4 ms·

I did something similar a while back but using all the invisible characters to encode extra data into telegram messages for metadata storage https://github.com

I did something similar a while back but using all the invisible characters to encode extra data into telegram messages for metadata storage https://github.com/sixhobbits/unisteg https://github.com/sixhobbits/unisteg

franga2000 1y ago
I was very confused why this would be useful for Telegram messages, but the Why? part of the readme makes perfect sense. Great workaround for a stupid limitation!
velcrovan 1y ago
I had fun writing a Racket version: #lang racket/base (require net/base64 threading) (define FIRST-INVISIBLE-CHAR 917760) (define (invis-encode str) (list->string (for/list ([c (in-list (string->list str))] #:do [(define cnum (char->integer c))] #:when (<= cnum 127)) (integer->char (+ cnum FIRST-INVISIBLE-CHAR))))) (define (invis-decode str) (list->string (for/list ([c (in-list (string->list str))] #:do [(define plaintxt-c (- (char->integer c) FIRST-INVISIBLE-CHAR))] #:when (> plaintxt-c 0)) (integer->char plaintxt-c)))) (define (hide secret plain) (~> (string->bytes/utf-8 secret) (base64-encode #"") ; use #"" vs #"\r\n" to prevent line-wrapping (bytes->string/utf-8) (invis-encode) (string-append plain _))) (define (unhide ciphertext) (~> (invis-decode ciphertext) (string->bytes/utf-8) (base64-decode) (bytes->string/utf-8))) (module+ test (require rackunit) (define secret "this is a s3cret message. ssh") (define plaintext "Hey you, nothing to see here.") (define to-share (hide secret plaintext)) (check-equal? (string-length to-share) 69) ; count of bytes (check-equal? (string-grapheme-count to-share) 29) ; 29 actually-visible graphemes (check-equal? secret (unhide to-share)))
- askonomm 1y ago
  Threading is done with the wave character ~ in Racket? I can't decide if I hate it or not (am used to Clojure's ->). I think my pinky finger doesn't like ~.
  - velcrovan 1y ago
    In this case ~> is a macro from a widely used package (https://docs.racket-lang.org/threading/index.html https://docs.racket-lang.org/threading/index.html) so if you defined an alias for it (or forked the package) you could use any valid identifier.
  - soegaard 1y ago
    The identifier `->` is already used for type annotations.

franga2000 1y ago

I was very confused why this would be useful for Telegram messages, but the Why? part of the readme makes perfect sense. Great workaround for a stupid limitation!

velcrovan 1y ago

I had fun writing a Racket version: #lang racket/base (require net/base64 threading) (define FIRST-INVISIBLE-CHAR 917760) (define (invis-encode str) (list->string (for/list ([c (in-list (string->list str))] #:do [(define cnum (char->integer c))] #:when (<= cnum 127)) (integer->char (+ cnum FIRST-INVISIBLE-CHAR))))) (define (invis-decode str) (list->string (for/list ([c (in-list (string->list str))] #:do [(define plaintxt-c (- (char->integer c) FIRST-INVISIBLE-CHAR))] #:when (> plaintxt-c 0)) (integer->char plaintxt-c)))) (define (hide secret plain) (~> (string->bytes/utf-8 secret) (base64-encode #"") ; use #"" vs #"\r\n" to prevent line-wrapping (bytes->string/utf-8) (invis-encode) (string-append plain _))) (define (unhide ciphertext) (~> (invis-decode ciphertext) (string->bytes/utf-8) (base64-decode) (bytes->string/utf-8))) (module+ test (require rackunit) (define secret "this is a s3cret message. ssh") (define plaintext "Hey you, nothing to see here.") (define to-share (hide secret plaintext)) (check-equal? (string-length to-share) 69) ; count of bytes (check-equal? (string-grapheme-count to-share) 29) ; 29 actually-visible graphemes (check-equal? secret (unhide to-share)))

askonomm 1y ago
Threading is done with the wave character ~ in Racket? I can't decide if I hate it or not (am used to Clojure's ->). I think my pinky finger doesn't like ~.
- velcrovan 1y ago
  In this case ~> is a macro from a widely used package (https://docs.racket-lang.org/threading/index.html https://docs.racket-lang.org/threading/index.html) so if you defined an alias for it (or forked the package) you could use any valid identifier.
- soegaard 1y ago
  The identifier `->` is already used for type annotations.