Upgrading dependencies to include logrus.

vendor/golang.org/x/crypto/hkdf/example_test.go

@@ -0,0 +1,56 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package hkdf_test
+
+import (
+	"bytes"
+	"crypto/rand"
+	"crypto/sha256"
+	"fmt"
+	"io"
+
+	"golang.org/x/crypto/hkdf"
+)
+
+// Usage example that expands one master secret into three other
+// cryptographically secure keys.
+func Example_usage() {
+	// Underlying hash function for HMAC.
+	hash := sha256.New
+
+	// Cryptographically secure master secret.
+	secret := []byte{0x00, 0x01, 0x02, 0x03} // i.e. NOT this.
+
+	// Non-secret salt, optional (can be nil).
+	// Recommended: hash-length random value.
+	salt := make([]byte, hash().Size())
+	if _, err := rand.Read(salt); err != nil {
+		panic(err)
+	}
+
+	// Non-secret context info, optional (can be nil).
+	info := []byte("hkdf example")
+
+	// Generate three 128-bit derived keys.
+	hkdf := hkdf.New(hash, secret, salt, info)
+
+	var keys [][]byte
+	for i := 0; i < 3; i++ {
+		key := make([]byte, 16)
+		if _, err := io.ReadFull(hkdf, key); err != nil {
+			panic(err)
+		}
+		keys = append(keys, key)
+	}
+
+	for i := range keys {
+		fmt.Printf("Key #%d: %v\n", i+1, !bytes.Equal(keys[i], make([]byte, 16)))
+	}
+
+	// Output:
+	// Key #1: true
+	// Key #2: true
+	// Key #3: true
+}