[openssl-users] Leading Zeros in ASN1_INTEGER?

Matthias Ballreich matthias.ballreich at outlook.de
Sat Jan 28 15:01:24 UTC 2017

Hi there,

is it normal that OpenSSL removes the leading Zeros in an ASN1_INTEGER?
I tried to read the Certificate Serial and the Certificate Serial in the AuthorityKeyID-Extension with C++, which works very well, but i noticed that OpenSSL removes the leading Zeros on it.
The real ASN1-Value is: 00BEED73EE for example, but i got only BEED73EE.
If i view the Certificate inside Microsoft Cert Tool (Certmgr.exe) the leading Zeros are listed there. Same on Firefox, if i Import and view the Certificate there.
So is this the correct way of handling inside OpenSSL or is it a bug or?

Is there a way to prevent that?

I’m using  OpenSSL 1.0.2j.

Hope someone could explain it a little bit.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mta.openssl.org/pipermail/openssl-users/attachments/20170128/855c12dd/attachment.html>

More information about the openssl-users mailing list