Building a DER sequence

[Ken Goldman]

On 6/26/2019 11:34 AM, Salz, Rich via openssl-users wrote:
>      Do I construct a sequence and add items to it - top down?
> 
> No, because then you have to go back and patch the sequence length and perhaps slide everything up or down a copule of bytes.
> 
> I would look at an existing simple sequence and start writing your own based on that; look for ASN1_SEQUENCE macros in crypto/x509/x*.c files.  Another set of macros will declare the i2d/d2i and PEM functions if needed.

I see those macros, but ... is there any documentation?

What partially worked was
	create an X509 item
	use i2d to serialize it
	ASN1_STRING_SET using the DER
	built an ASN1_TYPE from the ASN1_STRING with ASN1_TYPE_set
	sk_ASN1_TYPE_push

and then i2d_ASN1_SEQUENCE_ANY to get the DER result.

The items are _X509_NAME and X509_VAL.  Is there a shorter way?