Forge Errors with reading p12 and pfx files

Question

I am having the following errors when trying read/decode p12 and pfx files:

Cannot read PKCS#12 PFX. ASN.1 object is not an PKCS#12 PFX

Too few bytes to read ASN.1 value.

I am trying to read the file in Javascript with the following:

<input id="cert-file" type="file" name="cert" /><output id="p12cert"></output>

Using JQuery, I attach a "on change" event handler, to check the selected file.

$j("#cert-file").change(handleFileSelect);

function handleFileSelect(evt) {
    var files = evt.target.files; // FileList object
    getFile(files[0]);    
}

Then I try to read the file and decode it using forge.

function getFile(p12cert)
{
    var reader = new FileReader();

    var password = 'password';

    reader.onload = (function (theFile) {
        return function(eve) {

            var p12Der = forge.util.decode64(eve.target.result);

            // get p12 as ASN.1 object
            // Not working for one of my p12 files
            var p12Asn1 = forge.asn1.fromDer(p12Der);

            // decrypt p12 using the password 'password'
            // TODO: Not working for some reason for p12 and pfx file
            var p12 = forge.pkcs12.pkcs12FromAsn1(p12Asn1, password);
        };
    })(p12cert);

reader.readAsText(p12cert);

}

I'm not sure if I'm just reading the file in wrong. I was going off of the FileReader examples from here. Am I doing something wrong or could something possibly be wrong with my certs?

dlongley · Accepted Answer · 2014-09-25T21:39:03.103

Update: It looks like the problem is occurring before the data is passed to forge. The data isn't being read in the proper format. You can try one of these options instead:

Option 1:

reader.readAsDataURL(p12cert); // change from readAsText

// in reader.onload, parse out the base64 part:
var p12Der = forge.util.decode64(eve.target.result.split(',')[1]);

Option 2:

reader.readAsBinaryString(p12cert); // change from readAsText

// in reader.onload, skip base64 decoding step entirely since the data is
// already in a binary string that forge can work with -- the downside
// is that this method is deprecated in the FileReader API
var p12Der = eve.target.result;

Option 3:

// instead, use an ArrayBuffer
reader.readAsArrayBuffer(p12cert);

// in reader.onload, convert to base64 and then decode as you were doing before
var b64 = forge.util.binary.base64.encode(new Uint8Array(eve.target.result));

Option 4:

// instead, use an ArrayBuffer
reader.readAsArrayBuffer(p12cert);

// in reader.onload, just do a raw conversion to a binary string and skip
// the base64 decoding (though this may cause a stack overflow
// with the current implementation in forge which is experimental)
var p12Der = forge.util.binary.raw.encode(new Uint8Array(eve.target.result));

Old:

Have you tried loading the PKCS#12 in non-strict mode? This will often resolve this particular error:

var p12Asn1 = forge.asn1.fromDer(p12Der, false);

var p12 = forge.pkcs12.pkcs12FromAsn1(p12Asn1, false, password);

This did resolve the second error! However, I am still getting the first error: Cannot read PKCS#12 PFX. ASN.1 object is not an PKCS#12 PFX. — RavenBellVanessa, Sep 25 '14 at 18:54
The error should have a property ".errors" that may reveal more information if you print it out. You can also do console.log(forge.asn1.prettyPrint(p12Asn1)) to see what's been parsed from the DER data. — dlongley, Sep 25 '14 at 19:13
Thank you!! Very helpful. I wish I could upvote but not at that rep yet. — RavenBellVanessa, Sep 25 '14 at 22:16

score 0 · Answer 2 · answered Oct 31 '17 at 08:20

This will work perfectly

  // get p12 as ASN.1 object
  //here buffer is a result for readFileSync pkcs12 file

  var p12Asn1 = forge.asn1.fromDer(buffer);
  // decrypt p12 using the password 'password'
  var p12 = forge.pkcs12.pkcs12FromAsn1(p12Asn1, password);
  // get bags by type
  var certBags = p12.getBags({bagType: forge.pki.oids.certBag});
  var pkeyBags = p12.getBags({bagType: forge.pki.oids.pkcs8ShroudedKeyBag});
  // fetching certBag
  var certBag = certBags[forge.pki.oids.certBag][0];
  // fetching keyBag
  var keybag = pkeyBags[forge.pki.oids.pkcs8ShroudedKeyBag][0];
  // generate pem from private key
  var privateKeyPem = forge.pki.privateKeyToPem(keybag.key);
  // generate pem from cert
  var certificate = forge.pki.certificateToPem(certBag.cert);

Forge Errors with reading p12 and pfx files

2 Answers2