cmd/swarm, swarm/api/http, swarm/bmt, swarm/fuse, swarm/network/stream, swarm/storage, swarm/storage/encryption, swarm/testutil: use pseudo-random instead of crypto-random for test files content generation (#18083)

- Replace "crypto/rand" to "math/rand" for files content generation
- Remove swarm/network_test.go.Shuffle and swarm/btm/btm_test.go.Shuffle - because go1.9 support dropped (see https://github.com/ethereum/go-ethereum/pull/17807 and comments to swarm/network_test.go.Shuffle)

5 files changed, 30 insertions, 43 deletions

diff --git a/swarm/storage/chunker_test.go b/swarm/storage/chunker_test.go
index 6172d8a09..1f847edcb 100644
--- a/swarm/storage/chunker_test.go
+++ b/swarm/storage/chunker_test.go
@@ -19,13 +19,13 @@ package storage
 import (
 	"bytes"
 	"context"
-	"crypto/rand"
 	"encoding/binary"
 	"fmt"
 	"io"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/crypto/sha3"
+	"github.com/ethereum/go-ethereum/swarm/testutil"
 )
 
 /*
@@ -47,7 +47,7 @@ func newTestHasherStore(store ChunkStore, hash string) *hasherStore {
 }
 
 func testRandomBrokenData(n int, tester *chunkerTester) {
-	data := io.LimitReader(rand.Reader, int64(n))
+	data := testutil.RandomReader(1, n)
 	brokendata := brokenLimitReader(data, n, n/2)
 
 	buf := make([]byte, n)
@@ -56,7 +56,7 @@ func testRandomBrokenData(n int, tester *chunkerTester) {
 		tester.t.Fatalf("Broken reader is not broken, hence broken. Returns: %v", err)
 	}
 
-	data = io.LimitReader(rand.Reader, int64(n))
+	data = testutil.RandomReader(2, n)
 	brokendata = brokenLimitReader(data, n, n/2)
 
 	putGetter := newTestHasherStore(NewMapChunkStore(), SHA3Hash)
@@ -77,7 +77,8 @@ func testRandomData(usePyramid bool, hash string, n int, tester *chunkerTester)
 	input, found := tester.inputs[uint64(n)]
 	var data io.Reader
 	if !found {
-		data, input = GenerateRandomData(n)
+		input = testutil.RandomBytes(1, n)
+		data = bytes.NewReader(input)
 		tester.inputs[uint64(n)] = input
 	} else {
 		data = io.LimitReader(bytes.NewReader(input), int64(n))
@@ -118,14 +119,13 @@ func testRandomData(usePyramid bool, hash string, n int, tester *chunkerTester)
 	// testing partial read
 	for i := 1; i < n; i += 10000 {
 		readableLength := n - i
-		output := make([]byte, readableLength)
 		r, err := reader.ReadAt(output, int64(i))
 		if r != readableLength || err != io.EOF {
 			tester.t.Fatalf("readAt error with offset %v read: %v  n = %v  err = %v\n", i, r, readableLength, err)
 		}
 		if input != nil {
-			if !bytes.Equal(output, input[i:]) {
-				tester.t.Fatalf("input and output mismatch\n IN: %v\nOUT: %v\n", input[i:], output)
+			if !bytes.Equal(output[:readableLength], input[i:]) {
+				tester.t.Fatalf("input and output mismatch\n IN: %v\nOUT: %v\n", input[i:], output[:readableLength])
 			}
 		}
 	}
@@ -177,7 +177,8 @@ func TestDataAppend(t *testing.T) {
 		input, found := tester.inputs[uint64(n)]
 		var data io.Reader
 		if !found {
-			data, input = GenerateRandomData(n)
+			input = testutil.RandomBytes(i, n)
+			data = bytes.NewReader(input)
 			tester.inputs[uint64(n)] = input
 		} else {
 			data = io.LimitReader(bytes.NewReader(input), int64(n))
@@ -199,7 +200,8 @@ func TestDataAppend(t *testing.T) {
 		appendInput, found := tester.inputs[uint64(m)]
 		var appendData io.Reader
 		if !found {
-			appendData, appendInput = GenerateRandomData(m)
+			appendInput = testutil.RandomBytes(i, m)
+			appendData = bytes.NewReader(appendInput)
 			tester.inputs[uint64(m)] = appendInput
 		} else {
 			appendData = io.LimitReader(bytes.NewReader(appendInput), int64(m))
@@ -272,7 +274,7 @@ func benchReadAll(reader LazySectionReader) {
 func benchmarkSplitJoin(n int, t *testing.B) {
 	t.ReportAllocs()
 	for i := 0; i < t.N; i++ {
-		data := testDataReader(n)
+		data := testutil.RandomReader(i, n)
 
 		putGetter := newTestHasherStore(NewMapChunkStore(), SHA3Hash)
 		ctx := context.TODO()
@@ -292,7 +294,7 @@ func benchmarkSplitJoin(n int, t *testing.B) {
 func benchmarkSplitTreeSHA3(n int, t *testing.B) {
 	t.ReportAllocs()
 	for i := 0; i < t.N; i++ {
-		data := testDataReader(n)
+		data := testutil.RandomReader(i, n)
 		putGetter := newTestHasherStore(&FakeChunkStore{}, SHA3Hash)
 
 		ctx := context.Background()
@@ -311,7 +313,7 @@ func benchmarkSplitTreeSHA3(n int, t *testing.B) {
 func benchmarkSplitTreeBMT(n int, t *testing.B) {
 	t.ReportAllocs()
 	for i := 0; i < t.N; i++ {
-		data := testDataReader(n)
+		data := testutil.RandomReader(i, n)
 		putGetter := newTestHasherStore(&FakeChunkStore{}, BMTHash)
 
 		ctx := context.Background()
@@ -329,7 +331,7 @@ func benchmarkSplitTreeBMT(n int, t *testing.B) {
 func benchmarkSplitPyramidBMT(n int, t *testing.B) {
 	t.ReportAllocs()
 	for i := 0; i < t.N; i++ {
-		data := testDataReader(n)
+		data := testutil.RandomReader(i, n)
 		putGetter := newTestHasherStore(&FakeChunkStore{}, BMTHash)
 
 		ctx := context.Background()
@@ -347,7 +349,7 @@ func benchmarkSplitPyramidBMT(n int, t *testing.B) {
 func benchmarkSplitPyramidSHA3(n int, t *testing.B) {
 	t.ReportAllocs()
 	for i := 0; i < t.N; i++ {
-		data := testDataReader(n)
+		data := testutil.RandomReader(i, n)
 		putGetter := newTestHasherStore(&FakeChunkStore{}, SHA3Hash)
 
 		ctx := context.Background()
@@ -365,8 +367,8 @@ func benchmarkSplitPyramidSHA3(n int, t *testing.B) {
 func benchmarkSplitAppendPyramid(n, m int, t *testing.B) {
 	t.ReportAllocs()
 	for i := 0; i < t.N; i++ {
-		data := testDataReader(n)
-		data1 := testDataReader(m)
+		data := testutil.RandomReader(i, n)
+		data1 := testutil.RandomReader(t.N+i, m)
 
 		store := NewMapChunkStore()
 		putGetter := newTestHasherStore(store, SHA3Hash)
diff --git a/swarm/storage/common_test.go b/swarm/storage/common_test.go
index 600be164a..af104a5ae 100644
--- a/swarm/storage/common_test.go
+++ b/swarm/storage/common_test.go
@@ -19,7 +19,6 @@ package storage
 import (
 	"bytes"
 	"context"
-	"crypto/rand"
 	"flag"
 	"fmt"
 	"io"
@@ -31,7 +30,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/log"
 	ch "github.com/ethereum/go-ethereum/swarm/chunk"
-	colorable "github.com/mattn/go-colorable"
+	"github.com/mattn/go-colorable"
 )
 
 var (
@@ -151,10 +150,6 @@ func mget(store ChunkStore, hs []Address, f func(h Address, chunk Chunk) error)
 	return err
 }
 
-func testDataReader(l int) (r io.Reader) {
-	return io.LimitReader(rand.Reader, int64(l))
-}
-
 func (r *brokenLimitedReader) Read(buf []byte) (int, error) {
 	if r.off+len(buf) > r.errAt {
 		return 0, fmt.Errorf("Broken reader")
diff --git a/swarm/storage/encryption/encryption_test.go b/swarm/storage/encryption/encryption_test.go
index c3abefdce..0c0d0508c 100644
--- a/swarm/storage/encryption/encryption_test.go
+++ b/swarm/storage/encryption/encryption_test.go
@@ -18,12 +18,12 @@ package encryption
 
 import (
 	"bytes"
-	"crypto/rand"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/crypto/sha3"
+	"github.com/ethereum/go-ethereum/swarm/testutil"
 )
 
 var expectedTransformedHex = "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"
@@ -125,8 +125,7 @@ func testEncryptDecryptIsIdentity(t *testing.T, padding int, initCtr uint32, dat
 	key := GenerateRandomKey(keyLength)
 	enc := New(key, padding, initCtr, hashFunc)
 
-	data := make([]byte, dataLength)
-	rand.Read(data)
+	data := testutil.RandomBytes(1, dataLength)
 
 	encrypted, err := enc.Encrypt(data)
 	if err != nil {
diff --git a/swarm/storage/filestore_test.go b/swarm/storage/filestore_test.go
index 9fe58f60c..fb0f761a4 100644
--- a/swarm/storage/filestore_test.go
+++ b/swarm/storage/filestore_test.go
@@ -23,6 +23,8 @@ import (
 	"io/ioutil"
 	"os"
 	"testing"
+
+	"github.com/ethereum/go-ethereum/swarm/testutil"
 )
 
 const testDataSize = 0x0001000
@@ -49,9 +51,9 @@ func testFileStoreRandom(toEncrypt bool, t *testing.T) {
 	fileStore := NewFileStore(localStore, NewFileStoreParams())
 	defer os.RemoveAll("/tmp/bzz")
 
-	reader, slice := GenerateRandomData(testDataSize)
+	slice := testutil.RandomBytes(1, testDataSize)
 	ctx := context.TODO()
-	key, wait, err := fileStore.Store(ctx, reader, testDataSize, toEncrypt)
+	key, wait, err := fileStore.Store(ctx, bytes.NewReader(slice), testDataSize, toEncrypt)
 	if err != nil {
 		t.Fatalf("Store error: %v", err)
 	}
@@ -63,13 +65,13 @@ func testFileStoreRandom(toEncrypt bool, t *testing.T) {
 	if isEncrypted != toEncrypt {
 		t.Fatalf("isEncrypted expected %v got %v", toEncrypt, isEncrypted)
 	}
-	resultSlice := make([]byte, len(slice))
+	resultSlice := make([]byte, testDataSize)
 	n, err := resultReader.ReadAt(resultSlice, 0)
 	if err != io.EOF {
 		t.Fatalf("Retrieve error: %v", err)
 	}
-	if n != len(slice) {
-		t.Fatalf("Slice size error got %d, expected %d.", n, len(slice))
+	if n != testDataSize {
+		t.Fatalf("Slice size error got %d, expected %d.", n, testDataSize)
 	}
 	if !bytes.Equal(slice, resultSlice) {
 		t.Fatalf("Comparison error.")
@@ -114,9 +116,9 @@ func testFileStoreCapacity(toEncrypt bool, t *testing.T) {
 		DbStore:  db,
 	}
 	fileStore := NewFileStore(localStore, NewFileStoreParams())
-	reader, slice := GenerateRandomData(testDataSize)
+	slice := testutil.RandomBytes(1, testDataSize)
 	ctx := context.TODO()
-	key, wait, err := fileStore.Store(ctx, reader, testDataSize, toEncrypt)
+	key, wait, err := fileStore.Store(ctx, bytes.NewReader(slice), testDataSize, toEncrypt)
 	if err != nil {
 		t.Errorf("Store error: %v", err)
 	}
diff --git a/swarm/storage/types.go b/swarm/storage/types.go
index 092843db0..42557766e 100644
--- a/swarm/storage/types.go
+++ b/swarm/storage/types.go
@@ -25,7 +25,6 @@ import (
 	"fmt"
 	"hash"
 	"io"
-	"io/ioutil"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto/sha3"
@@ -251,16 +250,6 @@ func GenerateRandomChunks(dataSize int64, count int) (chunks []Chunk) {
 	return chunks
 }
 
-func GenerateRandomData(l int) (r io.Reader, slice []byte) {
-	slice, err := ioutil.ReadAll(io.LimitReader(rand.Reader, int64(l)))
-	if err != nil {
-		panic("rand error")
-	}
-	// log.Warn("generate random data", "len", len(slice), "data", common.Bytes2Hex(slice))
-	r = io.LimitReader(bytes.NewReader(slice), int64(l))
-	return r, slice
-}
-
 // Size, Seek, Read, ReadAt
 type LazySectionReader interface {
 	Context() context.Context