// 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 ( "internal/byteorder" "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 := byteorder.LeUint32(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 } `