github.com/hyperledger-labs/bdls@v2.1.1+incompatible/common/crypto/random.go (about)

     1  /*
     2  Copyright IBM Corp. 2016 All Rights Reserved.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8  		 http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package crypto
    18  
    19  import (
    20  	"crypto/rand"
    21  
    22  	"github.com/pkg/errors"
    23  )
    24  
    25  const (
    26  	// NonceSize is the default NonceSize
    27  	NonceSize = 24
    28  )
    29  
    30  // GetRandomBytes returns len random looking bytes
    31  func GetRandomBytes(len int) ([]byte, error) {
    32  	key := make([]byte, len)
    33  
    34  	// TODO: rand could fill less bytes then len
    35  	_, err := rand.Read(key)
    36  	if err != nil {
    37  		return nil, errors.Wrap(err, "error getting random bytes")
    38  	}
    39  
    40  	return key, nil
    41  }
    42  
    43  // GetRandomNonce returns a random byte array of length NonceSize
    44  func GetRandomNonce() ([]byte, error) {
    45  	return GetRandomBytes(NonceSize)
    46  }