ASN1.toObject

[microshine]

Propose to add new functionality.
Add feature allows to convert ASN structure in Javascript object using given schema.

Extension = {
    type: "SEQUENCE",
    value: {
        typeId: {type: "OBJECT ITDENTIFIER"},
        value: {type: "ANY"}
    }
}

var asn = ANS1.decode(data);
var o = asn.toObject(Extension);

// structure of 'o'
{
    typeId: "1.2.3.4.5.6",
    value: [18, 3, 1, 1, 0]
}

[lapo-luchini]

Sorry, I don't understand what is happening there… what are type and typeId and value used for exactly? How is the parameter formatted?

[microshine]

ASN1 structure
SEQUENCE (2 elem)
OBJECT IDENTIFIER 2.5.29.37
 
OCTET STRING (1 elem)
SEQUENCE (2 elem)
OBJECT IDENTIFIER 1.3.6.1.5.5.7.3.2
 
OBJECT IDENTIFIER 1.3.6.1.5.5.7.3.4
This is data of X509 Extension (RFC 5280)

Extension ::= SEQUENCE {
extnID OBJECT IDENTIFIER,
critical BOOLEAN DEFAULT FALSE,
extnValue OCTET STRING
-- contains the DER encoding of an ASN.1 value
-- corresponding to the extension type identified
-- by extnID
}
JavaScript schema

schemas.Extension = {
    type: "SEQUENCE",    // ASN1 type of element
    value: {                           // ASN1 element value or structure
        extnID: {
            type: "OBJECT IDENTIFIER" // it's not got a prop value because it's a simple ASN1 type
        },
        critical:{
             type: "BOOLEAN",
             default: false,
             optional: true // because critical has  'default '
        },
        extnValue: {
            type: "OCTET STRING"
        }
    }
}

JavaScrip code

asn.toObject(schemas.Extension)

return value of function is

{
    extnID: "2.5.29.37",
    crytical: false,
    extnValue: Uint8Array[...]
}

Среда, 22 апреля 2015, 7:06 -07:00 от Lapo Luchini [email protected]:

Sorry, I don't understand what is happening there… what are type and typeId and value used for exactly? How is the parameter formatted?
—
Reply to this email directly or view it on GitHub .

[email protected]

[lapo-luchini]

Ah ok, you mean parsing an ASN.1 format definition file and decoding using named structures instead of anonymous ASN.1 structures?
That's not so fast to do and isn't a feature I need, so I don't think I will implement that anytime soon.
But as you say it can be done as a post-processing on the current output from ASN1.decode(array), so if anyone feels like implementing it, I would certainly consider pull requests.

[microshine]

I wrote simple ASN1Schema JavaScript code. It has got only one method 'get'. I sent source code of my library to your email. Can you examinate it and tell me ypur oppinin. If you'd like it I can help you to write ASN1.toObject method.

Среда, 22 апреля 2015, 8:12 -07:00 от Lapo Luchini [email protected]:

Ah ok, you mean parsing an ASN.1 format definition file and decoding using named structures instead of anonymous ASN.1 structures?
That's not so fast to do and isn't a feature I need, so I don't think I will implement that anytime soon.
But as you say it can be done as a post-processing on the current output from ASN1.decode(array), so if anyone feels like implementing it, I would certainly consider pull requests.
—
Reply to this email directly or view it on GitHub .
[email protected]

[lapo-luchini]

@microshine I'm so sorry! This was good stuff, but at the time I was too stressed to think about it and then I totally forgot about this issue. :(

I started coding this feature myself a few days ago, using a different approach (parsing BNF definitions directly out of RFC sources).

I'll work on integrating that with the parser next.