Commit 3456614a authored by Niels Möller's avatar Niels Möller
Browse files

New file.

Rev: src/nettle/sparc/aes-decrypt-internal.asm:1.1
parent eb819e1e
C -*- mode: asm; asm-comment-char: ?C; -*-
C nettle, low-level cryptographics library
C
C Copyright (C) 2002, 2005 Niels Mller
C
C The nettle library is free software; you can redistribute it and/or modify
C it under the terms of the GNU Lesser General Public License as published by
C the Free Software Foundation; either version 2.1 of the License, or (at your
C option) any later version.
C
C The nettle library is distributed in the hope that it will be useful, but
C WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
C or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
C License for more details.
C
C You should have received a copy of the GNU Lesser General Public License
C along with the nettle library; see the file COPYING.LIB. If not, write to
C the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
C MA 02111-1307, USA.
C Arguments
define(<CTX>, <%i0>)
define(<T>, <%i1>)
define(<LENGTH>,<%i2>)
define(<DST>, <%i3>)
define(<SRC>, <%i4>)
C AES state, two copies for unrolling
define(<W0>, <%l0>)
define(<W1>, <%l1>)
define(<W2>, <%l2>)
define(<W3>, <%l3>)
define(<X0>, <%l4>)
define(<X1>, <%l5>)
define(<X2>, <%l6>)
define(<X3>, <%l7>)
C %o0-%03 are used for loop invariants T0-T3
define(<KEY>, <%o4>)
define(<ROUND>, <%o5>)
C %g1 and %g2 are TMP1 and TMP2
C Registers %g1-%g3 and %o0 - %o5 are free to use.
C The sparc32 stack frame looks like
C
C %fp - 4: OS-dependent link field
C %fp - 8: OS-dependent link field
C %fp - 24: tmp, uint32_t[4]
C %fp - 40: wtxt, uint32_t[4]
C %fp - 136: OS register save area.
define(<FRAME_SIZE>, 136)
.file "aes-decrypt-internal.asm"
C _aes_decrypt(struct aes_context *ctx,
C const struct aes_table *T,
C unsigned length, uint8_t *dst,
C uint8_t *src)
.section ".text"
.align 16
.proc 020
PROLOGUE(_nettle_aes_decrypt)
save %sp, -FRAME_SIZE, %sp
cmp LENGTH, 0
be .Lend
C Loop invariants
add T, AES_TABLE0, T0
add T, AES_TABLE1, T1
add T, AES_TABLE2, T2
add T, AES_TABLE3, T3
.Lblock_loop:
C Read src, and add initial subkey
add CTX, AES_KEYS, KEY
AES_LOAD(0, SRC, KEY, W0)
AES_LOAD(1, SRC, KEY, W1)
AES_LOAD(2, SRC, KEY, W2)
AES_LOAD(3, SRC, KEY, W3)
C Must be even, and includes the final round
ld [AES_NROUNDS + CTX], ROUND
add SRC, 16, SRC
add KEY, 16, KEY
srl ROUND, 1, ROUND
C Last two rounds handled specially
sub ROUND, 1, ROUND
.Lround_loop:
C The AES_ROUND macro uses T0,... T3
C Transform W -> X
AES_ROUND(0, W0, W3, W2, W1, KEY, X0)
AES_ROUND(1, W1, W0, W3, W2, KEY, X1)
AES_ROUND(2, W2, W1, W0, W3, KEY, X2)
AES_ROUND(3, W3, W2, W1, W0, KEY, X3)
C Transform X -> W
AES_ROUND(4, X0, X3, X2, X1, KEY, W0)
AES_ROUND(5, X1, X0, X3, X2, KEY, W1)
AES_ROUND(6, X2, X1, X0, X3, KEY, W2)
AES_ROUND(7, X3, X2, X1, X0, KEY, W3)
subcc ROUND, 1, ROUND
bne .Lround_loop
add KEY, 32, KEY
C Penultimate round
AES_ROUND(0, W0, W3, W2, W1, KEY, X0)
AES_ROUND(1, W1, W0, W3, W2, KEY, X1)
AES_ROUND(2, W2, W1, W0, W3, KEY, X2)
AES_ROUND(3, W3, W2, W1, W0, KEY, X3)
add KEY, 16, KEY
C Final round
AES_FINAL_ROUND(0, T, X0, X3, X2, X1, KEY, DST)
AES_FINAL_ROUND(1, T, X1, X0, X3, X2, KEY, DST)
AES_FINAL_ROUND(2, T, X2, X1, X0, X3, KEY, DST)
AES_FINAL_ROUND(3, T, X3, X2, X1, X0, KEY, DST)
subcc LENGTH, 16, LENGTH
bne .Lblock_loop
add DST, 16, DST
.Lend:
ret
restore
EPILOGUE(_nettle_aes_decrypt)
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