1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
C x86_64/poly1305-internal.asm
ifelse(<
Copyright (C) 2013 Niels Möller
This file is part of GNU Nettle.
GNU Nettle is free software: you can redistribute it and/or
modify it under the terms of either:
* the GNU Lesser General Public License as published by the Free
Software Foundation; either version 3 of the License, or (at your
option) any later version.
or
* 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.
or both in parallel, as here.
GNU Nettle 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 copies of the GNU General Public License and
the GNU Lesser General Public License along with this program. If
not, see http://www.gnu.org/licenses/.
>)
.file "poly1305-internal.asm"
C Registers mainly used by poly1305_block
define(<CTX>, <%rdi>)
define(<T0>, <%rcx>)
define(<T1>, <%rsi>)
define(<T2>, <%r8>)
define(<H0>, <%r9>)
define(<H1>, <%r10>)
define(<H2>, <%r11>)
C poly1305_set_key(struct poly1305_ctx *ctx, const uint8_t key[16])
.text
C Registers:
C %rdi: ctx
C %rsi: key
C %r8: mask
ALIGN(16)
PROLOGUE(nettle_poly1305_set_key)
W64_ENTRY(2,0)
mov $0x0ffffffc0fffffff, %r8
mov (%rsi), %rax
and %r8, %rax
and $-4, %r8
mov %rax, (CTX)
mov 8(%rsi), %rax
and %r8, %rax
mov %rax, P1305_R1 (CTX)
shr $2, %rax
imul $5, %rax
mov %rax, P1305_S1 (CTX)
xor XREG(%rax), XREG(%rax)
mov %rax, P1305_H0 (CTX)
mov %rax, P1305_H1 (CTX)
mov XREG(%rax), P1305_H2 (CTX)
W64_EXIT(2,0)
ret
EPILOGUE(nettle_poly1305_set_key)
C 64-bit multiplication mod 2^130 - 5
C
C (x_0 + B x_1 + B^2 x_2) * (r_0 + B r_1) =
C 1 B B^2 B^3
C x_0 r_0
C x_0 r_1
C x_1 r_0
C x_1 r_1
C x_2 r_0
C x_2 r_1
C Then r_1 B^2 = r_1/4 (2^130) = 5/4 r_1.
C and r_1 B^3 = 5/4 B r_1
C So we get
C
C x_0 r_0 + x_1 (5/4 r_1) + B (x_0 r_1 + x_1 r_0 + x_2 5/4 r_1 + B x_2 r_0)
C 1 B B^2 B^3
C x_0 r_0
C x_1 r'_1
C x_0 r_1
C x_1 r_0
C x_2 r'_1
C x_2 r_0
C _poly1305_block (struct poly1305_ctx *ctx, const uint8_t m[16], unsigned hi)
PROLOGUE(_nettle_poly1305_block)
W64_ENTRY(3, 0)
mov (%rsi), T0
mov 8(%rsi), T1
mov XREG(%rdx), XREG(T2)
C Registers:
C Inputs: CTX, T0, T1, T2,
C Outputs: H0, H1, H2, stored into the context.
add P1305_H0 (CTX), T0
adc P1305_H1 (CTX), T1
adc P1305_H2 (CTX), XREG(T2)
mov P1305_R0 (CTX), %rax
mul T0 C x0*r0
mov %rax, H0
mov %rdx, H1
mov P1305_S1 (CTX), %rax C 5/4 r1
mov %rax, H2
mul T1 C x1*r1'
imul T2, H2 C x2*r1'
imul P1305_R0 (CTX), T2 C x2*r0
add %rax, H0
adc %rdx, H1
mov P1305_R0 (CTX), %rax
mul T1 C x1*r0
add %rax, H2
adc %rdx, T2
mov P1305_R1 (CTX), %rax
mul T0 C x0*r1
add %rax, H2
adc %rdx, T2
mov T2, %rax
shr $2, %rax
imul $5, %rax
and $3, XREG(T2)
add %rax, H0
adc H2, H1
adc $0, XREG(T2)
mov H0, P1305_H0 (CTX)
mov H1, P1305_H1 (CTX)
mov XREG(T2), P1305_H2 (CTX)
W64_EXIT(3, 0)
ret
EPILOGUE(_nettle_poly1305_block)
C poly1305_digest (struct poly1305_ctx *ctx, uint8_t *s)
C Registers:
C %rdi: ctx
C %rsi: s
PROLOGUE(nettle_poly1305_digest)
W64_ENTRY(2, 0)
mov P1305_H0 (CTX), H0
mov P1305_H1 (CTX), H1
mov P1305_H2 (CTX), XREG(H2)
mov XREG(H2), XREG(%rax)
shr $2, XREG(%rax)
and $3, H2
imul $5, XREG(%rax)
add %rax, H0
adc $0, H1
adc $0, XREG(H2)
C Use %rax instead of %rsi
define(<T1>, <%rax>)
C Add 5, use result if >= 2^130
mov $5, T0
xor T1, T1
add H0, T0
adc H1, T1
adc $0, XREG(H2)
cmp $4, XREG(H2)
cmovnc T0, H0
cmovnc T1, H1
add H0, (%rsi)
adc H1, 8(%rsi)
xor XREG(%rax), XREG(%rax)
mov %rax, P1305_H0 (CTX)
mov %rax, P1305_H1 (CTX)
mov XREG(%rax), P1305_H2 (CTX)
W64_EXIT(2, 0)
ret
|
