Description: Vendor trivial library to avoid a new package in the archive.
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+++ b/vendor/github.com/sean-/seed/LICENSE
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+MIT License
+
+Copyright (c) 2017 Sean Chittenden
+Copyright (c) 2016 Alex Dadgar
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+=====
+
+Bits of Go-lang's `once.Do()` were cribbed and reused here, too.
+
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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+# `seed` - Quickly Seed Go's Random Number Generator
+
+Boiler-plate to securely [seed](https://en.wikipedia.org/wiki/Random_seed) Go's
+random number generator (if possible).  This library isn't anything fancy, it's
+just a canonical way of seeding Go's random number generator. Cribbed from
+[`Nomad`](https://github.com/hashicorp/nomad/commit/f89a993ec6b91636a3384dd568898245fbc273a1)
+before it was moved into
+[`Consul`](https://github.com/hashicorp/consul/commit/d695bcaae6e31ee307c11fdf55bb0bf46ea9fcf4)
+and made into a helper function, and now further modularized to be a super
+lightweight and reusable library.
+
+Time is better than
+[Go's default seed of `1`](https://golang.org/pkg/math/rand/#Seed), but friends
+don't let friends use time as a seed to a random number generator.  Use
+`seed.MustInit()` instead.
+
+`seed.Init()` is an idempotent and reentrant call that will return an error if
+it can't seed the value the first time it is called.  `Init()` is reentrant.
+
+`seed.MustInit()` is idempotent and reentrant call that will `panic()` if it
+can't seed the value the first time it is called.  `MustInit()` is reentrant.
+
+## Usage
+
+```
+package mypackage
+
+import (
+  "github.com/sean-/seed"
+)
+
+// MustInit will panic() if it is unable to set a high-entropy random seed:
+func init() {
+  seed.MustInit()
+}
+
+// Or if you want to not panic() and can actually handle this error:
+func init() {
+  if secure, err := !seed.Init(); !secure {
+    // Handle the error
+    //panic(fmt.Sprintf("Unable to securely seed Go's RNG: %v", err))
+  }
+}
+```
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+++ b/vendor/github.com/sean-/seed/init.go
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+package seed
+
+import (
+	crand "crypto/rand"
+	"fmt"
+	"math"
+	"math/big"
+	"math/rand"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+var (
+	m      sync.Mutex
+	secure int32
+	seeded int32
+)
+
+func cryptoSeed() error {
+	defer atomic.StoreInt32(&seeded, 1)
+
+	var err error
+	var n *big.Int
+	n, err = crand.Int(crand.Reader, big.NewInt(math.MaxInt64))
+	if err != nil {
+		rand.Seed(time.Now().UTC().UnixNano())
+		return err
+	}
+	rand.Seed(n.Int64())
+	atomic.StoreInt32(&secure, 1)
+	return nil
+}
+
+// Init provides best-effort seeding (which is better than running with Go's
+// default seed of 1).  If `/dev/urandom` is available, Init() will seed Go's
+// runtime with entropy from `/dev/urandom` and return true because the runtime
+// was securely seeded.  If Init() has already initialized the random number or
+// it had failed to securely initialize the random number generation, Init()
+// will return false.  See MustInit().
+func Init() (seededSecurely bool, err error) {
+	if atomic.LoadInt32(&seeded) == 1 {
+		return false, nil
+	}
+
+	// Slow-path
+	m.Lock()
+	defer m.Unlock()
+
+	if err := cryptoSeed(); err != nil {
+		return false, err
+	}
+
+	return true, nil
+}
+
+// MustInit provides guaranteed secure seeding.  If `/dev/urandom` is not
+// available, MustInit will panic() with an error indicating why reading from
+// `/dev/urandom` failed.  MustInit() will upgrade the seed if for some reason a
+// call to Init() failed in the past.
+func MustInit() {
+	if atomic.LoadInt32(&secure) == 1 {
+		return
+	}
+
+	// Slow-path
+	m.Lock()
+	defer m.Unlock()
+
+	if err := cryptoSeed(); err != nil {
+		panic(fmt.Sprintf("Unable to seed the random number generator: %v", err))
+	}
+}
+
+// Secure returns true if a cryptographically secure seed was used to
+// initialize rand.
+func Secure() bool {
+	return atomic.LoadInt32(&secure) == 1
+}
+
+// Seeded returns true if Init has seeded the random number generator.
+func Seeded() bool {
+	return atomic.LoadInt32(&seeded) == 1
+}
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+++ b/vendor/github.com/sean-/seed/init_test.go
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+package seed_test
+
+import (
+	"testing"
+
+	"github.com/sean-/seed"
+)
+
+func TestInit(t *testing.T) {
+	secure, err := seed.Init()
+	if !secure {
+		t.Fatalf("Failed to securely seed: %v", err)
+	}
+}
+
+func TestMustInit(t *testing.T) {
+	seed.MustInit()
+
+	if !seed.Seeded() {
+		t.Fatalf("MustInit() failed to seed")
+	}
+
+	if !seed.Secure() {
+		t.Fatalf("MustInit() failed to securely seed")
+	}
+}