Esp32forth Update
June 11, 2022
TOPICS
------
* Improvements to Esp32forth
* Revisiting simple modules
* Cryptographic Hashing
CHANGES SINCE APRIL
-------------------
* Added FROT
* Fixed bug in SFLOAT+
* Fixed bug in RSHIFT, added ARSHIFT
* Aligned INCLUDE / INCLUDED with Gforth
* Added NEEDS
* Added WiFi.softAP
* Emit CRLF, Accept CR, CRLF, LF, CRNIL
MODULES
-------
Dewey Val Shorre, "Adding Modules to Forth",
1980 FORML Proceedings, p. 71
-------
: INTERNAL ( -- xt ) current @ @ ;
: EXTERNAL ( -- xt ) :noname postpone ; ;
: MODULE ( xt xt -- ) >link& ! ;
INTERNAL
: square ( n -- n ) dup * ;
: sqrt ( n -- n ) 1 20 for 2dup / + 2/ next nip ;
EXTERNAL
: distance ( x y -- n ) square swap square + sqrt ;
MODULE
POLL
Should I add this module style?
Should I use it more?
CRYPTOGRAPHIC HASHING
---------------------
SHA1 (Secure Hash Algorithm 1)
* 64 byte blocks
* 20 byte digest
* Developed by NSA
* Used by Git
SHA256 (really SHA-2 Secure Hash Algorithm 2)
* 64 byte blocks
* 64 byte digest
* Developed by NSA
* Used by Bitcoin
0 VALUE h0 0 VALUE h1 0 VALUE h2 0 VALUE h3
0 VALUE h4 0 VALUE h5 0 VALUE h6 0 VALUE h7
0 VALUE a 0 VALUE b 0 VALUE c 0 VALUE d
0 VALUE e 0 VALUE f 0 VALUE g 0 VALUE h
0 VALUE temp1 0 VALUE temp2
CREATE w 80 4* ALLOT
: @w ( n -- n ) 4* w + UL@ ;
: !w ( n n -- ) 4* w + L! ;
: 32-bit ( n -- n ) $ffffffff AND ;
: L+ ( n n -- n ) + 32-bit ;
: <<< ( n n -- n )
2DUP LSHIFT -ROT 32
SWAP - RSHIFT OR 32-bit ;
VARIABLE ends
: <-> ( n - n )
ends ! 0 4 0 DO 8 LSHIFT ends I + C@ OR LOOP ;
: <->* ( a n -- )
0 ?DO DUP UL@ <-> OVER L! 4 + LOOP DROP ;
: >dig ( a n -- a )
BASE @ >R HEX <# # # # # # # # # #> R> BASE !
ROT 2DUP + >R SWAP CMOVE R> ;
: init $67452301 TO h0 $EFCDAB89 TO h1
$98BADCFE TO h2 $10325476 TO h3 $C3D2E1F0 TO h4 ;
: extend
80 16 DO
I 3 - @w I 8 - @w XOR I 14 - @w XOR I 16 - @w XOR 1 <<< I !w
LOOP
;
: step ( n i -- ) @w + a 5 <<< + e L+ ( to temp )
d TO e c TO d b 30 <<< TO c a TO b ( from temp ) TO a ;
: start h0 TO A h1 TO b h2 TO c h3 TO d h4 TO e ;
: chunk1 20 0 DO b c AND b INVERT d AND XOR $5A827999 + I step LOOP ;
: chunk2 40 20 DO b c XOR d XOR $6ED9EBA1 + I step LOOP ;
: chunk3 60 40 DO b c AND b d AND XOR c d AND XOR $8F1BBCDC + I step LOOP ;
: chunk4 80 60 DO b c XOR d XOR $CA62C1D6 + I step LOOP ;
: finish a h0 L+ TO h0 b h1 L+ TO h1 c h2 L+ TO h2
d h3 L+ TO h3 e h4 L+ TO h4 ;
: chunk extend start chunk1 chunk2 chunk3 chunk4 finish ;
: >w { msg n }
w 64 ERASE
msg w n CMOVE
$80 w n + c!
w 64 <->* ;
40 constant sha1-size
create sha1-hash sha1-size allot
: format
sha1-hash h0 >dig h1 >dig
h2 >dig h3 >dig
h4 >dig DROP ;
: sha1 { msg n -- hash n } n 64 /mod { edge wholes }
init
wholes 0 ?DO msg 64 >w chunk 64 +TO msg LOOP
edge 0= IF
0 0 >w
ELSE
msg edge >w
edge 56 >= IF chunk w 64 ERASE THEN
THEN
n 8 * 16 RSHIFT 16 RSHIFT 14 !w
n 8 * 15 !w chunk
format sha1-hash sha1-size
;
64 bytes at a time:
[xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx]
[xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx]
[xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx]
[xxxxxxxxxxxxxxxxx1000000000000000000000000SSSSSSSS]
ESP32 has hardware
SHA-1 and SHA-2!
$3ff0001c constant peri_clk_en
$3ff00020 constant peri_rst_en
$3ff03000 constant sha_text
$3ff03080 constant sha1_start
$3ff03084 constant sha1_continue
$3ff03088 constant sha1_load
$3ff0308c constant sha1_busy
Enable peri_clk_en and peri_rst_en
Load 64 byte chunks 64 into sha_text
Write 1 to sha1_start / sha1_continue
Wait for sha1_busy to be zero
Write 1 to sha1_load
Wait for sha1_busy to be zero
Hash in sha_text
Now just need to get it working!
QUESTIONS?
⚘
Thank you!