjj]

Can you please post the code that you're currently running?

[iamgabrielsoft]

  return cbor.decodeFirst(payload)
    .then((obj) => {
      let type = options.defaultType ? options.defaultType : this.Signtag;
      if (obj instanceof Tagged) {
        if (obj.tag !== this.Signtag && obj.tag !== this.Sign1Tag) {
          throw new Error('Unexpected cbor tag, \'' + obj.tag + '\'');
        }
        type = obj.tag;
        obj = obj.value;
      }

      if (!Array.isArray(obj)) {
        throw new Error('Expecting Array');
      }

      if (obj.length !== 4) {
        throw new Error('Expecting Array of lenght 4');
      }

      let [p, u, plaintext, signers] = obj;

      if (type === SignTag && !Array.isArray(signers)) {
        throw new Error('Expecting signature Array');
      }

      p = (!p.length) ? this.EMPTY_BUFFER : cbor.decodeFirstSync(p);
      u = (!u.size) ? this.EMPTY_BUFFER : u;

      let signer = (type === SignTag ? this.getSigner(signers, verifier) : signers);

      if (!signer) {
        throw new Error('Failed to find signer with kid' + verifier.key.kid);
      }

      if (type === SignTag) {
        const externalAAD = verifier.externalAAD || this.EMPTY_BUFFER;
        let [signerP, , sig] = signer;
        signerP = (!signerP.length) ? this.EMPTY_BUFFER : signerP;
        p = (!p.size) ? this.EMPTY_BUFFER : cbor.encode(p);
        const signerPMap = cbor.decode(signerP);
        const alg = signerPMap.get(Common.HeaderParameters.alg);
        const SigStructure = [
          'Signature',
          p,
          signerP,
          externalAAD,
          plaintext
        ];
        return this.doVerify(SigStructure, verifier, alg, sig)
          .then(() => {
            return plaintext;
          });
      } else {
        const externalAAD = verifier.externalAAD || this.EMPTY_BUFFER;

        const alg = this.getCommonParameter(p, u, Common.HeaderParameters.alg);
        p = (!p.size) ? this.EMPTY_BUFFER : cbor.encode(p);
        const SigStructure = [
          'Signature1',
          p,
          externalAAD,
          plaintext
        ];


        return this.doVerify(SigStructure, verifier, alg, signer)
          .then(() => {
            return plaintext;
          });
      }
    });

[iamgabrielsoft]

The paramters am passing are in Buffer

[hildjj]

change the first two lines to:

return cbor.decodeFirst(payload, {extendedResults: true})
    .then(({value: obj}) => {

[iamgabrielsoft]

return cbor.decodeFirst(payload, {extendedResults: true})
.then(({value: obj}) => {
console.log("value", obj)
})

Till the same

[hildjj]

what is the output of:

return cbor.decodeFirst(payload, {extendedResults: true})
.catch(e => console.log(payload.toString('hex'))

[iamgabrielsoft]

Error: Unexpected data: 0x44
at Decoder._parse (C:\Users\Softbook\Documents\Main Programs\Open Source\cose-js\node_modules\cbor\lib\decoder.js:357:15)
at _parse.next ()
at Decoder.BinaryParseStream._transform (C:\Users\Softbook\Documents\Main Programs\Open Source\cose-js\node_modules\cbor\vendor\binary-parse-stream\index.js:35:31)
at Decoder.Transform._read (internal/streams/transform.js:205:10)
at Decoder.Transform._write (internal/streams/transform.js:193:12)
at writeOrBuffer (internal/streams/writable.js:358:12)
at Decoder.Writable.write (internal/streams/writable.js:303:10)
at Decoder.Writable.end (internal/streams/writable.js:567:10)
at Object.decodeFirst (C:\Users\Softbook\Documents\Main Programs\Open Source\cose-js\node_modules\cbor\lib\decoder.js:282:7)
at Sign.verify (C:\Users\Softbook\Documents\Main Programs\Open Source\cose-js\lib\sign.js:177:32)``

[hildjj]

Do you have another place where you're calling decodeFirst than the one you changed?

[iamgabrielsoft]

yeah i do but passing a payload parameter