[dev.boringcrypto] cmd: use notsha256 instead of md5, sha1, sha256

When we add GOEXPERIMENT=boringcrypto, the bootstrap process
will not converge if the compiler itself depends on the boringcrypto
cgo-based implementations of sha1 and sha256.

Using notsha256 avoids boringcrypto and makes bootstrap converge.
Removing md5 is not strictly necessary but it seemed worthwhile to
be consistent.

For #51940.

Change-Id: Iba649507e0964d1a49a1d16e463dd23c4e348f14
Reviewed-on: https://go-review.googlesource.com/c/go/+/402595
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>

6 files changed, 18 insertions, 17 deletions

diff --git a/src/cmd/compile/internal/liveness/plive.go b/src/cmd/compile/internal/liveness/plive.go
index bd0a6fa1a3..93f49fad45 100644
--- a/src/cmd/compile/internal/liveness/plive.go
+++ b/src/cmd/compile/internal/liveness/plive.go
@@ -15,7 +15,6 @@
 package liveness
 
 import (
-	"crypto/sha1"
 	"fmt"
 	"os"
 	"sort"
@@ -30,6 +29,7 @@ import (
 	"cmd/compile/internal/ssa"
 	"cmd/compile/internal/typebits"
 	"cmd/compile/internal/types"
+	"cmd/internal/notsha256"
 	"cmd/internal/obj"
 	"cmd/internal/objabi"
 	"cmd/internal/src"
@@ -959,7 +959,7 @@ func (lv *liveness) enableClobber() {
 		// Clobber only functions where the hash of the function name matches a pattern.
 		// Useful for binary searching for a miscompiled function.
 		hstr := ""
-		for _, b := range sha1.Sum([]byte(lv.f.Name)) {
+		for _, b := range notsha256.Sum256([]byte(lv.f.Name)) {
 			hstr += fmt.Sprintf("%08b", b)
 		}
 		if !strings.HasSuffix(hstr, h) {
diff --git a/src/cmd/compile/internal/ssa/func.go b/src/cmd/compile/internal/ssa/func.go
index 35a9382663..75f17634ec 100644
--- a/src/cmd/compile/internal/ssa/func.go
+++ b/src/cmd/compile/internal/ssa/func.go
@@ -8,8 +8,8 @@ import (
 	"cmd/compile/internal/abi"
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/types"
+	"cmd/internal/notsha256"
 	"cmd/internal/src"
-	"crypto/sha1"
 	"fmt"
 	"io"
 	"math"
@@ -854,7 +854,7 @@ func (f *Func) DebugHashMatch(evname string) bool {
 	// We use this feature to do a binary search to
 	// find a function that is incorrectly compiled.
 	hstr := ""
-	for _, b := range sha1.Sum([]byte(name)) {
+	for _, b := range notsha256.Sum256([]byte(name)) {
 		hstr += fmt.Sprintf("%08b", b)
 	}
 
diff --git a/src/cmd/compile/internal/ssa/print.go b/src/cmd/compile/internal/ssa/print.go
index 96cd2c7c90..aea9ce9e33 100644
--- a/src/cmd/compile/internal/ssa/print.go
+++ b/src/cmd/compile/internal/ssa/print.go
@@ -6,10 +6,11 @@ package ssa
 
 import (
 	"bytes"
-	"cmd/internal/src"
-	"crypto/sha256"
 	"fmt"
 	"io"
+
+	"cmd/internal/notsha256"
+	"cmd/internal/src"
 )
 
 func printFunc(f *Func) {
@@ -17,7 +18,7 @@ func printFunc(f *Func) {
 }
 
 func hashFunc(f *Func) []byte {
-	h := sha256.New()
+	h := notsha256.New()
 	p := stringFuncPrinter{w: h, printDead: true}
 	fprintFunc(p, f)
 	return h.Sum(nil)
@@ -32,7 +33,7 @@ func (f *Func) String() string {
 
 // rewriteHash returns a hash of f suitable for detecting rewrite cycles.
 func (f *Func) rewriteHash() string {
-	h := sha256.New()
+	h := notsha256.New()
 	p := stringFuncPrinter{w: h, printDead: false}
 	fprintFunc(p, f)
 	return fmt.Sprintf("%x", h.Sum(nil))
diff --git a/src/cmd/compile/internal/staticdata/data.go b/src/cmd/compile/internal/staticdata/data.go
index b114bb2df6..b8b645f246 100644
--- a/src/cmd/compile/internal/staticdata/data.go
+++ b/src/cmd/compile/internal/staticdata/data.go
@@ -5,7 +5,6 @@
 package staticdata
 
 import (
-	"crypto/sha256"
 	"fmt"
 	"go/constant"
 	"io"
@@ -20,6 +19,7 @@ import (
 	"cmd/compile/internal/objw"
 	"cmd/compile/internal/typecheck"
 	"cmd/compile/internal/types"
+	"cmd/internal/notsha256"
 	"cmd/internal/obj"
 	"cmd/internal/objabi"
 	"cmd/internal/src"
@@ -73,7 +73,7 @@ func StringSym(pos src.XPos, s string) (data *obj.LSym) {
 		// Indulge in some paranoia by writing the length of s, too,
 		// as protection against length extension attacks.
 		// Same pattern is known to fileStringSym below.
-		h := sha256.New()
+		h := notsha256.New()
 		io.WriteString(h, s)
 		symname = fmt.Sprintf(stringSymPattern, len(s), h.Sum(nil))
 	} else {
@@ -131,7 +131,7 @@ func fileStringSym(pos src.XPos, file string, readonly bool, hash []byte) (*obj.
 			sym = slicedata(pos, string(data)).Linksym()
 		}
 		if len(hash) > 0 {
-			sum := sha256.Sum256(data)
+			sum := notsha256.Sum256(data)
 			copy(hash, sum[:])
 		}
 		return sym, size, nil
@@ -148,7 +148,7 @@ func fileStringSym(pos src.XPos, file string, readonly bool, hash []byte) (*obj.
 	// Compute hash if needed for read-only content hashing or if the caller wants it.
 	var sum []byte
 	if readonly || len(hash) > 0 {
-		h := sha256.New()
+		h := notsha256.New()
 		n, err := io.Copy(h, f)
 		if err != nil {
 			return nil, 0, err
diff --git a/src/cmd/compile/internal/typecheck/iexport.go b/src/cmd/compile/internal/typecheck/iexport.go
index 12159b71e1..9436aa5504 100644
--- a/src/cmd/compile/internal/typecheck/iexport.go
+++ b/src/cmd/compile/internal/typecheck/iexport.go
@@ -236,7 +236,6 @@ package typecheck
 
 import (
 	"bytes"
-	"crypto/md5"
 	"encoding/binary"
 	"fmt"
 	"go/constant"
@@ -250,6 +249,7 @@ import (
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/types"
 	"cmd/internal/goobj"
+	"cmd/internal/notsha256"
 	"cmd/internal/src"
 )
 
@@ -353,7 +353,7 @@ func WriteExports(out io.Writer, extensions bool) {
 	hdr.uint64(dataLen)
 
 	// Flush output.
-	h := md5.New()
+	h := notsha256.New()
 	wr := io.MultiWriter(out, h)
 	io.Copy(wr, &hdr)
 	io.Copy(wr, &p.strings)
diff --git a/src/cmd/compile/internal/types/fmt.go b/src/cmd/compile/internal/types/fmt.go
index bdd3ca1d28..3c02cb8681 100644
--- a/src/cmd/compile/internal/types/fmt.go
+++ b/src/cmd/compile/internal/types/fmt.go
@@ -6,7 +6,6 @@ package types
 
 import (
 	"bytes"
-	"crypto/md5"
 	"encoding/binary"
 	"fmt"
 	"go/constant"
@@ -15,6 +14,7 @@ import (
 	"sync"
 
 	"cmd/compile/internal/base"
+	"cmd/internal/notsha256"
 )
 
 // BuiltinPkg is a fake package that declares the universe block.
@@ -771,7 +771,7 @@ func FmtConst(v constant.Value, sharp bool) string {
 func TypeHash(t *Type) uint32 {
 	p := tconv(t, 0, fmtTypeIDHash)
 
-	// Using MD5 is overkill, but reduces accidental collisions.
-	h := md5.Sum([]byte(p))
+	// Using SHA256 is overkill, but reduces accidental collisions.
+	h := notsha256.Sum256([]byte(p))
 	return binary.LittleEndian.Uint32(h[:4])
 }