Hi I think I didn't make myself clear about my problem in the last message. I have the DER encoded value (byte [] (03:7C:02:01...) of the whole ASN1 Object that corresponds to the SEQUENCE with 3 elements
> 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... This structures corresponds to a version, digest algorithm and message digest. I would like to read each of these values separately. In particular. I want to get the message digest and digest algorithm. Is there any methods in open ssl that I can use to get these values? I tired using ASN1_seq_unpack_ASN1_TYPE and I could see that the structure has 3 elements. But the value (sk_value) for each element doesn't seem to be corresponding to the values of the above sequence. How to do get the values inside the structure? Please help. Thanks Regards, Venkata -----Original Message----- From: Venkata Sairam [mailto:[EMAIL PROTECTED] Sent: Monday, December 05, 2005 10:27 AM To: 'openssl-users@openssl.org' Subject: RE: ASN1 parsing Hi I am still stuck in the implementation of the ASN1 module for the data. I am kinda lost. Can anyone provide some insights about implementing the ASN1 parser for the data below. > 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... Thanks Regards, Venkat -----Original Message----- From: Venkata Sairam [mailto:[EMAIL PROTECTED] Sent: Friday, December 02, 2005 10:57 AM To: 'openssl-users@openssl.org' Subject: RE: ASN1 parsing 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]
