github.com/twelsh-aw/go/src@v0.0.0-20230516233729-a56fe86a7c81/crypto/subtle/xor_test.go (about)

     1  // Copyright 2013 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package subtle_test
     6  
     7  import (
     8  	"bytes"
     9  	"crypto/rand"
    10  	. "crypto/subtle"
    11  	"fmt"
    12  	"io"
    13  	"testing"
    14  )
    15  
    16  func TestXORBytes(t *testing.T) {
    17  	for n := 1; n <= 1024; n++ {
    18  		if n > 16 && testing.Short() {
    19  			n += n >> 3
    20  		}
    21  		for alignP := 0; alignP < 8; alignP++ {
    22  			for alignQ := 0; alignQ < 8; alignQ++ {
    23  				for alignD := 0; alignD < 8; alignD++ {
    24  					p := make([]byte, alignP+n, alignP+n+10)[alignP:]
    25  					q := make([]byte, alignQ+n, alignQ+n+10)[alignQ:]
    26  					if n&1 != 0 {
    27  						p = p[:n]
    28  					} else {
    29  						q = q[:n]
    30  					}
    31  					if _, err := io.ReadFull(rand.Reader, p); err != nil {
    32  						t.Fatal(err)
    33  					}
    34  					if _, err := io.ReadFull(rand.Reader, q); err != nil {
    35  						t.Fatal(err)
    36  					}
    37  
    38  					d := make([]byte, alignD+n, alignD+n+10)
    39  					for i := range d {
    40  						d[i] = 0xdd
    41  					}
    42  					want := make([]byte, len(d), cap(d))
    43  					copy(want[:cap(want)], d[:cap(d)])
    44  					for i := 0; i < n; i++ {
    45  						want[alignD+i] = p[i] ^ q[i]
    46  					}
    47  
    48  					if XORBytes(d[alignD:], p, q); !bytes.Equal(d, want) {
    49  						t.Fatalf("n=%d alignP=%d alignQ=%d alignD=%d:\n\tp = %x\n\tq = %x\n\td = %x\n\twant %x\n", n, alignP, alignQ, alignD, p, q, d, want)
    50  					}
    51  				}
    52  			}
    53  		}
    54  	}
    55  }
    56  
    57  func TestXorBytesPanic(t *testing.T) {
    58  	mustPanic(t, "subtle.XORBytes: dst too short", func() {
    59  		XORBytes(nil, make([]byte, 1), make([]byte, 1))
    60  	})
    61  	mustPanic(t, "subtle.XORBytes: dst too short", func() {
    62  		XORBytes(make([]byte, 1), make([]byte, 2), make([]byte, 3))
    63  	})
    64  }
    65  
    66  func min(a, b []byte) int {
    67  	n := len(a)
    68  	if len(b) < n {
    69  		n = len(b)
    70  	}
    71  	return n
    72  }
    73  
    74  func BenchmarkXORBytes(b *testing.B) {
    75  	dst := make([]byte, 1<<15)
    76  	data0 := make([]byte, 1<<15)
    77  	data1 := make([]byte, 1<<15)
    78  	sizes := []int64{1 << 3, 1 << 7, 1 << 11, 1 << 15}
    79  	for _, size := range sizes {
    80  		b.Run(fmt.Sprintf("%dBytes", size), func(b *testing.B) {
    81  			s0 := data0[:size]
    82  			s1 := data1[:size]
    83  			b.SetBytes(int64(size))
    84  			for i := 0; i < b.N; i++ {
    85  				XORBytes(dst, s0, s1)
    86  			}
    87  		})
    88  	}
    89  }
    90  
    91  func mustPanic(t *testing.T, expected string, f func()) {
    92  	t.Helper()
    93  	defer func() {
    94  		switch msg := recover().(type) {
    95  		case nil:
    96  			t.Errorf("expected panic(%q), but did not panic", expected)
    97  		case string:
    98  			if msg != expected {
    99  				t.Errorf("expected panic(%q), but got panic(%q)", expected, msg)
   100  			}
   101  		default:
   102  			t.Errorf("expected panic(%q), but got panic(%T%v)", expected, msg, msg)
   103  		}
   104  	}()
   105  	f()
   106  }