Exponent 3 damage spreads...

[James A. Donald]

     --
: :	 10.2.3 Data decoding
: : The data D shall be BER-decoded to give an ASN.1
: : value of type DigestInfo, which shall be separated
: : into a message digest MD and a message-digest
: : algorithm identifier. The message-digest algorithm
: : identifier shall determine the "selected"
: : message-digest algorithm for the next step.

Leichter, Jerry wrote:
 > The only reasonable reading of the text quoted above
 > is that the D must consist of, and *only* of, an ASN.1
 > value of the given type.

That is not what it says.

It says "shall be decoded to give", not "shall be
decoded to give and only give"

Further, similar text appears in lots of places where
the correct behavior, to allow for future extension, is
to allow for more stuff.

A major design consideration in ASN.1 was *to* allow for
more stuff, in order that multiple versions of the
specification can peacefully coexist.

Therefore, in the context of ASN.1, the correct
interpretation of the specification is to allow for
arbitrary expansion - which is a bad spec.

     --digsig
          James A. Donald
      6YeGpsZR+nOTh/cGwvITnSR3TdzclVpR0+pr3YYQdkG
      uTSBsEVoGqap3qSR80twUH+gg5Q8MDBgQhB2Wyxw
      4AjRA5gK1azQkXrhC7CakjCPKw7vvSVL7qWID8o/o

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