; Copyright 2015 Egor Tensin <Egor.Tensin@gmail.com>
; This file is licensed under the terms of the MIT License.
; See LICENSE.txt for details.
.586
.xmm
.model flat
.data
align 10h
key_schedule oword 13 dup(0)
align 10h
inverted_key_schedule oword 13 dup(0)
.code
@raw_aes192ecb_encrypt@48 proc
call expand_keys_192ecb
pxor xmm0, [key_schedule]
aesenc xmm0, [key_schedule + 10h]
aesenc xmm0, [key_schedule + 20h]
aesenc xmm0, [key_schedule + 30h]
aesenc xmm0, [key_schedule + 40h]
aesenc xmm0, [key_schedule + 50h]
aesenc xmm0, [key_schedule + 60h]
aesenc xmm0, [key_schedule + 70h]
aesenc xmm0, [key_schedule + 80h]
aesenc xmm0, [key_schedule + 90h]
aesenc xmm0, [key_schedule + 0A0h]
aesenc xmm0, [key_schedule + 0B0h]
aesenclast xmm0, [key_schedule + 0C0h]
ret
@raw_aes192ecb_encrypt@48 endp
@raw_aes192ecb_decrypt@48 proc
call expand_keys_192ecb
pxor xmm0, [inverted_key_schedule]
aesdec xmm0, [inverted_key_schedule + 10h]
aesdec xmm0, [inverted_key_schedule + 20h]
aesdec xmm0, [inverted_key_schedule + 30h]
aesdec xmm0, [inverted_key_schedule + 40h]
aesdec xmm0, [inverted_key_schedule + 50h]
aesdec xmm0, [inverted_key_schedule + 60h]
aesdec xmm0, [inverted_key_schedule + 70h]
aesdec xmm0, [inverted_key_schedule + 80h]
aesdec xmm0, [inverted_key_schedule + 90h]
aesdec xmm0, [inverted_key_schedule + 0A0h]
aesdec xmm0, [inverted_key_schedule + 0B0h]
aesdeclast xmm0, [inverted_key_schedule + 0C0h]
ret
@raw_aes192ecb_decrypt@48 endp
expand_keys_192ecb proc
; A "word" (in terms of the FIPS 187 standard) is a 32-bit block.
; Words are denoted by `w[N]`.
;
; A key schedule is composed of 12 "regular" keys and a dumb key for
; the "whitening" step.
; It's stored in `key_schedule`.
;
; A key schedule is thus composed of 52 "words".
; The FIPS standard includes an algorithm to calculate these words via
; a simple loop:
;
; i = 6
; while i < 52:
; temp = w[i - 1]
; if i % 6 == 0:
; temp = SubWord(RotWord(temp))^Rcon
; w[i] = w[i - 6]^temp
; i = i + 1
;
; The loop above may be unrolled like this:
;
; w[6] = SubWord(RotWord(w[5]))^Rcon^w[0]
; w[7] = w[6]^w[1]
; = SubWord(RotWord(w[5]))^Rcon^w[0]^w[1]
; w[8] = w[7]^w[2]
; = SubWord(RotWord(w[5]))^Rcon^w[0]^w[1]^w[2]
; w[9] = w[8]^w[3]
; = SubWord(RotWord(w[5]))^Rcon^w[0]^w[1]^w[2]^w[3]
; w[10] = w[9]^w[4]
; = SubWord(RotWord(w[5]))^Rcon^w[0]^w[1]^w[2]^w[3]^w[4]
; w[11] = w[10]^w[5]
; = SubWord(RotWord(w[5]))^Rcon^w[0]^w[1]^w[2]^w[3]^w[4]^w[5]
; w[12] = SubWord(RotWord(w[11]))^Rcon^w[6]
; w[13] = w[12]^w[7]
; = SubWord(RotWord(w[11]))^Rcon^w[6]^w[7]
; w[14] = w[13]^w[8]
; = SubWord(RotWord(w[11]))^Rcon^w[6]^w[7]^w[8]
; w[15] = w[14]^w[9]
; = SubWord(RotWord(w[11]))^Rcon^w[6]^w[7]^w[8]^w[9]
; w[16] = w[15]^w[10]
; = SubWord(RotWord(w[11]))^Rcon^w[6]^w[7]^w[8]^w[9]^w[10]
; w[17] = w[16]^w[11]
; = SubWort(RotWord(w[11]))^Rcon^w[6]^w[7]^w[8]^w[9]^w[10]^w[11]
;
; ... and so on.
;
; The Intel AES-NI instruction set facilitates calculating SubWord
; and RotWord using `aeskeygenassist`, which is used in this routine.
;
; Preconditions:
; * xmm2[63:32] == w[5],
; * xmm2[31:0] == w[4],
; * xmm1[127:96] == w[3],
; * xmm1[95:64] == w[2],
; * xmm1[63:32] == w[1],
; * xmm1[31:0] == w[0].
movdqa [key_schedule], xmm1 ; sets w[0], w[1], w[2], w[3]
movdqa [key_schedule + 10h], xmm2 ; sets w[4], w[5]
lea ecx, [key_schedule + 18h] ; ecx = &w[6]
aeskeygenassist xmm7, xmm2, 1 ; xmm7[63:32] = RotWord(SubWord(w[5]))^Rcon,
call gen_round_key ; sets w[6], w[7], w[8], w[9], w[10], w[11]
aeskeygenassist xmm7, xmm2, 2 ; xmm7[63:32] = RotWord(SubWord(w[11]))^Rcon
call gen_round_key ; sets w[12], w[13], w[14], w[15], w[16], w[17]
aeskeygenassist xmm7, xmm2, 4 ; xmm7[63:32] = RotWord(SubWord(w[17]))^Rcon
call gen_round_key ; sets w[18], w[19], w[20], w[21], w[22], w[23]
aeskeygenassist xmm7, xmm2, 8 ; xmm7[63:32] = RotWord(SubWord(w[23]))^Rcon
call gen_round_key ; sets w[24], w[25], w[26], w[27], w[28], w[29]
aeskeygenassist xmm7, xmm2, 10h ; xmm7[63:32] = RotWord(SubWord(w[29]))^Rcon
call gen_round_key ; sets w[30], w[31], w[32], w[33], w[34], w[35]
aeskeygenassist xmm7, xmm2, 20h ; xmm7[63:32] = RotWord(SubWord(w[35]))^Rcon
call gen_round_key ; sets w[36], w[37], w[38], w[39], w[40], w[41]
aeskeygenassist xmm7, xmm2, 40h ; xmm7[63:32] = RotWord(SubWord(w[41]))^Rcon
call gen_round_key ; sets w[42], w[43], w[44], w[45], w[46], w[47]
aeskeygenassist xmm7, xmm2, 80h ; xmm7[63:32] = RotWord(SubWord(w[49]))^Rcon
call gen_round_key ; sets w[48], w[49], w[50], w[51], w[52], w[53] // FIXME
call invert_key_schedule
ret
gen_round_key:
; Preconditions:
; * xmm2[127:96] == 0,
; * xmm2[95:64] == 0,
; * xmm2[63:32] == w[i+5],
; * xmm2[31:0] == w[i+4],
; * xmm1[127:96] == w[i+3],
; * xmm1[95:64] == w[i+2],
; * xmm1[63:32] == w[i+1],
; * xmm1[31:0] == w[i],
; * xmm7[63:32] == RotWord(SubWord(w[i+5]))^Rcon,
; * ecx == &w[i+6].
;
; Postconditions:
; * xmm2[127:96] == 0,
; * xmm2[95:64] == 0,
; * xmm2[63:32] == w[i+11] == RotWord(SubWord(w[i+5]))^Rcon^w[i+5]^w[i+4]^w[i+3]^w[i+2]^w[i+1]^w[i],
; * xmm2[31:0] == w[i+10] == RotWord(SubWord(w[i+5]))^Rcon^w[i+4]^w[i+3]^w[i+2]^w[i+1]^w[i],
; * xmm1[127:96] == w[i+9] == RotWord(SubWord(w[i+5]))^Rcon^w[i+3]^w[i+2]^w[i+1]^w[i],
; * xmm1[95:64] == w[i+8] == RotWord(SubWord(w[i+5]))^Rcon^w[i+2]^w[i+1]^w[i],
; * xmm1[63:32] == w[i+7] == RotWord(SubWord(w[i+5]))^Rcon^w[i+1]^w[i],
; * xmm1[31:0] == w[i+6] == RotWord(SubWord(w[i+5]))^Rcon^w[i],
; * ecx == &w[i+12],
; * the value in xmm6 is also modified.
; Calculate
; w[i+3]^w[i+2]^w[i+1]^w[i],
; w[i+2]^w[i+1]^w[i],
; w[i+1]^w[i] and
; w[i].
movdqa xmm6, xmm1 ; xmm6 = xmm1
pslldq xmm6, 4 ; xmm6 <<= 32
pxor xmm1, xmm6 ; xmm1 ^= xmm6
pslldq xmm6, 4 ; xmm6 <<= 32
pxor xmm1, xmm6 ; xmm1 ^= xmm6
pslldq xmm6, 4 ; xmm6 <<= 32
pxor xmm1, xmm6 ; xmm1 ^= xmm6
; xmm1[127:96] == w[i+3]^w[i+2]^w[i+1]^w[i]
; xmm1[95:64] == w[i+2]^w[i+1]^w[i]
; xmm1[63:32] == w[i+1]^w[i]
; xmm1[31:0] == w[i]
; Calculate
; w[i+9] == RotWord(SubWord(w[i+5]))^Rcon^w[i+3]^w[i+2]^w[i+1]^w[i],
; w[i+8] == RotWord(SubWord(w[i+5]))^Rcon^w[i+2]^w[i+1]^w[i],
; w[i+7] == RotWord(SubWord(w[i+5]))^Rcon^w[i+1]^w[i] and
; w[i+6] == RotWord(SubWord(w[i+5]))^Rcon^w[i].
pshufd xmm6, xmm7, 55h ; xmm6[127:96] = xmm6[95:64] = xmm6[63:32] = xmm6[31:0] = xmm7[63:32]
pxor xmm1, xmm6 ; xmm1 ^= xmm6
; xmm1[127:96] == w[i+9] == RotWord(SubWord(w[i+5]))^Rcon^w[i+3]^w[i+2]^w[i+1]^w[i]
; xmm1[95:64] == w[i+8] == RotWord(SubWord(w[i+5]))^Rcon^w[i+2]^w[i+1]^w[i]
; xmm1[63:32] == w[i+7] == RotWord(SubWord(w[i+5]))^Rcon^w[i+1]^w[i]
; xmm1[31:0] == w[i+6] == RotWord(SubWord(w[i+5]))^Rcon^w[i]
; Set w[i+6], w[i+7], w[i+8] and w[i+9].
movdqu [ecx], xmm1 ; w[i+6] = RotWord(SubWord(w[i+5]))^Rcon^w[i]
; w[i+7] = RotWord(SubWord(w[i+5]))^Rcon^w[i+1]^w[i]
; w[i+8] = RotWord(SubWord(w[i+5]))^Rcon^w[i+2]^w[i+1]^w[i]
; w[i+9] = RotWord(SubWord(w[i+5]))^Rcon^w[i+3]^w[i+2]^w[i+1]^w[i]
add ecx, 10h ; ecx = &w[i+10]
; Calculate
; w[i+5]^w[i+4],
; w[i+4].
pshufd xmm6, xmm2, 0F3h ; xmm6 = xmm2[31:0] << 32
pxor xmm2, xmm6 ; xmm2 ^= xmm7
; xmm2[63:32] == w[i+5]^w[i+4]
; xmm2[31:0] == w[i+4]
; Calculate
; w[i+10] == RotWord(SubWord(w[i+5]))^Rcon^w[i+5]^w[i+4]^w[i+3]^w[i+2]^w[i+1]^w[i],
; w[i+11] == RotWord(SubWord(w[i+5]))^Rcon^w[i+4]^w[i+3]^w[i+2]^w[i+1]^w[i].
pshufd xmm6, xmm1, 0FFh ; xmm6[127:96] = xmm6[95:64] = xmm6[63:32] = xmm6[31:0] = xmm1[127:96]
psrldq xmm6, 8 ; xmm6 >>= 64
pxor xmm2, xmm6 ; xmm2 ^= xmm6
; xmm2[63:32] == w[i+11] == RotWord(SubWord(w[i+5]))^Rcon^w[i+5]^w[i+4]^w[i+3]^w[i+2]^w[i+1]^w[i]
; xmm2[31:0] == w[i+10] == RotWord(SubWord(w[i+5]))^Rcon^w[i+4]^w[i+3]^w[i+2]^w[i+1]^w[i]
; Set w[i+10] and w[i+11].
movq qword ptr [ecx], xmm2 ; w[i+10] = RotWord(SubWord(w[i+5]))^Rcon^w[i+4]^w[i+3]^w[i+2]^w[i+1]^w[i]
; w[i+11] = RotWord(SubWord(w[i+5]))^Rcon^w[i+5]^w[i+4]^w[i+3]^w[i+2]^w[i+1]^w[i]
add ecx, 8 ; ecx = &w[i+12]
ret
invert_key_schedule:
movdqa xmm7, [key_schedule]
movdqa xmm6, [key_schedule + 0C0h]
movdqa [inverted_key_schedule], xmm6
movdqa [inverted_key_schedule + 0C0h], xmm7
aesimc xmm7, [key_schedule + 10h]
aesimc xmm6, [key_schedule + 0B0h]
movdqa [inverted_key_schedule + 10h], xmm6
movdqa [inverted_key_schedule + 0B0h], xmm7
aesimc xmm7, [key_schedule + 20h]
aesimc xmm6, [key_schedule + 0A0h]
movdqa [inverted_key_schedule + 20h], xmm6
movdqa [inverted_key_schedule + 0A0h], xmm7
aesimc xmm7, [key_schedule + 30h]
aesimc xmm6, [key_schedule + 90h]
movdqa [inverted_key_schedule + 30h], xmm6
movdqa [inverted_key_schedule + 90h], xmm7
aesimc xmm7, [key_schedule + 40h]
aesimc xmm6, [key_schedule + 80h]
movdqa [inverted_key_schedule + 40h], xmm6
movdqa [inverted_key_schedule + 80h], xmm7
aesimc xmm7, [key_schedule + 50h]
aesimc xmm6, [key_schedule + 70h]
movdqa [inverted_key_schedule + 50h], xmm6
movdqa [inverted_key_schedule + 70h], xmm7
aesimc xmm7, [key_schedule + 60h]
movdqa [inverted_key_schedule + 60h], xmm7
ret
expand_keys_192ecb endp
end
