github.com/deroproject/derosuite@v2.1.6-1.0.20200307070847-0f2e589c7a2b+incompatible/globals/random.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 globals
    18  
    19  import mathrand "math/rand"
    20  import "crypto/rand"
    21  import "encoding/binary"
    22  
    23  // random source which is cryptographically secure
    24  // this is to be used in random sorting and selections where necessary
    25  
    26  type CryptoRandSource struct{}
    27  
    28  func NewCryptoRandSource() CryptoRandSource {
    29  	return CryptoRandSource{}
    30  }
    31  
    32  func (_ CryptoRandSource) Int63() int64 {
    33  	var b [8]byte
    34  	rand.Read(b[:])
    35  	// mask off sign bit to ensure positive number
    36  	return int64(binary.LittleEndian.Uint64(b[:]) & (1<<63 - 1))
    37  }
    38  
    39  func (_ CryptoRandSource) Seed(_ int64) {}
    40  
    41  
    42  var Global_Random = mathrand.New(NewCryptoRandSource())