Why doesn't asn1parse parse all DER encoding strings?

Question

I have a file - crl.txt - that contains the following:

MDYwNKAyoDCGLmh0dHA6Ly93d3cyLnB1YmxpYy10cnVzdC5jb20vY3JsL2N0L2N0cm9vdC5jcmw=

It's from one of the extensions in a particular X.509 cert. Why is it that when I run the following command nothing happens?:

openssl asn1parse -inform PEM -in crl.txt -i

Here's the hex encoding of that string:

00000000  30:36:30:34:a0:32:a0:30:86:2e:68:74:74:70:3a:2f  0604.2.0..http:/
00000010  2f:77:77:77:32:2e:70:75:62:6c:69:63:2d:74:72:75  /www2.public-tru
00000020  73:74:2e:63:6f:6d:2f:63:72:6c:2f:63:74:2f:63:74  st.com/crl/ct/ct
00000030  72:6f:6f:74:2e:63:72:6c                          root.crl

The DER decoding (unless I'm mistaken) is as follows:

SEQUENCE {
  SEQUENCE {
    [0] {
      [0] {
        [6] 'http://www2.public-trust.com/crl/ct/ctroot.crl'
        }
      }
    }
  }

It's the id-ce-cRLDistributionPoints extension. The first [0] is for distributionPoint, the second [0] is for fullName and the [6] is for uniformResourceIdentifier (an implicitly encoded IA5String).

Answer 1

With OpenSSL 0.9.8r, I get this:

$ cat crl.txt
MDYwNKAyoDCGLmh0dHA6Ly93d3cyLnB1YmxpYy10cnVzdC5jb20vY3JsL2N0L2N0cm9vdC5jcmw=
$ /usr/bin/openssl asn1parse -inform PEM -in crl.txt -i
    0:d=0  hl=2 l=  54 cons: SEQUENCE          
    2:d=1  hl=2 l=  52 cons:  SEQUENCE          
    4:d=2  hl=2 l=  50 cons:   cont [ 0 ]        
    6:d=3  hl=2 l=  48 cons:    cont [ 0 ]        
    8:d=4  hl=2 l=  46 prim:     cont [ 6 ]

If your OpenSSL does "nothing" then there is something wrong with it or with your computer.

Note that "PEM", stricto sensu, is for Base64 with header and footer: it shall begin with -----BEGIN FOO----- (from some "FOO") and end with -----END FOO-----. OpenSSL is quite urbane to accept processing your headerless Base64 (or maybe it does not, in your case ?).