parsing DER format data using SecAsn1Decode

Hi,

I'm working on the output of method `distinguishedNames` that available under challenge.protectionSpace when my application receieve callback from the server (didReceieveChallenge) of type NSURLAuthenticationMethodClientCertificate. In this case the server ask for certificate from the client that was signed by issuer from the issuersList provided by the server.

The method challenge.protectionSpace.distinguishedNames returns as a DER encoded data, and I wish to decode it and get the issuer distiguished name.

Since openssl is no longer native mac code, i turned to SecAsn1Decode and realized that it also expect to have a template of the DER format (SecAsn1Template).. so I pretty much need to have the formatted layout before I want to decode an instance formatted in this way.

Conceptually, I'm not sure I understand why this template is really needed, because the DER format explain the format by itself.

I've tested my assumption by copying the output of distinguishedNames and using asn.1 online converter to human readble text, and it revealed the format by itself.

here's the input :

30 81 8E 31 0B 30 09 06 03 55 04 06 13 02 49 49

31 0F 30 0D 06 03 55 04 08 0C 06 62 62 62 62 62

6C 31 0C 30 0A 06 03 55 04 07 0C 03 54 4C 56 31

0B 30 09 06 03 55 04 0A 0C 02 54 53 31 1E 30 1C

06 03 55 04 0B 0C 15 43 41 5F 63 65 72 74 69 66

69 63 61 74 65 5F 73 65 72 76 65 72 31 1B 30 19

06 03 55 04 03 0C 12 62 62 62 62 62 73 5F 4D 61

63 42 6F 6F 6B 5F 50 72 6F 31 16 30 14 06 09 2A

86 48 86 F7 0D 01 09 01 16 07 7A 40 7A 2E 63 6F

6D

and the output :

SEQUENCE (7 elem)