Thanks Dominik for the tip. Actually, I have been poring over the OpenSSL code, though we're using the 0.9.8 branch, hoping to find a built-in primitive SEQUENCE to use but to no avail. As you say, there are templates for primitives and I looked at how the PKCS7 was composed from those primitives but there are so many levels of indirection that it's time consuming to follow. I guess using C to implement features that object oriented languages such as C++ expose declaratively makes things more complex. I'll keep looking...
-CLee On Thu, Sep 22, 2011 at 2:41 AM, Dominik Oepen < oe...@informatik.hu-berlin.de> wrote: > Am 21.09.2011 23:27, schrieb Chang Lee: > > Does anyone know of a way to take an ASN1_OCTET_STRING that contains a > > DER encoded Sequence and extract the contents of the Sequence as an > > ASN1_STRING. Essentially, I want to construct an ASN1 object of the > > Sequence. I guess I could manually parse the Sequence (and deal with > > the different types of length encoding) but I figure there must be an > > easier way. > > You can use the macros in asn1t.h for parsing DER encoded data. Have a > look at the comment starting at line 132 (I'm using OpenSSL 1.0.0e) of > this header file. It explains how to declare an ASN1 SEQUENCE. You can > find plenty of examples using these macros within the OpenSSL source > (for example crypto/pkcs7/p7_asn1.c). > > However, I'm not exactly sure whether or not the ASN1 subsystem is meant > to be used outside of OpenSSL. I couldn't find a lot of documentation > about it and learned how to use it by reading the source. Maybe one of > the OpenSSL developers could comment on this. > > Best regards, > Dominik > ______________________________________________________________________ > OpenSSL Project http://www.openssl.org > User Support Mailing List openssl-users@openssl.org > Automated List Manager majord...@openssl.org >
