rn-x509-decoder

Parsing X509 DER from base64 string

Install

yarn add rn-x509-decoder 

Usage

The X.509 DER encoding is based on TLV(type-length-value) type. X509DERSpec class extends TLV interface and TLV has 4 properties. buffer, identifier, contentLength, content TLV.buffer is whole content of the code. It is a UInt8Array type. Others are results of parsing. TLV.content may be a string or a boolean or a list of other TLV. If identifier.pc is Constructed then it's content will be a list of TLVs. TLV content can be represented different way by id.tag type.

TAG type

X509Paser represent the content of almost tag as just the buffer. OID, OCTET_STRING, BIT_STRING, BMP_STRING etc ...

name	tag encoding	represent
EOC	0
BOOLEAN	1	boolean
INTEGER	2
BIT_STRING	3
OCTET_STRING	4
NULL	5
OID	6
Object_Descriptor	7
EXTERNAL	8
REAL	9
ENUMERATED	10
EMBEDDED_PDV	11
UTF8String	12	string
RELATIVE_OID	13
TIME	14
Reserved	15
SEQUENCE	16	TVL
SET	17	TVL
NumericString	18
PrintableString	19	string
T61String	20
VideotexSt	21
IA5String	22	string
UTCTime	23	string
GeneralizedTime	24
GraphicString	25
VisibleString	26
GeneralString	27
UniversalString	28
CHARACTER_STRING	29
BMPString	30
DATE	31
TIME_OF_DAY	32
DATE_TIME	33
DURATION	34
OID_IRI	35
RELATIVE_OID_IRI	36

Import

Get X509DERSpec object

import X509DERSpec from 'rn-x509der-parser';
 
... 
 
const pubKeyStirng: string = getBase64String();
const der = new X509DERSpec(pubKeyString);
console.log(der.toString());

RESULT

Certificate:
 Version: 
   INTEGER: : 02
 Serial Number: 26 EB 43 6E
 Signature: 
   OID: : 2A 86 48 86 F7 0D 01 01 0B
   NULL: : 
 Issuer: 
   SET: : 
    SEQUENCE: : 
     OID: : 55 04 06
     PrintableString: : kr
   SET: : 
    SEQUENCE: : 
     OID: : 55 04 0A
     UTF8String: : yessign
   SET: : 
    SEQUENCE: : 
     OID: : 55 04 0B
     UTF8String: : AccreditedCA
   SET: : 
    SEQUENCE: : 
     OID: : 55 04 03
     UTF8String: : yessignCA Class 2
 Validity: 
   UTCTime: : 200129150000Z
   UTCTime: : 210130145959Z
 Subject: 
   SET: : 
    SEQUENCE: : 
     OID: : 55 04 06
     PrintableString: : kr
   SET: : 
    SEQUENCE: : 
     OID: : 55 04 0A
     UTF8String: : yessign
   SET: : 
    SEQUENCE: : 
     OID: : 55 04 0B
     UTF8String: : personal4IB
   SET: : 
    SEQUENCE: : 
     OID: : 55 04 0B
     UTF8String: : WOORI
   SET: : 
    SEQUENCE: : 
     OID: : 55 04 03
     UTF8String: : ...
 Subject Public Key Info: 
   SEQUENCE: : 
    OID: : 2A 86 48 86 F7 0D 01 01 01
    NULL: : 
   BIT_STRING: : ...
 Issuer Unique Identifier: 
   SEQUENCE: : 
    SEQUENCE: : 
     OID: : 55 1D 23
     OCTET_STRING: : ...
    SEQUENCE: : 
     OID: : 55 1D 0E
     OCTET_STRING: : ...
    SEQUENCE: : 
     OID: : 55 1D 0F
     BOOLEAN: : true
     OCTET_STRING: : 
      BIT_STRING: : 06 C0
    SEQUENCE: : 
     OID: : 55 1D 20
     BOOLEAN: : true
     OCTET_STRING: : 
      SEQUENCE: : 
       SEQUENCE: : 
        OID: : 2A 83 1A 8C 9A 45 01 01 04
        SEQUENCE: : 
         SEQUENCE: : 
          OID: : 2B 06 01 05 05 07 02 02
          SEQUENCE: : 
           BMPString: : ...
         SEQUENCE: : 
          OID: : 2B 06 01 05 05 07 02 01
          IA5String: : ...
    SEQUENCE: : 
     OID: : 55 1D 11
     OCTET_STRING: : ...
    SEQUENCE: : 
     OID: : ...
     OCTET_STRING: : ...
    SEQUENCE: : 
     OID: : ...
     OCTET_STRING: : ...
 Subject Unique Identifierundefined
 Extensionsundefined

Certificate Signature Algorithm:: 
  OID: : ...
  NULL: : 
Certificate Signature:: ...

Get Certificate

const pubKeyStirng: string = getBase64String();
const der = new X509DERSpec(pubKeyString);
console.log(der.certificate.toString());

RESULT

This result is included the result of above.

Version: 
  INTEGER: : 02
Serial Number: 26 EB 43 6E
Signature: 
  OID: : 2A 86 48 86 F7 0D 01 01 0B
  NULL: : 
Issuer: 

...

Decode TLV

You can also directly decode the TLV from buffer

import {decodeTLV} from 'rn-x509der-parser';
import {Buffer} from 'buffer';
 
...
 
const buffer: Buffer = new Buffer(pubKeyString);
const tLVArray: TLV[] = decodeTLV(buffer);

To do next

• represent the content of other tags ...

Reference

https://en.wikipedia.org/wiki/X.509

https://en.wikipedia.org/wiki/X.690