github.com/nats-io/nats-server/v2@v2.11.0-preview.2/server/nkey.go (about)

     1  // Copyright 2018 The NATS Authors
     2  // Licensed under the Apache License, Version 2.0 (the "License");
     3  // you may not use this file except in compliance with the License.
     4  // You may obtain a copy of the License at
     5  //
     6  // http://www.apache.org/licenses/LICENSE-2.0
     7  //
     8  // Unless required by applicable law or agreed to in writing, software
     9  // distributed under the License is distributed on an "AS IS" BASIS,
    10  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package server
    15  
    16  import (
    17  	crand "crypto/rand"
    18  	"encoding/base64"
    19  )
    20  
    21  // Raw length of the nonce challenge
    22  const (
    23  	nonceRawLen = 11
    24  	nonceLen    = 15 // base64.RawURLEncoding.EncodedLen(nonceRawLen)
    25  )
    26  
    27  // NonceRequired tells us if we should send a nonce.
    28  func (s *Server) NonceRequired() bool {
    29  	s.mu.Lock()
    30  	defer s.mu.Unlock()
    31  	return s.nonceRequired()
    32  }
    33  
    34  // nonceRequired tells us if we should send a nonce.
    35  // Lock should be held on entry.
    36  func (s *Server) nonceRequired() bool {
    37  	return s.getOpts().AlwaysEnableNonce || len(s.nkeys) > 0 || s.trustedKeys != nil
    38  }
    39  
    40  // Generate a nonce for INFO challenge.
    41  // Assumes server lock is held
    42  func (s *Server) generateNonce(n []byte) {
    43  	var raw [nonceRawLen]byte
    44  	data := raw[:]
    45  	crand.Read(data)
    46  	base64.RawURLEncoding.Encode(n, data)
    47  }