1#!/bin/bash
2# Copyright 2020 The Go Authors. All rights reserved.
3# Use of this source code is governed by a BSD-style
4# license that can be found in the LICENSE file.
5
6# Do not run directly; run build.sh, which runs this in Docker.
7# This script builds goboringcrypto's syso, after boringssl has been built.
8
9export TERM=dumb
10
11set -e
12set -x
13id
14date
15export LANG=C
16unset LANGUAGE
17
18case $(uname -m) in
19x86_64) export GOARCH=amd64 ;;
20aarch64) export GOARCH=arm64 ;;
21*)
22 echo 'unknown uname -m:' $(uname -m) >&2
23 exit 2
24esac
25
26export CGO_ENABLED=0
27
28# Build and run test C++ program to make sure goboringcrypto.h matches openssl/*.h.
29# Also collect list of checked symbols in syms.txt
30set -e
31cd /boring/godriver
32cat >goboringcrypto.cc <<'EOF'
33#include <cassert>
34#include "goboringcrypto0.h"
35#include "goboringcrypto1.h"
36#define check_size(t) if(sizeof(t) != sizeof(GO_ ## t)) {printf("sizeof(" #t ")=%d, but sizeof(GO_" #t ")=%d\n", (int)sizeof(t), (int)sizeof(GO_ ## t)); ret=1;}
37#define check_func(f) { auto x = f; x = _goboringcrypto_ ## f ; }
38#define check_value(n, v) if(n != v) {printf(#n "=%d, but goboringcrypto.h defines it as %d\n", (int)n, (int)v); ret=1;}
39int main() {
40int ret = 0;
41#include "goboringcrypto.x"
42return ret;
43}
44EOF
45
46cat >boringx.awk <<'EOF'
47BEGIN {
48 exitcode = 0
49}
50
51# Ignore comments, #includes, blank lines.
52/^\/\// || /^#/ || NF == 0 { next }
53
54# Ignore unchecked declarations.
55/\/\*unchecked/ { next }
56
57# Check enum values.
58!enum && ($1 == "enum" || $2 == "enum") && $NF == "{" {
59 enum = 1
60 next
61}
62enum && $1 == "};" {
63 enum = 0
64 next
65}
66enum && /^}.*;$/ {
67 enum = 0
68 next
69}
70enum && NF == 3 && $2 == "=" {
71 name = $1
72 sub(/^GO_/, "", name)
73 val = $3
74 sub(/,$/, "", val)
75 print "check_value(" name ", " val ")" > "goboringcrypto.x"
76 next
77}
78enum {
79 print FILENAME ":" NR ": unexpected line in enum: " $0 > "/dev/stderr"
80 exitcode = 1
81 next
82}
83
84# Check struct sizes.
85/^typedef struct / && $NF ~ /^GO_/ {
86 name = $NF
87 sub(/^GO_/, "", name)
88 sub(/;$/, "", name)
89 print "check_size(" name ")" > "goboringcrypto.x"
90 next
91}
92
93# Check function prototypes.
94/^(const )?[^ ]+ \**_goboringcrypto_.*\(/ {
95 name = $2
96 if($1 == "const")
97 name = $3
98 sub(/^\**_goboringcrypto_/, "", name)
99 sub(/\(.*/, "", name)
100 print "check_func(" name ")" > "goboringcrypto.x"
101 print name > "syms.txt"
102 next
103}
104
105{
106 print FILENAME ":" NR ": unexpected line: " $0 > "/dev/stderr"
107 exitcode = 1
108}
109
110END {
111 exit exitcode
112}
113EOF
114
115cat >boringh.awk <<'EOF'
116/^\/\/ #include/ {sub(/\/\//, ""); print > "goboringcrypto0.h"; next}
117/typedef struct|enum ([a-z_]+ )?{|^[ \t]/ {print >"goboringcrypto1.h";next}
118{gsub(/GO_/, ""); gsub(/enum go_/, "enum "); gsub(/go_point_conv/, "point_conv"); print >"goboringcrypto1.h"}
119EOF
120
121awk -f boringx.awk goboringcrypto.h # writes goboringcrypto.x
122awk -f boringh.awk goboringcrypto.h # writes goboringcrypto[01].h
123
124ls -l ../boringssl/include
125clang++ -std=c++11 -fPIC -I../boringssl/include -O2 -o a.out goboringcrypto.cc
126./a.out || exit 2
127
128# clang implements u128 % u128 -> u128 by calling __umodti3,
129# which is in libgcc. To make the result self-contained even if linking
130# against a different compiler version, link our own __umodti3 into the syso.
131# This one is specialized so it only expects divisors below 2^64,
132# which is all BoringCrypto uses. (Otherwise it will seg fault.)
133cat >umod-amd64.s <<'EOF'
134# tu_int __umodti3(tu_int x, tu_int y)
135# x is rsi:rdi, y is rcx:rdx, return result is rdx:rax.
136.globl __umodti3
137__umodti3:
138 # specialized to u128 % u64, so verify that
139 test %rcx,%rcx
140 jne 1f
141
142 # save divisor
143 movq %rdx, %r8
144
145 # reduce top 64 bits mod divisor
146 movq %rsi, %rax
147 xorl %edx, %edx
148 divq %r8
149
150 # reduce full 128-bit mod divisor
151 # quotient fits in 64 bits because top 64 bits have been reduced < divisor.
152 # (even though we only care about the remainder, divq also computes
153 # the quotient, and it will trap if the quotient is too large.)
154 movq %rdi, %rax
155 divq %r8
156
157 # expand remainder to 128 for return
158 movq %rdx, %rax
159 xorl %edx, %edx
160 ret
161
1621:
163 # crash - only want 64-bit divisor
164 xorl %ecx, %ecx
165 movl %ecx, 0(%ecx)
166 jmp 1b
167
168.section .note.GNU-stack,"",@progbits
169EOF
170
171cat >umod-arm64.c <<'EOF'
172typedef unsigned int u128 __attribute__((mode(TI)));
173
174static u128 div(u128 x, u128 y, u128 *rp) {
175 int n = 0;
176 while((y>>(128-1)) != 1 && y < x) {
177 y<<=1;
178 n++;
179 }
180 u128 q = 0;
181 for(;; n--, y>>=1, q<<=1) {
182 if(x>=y) {
183 x -= y;
184 q |= 1;
185 }
186 if(n == 0)
187 break;
188 }
189 if(rp)
190 *rp = x;
191 return q;
192}
193
194u128 __umodti3(u128 x, u128 y) {
195 u128 r;
196 div(x, y, &r);
197 return r;
198}
199
200u128 __udivti3(u128 x, u128 y) {
201 return div(x, y, 0);
202}
203EOF
204
205extra=""
206case $GOARCH in
207amd64)
208 cp umod-amd64.s umod.s
209 clang -c -o umod.o umod.s
210 extra=umod.o
211 ;;
212arm64)
213 cp umod-arm64.c umod.c
214 clang -c -o umod.o umod.c
215 extra=umod.o
216 ;;
217esac
218
219# Prepare copy of libcrypto.a with only the checked functions renamed and exported.
220# All other symbols are left alone and hidden.
221echo BORINGSSL_bcm_power_on_self_test >>syms.txt
222awk '{print "_goboringcrypto_" $0 }' syms.txt >globals.txt
223awk '{print $0 " _goboringcrypto_" $0 }' syms.txt >renames.txt
224objcopy --globalize-symbol=BORINGSSL_bcm_power_on_self_test \
225 ../boringssl/build/crypto/libcrypto.a libcrypto.a
226
227# Link together bcm.o and libcrypto.a into a single object.
228ld -r -nostdlib --whole-archive -o goboringcrypto.o libcrypto.a $extra
229
230echo __umodti3 _goboringcrypto___umodti3 >>renames.txt
231echo __udivti3 _goboringcrypto___udivti3 >>renames.txt
232objcopy --remove-section=.llvm_addrsig goboringcrypto.o goboringcrypto1.o # b/179161016
233objcopy --redefine-syms=renames.txt goboringcrypto1.o goboringcrypto2.o
234objcopy --keep-global-symbols=globals.txt --strip-unneeded goboringcrypto2.o goboringcrypto_linux_$GOARCH.syso
235
236# Done!
237ls -l goboringcrypto_linux_$GOARCH.syso
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