Import private key from .p12 file to sign an XML file with XAdES using xadesjs

Question

Hello everyone I'm using xadesjs specifically the XAdES-BES Signature,I've been following the steps of the documentation.

var xadesjs = require("xadesjs");
var { Crypto } = require("@peculiar/webcrypto");

xadesjs.Application.setEngine("NodeJS", new Crypto());

// Generate RSA key pair
var privateKey, publicKey;
xadesjs.Application.crypto.subtle.generateKey(
    {
        name: "RSASSA-PKCS1-v1_5",
        modulusLength: 1024, //can be 1024, 2048, or 4096,
        publicExponent: new Uint8Array([1, 0, 1]),
        hash: { name: "SHA-1" }, //can be "SHA-1", "SHA-256", "SHA-384", or "SHA-512"
    },
    false, //whether the key is extractable (i.e. can be used in exportKey)
    ["sign", "verify"] //can be any combination of "sign" and "verify"
)
    .then(function (keyPair) {
        // Push ganerated keys to global variable
        privateKey = keyPair.privateKey;
        publicKey = keyPair.publicKey;

        // Call sign function
        var xmlString = '<player bats="left" id="10012" throws="right">\n\t<!-- Here\'s a comment -->\n\t<name>Alfonso Soriano</name>\n\t<position>2B</position>\n\t<team>New York Yankees</team>\n</player>';
        return SignXml(xmlString, keyPair, { name: "RSASSA-PKCS1-v1_5", hash: { name: "SHA-1" } });
    })
    .then(function (signedDocument) {
        console.log("Signed document:\n\n", signedDocument);
    })
    .catch(function (e) {
        console.error(e);
    });


function SignXml(xmlString, keys, algorithm) {
    return Promise.resolve()
        .then(() => {
            var xmlDoc = xadesjs.Parse(xmlString);
            var signedXml = new xadesjs.SignedXml();

            return signedXml.Sign(               // Signing document
                algorithm,                              // algorithm
                keys.privateKey,                        // key
                xmlDoc,                                 // document
                {                                       // options
                    keyValue: keys.publicKey,
                    references: [
                        { hash: "SHA-256", transforms: ["enveloped"] }
                    ],
                    productionPlace: {
                        country: "Country",
                        state: "State",
                        city: "City",
                        code: "Code",
                    },
                    signingCertificate: "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"
                })
            })
            .then(signature => signature.toString());
}

In this example they show you how to sign an XML file with XAdESBES, but in the example they generate the private key and the public key. I want to import my own private key from a .p12 file and sign the XML file

I've implemented the following code based on the examples of the documentation of the repository and have the following error:

My implementation to read my private key from the .p12 file and try to sign the xml file

const fs = require("fs");
var { Crypto } = require("@peculiar/webcrypto");
const xadesjs = require("xadesjs");
const { XMLSerializer } = require("xmldom");

const crypto = new Crypto();
xadesjs.Application.setEngine("NodeJS", new Crypto());

// Hash and algorith from the example
const hash = "SHA-1";
const alg = {
  name: "RSASSA-PKCS1-v1_5",
  hash,
};

function preparePem(pem) {
  return (
    pem
      // remove BEGIN/END
      .replace(/-----(BEGIN|END)[\w\d\s]+-----/g, "")
      // remove \r, \n
      .replace(/[\r\n]/g, "")
  );
}

function pem2der(pem) {
  pem = preparePem(pem);
  // convert base64 to ArrayBuffer
  return new Uint8Array(Buffer.from(pem, "base64")).buffer;
}

// Set the path of the  .p12 file
const path = require("path");
const p12Path = path.resolve(__dirname, "cert.p12");

//Read key
const keyPem = fs.readFileSync(p12Path, { encoding: "utf-8" });
const keyDer = pem2der(keyPem);

//Retrieve the key to sign the document
const key = xadesjs.Application.crypto.subtle.importKey(
  "pkcs8",
  keyDer,
  alg,
  false,
  ["sign"]
);

The Error:

            throw new Error(asn1Parsed.result.error);
                  ^

Error: End of input reached before message was fully decoded (inconsistent offset and length values)
    at Function.parse (/home/baeto/Documents/xades/node_modules/@peculiar/asn1-schema/build/cjs/parser.js:14:19)
    at Function.importKey (/home/baeto/Documents/xades/node_modules/@peculiar/webcrypto/build/webcrypto.js:863:54)
    at RsaSsaProvider.onImportKey (/home/baeto/Documents/xades/node_modules/@peculiar/webcrypto/build/webcrypto.js:1036:37)
    at RsaSsaProvider.importKey (/home/baeto/Documents/xades/node_modules/webcrypto-core/build/webcrypto-core.js:234:33)
    at SubtleCrypto.importKey (/home/baeto/Documents/xades/node_modules/webcrypto-core/build/webcrypto-core.js:1475:29)
    at Object.<anonymous> (/home/baeto/Documents/xades/index.js:42:47)
    at Module._compile (node:internal/modules/cjs/loader:1105:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1159:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)