a2audit/shasum/shasum.a
2016-09-21 21:58:40 -04:00

195 lines
2.5 KiB
Plaintext

!to "shasum.o", plain
* = $6000
jmp main
;; clear addresses:
;; (http://apple2.org.za/gswv/a2zine/faqs/csa2pfaq.html#017)
;; 06-09
;; EB-EF
;; FA-FD
!addr SRC = $06
!addr DEST = $08
!addr INPUT = $eb
!addr LENGTH = $ee
!addr PRBYTE = $FDDA
!addr COUT = $FDED
h0: !32 0 ; return value (hash)
h1: !32 0
h2: !32 0
h3: !32 0
h4: !32 0
ml: !32 0, 0 ; message length
w: !fill 64, 0
w_next: !fill 64, 0
kh0: !be32 $67452301 ; initial values for h0..h4
kh1: !be32 $EFCDAB89
kh2: !be32 $98BADCFE
kh3: !be32 $10325476
kh4: !be32 $C3D2E1F0
k1: !be32 $5A827999 ; k = constants
k2: !be32 $6ED9EBA1
k3: !be32 $8F1BBCDC
k4: !be32 $CA62C1D6
;;; Print a string of bytes, as hex.
;;; Address in SRC, count in A.
;;; Burns Y, A.
prbytes:
ldy #0
- pha
lda (SRC),y
jsr PRBYTE
iny
pla
adc #$ff
bne -
rts
main:
;; Test PRBYTES
;; lda #<kh0
;; sta SRC
;; lda #>kh0
;; sta SRC+1
;; lda #8
;; jsr prbytes
;; LDA #$8D
;; jsr COUT
;; Test shasum
lda #0
sta INPUT
lda #$ff
sta INPUT+1
lda #0
sta LENGTH+1
lda #$37
sta LENGTH
jsr shasum
rts
shasum:
;; Initialize h0..h4
ldy #(ml-h0-1)
- lda kh0,y
sta h0,y
dey
bpl -
;; Initialize message length (ml)
lda #0
ldy #4
- sta ml, y
dey
bpl -
lda LENGTH
sta ml+7
lda LENGTH+1
sta ml+6
;; Message length is in bits
ldy #3
- clc
rol ml+7
rol ml+6
rol ml+5
dey
bne -
;; Initialize chunk counter
;; ldy #0 ; already zero
;; Invert length so we can inc instead of dec
lda LENGTH
sec
lda #0
sbc LENGTH
sta LENGTH
lda #0
sbc LENGTH+1
sta LENGTH+1
ora LENGTH
beq .msgdone
.loop lda (INPUT),y
sta w,y
iny
cpy #$40
bne +
;; Call do_chunk
jsr do_chunk
ldy #0
clc
lda INPUT
adc #$40
sta INPUT
bcc +
inc INPUT+1
+ inc LENGTH
bne .loop
inc LENGTH+1
bne .loop
.msgdone:
lda #$80
sta w,y
iny
cpy #$40
bne .zeros
jsr do_chunk
ldy #0
.zeros
cpy #$38
beq .length
lda #0
sta w,y
iny
cpy #$40
bne .zeros
jsr do_chunk
ldy #0
jmp .zeros
.length
ldy #7
- lda ml,y
sta w+$38,y
dey
bpl -
jsr do_chunk
rts
do_chunk:
lda #<w
sta SRC
lda #>w
sta SRC+1
lda #$40
jsr prbytes
lda #$8D
jsr COUT
rts
!eof
TODOs
[X] Routine to print n hex bytes (address, length (byte))
[X] Routine to get the next 16 values (64 bytes) of input
[ ] Routine to get w[i] one i at a time, and rebuild next 16 values
Needed arithmetic routines for sha1sum:
- [ ] add32
- [ ] and32
- [ ] or32
- [ ] xor32
- [ ] not32
- [ ] ROL1
- [ ] ROR1
- [ ] ROL5 --> ROL8, (ROR1,ROR1,ROR1)
- [ ] ROL30 --> (ROR1,ROR1)