--- /dev/null
+/* md5-asm.S */
+/*
+ This file is part of the AVR-Crypto-Lib.
+ Copyright (C) 2008 Daniel Otte (daniel.otte@rub.de)
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+/*
+ * Author: Daniel Otte
+ * License: GPLv3 or later
+ * Date: 2008-11-15
+*/
+
+
+#include "avr-asm-macros.S"
+
+;###########################################################
+; S-BOX
+
+T_table:
+.hword 0xa478, 0xd76a, 0xb756, 0xe8c7, 0x70db, 0x2420, 0xceee, 0xc1bd, 0x0faf, 0xf57c
+.hword 0xc62a, 0x4787, 0x4613, 0xa830, 0x9501, 0xfd46, 0x98d8, 0x6980, 0xf7af, 0x8b44
+.hword 0x5bb1, 0xffff, 0xd7be, 0x895c, 0x1122, 0x6b90, 0x7193, 0xfd98, 0x438e, 0xa679
+.hword 0x0821, 0x49b4, 0x2562, 0xf61e, 0xb340, 0xc040, 0x5a51, 0x265e, 0xc7aa, 0xe9b6
+.hword 0x105d, 0xd62f, 0x1453, 0x0244, 0xe681, 0xd8a1, 0xfbc8, 0xe7d3, 0xcde6, 0x21e1
+.hword 0x07d6, 0xc337, 0x0d87, 0xf4d5, 0x14ed, 0x455a, 0xe905, 0xa9e3, 0xa3f8, 0xfcef
+.hword 0x02d9, 0x676f, 0x4c8a, 0x8d2a, 0x3942, 0xfffa, 0xf681, 0x8771, 0x6122, 0x6d9d
+.hword 0x380c, 0xfde5, 0xea44, 0xa4be, 0xcfa9, 0x4bde, 0x4b60, 0xf6bb, 0xbc70, 0xbebf
+.hword 0x7ec6, 0x289b, 0x27fa, 0xeaa1, 0x3085, 0xd4ef, 0x1d05, 0x0488, 0xd039, 0xd9d4
+.hword 0x99e5, 0xe6db, 0x7cf8, 0x1fa2, 0x5665, 0xc4ac, 0x2244, 0xf429, 0xff97, 0x432a
+.hword 0x23a7, 0xab94, 0xa039, 0xfc93, 0x59c3, 0x655b, 0xcc92, 0x8f0c, 0xf47d, 0xffef
+.hword 0x5dd1, 0x8584, 0x7e4f, 0x6fa8, 0xe6e0, 0xfe2c, 0x4314, 0xa301, 0x11a1, 0x4e08
+.hword 0x7e82, 0xf753, 0xf235, 0xbd3a, 0xd2bb, 0x2ad7, 0xd391, 0xeb86
+
+
+#define MD5_init_fast
+
+.global md5_init
+#ifndef MD5_init_fast
+;###########################################################
+;void md5_init(md5_ctx_t *state)
+; param1: (r24,r25) 16-bit pointer to sha256_ctx_t struct in ram
+; modifys: Z(r30,r31), X(r25,r26)
+; size = 9+5*4 WORDS = 29 WORDS = 58 Bytes
+md5_init:
+ movw r26, r24 ; (24,25) --> (26,27) load X with param1
+ ldi r30, lo8(md5_init_vector)
+ ldi r31, hi8(md5_init_vector)
+ ldi r24, 16+4
+md5_init_vloop:
+ lpm r0, Z+
+ st X+, r0
+ dec r24
+ brne md5_init_vloop
+ ret
+
+md5_init_vector:
+.hword 0x2301, 0x6745
+.hword 0xAB89, 0xEFCD
+.hword 0xDCFE, 0x98BA
+.hword 0x5476, 0x1032
+.hword 0x0000, 0x0000
+
+#else
+;###########################################################
+.global md5_init_fast
+;void md5_init(md5_ctx_t *state)
+; param1: (r24,r25) 16-bit pointer to sha256_ctx_t struct in ram
+; modifys: r23, r22
+; cycles = 1+16*3+4*2+4 = 1+48+12 = 61
+; size = 1+16*2+4+1 WORDS = 38 WORDS = 76 Bytes
+md5_init:
+md5_init_fast:
+ movw r26, r24
+ ldi r24, 0x01
+ st X+, r24
+ ldi r24, 0x23
+ st X+, r24
+ ldi r24, 0x45
+ st X+, r24
+ ldi r24, 0x67
+ st X+, r24
+ ldi r24, 0x89
+ st X+, r24
+ ldi r24, 0xAB
+ st X+, r24
+ ldi r24, 0xCD
+ st X+, r24
+ ldi r24, 0xEF
+ st X+, r24
+ ldi r24, 0xFE
+ st X+, r24
+ ldi r24, 0xDC
+ st X+, r24
+ ldi r24, 0xBA
+ st X+, r24
+ ldi r24, 0x98
+ st X+, r24
+ ldi r24, 0x76
+ st X+, r24
+ ldi r24, 0x54
+ st X+, r24
+ ldi r24, 0x32
+ st X+, r24
+ ldi r24, 0x10
+ st X+, r24
+ st X+, r1
+ st X+, r1
+ st X+, r1
+ st X+, r1
+ ret
+#endif
+;###########################################################
+
+/*
+static
+uint32_t md5_F(uint32_t x, uint32_t y, uint32_t z){
+ return ((x&y)|((~x)&z));
+}
+*/
+; x: r22-r25
+; y: r18-r21
+; z: r14-r17
+md5_F:
+ and r18, r22
+ and r19, r23
+ and r20, r24
+ and r21, r25
+ com r22
+ com r23
+ com r24
+ com r25
+ and r22, r14
+ and r23, r15
+ and r24, r16
+ and r25, r17
+ or r22, r18
+ or r23, r19
+ or r24, r20
+ or r25, r21
+ rjmp md5_core_F_exit
+
+/*
+static
+uint32_t md5_G(uint32_t x, uint32_t y, uint32_t z){
+ return ((x&z)|((~z)&y));
+}
+*/
+
+; x: r22-r25
+; y: r18-r21
+; z: r14-r17
+md5_G:
+ and r22, r14
+ and r23, r15
+ and r24, r16
+ and r25, r17
+ com r14
+ com r15
+ com r16
+ com r17
+ and r18, r14
+ and r19, r15
+ and r20, r16
+ and r21, r17
+ or r22, r18
+ or r23, r19
+ or r24, r20
+ or r25, r21
+ rjmp md5_core_F_exit
+/*
+static
+uint32_t md5_H(uint32_t x, uint32_t y, uint32_t z){
+ return (x^y^z);
+}
+*/
+; x: r22-r25
+; y: r18-r21
+; z: r14-r17
+md5_H:
+ eor r22, r18
+ eor r22, r14
+ eor r23, r19
+ eor r23, r15
+ eor r24, r20
+ eor r24, r16
+ eor r25, r21
+ eor r25, r17
+ rjmp md5_core_F_exit
+/*
+static
+uint32_t md5_I(uint32_t x, uint32_t y, uint32_t z){
+ return (y ^ (x | (~z)));
+}
+*/
+
+jump_table:
+ rjmp md5_F
+ rjmp md5_G
+ rjmp md5_H
+; rjmp md5_I
+
+; x: r22-r25
+; y: r18-r21
+; z: r14-r17
+md5_I:
+ com r14
+ com r15
+ com r16
+ com r17
+ or r22, r14
+ or r23, r15
+ or r24, r16
+ or r25, r17
+ eor r22, r18
+ eor r23, r19
+ eor r24, r20
+ eor r25, r21
+ rjmp md5_core_F_exit
+
+as_table:
+; (as+0)&3 (as+3)&3 (as+1)&3 (as+2)&3
+; Z X Y
+; AS_SAVE0 AS_SAVE1 AS_SAVE2 AS_SAVE3
+.byte 1*4, 0*4, 2*4, 3*4 ;as=1
+.byte 2*4, 1*4, 3*4, 0*4 ;as=2
+.byte 3*4, 2*4, 0*4, 1*4 ;as=3
+.byte 0*4, 3*4, 1*4, 2*4 ;as=4
+
+;###########################################################
+.global md5_core
+md5_core:
+ mov r21, r20
+ mov r20, r18
+ mov r19, r16
+ mov r18, r14
+; rjmp md5_core_asm
+/*
+void md5_core(uint32_t* a, void* block, uint8_t as, uint8_t s, uint8_t i, uint8_t fi){
+ uint32_t t;
+ md5_func_t* funcs[]={md5_F, md5_G, md5_H, md5_I};
+ as &= 0x3;
+ / * a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s). * /
+ t = a[as] + funcs[fi](a[(as+1)&3], a[(as+2)&3], a[(as+3)&3]) + *((uint32_t*)block) + md5_T[i] ;
+ a[as]=a[(as+1)&3] + ROTL32(t, s);
+}
+*/
+; a: r24-r25
+; block: r22-r23
+; as: r21
+; s: r20
+; i: r19
+; fi: r18
+P_A0 = 24
+P_A1 = 25
+P_B0 = 22
+P_B1 = 23
+P_AS = 21
+P_S = 20
+P_I = 19
+P_FI = 18
+
+; x: r22-r25
+; y: r18-r21
+; z: r14-r17
+
+
+AS_SAVE0 = 4
+AS_SAVE1 = 5
+AS_SAVE2 = 6
+AS_SAVE3 = 7
+FI_SAVE = 8
+S_SAVE = 9
+ACCU0 = 10
+ACCU1 = 11
+ACCU2 = 12
+ACCU3 = 13
+ARG_X0 = 22
+ARG_X1 = 23
+ARG_X2 = 24
+ARG_X3 = 25
+ARG_Y0 = 18
+ARG_Y1 = 19
+ARG_Y2 = 20
+ARG_Y3 = 21
+ARG_Z0 = 14
+ARG_Z1 = 15
+ARG_Z2 = 16
+ARG_Z3 = 17
+
+
+md5_core_asm:
+ push r16
+ push r17
+ push_range 4, 8
+ ldi r30, lo8(T_table)
+ ldi r31, hi8(T_table)
+ lsl P_I
+ rol r1
+ lsl P_I
+ rol r1
+ add r30, P_I
+ adc r31, r1
+ clr r1
+ mov FI_SAVE, r18
+ /* loading T[i] into ACCU */
+ lpm ACCU0, Z+
+ lpm ACCU1, Z+
+ lpm ACCU2, Z+
+ lpm ACCU3, Z
+ /* add *block to ACCU */
+ movw r30, P_B0
+ ld r0, Z+
+ add ACCU0, r0
+ ld r0, Z+
+ adc ACCU1, r0
+ ld r0, Z+
+ adc ACCU2, r0
+ ld r0, Z+
+ adc ACCU3, r0
+ /* add a[as+0&3] to ACCU */
+ ldi r30, lo8(as_table)
+ ldi r31, hi8(as_table)
+ dec P_AS
+ andi P_AS, 0x03
+ lsl P_AS
+ lsl P_AS
+ add r30, r21
+ adc r31, r1 ; Z points to the correct row in as_table
+ lpm AS_SAVE0, Z+
+ lpm AS_SAVE1, Z+
+ lpm AS_SAVE2, Z+
+ lpm AS_SAVE3, Z
+ movw r26, r24 ; X points to a[0]
+ add r26, AS_SAVE0
+ adc r27, r1 ; X points at a[as&3]
+ ld r0, X+
+ add ACCU0, r0
+ ld r0, X+
+ adc ACCU1, r0
+ ld r0, X+
+ adc ACCU2, r0
+ ld r0, X+
+ adc ACCU3, r0
+ mov S_SAVE, r20
+
+ movw r28, r24
+ /* loading z value */
+ movw r26, r28
+ add r26, AS_SAVE1
+ adc r27, r1
+ ld ARG_Z0, X+
+ ld ARG_Z1, X+
+ ld ARG_Z2, X+
+ ld ARG_Z3, X
+
+ /* loading x value */
+ movw r26, r28
+ add r26, AS_SAVE2
+ adc r27, r1
+ ld ARG_X0, X+
+ ld ARG_X1, X+
+ ld ARG_X2, X+
+ ld ARG_X3, X
+
+ /* loading y value */
+ movw r26, r28
+ add r26, AS_SAVE3
+ adc r27, r1
+ ldi r30, pm_lo8(jump_table)
+ ldi r31, pm_hi8(jump_table)
+ add r30, FI_SAVE
+ adc r31, r1 ; Z points to the correct entry in our jump table
+ ld ARG_Y0, X+
+ ld ARG_Y1, X+
+ ld ARG_Y2, X+
+ ld ARG_Y3, X
+
+ ijmp /* calls the function pointed by Z */
+md5_core_F_exit:
+
+ /* add ACCU to result of f() */
+ add r22, ACCU0
+ adc r23, ACCU1
+ adc r24, ACCU2
+ adc r25, ACCU3
+
+ /* rotate */
+ mov r20, S_SAVE
+rotl32:
+ cpi r20, 8
+ brlo bitrotl
+ mov r21, r25
+ mov r25, r24
+ mov r24, r23
+ mov r23, r22
+ mov r22, r21
+ subi r20, 8
+ rjmp rotl32
+bitrotl:
+ mov r21, r25
+bitrotl_loop:
+ tst r20
+ breq fixrotl
+bitrotl_loop2:
+ lsl r21
+ rol r22
+ rol r23
+ rol r24
+ rol r25
+ dec r20
+ brne bitrotl_loop2
+fixrotl:
+
+ /* add a[(as+1)&3] */
+ movw r26, r28
+ add r26, AS_SAVE2
+ adc r27, r1
+ ld r0, X+
+ add r22, r0
+ ld r0, X+
+ adc r23, r0
+ ld r0, X+
+ adc r24, r0
+ ld r0, X
+ adc r25, r0
+
+ /* store result */
+ movw r26, r28
+ add r26, AS_SAVE0
+ adc r27, r1
+ st X+, r22
+ st X+, r23
+ st X+, r24
+ st X , r25
+md5_core_exit:
+ pop_range 4, 8
+ pop r17
+ pop r16
+ ret
+
+;###################################################################
+/*
+void md5_nextBlock(md5_ctx_t *state, void* block){
+ uint32_t a[4];
+ uint8_t m,n,i=0;
+
+ a[0]=state->a[0];
+ a[1]=state->a[1];
+ a[2]=state->a[2];
+ a[3]=state->a[3];
+
+ / * round 1 * /
+ uint8_t s1t[]={7,12,17,22}; // 1,-1 1,4 2,-1 3,-2
+ for(m=0;m<4;++m){
+ for(n=0;n<4;++n){
+ md5_core(a, &(((uint32_t*)block)[m*4+n]), 4-n, s1t[n],i++,0);
+ }
+ }
+ / * round 2 * /
+ uint8_t s2t[]={5,9,14,20}; // 1,-3 1,1 2,-2 2,4
+ for(m=0;m<4;++m){
+ for(n=0;n<4;++n){
+ md5_core(a, &(((uint32_t*)block)[(1+m*4+n*5)&0xf]), 4-n, s2t[n],i++,1);
+ }
+ }
+ / * round 3 * /
+ uint8_t s3t[]={4,11,16,23}; // 0,4 1,3 2,0 3,-1
+ for(m=0;m<4;++m){
+ for(n=0;n<4;++n){
+ md5_core(a, &(((uint32_t*)block)[(5-m*4+n*3)&0xf]), 4-n, s3t[n],i++,2);
+ }
+ }
+ / * round 4 * /
+ uint8_t s4t[]={6,10,15,21}; // 1,-2 1,2 2,-1 3,-3
+ for(m=0;m<4;++m){
+ for(n=0;n<4;++n){
+ md5_core(a, &(((uint32_t*)block)[(0-m*4+n*7)&0xf]), 4-n, s4t[n],i++,3);
+ }
+ }
+ state->a[0] += a[0];
+ state->a[1] += a[1];
+ state->a[2] += a[2];
+ state->a[3] += a[3];
+ state->counter++;
+}
+*/
+
+shift_table_1: .byte 7,12,17,22
+shift_table_2: .byte 5, 9,14,20
+shift_table_3: .byte 4,11,16,23
+shift_table_4: .byte 6,10,15,21
+
+index_table_r2:
+;(1+m*4+n*5)&0xf:
+ .byte 0x04, 0x18, 0x2c, 0x00
+ .byte 0x14, 0x28, 0x3c, 0x10
+ .byte 0x24, 0x38, 0x0c, 0x20
+ .byte 0x34, 0x08, 0x1c, 0x30
+
+index_table_r3:
+;(5-m*4+n*3)&0xf:
+ .byte 0x14, 0x20, 0x2c, 0x38
+ .byte 0x04, 0x10, 0x1c, 0x28
+ .byte 0x34, 0x00, 0x0c, 0x18
+ .byte 0x24, 0x30, 0x3c, 0x08
+
+index_table_r4:
+;(0-m*4+n*7)&0xf:
+ .byte 0x00, 0x1c, 0x38, 0x14
+ .byte 0x30, 0x0c, 0x28, 0x04
+ .byte 0x20, 0x3c, 0x18, 0x34
+ .byte 0x10, 0x2c, 0x08, 0x24
+
+APTR_REG = 2
+BPTR_REG = 4
+N_REG = 6
+M_REG = 7
+I_REG = 8
+.global md5_nextBlock
+md5_nextBlock:
+ stack_alloc 16
+ push_range 2, 17
+ push r28
+ push r29
+ push r24
+ push r25
+ adiw r30, 1 /* Z now points to the beginning of the allocated memory */
+ movw r2, r30
+ movw r4, r22
+ movw r26, r24
+ ldi r20, 16
+1:
+ ld r0, X+
+ st Z+, r0
+ dec r20
+ brne 1b
+ /* state now copied to stack memory */
+ clr I_REG
+ /* Round 1 */
+ clr M_REG
+ ldi r17, 4
+1:
+ clr N_REG
+ ldi r16, 4
+2:
+ movw r24, APTR_REG
+ movw r22, BPTR_REG
+ mov r0, M_REG
+ lsl r0
+ lsl r0
+ add r0, N_REG
+ lsl r0
+ lsl r0
+ add r22, r0
+ adc r23, r1
+ mov r21, r16
+ ldi r30, lo8(shift_table_1)
+ ldi r31, hi8(shift_table_1)
+ add r30, N_REG
+ adc r31, r1
+ lpm r20, Z
+ mov r19, I_REG
+ ldi r18, 0
+ rcall md5_core_asm
+ inc I_REG
+ inc N_REG
+ dec r16
+ brne 2b
+ inc M_REG
+ dec r17
+ brne 1b
+
+ /* Round 2 */
+ clr M_REG
+ ldi r17, 4
+1:
+ clr N_REG
+ ldi r16, 4
+2:
+ movw r24, APTR_REG
+ movw r22, BPTR_REG
+ ldi r30, lo8(index_table_r2)
+ ldi r31, hi8(index_table_r2)
+ mov r0, M_REG
+ lsl r0
+ lsl r0
+ add r0, N_REG
+ add r30, r0
+ adc r31, r1
+ lpm r0, Z
+ add r22, r0
+ adc r23, r1
+ mov r21, r16
+ ldi r30, lo8(shift_table_2)
+ ldi r31, hi8(shift_table_2)
+ add r30, N_REG
+ adc r31, r1
+ lpm r20, Z
+ mov r19, I_REG
+ ldi r18, 1
+ rcall md5_core_asm
+ inc I_REG
+ inc N_REG
+ dec r16
+ brne 2b
+ inc M_REG
+ dec r17
+ brne 1b
+
+ /* Round 3 */
+ clr M_REG
+ ldi r17, 4
+1:
+ clr N_REG
+ ldi r16, 4
+2:
+ movw r24, APTR_REG
+ movw r22, BPTR_REG
+ ldi r30, lo8(index_table_r3)
+ ldi r31, hi8(index_table_r3)
+ mov r0, M_REG
+ lsl r0
+ lsl r0
+ add r0, N_REG
+ add r30, r0
+ adc r31, r1
+ lpm r0, Z
+ add r22, r0
+ adc r23, r1
+ mov r21, r16
+ ldi r30, lo8(shift_table_3)
+ ldi r31, hi8(shift_table_3)
+ add r30, N_REG
+ adc r31, r1
+ lpm r20, Z
+ mov r19, I_REG
+ ldi r18, 2
+ rcall md5_core_asm
+ inc I_REG
+ inc N_REG
+ dec r16
+ brne 2b
+ inc M_REG
+ dec r17
+ brne 1b
+
+ /* Round 4 */
+ clr M_REG
+ ldi r17, 4
+1:
+ clr N_REG
+ ldi r16, 4
+2:
+ movw r24, APTR_REG
+ movw r22, BPTR_REG
+ ldi r30, lo8(index_table_r4)
+ ldi r31, hi8(index_table_r4)
+ mov r0, M_REG
+ lsl r0
+ lsl r0
+ add r0, N_REG
+ add r30, r0
+ adc r31, r1
+ lpm r0, Z
+ add r22, r0
+ adc r23, r1
+ mov r21, r16
+ ldi r30, lo8(shift_table_4)
+ ldi r31, hi8(shift_table_4)
+ add r30, N_REG
+ adc r31, r1
+ lpm r20, Z
+ mov r19, I_REG
+ ldi r18, 3
+ rcall md5_core_asm
+ inc I_REG
+ inc N_REG
+ dec r16
+ brne 2b
+ inc M_REG
+ dec r17
+ brne 1b
+
+
+ pop r27
+ pop r26 /* X now points to the context */
+ movw r30, APTR_REG
+ ldi r16, 4
+1:
+ ld r0, X
+ ld r2, Z+
+ add r0, r2
+ st X+, r0
+ ld r0, X
+ ld r2, Z+
+ adc r0, r2
+ st X+, r0
+ ld r0, X
+ ld r2, Z+
+ adc r0, r2
+ st X+, r0
+ ld r0, X
+ ld r2, Z+
+ adc r0, r2
+ st X+, r0
+ dec r16
+ brne 1b
+
+ ld r0, X
+ inc r0
+ st X+, r0
+ brne 2f
+ ld r0, X
+ inc r0
+ st X+, r0
+ brne 2f
+ ld r0, X
+ inc r0
+ st X+, r0
+ brne 2f
+ ld r0, X
+ inc r0
+ st X+, r0
+2:
+
+ pop r29
+ pop r28
+ pop_range 2, 17
+ stack_free 16
+ ret
+
+;###############################################################################
+/*
+void md5_lastBlock(md5_ctx_t *state, const void* block, uint16_t length_b){
+ uint16_t l;
+ uint8_t b[64];
+ while (length_b >= 512){
+ md5_nextBlock(state, block);
+ length_b -= 512;
+ block = ((uint8_t*)block) + 512/8;
+ }
+ memset(b, 0, 64);
+ memcpy(b, block, length_b/8);
+ / * insert padding one * /
+ l=length_b/8;
+ if(length_b%8){
+ uint8_t t;
+ t = ((uint8_t*)block)[l];
+ t |= (0x80>>(length_b%8));
+ b[l]=t;
+ }else{
+ b[l]=0x80;
+ }
+ / * insert length value * /
+ if(l+sizeof(uint64_t) >= 512/8){
+ md5_nextBlock(state, b);
+ state->counter--;
+ memset(b, 0, 64-8);
+ }
+ *((uint64_t*)&b[64-sizeof(uint64_t)]) = (state->counter * 512) + length_b;
+ md5_nextBlock(state, b);
+}
+*/
+; state_ptr : r24,r25
+; block_ptr : r22,r23
+; length_b : r20,r21
+.global md5_lastBlock
+md5_lastBlock:
+ stack_alloc_large 64
+ push_range 12, 17
+ push r30
+ push r31
+ movw r16, r20 /* length_b */
+ movw r14, r22 /* block_ptr */
+ movw r12, r24 /* state_ptr */
+ ldi r18, 64
+2:
+ cpi r17, 2 /* hi8(512) */
+ brlo 2f
+1:
+ movw r24, r12
+ movw r22, r14
+ rcall md5_nextBlock
+ add r14, r18
+ adc r15, r1
+ subi r17, 2
+ rjmp 2b
+2:
+ pop r31
+ pop r30
+
+ adiw r30, 1 /* adjust Z to point to buffer */
+ movw r26, r14
+ movw r24, r16
+ adiw r24, 7
+
+ lsr r25
+ ror r24
+ lsr r25
+ ror r24
+ lsr r24 /* r24 now holds how many bytes are to copy */
+ ldi r18, 64
+ sub r18, r24 /* r18 will hold the amount of used bytes in buffer */
+ tst r24
+4:
+ breq 5f
+ ld r0, X+
+ st Z+, r0
+ dec r24
+ rjmp 4b /* Z points to the byte after msg in buffer */
+5: /* append 1-bit */
+ mov r20, r16
+ ldi r19, 0x80
+ andi r20, 0x07
+ brne bit_fucking
+ st Z+, r19
+ dec r18 /* 'allocate' another byte in buffer */
+ rjmp after_bit_fucking
+bit_fucking:
+1:
+ lsr r19
+ dec r20
+ brne 1b
+ or r0, r19
+ st -Z, r0
+ adiw r30, 1
+after_bit_fucking:
+ clt
+ cpi r18, 8
+ brmi 2f
+ set /* store in t if the counter will also fit in this block (1 if fit)*/
+2:
+ tst r18
+ breq 2f
+1: /* fill remaning buffer with zeros */
+ st Z+, r1
+ dec r18
+ brne 1b
+2:
+ sbiw r30, 63
+ sbiw r30, 1
+ movw r14, r30 /* r14:r15 now points to buffer */
+ brts load_counter
+ /* counter does not fit, finalize this block */
+ movw r24, r12
+ movw r22, r14
+ rcall md5_nextBlock
+ movw r30, r14
+ ldi r20, 64-8
+3:
+ st Z+, r1
+ dec r20
+ brne 3b
+
+load_counter:
+ movw r26, r12 /* X points to state */
+ adiw r26, 16
+ ld r19, X+
+ ld r20, X+
+ ld r21, X+
+ ld r22, X+
+ brts post_counter_decrement /* do not decremen because counter fits */
+counter_decrement:
+ subi r19, 1
+ sbci r20, 0
+ sbci r21, 0
+ sbci r22, 0
+post_counter_decrement:
+ clr r18
+ clr r23
+ lsl r19
+ rol r20
+ rol r21
+ rol r22
+ rol r23
+ mov r18, r16 /* r16:r17 length_b */
+ add r19, r17
+ adc r20, r1
+ adc r21, r1
+ adc r22, r1
+ adc r23, r1
+ movw r30, r14
+ adiw r30, 64-8
+ st Z+, r18
+ st Z+, r19
+ st Z+, r20
+ st Z+, r21
+ st Z+, r22
+ st Z+, r23
+ st Z+, r1
+ st Z, r1
+
+ sbiw r30, 63
+; sbiw r30, 1
+ movw r24, r12
+ movw r22, r30
+ rcall md5_nextBlock
+md5_lastBlock_exit:
+ pop_range 12, 17
+ stack_free_large 64
+ ret
+
+
+;###############################################################################
+
+
+.global md5_ctx2hash
+md5_ctx2hash:
+ movw r26, r24
+ movw r30, r22
+ ldi r22, 16
+1:
+ ld r0, Z+
+ st X+, r0
+ dec r22
+ brne 1b
+ ret
+
+
+;###############################################################################
+
+
+.global md5
+md5:
+ stack_alloc 20
+ push_range 8, 17
+ adiw r30, 1
+ movw r8, r30 /* ctx */
+ movw r10, r24 /* dest */
+ movw r12, r22 /* msg */
+ movw r14, r18 /* length (low) */
+ movw r16, r20 /* length (high) */
+ movw r24, r30
+ rcall md5_init
+1:
+ tst r16
+ brne next_round
+ tst r17
+ breq last_round
+next_round:
+ movw r24, r8
+ movw r22, r12
+ rcall md5_nextBlock
+ ldi r22, 64
+ add r12, r22
+ adc r13, r1
+ ldi r22, 2
+ sub r15, r22
+ sbci r16, 0
+ sbci r17, 0
+ rjmp 1b
+last_round:
+ movw r24, r8
+ movw r22, r12
+ movw r20, r14
+ rcall md5_lastBlock
+ movw r24, r10
+ movw r22, r8
+ rcall md5_ctx2hash
+ pop_range 8, 17
+ stack_free 20
+ ret
+
+
+