; libcrash -- cryptographic hash (and other) functions
;
; Copyright (C) <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/>.
macro max target, [source] {
common
target = 0
forward
if target < source
target = source
end if
}
max MAX_HMAC_HASH_CTX_SIZE, sizeof.ctx_sha2_224256, sizeof.ctx_sha2_384512
max MAX_HMAC_HASH_BLOCK_SIZE, SHA2_224256_BLOCK_SIZE, SHA2_384512_BLOCK_SIZE
max MAX_HMAC_HASH_LEN, SHA2_256_LEN, SHA2_512_LEN
struct ctx_hmac
ctx_hash rb MAX_HMAC_HASH_CTX_SIZE
key_pad rb MAX_HMAC_HASH_BLOCK_SIZE
mac rd MAX_HMAC_HASH_LEN/4
hash_init dd ?
hash_update dd ?
hash_finish dd ?
hash_oneshot dd ?
block_size dd ?
hash_size dd ?
ends
assert sizeof.ctx_hmac <= LIBCRASH_CTX_LEN
; ebx = _ctx
proc hmac._.init uses ebx esi edi, _key, _key_len
mov ecx, [_key_len]
cmp ecx, [ebx+ctx_hmac.block_size]
mov esi, [_key]
jbe .pad
; hash
lea esi, [ebx+ctx_hmac.ctx_hash]
stdcall [ebx+ctx_hmac.hash_oneshot], esi, [_key], [_key_len]
mov ecx, [ebx+ctx_hmac.hash_size]
.pad:
lea edi, [ebx+ctx_hmac.key_pad]
mov edx, [ebx+ctx_hmac.block_size]
sub edx, ecx
xor eax, eax
rep movsb
mov ecx, edx
rep stosb
; xor with 0x36
mov eax, 0x36363636
lea edx, [ebx+ctx_hmac.key_pad]
mov ecx, [ebx+ctx_hmac.block_size]
shr ecx, 2
@@:
xor [edx], eax
add edx, 4
dec ecx
jnz @b
lea esi, [ebx+ctx_hmac.ctx_hash]
stdcall [ebx+ctx_hmac.hash_init], esi
lea eax, [ebx+ctx_hmac.key_pad]
stdcall [ebx+ctx_hmac.hash_update], esi, eax, [ebx+ctx_hmac.block_size]
; xor with 0x36 xor 0x5c
mov eax, 0x36363636 XOR 0x5c5c5c5c
lea edx, [ebx+ctx_hmac.key_pad]
mov ecx, [ebx+ctx_hmac.block_size]
shr ecx, 2
@@:
xor [edx], eax
add edx, 4
dec ecx
jnz @b
ret
endp
proc hmac_sha2_256.init uses ebx, _ctx, _key, _key_len
mov ebx, [_ctx]
mov [ebx+ctx_hmac.hash_init], sha2_256.init
mov [ebx+ctx_hmac.hash_update], sha2_256.update
mov [ebx+ctx_hmac.hash_finish], sha2_256.finish
mov [ebx+ctx_hmac.hash_oneshot], sha2_256.oneshot
mov [ebx+ctx_hmac.block_size], SHA2_256_BLOCK_SIZE
mov [ebx+ctx_hmac.hash_size], SHA2_256_LEN
stdcall hmac._.init, [_key], [_key_len]
ret
endp
proc hmac_sha2_512.init uses ebx, _ctx, _key, _key_len
mov ebx, [_ctx]
mov [ebx+ctx_hmac.hash_init], sha2_512.init
mov [ebx+ctx_hmac.hash_update], sha2_512.update
mov [ebx+ctx_hmac.hash_finish], sha2_512.finish
mov [ebx+ctx_hmac.hash_oneshot], sha2_512.oneshot
mov [ebx+ctx_hmac.block_size], SHA2_512_BLOCK_SIZE
mov [ebx+ctx_hmac.hash_size], SHA2_512_LEN
stdcall hmac._.init, [_key], [_key_len]
ret
endp
hmac_sha2_256.update = hmac._.update
hmac_sha2_512.update = hmac._.update
proc hmac._.update uses ebx esi edi, _ctx, _in, _len
mov ebx, [_ctx]
lea eax, [ebx+ctx_hmac.ctx_hash]
stdcall [ebx+ctx_hmac.hash_update], eax, [_in], [_len]
.quit:
ret
endp
hmac_sha2_256.finish = hmac._.finish
hmac_sha2_512.finish = hmac._.finish
proc hmac._.finish uses ebx esi edi, _ctx
mov ebx, [_ctx]
lea esi, [ebx+ctx_hmac.ctx_hash]
stdcall [ebx+ctx_hmac.hash_finish], esi
lea edi, [ebx+ctx_hmac.mac]
mov ecx, [ebx+ctx_hmac.hash_size]
rep movsb
lea esi, [ebx+ctx_hmac.ctx_hash]
stdcall [ebx+ctx_hmac.hash_init], esi
lea eax, [ebx+ctx_hmac.key_pad]
stdcall [ebx+ctx_hmac.hash_update], esi, eax, [ebx+ctx_hmac.block_size]
lea eax, [ebx+ctx_hmac.mac]
stdcall [ebx+ctx_hmac.hash_update], esi, eax, [ebx+ctx_hmac.hash_size]
stdcall [ebx+ctx_hmac.hash_finish], esi
ret
endp
proc hmac_sha2_256.oneshot _ctx, _in, _len, _key, _key_len
stdcall hmac_sha2_256.init, [_ctx], [_key], [_key_len]
stdcall hmac_sha2_256.update, [_ctx], [_in], [_len]
stdcall hmac_sha2_256.finish, [_ctx]
ret
endp
proc hmac_sha2_512.oneshot _ctx, _in, _len, _key, _key_len
stdcall hmac_sha2_512.init, [_ctx], [_key], [_key_len]
stdcall hmac_sha2_512.update, [_ctx], [_in], [_len]
stdcall hmac_sha2_512.finish, [_ctx]
ret
endp