Add asn.1 definitions

[nicorusti]

Resolves #28

[nicorusti]

I'm not sure about this section

[nicorusti]

I tried to build an ASN.1 module for TRCs based on what is in docs and in the draft already, then use it to verify that the SSFN & SSUN TRCs can somehow be verified. I used code generated by the ASN.1 compiler asn1c. I think what is on docs is outdated and that there are some differences.

This is what I did:

1. Compile the ASN.1 module (note that I also had to feed PKIX1Explicit88 containing ASN.1 modules from RFC 3280

asn1c -pdu=TRCPayload ../PKIX1Explicit88.asn1 ../trc.asn1
make -f Makefile.am.sample

2. In the TRC, find the offset where CMS data is: Look at the output for an OCTET STRING that appears shortly after the pkcs7-data object identifier. It will have an offset number on the far left (for example, 60).

sed 's/BEGIN TRC/BEGIN CMS/g; s/END TRC/END CMS/g' ': sed 's/BEGIN TRC/BEGIN CMS/g; s/END TRC/END CMS/g' ISD76-495dd7abbc765925299032679fc61b79.bundle | openssl asn1parse -inform PEM -strparse 60 -out ssun_trc.der -noout

3. Extract the payload using that offset

sed 's/BEGIN TRC/BEGIN CMS/g; s/END TRC/END CMS/g' SD76-495dd7abbc765925299032679fc61b79.bundle | openssl asn1parse -inform PEM -strparse 60 -out ssun_trc.der -noout

4. Check if the compiled ASN.1 module can verify the TRC content. Here I get stuck, likely because the ASN.1 module does not match the TRC

./progname -d  -iber -otext ../ssun_trc.der
AD: Processing ../ssun_trc.der
AD: Decoding 8192 bytes
AD: decode(0) consumed 65+0b (8192), code 2
AD: Clean up partially decoded structure
AD: ofp 1, no=65, oo=0, dbl=0
../ssun_trc.der: Decode failed past byte 65: Input processing error

Looking at the TRC content, I see a few things that maybe don't match the ASN.1 module (see comments). I got as far as this, I need support from someone more familiar with this.

[nicorusti]

In the version on docs.scion.org, Validity his is defined, while it can perhaps be imported.

[nicorusti]

AS numbers in TRCs seems using a PRINTABLESTRING while the ASN.1 module uses INTEGER (1..281474976710655)