Click here to Skip to main content
13,348,874 members (77,967 online)
Click here to Skip to main content
Add your own
alternative version


97 bookmarked
Posted 2 Sep 2003

ASN.1 Editor

, 30 Jun 2008
Rate this:
Please Sign up or sign in to vote.
An editor to view, analyse and modify ASN.1 DER encoded data
ASN.1 Editor Main Screen


Abstract Syntax Notation One (ASN.1) Distinguished Encoding Rule (DER) encoded data is widely used in digital security protocols (i.e. X509 digital certificate). The encoded data is not readable by regular text editors. The Asn1Processor Library is designed to parse and modify ASN.1 DER encoded data. The ASN.1 Editor is a sample project that uses the Asn1Processor library to view and to edit DER encoded data. The Asn1Processor Library source code and reference documentation (Asn1EditorLib.chm) are also included in the downloadable source code zip file.

The ASN.1 Editor doesn't do any schema checking. The user needs to make sure the edited data conforms to certain constrains (i.e. OCSP request or Key Info structure).

Main Features

1. Dump Text Format Data

You can view the selected node branch text dump by right-clicking the designated node and selecting "View Node Text". View Node Text

2. Atomically Parse “Encapsulates” Data

OCTET and BITSTRING may encapsulate ASN.1 DER encoded data, for example:

Encapsulate Parse Sample

The ASN.1 Editor can automatically parse the data structure.

3. Hex Data Viewer

Click "View->Hex Viewer" and you can view the binary data structure.

Hex Viewer

4. Extensible OID Table

OID.txt file is installed in the same directory as Asn1Editor.EXE.

Here are the sample records:

0.9.2342.19200300.100.1.25, domainComponent, Signet pilot, Signet intraNet, Signet personal, Signet securityPolicy

The OID and the description are comma separated. It can be extended in order to add in additional OIDs.

5. Change Node Content

Double click the selected node and you can see the "Node Content Editor".

Node Content Editor

6. Save Selected Node Data into Another File

You can save the designated node data into a file by right-clicking the node and selecting "Save selected node as...".

7. Copy Selected Node Data into Clipboard

Right-click the node and select "Copy".

8. Paste Node Data from Clipboard

Right-click the insertion point node and select "Paste as last child node", "Paste before current node", or "Paste after current node" to perform the insert operation.

9. Binary/Hex/Base64 Data Converter

Convert the data format between Hex, Base64, and PEM using the "Data Converter".

Data Converter


  • 3rd September, 2003: Initial post
  • 29th June, 2008: Updated source code and installer
    The changes are mainly for bug fixing, Visual Studio 2005, and Vista support.


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


About the Author

Liping Dai
Software Developer (Senior)
United States United States
Liping Dai has worked in IT industry more than 17 years. He moved to Canada in 1996. After worked in Toronto for 4 years, he relocated to Silicon Valley. He has strong passion in the area of Multi-core/Multi thread programming, Parallel Computing, Image Reorganization, Secure Communication, and Mobile Device development.

You may also be interested in...

Comments and Discussions

GeneralRe: INTEGER value 0 encoding error Pin
Liping Dai25-Apr-05 21:44
memberLiping Dai25-Apr-05 21:44 
QuestionIs this project still moving? Pin
Tony Morris3-Apr-05 15:10
memberTony Morris3-Apr-05 15:10 
AnswerRe: Is this project still moving? Pin
Liping Dai3-Apr-05 17:43
memberLiping Dai3-Apr-05 17:43 
GeneralRe: Is this project still moving? Pin
[Tony Morris]3-Apr-05 19:41
suss[Tony Morris]3-Apr-05 19:41 
GeneralRe: Is this project still moving? Pin
Liping Dai3-Apr-05 20:21
memberLiping Dai3-Apr-05 20:21 
GeneralRe: Is this project still moving? Pin
Tony Morris4-Apr-05 19:09
memberTony Morris4-Apr-05 19:09 
GeneralRe: Is this project still moving? Pin
Liping Dai4-Apr-05 21:10
memberLiping Dai4-Apr-05 21:10 
GeneralOID Encoding Error Pin
jfrazier00426-Mar-05 10:08
memberjfrazier00426-Mar-05 10:08 
I think you may have an error in how you encode OIDs. Try encoding the OID The problem is the last number of course. I get 0xe1 0xfa 0x19 but your encoding routine returns 0x80 0xe1 0xfa 0x19. Encoding with another tool agrees with my result, but that's not definitive. Why the extra 0x80? Am I missing an encoding rule here?
GeneralRe: OID Encoding Error Pin
Liping Dai27-Mar-05 13:46
memberLiping Dai27-Mar-05 13:46 
General.ber and . der Pin
BigAzam23-Feb-05 16:02
memberBigAzam23-Feb-05 16:02 
GeneralRe: .ber and . der Pin
Anonymous23-Feb-05 20:15
sussAnonymous23-Feb-05 20:15 
GeneralRe: .ber and . der Pin
BigAzam7-Apr-05 7:20
memberBigAzam7-Apr-05 7:20 
QuestionHow to detect if the node has one or multiple tags? Pin
greatx16-Feb-05 17:17
sussgreatx16-Feb-05 17:17 
AnswerRe: How to detect if the node has one or multiple tags? Pin
Liping Dai16-Feb-05 20:28
memberLiping Dai16-Feb-05 20:28 
GeneralOpening X509 signed files. Pin
sillypuppy23-Jan-05 23:41
membersillypuppy23-Jan-05 23:41 
GeneralRe: Opening X509 signed files. Pin
Liping Dai24-Jan-05 20:10
memberLiping Dai24-Jan-05 20:10 
GeneralRe: Opening X509 signed files. Pin
sillypuppy25-Jan-05 0:48
membersillypuppy25-Jan-05 0:48 
GeneralFantastic tool. Pin
sillypuppy22-Jan-05 6:48
membersillypuppy22-Jan-05 6:48 
GeneralRe: Fantastic tool. Pin
Liping Dai22-Jan-05 8:15
memberLiping Dai22-Jan-05 8:15 
GeneralRe: Fantastic tool. Pin
sillypuppy23-Jan-05 2:33
membersillypuppy23-Jan-05 2:33 
GeneralRe: Fantastic tool. Pin
Liping Dai23-Jan-05 9:15
memberLiping Dai23-Jan-05 9:15 
GeneralRe: Fantastic tool. Pin
sillypuppy23-Jan-05 23:16
membersillypuppy23-Jan-05 23:16 
GeneralGreat Stuff and Thanks for your generousness Pin
yianfang24-May-04 9:55
memberyianfang24-May-04 9:55 
GeneralRe: Great Stuff and Thanks for your generousness Pin
Liping Dai27-May-04 23:16
memberLiping Dai27-May-04 23:16 
GeneralI got it Pin
CS_Sniper28-Dec-03 19:48
memberCS_Sniper28-Dec-03 19:48 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

Permalink | Advertise | Privacy | Terms of Use | Mobile
Web02 | 2.8.180111.1 | Last Updated 30 Jun 2008
Article Copyright 2003 by Liping Dai
Everything else Copyright © CodeProject, 1999-2018
Layout: fixed | fluid