; libcrash -- cryptographic hash (and other) functions
;
; Copyright (C) <2012-2013,2016,2019,2021> Ivan Baravy
;
; SPDX-License-Identifier: GPL-2.0-or-later
;
; 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 2 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/>.
SHA1_BLOCK_SIZE = 64
SHA1_ALIGN = 4
SHA1_ALIGN_MASK = SHA1_ALIGN - 1
struct ctx_sha1
hash rb SHA1_LEN
block rb SHA1_BLOCK_SIZE
index rd 1
msglen_0 rd 1
msglen_1 rd 1
ends
assert sizeof.ctx_sha1 <= LIBCRASH_CTX_LEN
proc sha1._.f
push ebx ecx edx
xor ecx, edx
and ebx, ecx
xor ebx, edx
mov esi, ebx
pop edx ecx ebx
ret
endp
proc sha1._.g
push ebx ecx edx
xor ebx, ecx
xor ebx, edx
mov esi, ebx
pop edx ecx ebx
ret
endp
proc sha1._.h
push ebx ecx edx
mov esi, ebx
and ebx, ecx
and ecx, edx
and esi, edx
or ebx, ecx
or esi, ebx
pop edx ecx ebx
ret
endp
macro sha1._.round f, k, c
{
mov esi, eax
rol esi, 5
mov [temp], esi
call f
add esi, edi
add [temp], esi
mov esi, [w + (c)*4]
add esi, k
add [temp], esi
mov edi, edx
mov edx, ecx
mov ecx, ebx
rol ecx, 30
mov ebx, eax
mov eax, [temp]
}
proc sha1.init uses ebx esi edi, _ctx
mov ebx, [_ctx]
lea edi, [ebx + ctx_sha1.hash]
mov esi, sha1._.hash_init
mov ecx, SHA1_LEN/4
rep movsd
xor eax, eax
mov [ebx + ctx_sha1.index], eax
mov [ebx + ctx_sha1.msglen_0], eax
mov [ebx + ctx_sha1.msglen_1], eax
ret
endp
proc sha1._.block _hash
locals
temp rd 1
w rd 80
endl
lea edi, [w]
xor ecx, ecx
@@:
mov eax, [esi]
add esi, 4
bswap eax
mov [edi], eax
add edi, 4
add ecx, 1
cmp ecx, 16
jne @b
@@:
mov eax, [w + (ecx - 3)*4]
xor eax, [w + (ecx - 8)*4]
xor eax, [w + (ecx - 14)*4]
xor eax, [w + (ecx - 16)*4]
rol eax, 1
mov [w + ecx*4], eax
add ecx, 1
cmp ecx, 80
jne @b
mov edi, [_hash]
mov eax, [edi + 0x00]
mov ebx, [edi + 0x04]
mov ecx, [edi + 0x08]
mov edx, [edi + 0x0c]
mov edi, [edi + 0x10]
push esi
repeat 20
sha1._.round sha1._.f, 0x5a827999, %-1
end repeat
repeat 20
sha1._.round sha1._.g, 0x6ed9eba1, %-1+20
end repeat
repeat 20
sha1._.round sha1._.h, 0x8f1bbcdc, %-1+40
end repeat
repeat 20
sha1._.round sha1._.g, 0xca62c1d6, %-1+60
end repeat
pop esi
mov [temp], edi
mov edi, [_hash]
add [edi + 0x00], eax
add [edi + 0x04], ebx
add [edi + 0x08], ecx
add [edi + 0x0c], edx
mov eax, [temp]
add [edi + 0x10], eax
ret
endp
proc sha1.update uses ebx esi edi, _ctx, _msg, _size
mov ebx, [_ctx]
mov ecx, [_size]
add [ebx + ctx_sha1.msglen_0], ecx
adc [ebx + ctx_sha1.msglen_1], 0
.next_block:
mov ebx, [_ctx]
mov esi, [_msg]
mov eax, [ebx + ctx_sha1.index]
and eax, SHA1_BLOCK_SIZE-1
jnz .copy_to_buf
test esi, SHA1_ALIGN_MASK
jnz .copy_to_buf
.no_copy:
; data is aligned, hash it in place without copying
mov ebx, [_ctx]
cmp [_size], SHA1_BLOCK_SIZE
jb .copy_quit
lea eax, [ebx + ctx_sha1.hash]
stdcall sha1._.block, eax
sub [_size], SHA1_BLOCK_SIZE
; add esi, SHA1_BLOCK_SIZE ; FIXME
jmp .no_copy
.copy_to_buf:
lea edi, [ebx + ctx_sha1.block]
add edi, eax
mov ecx, SHA1_BLOCK_SIZE
sub ecx, eax
cmp [_size], ecx
jb .copy_quit
sub [_size], ecx
add [_msg], ecx
add [ebx + ctx_sha1.index], ecx
rep movsb
lea eax, [ebx + ctx_sha1.hash]
lea esi, [ebx + ctx_sha1.block]
stdcall sha1._.block, eax
jmp .next_block
.copy_quit:
mov ebx, [_ctx]
lea edi, [ebx + ctx_sha1.block]
mov eax, [ebx + ctx_sha1.index]
and eax, SHA1_BLOCK_SIZE-1
add edi, eax
mov ecx, [_size]
add [ebx + ctx_sha1.index], ecx
rep movsb
.quit:
ret
endp
proc sha1.finish uses ebx esi edi, _ctx
mov ebx, [_ctx]
lea edi, [ebx + ctx_sha1.block]
mov ecx, [ebx + ctx_sha1.msglen_0]
and ecx, SHA1_BLOCK_SIZE-1
add edi, ecx
mov byte[edi], 0x80
inc edi
neg ecx
add ecx, SHA1_BLOCK_SIZE
cmp ecx, 8
ja .last
dec ecx
xor eax, eax
rep stosb
lea esi, [ebx + ctx_sha1.block]
lea eax, [ebx + ctx_sha1.hash]
stdcall sha1._.block, eax
mov ebx, [_ctx]
lea edi, [ebx + ctx_sha1.block]
mov ecx, SHA1_BLOCK_SIZE+1
.last:
dec ecx
sub ecx, 8
xor eax, eax
rep stosb
mov eax, [ebx + ctx_sha1.msglen_0]
mov edx, [ebx + ctx_sha1.msglen_1]
shld edx, eax, 3
shl eax, 3
bswap eax
bswap edx
mov dword[edi], edx
mov dword[edi+4], eax
lea esi, [ebx + ctx_sha1.block]
lea eax, [ebx + ctx_sha1.hash]
stdcall sha1._.block, eax
mov ebx, [_ctx]
lea eax, [ebx + ctx_sha1.hash]
stdcall sha1._.postprocess, ebx, eax
ret
endp
proc sha1._.postprocess _ctx, _hash
mov ecx, 5
mov esi, [_hash]
mov edi, esi
@@:
lodsd
bswap eax
stosd
dec ecx
jnz @b
ret
endp
proc sha1.oneshot _ctx, _data, _len
stdcall sha1.init, [_ctx]
stdcall sha1.update, [_ctx], [_data], [_len]
stdcall sha1.finish, [_ctx]
ret
endp
iglobal
align SHA1_ALIGN
sha1._.hash_init dd 0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0xc3d2e1f0
endg