[TUHS] A fuzzy awk.

[Ralph Corderoy]

Hi,

Doug wrote:
> I commend attention to the LangSec movement, which advocates for
> rigorously enforced separation between legal and illegal inputs.

    https://langsec.org

   ‘The Language-theoretic approach (LangSec) regards the Internet
    insecurity epidemic as a consequence of ‘ad hoc’ programming of
    input handling at all layers of network stacks, and in other kinds
    of software stacks.  LangSec posits that the only path to
    trustworthy software that takes untrusted inputs is treating all
    valid or expected inputs as a formal language, and the respective
    input-handling routines as a ‘recognizer’ for that language.
    The recognition must be feasible, and the recognizer must match the
    language in required computation power.

   ‘When input handling is done in ad hoc way, the ‘de facto’
    recognizer, i.e. the input recognition and validation code ends up
    scattered throughout the program, does not match the programmers'
    assumptions about safety and validity of data, and thus provides
    ample opportunities for exploitation.  Moreover, for complex input
    languages the problem of full recognition of valid or expected
    inputs may be *undecidable*, in which case no amount of
    input-checking code or testing will suffice to secure the program.
    Many popular protocols and formats fell into this trap, the
    empirical fact with which security practitioners are all too
    familiar.

   ‘LangSec helps draw the boundary between protocols and API designs
    that can and cannot be secured and implemented securely, and charts
    a way to building truly trustworthy protocols and systems.  A longer
    summary of LangSec in this USENIX Security BoF hand-out, and in the
    talks, articles, and papers below.’

That does look interesting; I'd not heard of it.

-- 
Cheers, Ralph.