+/* sha1-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
+*/
+; SHA1 implementation in assembler for AVR
+SHA1_BLOCK_BITS = 512
+SHA1_HASH_BITS = 160
+
+.macro precall
+ /* push r18 - r27, r30 - r31*/
+ push r0
+ push r1
+ push r18
+ push r19
+ push r20
+ push r21
+ push r22
+ push r23
+ push r24
+ push r25
+ push r26
+ push r27
+ push r30
+ push r31
+ clr r1
+.endm
+
+.macro postcall
+ pop r31
+ pop r30
+ pop r27
+ pop r26
+ pop r25
+ pop r24
+ pop r23
+ pop r22
+ pop r21
+ pop r20
+ pop r19
+ pop r18
+ pop r1
+ pop r0
+.endm
+
+
+.macro hexdump length
+ push r27
+ push r26
+ ldi r25, '\r'
+ mov r24, r25
+ call uart_putc
+ ldi r25, '\n'
+ mov r24, r25
+ call uart_putc
+ pop r26
+ pop r27
+ movw r24, r26
+.if \length > 16
+ ldi r22, lo8(16)
+ ldi r23, hi8(16)
+ push r27
+ push r26
+ call uart_hexdump
+ pop r26
+ pop r27
+ adiw r26, 16
+ hexdump \length-16
+.else
+ ldi r22, lo8(\length)
+ ldi r23, hi8(\length)
+ call uart_hexdump
+.endif
+.endm
+
+.macro delay
+/*
+ push r0
+ push r1
+ clr r0
+1: clr r1
+2: dec r1
+ brne 2b
+ dec r0
+ brne 1b
+ pop r1
+ pop r0 // */
+.endm
+
+/* X points to Block */
+.macro dbg_hexdump length
+/*
+ precall
+ hexdump \length
+ postcall
+ // */
+.endm
+
+
+
+.section .text
+
+SPL = 0x3D
+SPH = 0x3E
+SREG = 0x3F
+
+
+;
+;sha1_ctx_t is:
+;
+; [h0][h1][h2][h3][h4][length]
+; hn is 32 bit large, length is 64 bit large
+
+;###########################################################
+
+.global sha1_ctx2hash
+; === sha1_ctx2hash ===
+; this function converts a state into a normal hash (bytestring)
+; param1: the 16-bit destination pointer
+; given in r25,r24 (r25 is most significant)
+; param2: the 16-bit pointer to sha1_ctx structure
+; given in r23,r22
+sha1_ctx2hash:
+ movw r26, r22
+ movw r30, r24
+ ldi r21, 5
+ sbiw r26, 4
+1:
+ ldi r20, 4
+ adiw r26, 8
+2:
+ ld r0, -X
+ st Z+, r0
+ dec r20
+ brne 2b
+
+ dec r21
+ brne 1b
+
+ ret
+
+;###########################################################
+
+.global sha1
+; === sha1 ===
+; this function calculates SHA-1 hashes from messages in RAM
+; param1: the 16-bit hash destination pointer
+; given in r25,r24 (r25 is most significant)
+; param2: the 16-bit pointer to message
+; given in r23,r22
+; param3: 32-bit length value (length of message in bits)
+; given in r21,r20,r19,r18
+sha1:
+sha1_prolog:
+ push r8
+ push r9
+ push r10
+ push r11
+ push r12
+ push r13
+ push r16
+ push r17
+ in r30, SPL
+ in r31, SPH
+ sbiw r30, 5*4+8
+ in r0, SREG
+ cli
+ out SPL, r30
+ out SREG, r0
+ out SPH, r31
+
+ push r25
+ push r24
+ adiw r30, 1
+ movw r16, r30
+
+ movw r8, r18 /* backup of length*/
+ movw r10, r20
+
+ movw r12, r22 /* backup pf msg-ptr */
+
+ movw r24, r16
+ rcall sha1_init
+ /* if length >= 512 */
+1:
+ tst r11
+ brne 2f
+ tst r10
+ breq 4f
+2:
+ movw r24, r16
+ movw r22, r12
+ rcall sha1_nextBlock
+ ldi r19, 64
+ add r12, r19
+ adc r13, r1
+ /* length -= 512 */
+ ldi r19, 0x02
+ sub r9, r19
+ sbc r10, r1
+ sbc r11, r1
+ rjmp 1b
+
+4:
+ movw r24, r16
+ movw r22, r12
+ movw r20, r8
+ rcall sha1_lastBlock
+
+ pop r24
+ pop r25
+ movw r22, r16
+ rcall sha1_ctx2hash
+
+sha1_epilog:
+ in r30, SPL
+ in r31, SPH
+ adiw r30, 5*4+8
+ in r0, SREG
+ cli
+ out SPL, r30
+ out SREG, r0
+ out SPH, r31
+ pop r17
+ pop r16
+ pop r13
+ pop r12
+ pop r11
+ pop r10
+ pop r9
+ pop r8
+ ret
+
+;###########################################################
+
+
+; block MUST NOT be larger than 64 bytes
+
+.global sha1_lastBlock
+; === sha1_lastBlock ===
+; this function does padding & Co. for calculating SHA-1 hashes
+; param1: the 16-bit pointer to sha1_ctx structure
+; given in r25,r24 (r25 is most significant)
+; param2: an 16-bit pointer to 64 byte block to hash
+; given in r23,r22
+; param3: an 16-bit integer specifing length of block in bits
+; given in r21,r20
+sha1_lastBlock_localSpace = (SHA1_BLOCK_BITS/8+1)
+
+
+sha1_lastBlock:
+ cpi r21, 0x02
+ brlo sha1_lastBlock_prolog
+ push r25
+ push r24
+ push r23
+ push r22
+ push r21
+ push r20
+ rcall sha1_nextBlock
+ pop r20
+ pop r21
+ pop r22
+ pop r23
+ pop r24
+ pop r25
+ subi r21, 2
+ ldi r19, 64
+ add r22, r19
+ adc r23, r1
+ rjmp sha1_lastBlock
+sha1_lastBlock_prolog:
+ /* allocate space on stack */
+ in r30, SPL
+ in r31, SPH
+ in r0, SREG
+ subi r30, lo8(64)
+ sbci r31, hi8(64) /* ??? */
+ cli
+ out SPL, r30
+ out SREG, r0
+ out SPH, r31
+
+ adiw r30, 1 /* SP points to next free byte on stack */
+ mov r18, r20 /* r20 = LSB(length) */
+ lsr r18
+ lsr r18
+ lsr r18
+ bst r21, 0 /* may be we should explain this ... */
+ bld r18, 5 /* now: r18 == length/8 (aka. length in bytes) */
+
+
+ movw r26, r22 /* X points to begin of msg */
+ tst r18
+ breq sha1_lastBlock_post_copy
+ mov r1, r18
+sha1_lastBlock_copy_loop:
+ ld r0, X+
+ st Z+, r0
+ dec r1
+ brne sha1_lastBlock_copy_loop
+sha1_lastBlock_post_copy:
+sha1_lastBlock_insert_stuffing_bit:
+ ldi r19, 0x80
+ mov r0,r19
+ ldi r19, 0x07
+ and r19, r20 /* if we are in bitmode */
+ breq 2f /* no bitmode */
+1:
+ lsr r0
+ dec r19
+ brne 1b
+ ld r19, X
+/* maybe we should do some ANDing here, just for safety */
+ or r0, r19
+2:
+ st Z+, r0
+ inc r18
+
+/* checking stuff here */
+ cpi r18, 64-8+1
+ brsh 0f
+ rjmp sha1_lastBlock_insert_zeros
+0:
+ /* oh shit, we landed here */
+ /* first we have to fill it up with zeros */
+ ldi r19, 64
+ sub r19, r18
+ breq 2f
+1:
+ st Z+, r1
+ dec r19
+ brne 1b
+2:
+ sbiw r30, 63
+ sbiw r30, 1
+ movw r22, r30
+
+ push r31
+ push r30
+ push r25
+ push r24
+ push r21
+ push r20
+ rcall sha1_nextBlock
+ pop r20
+ pop r21
+ pop r24
+ pop r25
+ pop r30
+ pop r31
+
+ /* now we should subtract 512 from length */
+ movw r26, r24
+ adiw r26, 4*5+1 /* we can skip the lowest byte */
+ ld r19, X
+ subi r19, hi8(512)
+ st X+, r19
+ ldi r18, 6
+1:
+ ld r19, X
+ sbci r19, 0
+ st X+, r19
+ dec r18
+ brne 1b
+
+; clr r18 /* not neccessary ;-) */
+ /* reset Z pointer to begin of block */
+
+sha1_lastBlock_insert_zeros:
+ ldi r19, 64-8
+ sub r19, r18
+ breq sha1_lastBlock_insert_length
+ clr r1
+1:
+ st Z+, r1 /* r1 is still zero */
+ dec r19
+ brne 1b
+
+; rjmp sha1_lastBlock_epilog
+sha1_lastBlock_insert_length:
+ movw r26, r24 /* X points to state */
+ adiw r26, 5*4 /* X points to (state.length) */
+ adiw r30, 8 /* Z points one after the last byte of block */
+ ld r0, X+
+ add r0, r20
+ st -Z, r0
+ ld r0, X+
+ adc r0, r21
+ st -Z, r0
+ ldi r19, 6
+1:
+ ld r0, X+
+ adc r0, r1
+ st -Z, r0
+ dec r19
+ brne 1b
+
+ sbiw r30, 64-8
+ movw r22, r30
+ rcall sha1_nextBlock
+
+sha1_lastBlock_epilog:
+ in r30, SPL
+ in r31, SPH
+ in r0, SREG
+ adiw r30, 63 ; lo8(64)
+ adiw r30, 1 ; hi8(64)
+ cli
+ out SPL, r30
+ out SREG, r0
+ out SPH, r31
+ clr r1
+ ret
+
+/**/
+;###########################################################
+
+.global sha1_nextBlock
+; === sha1_nextBlock ===
+; this is the core function for calculating SHA-1 hashes
+; param1: the 16-bit pointer to sha1_ctx structure
+; given in r25,r24 (r25 is most significant)
+; param2: an 16-bit pointer to 64 byte block to hash
+; given in r23,r22
+sha1_nextBlock_localSpace = (16+5+1)*4 ; 16 32-bit values for w array and 5 32-bit values for a array (total 84 byte)
+
+xtmp = 0
+xNULL = 1
+W1 = 10
+W2 = 11
+T1 = 12
+T2 = 13
+T3 = 14
+T4 = 15
+LoopC = 16
+S = 17
+tmp1 = 18
+tmp2 = 19
+tmp3 = 20
+tmp4 = 21
+F1 = 22
+F2 = 23
+F3 = 24
+F4 = 25
+
+/* byteorder: high number <--> high significance */
+sha1_nextBlock:
+ ; initial, let's make some space ready for local vars
+ /* replace push & pop by mem ops? */
+ push r10
+ push r11
+ push r12
+ push r13
+ push r14
+ push r15
+ push r16
+ push r17
+ push r28
+ push r29
+ in r20, SPL
+ in r21, SPH
+ movw r18, r20 ;backup SP
+; movw r26, r20 ; X points to free space on stack /* maybe removeable? */
+ movw r30, r22 ; Z points to message
+ subi r20, lo8(sha1_nextBlock_localSpace) ;sbiw can do only up to 63
+ sbci r21, hi8(sha1_nextBlock_localSpace)
+ movw r26, r20 ; X points to free space on stack
+ in r0, SREG
+ cli ; we want to be uninterrupted while updating SP
+ out SPL, r20
+ out SREG, r0
+ out SPH, r21
+
+ push r18
+ push r19 /* push old SP on new stack */
+ push r24
+ push r25 /* param1 will be needed later */
+
+ /* load a[] with state */
+ movw 28, r24 /* load pointer to state in Y */
+ adiw r26, 1 ; X++
+
+ ldi LoopC, 5*4
+1: ld tmp1, Y+
+ st X+, tmp1
+ dec LoopC
+ brne 1b
+
+ movw W1, r26 /* save pointer to w[0] */
+ /* load w[] with endian fixed message */
+ /* we might also use the changeendian32() function at bottom */
+ movw r30, r22 /* mv param2 (ponter to msg) to Z */
+ ldi LoopC, 16
+1:
+ ldd tmp1, Z+3
+ st X+, tmp1
+ ldd tmp1, Z+2
+ st X+, tmp1
+ ldd tmp1, Z+1
+ st X+, tmp1
+ ld tmp1, Z
+ st X+, tmp1
+ adiw r30, 4
+ dec LoopC
+ brne 1b
+
+ ;clr LoopC /* LoopC is named t in FIPS 180-2 */
+ clr xtmp
+sha1_nextBlock_mainloop:
+ mov S, LoopC
+ lsl S
+ lsl S
+ andi S, 0x3C /* S is a bytepointer so *4 */
+ /* load w[s] */
+ movw r26, W1
+ add r26, S /* X points at w[s] */
+ adc r27, xNULL
+ ld T1, X+
+ ld T2, X+
+ ld T3, X+
+ ld T4, X+
+
+/*
+ push r26
+ push r27
+ push T4
+ push T3
+ push T2
+ push T1
+ in r26, SPL
+ in r27, SPH
+ adiw r26, 1
+ dbg_hexdump 4
+ pop T1
+ pop T2
+ pop T3
+ pop T4
+ pop r27
+ pop r26
+*/
+
+ cpi LoopC, 16
+ brlt sha1_nextBlock_mainloop_core
+ /* update w[s] */
+ ldi tmp1, 2*4
+ rcall 1f
+ ldi tmp1, 8*4
+ rcall 1f
+ ldi tmp1, 13*4
+ rcall 1f
+ rjmp 2f
+1: /* this might be "outsourced" to save the jump above */
+ add tmp1, S
+ andi tmp1, 0x3f
+ movw r26, W1
+ add r26, tmp1
+ adc r27, xNULL
+ ld tmp2, X+
+ eor T1, tmp2
+ ld tmp2, X+
+ eor T2, tmp2
+ ld tmp2, X+
+ eor T3, tmp2
+ ld tmp2, X+
+ eor T4, tmp2
+ ret
+2: /* now we just hav to do a ROTL(T) and save T back */
+ mov tmp2, T4
+ rol tmp2
+ rol T1
+ rol T2
+ rol T3
+ rol T4
+ movw r26, W1
+ add r26, S
+ adc r27, xNULL
+ st X+, T1
+ st X+, T2
+ st X+, T3
+ st X+, T4
+
+sha1_nextBlock_mainloop_core: /* ther core function; T=ROTL5(a) ....*/
+ /* T already contains w[s] */
+ movw r26, W1
+ sbiw r26, 4*1 /* X points at a[4] aka e */
+ ld tmp1, X+
+ add T1, tmp1
+ ld tmp1, X+
+ adc T2, tmp1
+ ld tmp1, X+
+ adc T3, tmp1
+ ld tmp1, X+
+ adc T4, tmp1 /* T = w[s]+e */
+ sbiw r26, 4*5 /* X points at a[0] aka a */
+ ld F1, X+
+ ld F2, X+
+ ld F3, X+
+ ld F4, X+
+ mov tmp1, F4 /* X points at a[1] aka b */
+ ldi tmp2, 5
+1:
+ rol tmp1
+ rol F1
+ rol F2
+ rol F3
+ rol F4
+ dec tmp2
+ brne 1b
+
+ add T1, F1
+ adc T2, F2
+ adc T3, F3
+ adc T4, F4 /* T = ROTL(a,5) + e + w[s] */
+
+ /* now we have to do this fucking conditional stuff */
+ ldi r30, lo8(sha1_nextBlock_xTable)
+ ldi r31, hi8(sha1_nextBlock_xTable)
+ add r30, xtmp
+ adc r31, xNULL
+ lpm tmp1, Z
+ cp tmp1, LoopC
+ brne 1f
+ inc xtmp
+1: ldi r30, lo8(sha1_nextBlock_KTable)
+ ldi r31, hi8(sha1_nextBlock_KTable)
+ lsl xtmp
+ lsl xtmp
+ add r30, xtmp
+ adc r31, xNULL
+ lsr xtmp
+ lsr xtmp
+
+ lpm tmp1, Z+
+ add T1, tmp1
+ lpm tmp1, Z+
+ adc T2, tmp1
+ lpm tmp1, Z+
+ adc T3, tmp1
+ lpm tmp1, Z+
+ adc T4, tmp1
+ /* T = ROTL(a,5) + e + kt + w[s] */
+
+ /* Z-4 is just pointing to kt ... */
+ movw r28, r26 /* copy X in Y */
+ adiw r30, 3*4 /* now Z points to the rigth locatin in our jump-vector-table */
+ lsr r31
+ ror r30
+
+ icall
+ mov F1, tmp1
+ icall
+ mov F2, tmp1
+ icall
+ mov F3, tmp1
+ icall
+
+ add T1, F1
+ adc T2, F2
+ adc T3, F3
+ adc T4, tmp1 /* T = ROTL5(a) + f_t(b,c,d) + e + k_t + w[s] */
+ /* X points still at a[1] aka b, Y points at a[2] aka c */
+ /* update a[] */
+sha1_nextBlock_update_a:
+ /*first we move all vars in a[] "one up" e=d, d=c, c=b, b=a*/
+ //adiw r28, 3*4 /* Y should point at a[4] aka e */
+ movw r28, W1
+ sbiw r28, 4
+
+ ldi tmp2, 4*4
+1:
+ ld tmp1, -Y
+ std Y+4, tmp1
+ dec tmp2
+ brne 1b
+ /* Y points at a[0] aka a*/
+
+ movw r28, W1
+ sbiw r28, 5*4
+ /* store T in a[0] aka a */
+ st Y+, T1
+ st Y+, T2
+ st Y+, T3
+ st Y+, T4
+ /* Y points at a[1] aka b*/
+
+ /* rotate c */
+ ldd T1, Y+1*4
+ ldd T2, Y+1*4+1
+ ldd T3, Y+1*4+2
+ ldd T4, Y+1*4+3
+ mov tmp1, T1
+ ldi tmp2, 2
+1: ror tmp1
+ ror T4
+ ror T3
+ ror T2
+ ror T1
+ dec tmp2
+ brne 1b
+ std Y+1*4+0, T1
+ std Y+1*4+1, T2
+ std Y+1*4+2, T3
+ std Y+1*4+3, T4
+/*
+ push r27
+ push r26
+ movw r26, W1
+ sbiw r26, 4*5
+ dbg_hexdump 4*5
+ pop r26
+ pop r27
+*/
+ inc LoopC
+ cpi LoopC, 80
+ brge 1f
+ rjmp sha1_nextBlock_mainloop
+/**************************************/
+1:
+ /* littel patch */
+ sbiw r28, 4
+
+/* add a[] to state and inc length */
+ pop r27
+ pop r26 /* now X points to state (and Y still at a[0]) */
+ ldi tmp4, 5
+1: clc
+ ldi tmp3, 4
+2: ld tmp1, X
+ ld tmp2, Y+
+ adc tmp1, tmp2
+ st X+, tmp1
+ dec tmp3
+ brne 2b
+ dec tmp4
+ brne 1b
+
+ /* now length += 512 */
+ adiw r26, 1 /* we skip the least significant byte */
+ ld tmp1, X
+ ldi tmp2, hi8(512) /* 2 */
+ add tmp1, tmp2
+ st X+, tmp1
+ ldi tmp2, 6
+1:
+ ld tmp1, X
+ adc tmp1, xNULL
+ st X+, tmp1
+ dec tmp2
+ brne 1b
+
+; EPILOG
+sha1_nextBlock_epilog:
+/* now we should clean up the stack */
+ pop r21
+ pop r20
+ in r0, SREG
+ cli ; we want to be uninterrupted while updating SP
+ out SPL, r20
+ out SREG, r0
+ out SPH, r21
+
+ clr r1
+ pop r29
+ pop r28
+ pop r17
+ pop r16
+ pop r15
+ pop r14
+ pop r13
+ pop r12
+ pop r11
+ pop r10
+ ret
+
+sha1_nextBlock_xTable:
+.byte 20,40,60,0
+sha1_nextBlock_KTable:
+.int 0x5a827999
+.int 0x6ed9eba1
+.int 0x8f1bbcdc
+.int 0xca62c1d6
+sha1_nextBlock_JumpTable:
+rjmp sha1_nextBlock_Ch
+ nop
+rjmp sha1_nextBlock_Parity
+ nop
+rjmp sha1_nextBlock_Maj
+ nop
+rjmp sha1_nextBlock_Parity
+
+ /* X and Y still point at a[1] aka b ; return value in tmp1 */
+sha1_nextBlock_Ch:
+ ld tmp1, Y+
+ mov tmp2, tmp1
+ com tmp2
+ ldd tmp3, Y+3 /* load from c */
+ and tmp1, tmp3
+ ldd tmp3, Y+7 /* load from d */
+ and tmp2, tmp3
+ eor tmp1, tmp2
+ ret
+
+sha1_nextBlock_Maj:
+ ld tmp1, Y+
+ mov tmp2, tmp1
+ ldd tmp3, Y+3 /* load from c */
+ and tmp1, tmp3
+ ldd tmp4, Y+7 /* load from d */
+ and tmp2, tmp4
+ eor tmp1, tmp2
+ and tmp3, tmp4
+ eor tmp1, tmp3
+ ret
+
+sha1_nextBlock_Parity:
+ ld tmp1, Y+
+ ldd tmp2, Y+3 /* load from c */
+ eor tmp1, tmp2
+ ldd tmp2, Y+7 /* load from d */
+ eor tmp1, tmp2
+ ret
+/*
+ch_str: .asciz "\r\nCh"
+maj_str: .asciz "\r\nMaj"
+parity_str: .asciz "\r\nParity"
+*/
+;###########################################################
+
+.global sha1_init
+;void sha1_init(sha1_ctx_t *state){
+; DEBUG_S("\r\nSHA1_INIT");
+; state->h[0] = 0x67452301;
+; state->h[1] = 0xefcdab89;
+; state->h[2] = 0x98badcfe;
+; state->h[3] = 0x10325476;
+; state->h[4] = 0xc3d2e1f0;
+; state->length = 0;
+;}
+; param1: (Func3,r24) 16-bit pointer to sha1_ctx_t struct in ram
+; modifys: Z(r30,r31), Func1, r22
+sha1_init:
+ movw r26, r24 ; (24,25) --> (26,27) load X with param1
+ ldi r30, lo8((sha1_init_vector))
+ ldi r31, hi8((sha1_init_vector))
+ ldi r22, 5*4 /* bytes to copy */
+sha1_init_vloop:
+ lpm r23, Z+
+ st X+, r23
+ dec r22
+ brne sha1_init_vloop
+ ldi r22, 8
+sha1_init_lloop:
+ st X+, r1
+ dec r22
+ brne sha1_init_lloop
+ ret
+
+sha1_init_vector:
+.int 0x67452301;
+.int 0xefcdab89;
+.int 0x98badcfe;
+.int 0x10325476;
+.int 0xc3d2e1f0;
+