diff options
Diffstat (limited to 'src/crypto/md5/gen.go')
| -rw-r--r-- | src/crypto/md5/gen.go | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/src/crypto/md5/gen.go b/src/crypto/md5/gen.go new file mode 100644 index 0000000..cd2700a --- /dev/null +++ b/src/crypto/md5/gen.go @@ -0,0 +1,259 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +//go:build ignore + +// This program generates md5block.go +// Invoke as +// +// go run gen.go -output md5block.go + +package main + +import ( + "bytes" + "flag" + "go/format" + "log" + "os" + "strings" + "text/template" +) + +var filename = flag.String("output", "md5block.go", "output file name") + +func main() { + flag.Parse() + + var buf bytes.Buffer + + t := template.Must(template.New("main").Funcs(funcs).Parse(program)) + if err := t.Execute(&buf, data); err != nil { + log.Fatal(err) + } + + data, err := format.Source(buf.Bytes()) + if err != nil { + log.Fatal(err) + } + err = os.WriteFile(*filename, data, 0644) + if err != nil { + log.Fatal(err) + } +} + +type Data struct { + a, b, c, d string + Shift1 []int + Shift2 []int + Shift3 []int + Shift4 []int + Table1 []uint32 + Table2 []uint32 + Table3 []uint32 + Table4 []uint32 +} + +var funcs = template.FuncMap{ + "dup": dup, + "relabel": relabel, + "rotate": rotate, + "idx": idx, + "seq": seq, +} + +func dup(count int, x []int) []int { + var out []int + for i := 0; i < count; i++ { + out = append(out, x...) + } + return out +} + +func relabel(s string) string { + return strings.NewReplacer("arg0", data.a, "arg1", data.b, "arg2", data.c, "arg3", data.d).Replace(s) +} + +func rotate() string { + data.a, data.b, data.c, data.d = data.d, data.a, data.b, data.c + return "" // no output +} + +func idx(round, index int) int { + v := 0 + switch round { + case 1: + v = index + case 2: + v = (1 + 5*index) & 15 + case 3: + v = (5 + 3*index) & 15 + case 4: + v = (7 * index) & 15 + } + return v +} + +func seq(i int) []int { + s := make([]int, i) + for i := range s { + s[i] = i + } + return s +} + +var data = Data{ + a: "a", + b: "b", + c: "c", + d: "d", + Shift1: []int{7, 12, 17, 22}, + Shift2: []int{5, 9, 14, 20}, + Shift3: []int{4, 11, 16, 23}, + Shift4: []int{6, 10, 15, 21}, + + // table[i] = int((1<<32) * abs(sin(i+1 radians))). + Table1: []uint32{ + // round 1 + 0xd76aa478, + 0xe8c7b756, + 0x242070db, + 0xc1bdceee, + 0xf57c0faf, + 0x4787c62a, + 0xa8304613, + 0xfd469501, + 0x698098d8, + 0x8b44f7af, + 0xffff5bb1, + 0x895cd7be, + 0x6b901122, + 0xfd987193, + 0xa679438e, + 0x49b40821, + }, + Table2: []uint32{ + // round 2 + 0xf61e2562, + 0xc040b340, + 0x265e5a51, + 0xe9b6c7aa, + 0xd62f105d, + 0x2441453, + 0xd8a1e681, + 0xe7d3fbc8, + 0x21e1cde6, + 0xc33707d6, + 0xf4d50d87, + 0x455a14ed, + 0xa9e3e905, + 0xfcefa3f8, + 0x676f02d9, + 0x8d2a4c8a, + }, + Table3: []uint32{ + // round3 + 0xfffa3942, + 0x8771f681, + 0x6d9d6122, + 0xfde5380c, + 0xa4beea44, + 0x4bdecfa9, + 0xf6bb4b60, + 0xbebfbc70, + 0x289b7ec6, + 0xeaa127fa, + 0xd4ef3085, + 0x4881d05, + 0xd9d4d039, + 0xe6db99e5, + 0x1fa27cf8, + 0xc4ac5665, + }, + Table4: []uint32{ + // round 4 + 0xf4292244, + 0x432aff97, + 0xab9423a7, + 0xfc93a039, + 0x655b59c3, + 0x8f0ccc92, + 0xffeff47d, + 0x85845dd1, + 0x6fa87e4f, + 0xfe2ce6e0, + 0xa3014314, + 0x4e0811a1, + 0xf7537e82, + 0xbd3af235, + 0x2ad7d2bb, + 0xeb86d391, + }, +} + +var program = `// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Code generated by go run gen.go -output md5block.go; DO NOT EDIT. + +package md5 + +import ( + "encoding/binary" + "math/bits" +) + +func blockGeneric(dig *digest, p []byte) { + // load state + a, b, c, d := dig.s[0], dig.s[1], dig.s[2], dig.s[3] + + for i := 0; i <= len(p)-BlockSize; i += BlockSize { + // eliminate bounds checks on p + q := p[i:] + q = q[:BlockSize:BlockSize] + + // save current state + aa, bb, cc, dd := a, b, c, d + + // load input block + {{range $i := seq 16 -}} + {{printf "x%x := binary.LittleEndian.Uint32(q[4*%#x:])" $i $i}} + {{end}} + + // round 1 + {{range $i, $s := dup 4 .Shift1 -}} + {{printf "arg0 = arg1 + bits.RotateLeft32((((arg2^arg3)&arg1)^arg3)+arg0+x%x+%#08x, %d)" (idx 1 $i) (index $.Table1 $i) $s | relabel}} + {{rotate -}} + {{end}} + + // round 2 + {{range $i, $s := dup 4 .Shift2 -}} + {{printf "arg0 = arg1 + bits.RotateLeft32((((arg1^arg2)&arg3)^arg2)+arg0+x%x+%#08x, %d)" (idx 2 $i) (index $.Table2 $i) $s | relabel}} + {{rotate -}} + {{end}} + + // round 3 + {{range $i, $s := dup 4 .Shift3 -}} + {{printf "arg0 = arg1 + bits.RotateLeft32((arg1^arg2^arg3)+arg0+x%x+%#08x, %d)" (idx 3 $i) (index $.Table3 $i) $s | relabel}} + {{rotate -}} + {{end}} + + // round 4 + {{range $i, $s := dup 4 .Shift4 -}} + {{printf "arg0 = arg1 + bits.RotateLeft32((arg2^(arg1|^arg3))+arg0+x%x+%#08x, %d)" (idx 4 $i) (index $.Table4 $i) $s | relabel}} + {{rotate -}} + {{end}} + + // add saved state + a += aa + b += bb + c += cc + d += dd + } + + // save state + dig.s[0], dig.s[1], dig.s[2], dig.s[3] = a, b, c, d +} +` |