Hi Thanks for the reply.
I will try to implement a ASN1 module for the data. I am new to openssl and tried to get some sample code but couldn't find any. Can you please point me to few sample examples of the implementation (may be one simple and one complex one)? Thanks once again. -Venkat -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Dr. Stephen Henson Sent: Thursday, December 01, 2005 10:27 PM To: openssl-users@openssl.org Subject: Re: ASN1 parsing On Thu, Dec 01, 2005, Venkata Sairam wrote: > Hi > > I am trying to parse a ASN format that has the following structure. > ASNSEQUENCE[C] = 3 elements > INTEGER = 0 > SEQUENCE[C] = 2 elements > OBJECT ID = SHA > NULL = null > SEQUENCE[C] = 1 elements > SEQUENCE[C] = 2 elements > INTEGER = 1 > OCTET STRING = 20 bytes: 98:F7:6A:06:E1... > > My input is der encoding of this structure. > > I am not sure how to correctly read all the elements inside a SEQUENCE. In > particular, I want to read the digest and the digest algorithm. > I tried using the method ASN1_seq_unpack_ASN1_TYPE. Can anyone provide > sample codes or provide an explanation on how to parse? > The easiest thing to do is to write an ASN1 module for the data. There are examples of varying complexity all over OpenSSL. Do a grep for ASN1_SEQUENCE in the source. Some of that structure looks like it uses some standard structures. For example the second SEQUENCE looks like a DigestAlgorithmIdentifier which is the type X509_ALGOR in OpenSSL. Steve. -- Dr Stephen N. Henson. Email, S/MIME and PGP keys: see homepage OpenSSL project core developer and freelance consultant. Funding needed! Details on homepage. Homepage: http://www.drh-consultancy.demon.co.uk ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager [EMAIL PROTECTED] ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager [EMAIL PROTECTED]
