/
options.go
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/
options.go
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// Copyright 2018 Google LLC All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package random
import "math/rand"
// Option is an optional parameter to the random functions
type Option func(opts *options)
type options struct {
source rand.Source
// TODO opens the door to add this in the future
// algorithm digest.Algorithm
}
func getOptions(opts []Option) *options {
// get a random seed
// TODO in go 1.20 this is fine (it will be random)
seed := rand.Int63() //nolint:gosec
/*
// in prior go versions this needs to come from crypto/rand
var b [8]byte
_, err := crypto_rand.Read(b[:])
if err != nil {
panic("cryptographically secure random number generator is not working")
}
seed := int64(binary.LittleEndian.Int64(b[:]))
*/
// defaults
o := &options{
source: rand.NewSource(seed),
}
for _, opt := range opts {
opt(o)
}
return o
}
// WithSource sets the random number generator source
func WithSource(source rand.Source) Option {
return func(opts *options) {
opts.source = source
}
}