github.com/deroproject/derosuite@v2.1.6-1.0.20200307070847-0f2e589c7a2b+incompatible/crypto/ringct/varint_test.go (about)

     1  // Copyright 2017-2018 DERO Project. All rights reserved.
     2  // Use of this source code in any form is governed by RESEARCH license.
     3  // license can be found in the LICENSE file.
     4  // GPG: 0F39 E425 8C65 3947 702A  8234 08B2 0360 A03A 9DE8
     5  //
     6  //
     7  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
     8  // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     9  // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
    10  // THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    11  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
    12  // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    13  // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
    14  // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
    15  // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    16  
    17  package ringct
    18  
    19  import "bytes"
    20  import "testing"
    21  
    22  // this package needs to be verified for bug,
    23  // just in case, the top bit is set, it is impossible to do varint 64 bit number into 8 bytes, if the number is too big
    24  // in that case go needs 9 bytes, we should verify whether the number can ever reach there and thus place
    25  // suitable checks to avoid falling into the trap later on
    26  func TestVarInt(t *testing.T) {
    27  	tests := []struct {
    28  		name   string
    29  		varInt []byte
    30  		want   uint64
    31  	}{
    32  		{
    33  			name:   "1 byte",
    34  			varInt: []byte{0x01},
    35  			want:   1,
    36  		},
    37  		{
    38  			name:   "3 bytes",
    39  			varInt: []byte{0x8f, 0xd6, 0x17},
    40  			want:   387855,
    41  		},
    42  		{
    43  			name:   "4 bytes",
    44  			varInt: []byte{0x80, 0x92, 0xf4, 0x01},
    45  			want:   4000000,
    46  		},
    47  		{
    48  			name:   "7 bytes",
    49  			varInt: []byte{0x80, 0xc0, 0xca, 0xf3, 0x84, 0xa3, 0x02},
    50  			want:   10000000000000,
    51  		},
    52  	}
    53  	var got uint64
    54  	var err error
    55  	var gotVarInt []byte
    56  	buf := new(bytes.Buffer)
    57  	for _, test := range tests {
    58  		gotVarInt = Uint64ToBytes(test.want)
    59  		if bytes.Compare(gotVarInt, test.varInt) != 0 {
    60  			t.Errorf("%s: varint want %x, got %x", test.name, test.varInt, gotVarInt)
    61  			continue
    62  		}
    63  		buf.Reset()
    64  		buf.Write(test.varInt)
    65  		got, err = ReadVarInt(buf)
    66  		if err != nil {
    67  			t.Errorf("%s: %s", test.name, err)
    68  			continue
    69  		}
    70  		if test.want != got {
    71  			t.Errorf("%s: want %d, got %d", test.name, test.want, got)
    72  			continue
    73  		}
    74  	}
    75  }