Merge branch 'hotfix/generateSecret' into 'release'

Add GenerateSecret helper function

See merge request !655

bindings/secrets.go

+///////////////////////////////////////////////////////////////////////////////
+// Copyright © 2020 xx network SEZC                                          //
+//                                                                           //
+// Use of this source code is governed by a license that can be found in the //
+// LICENSE file                                                              //
+///////////////////////////////////////////////////////////////////////////////
+
+package bindings
+
+import (
+	jww "github.com/spf13/jwalterweatherman"
+	"gitlab.com/xx_network/crypto/csprng"
+)
+
+// GenerateSecret creates a secret password using a system-based
+// pseudorandom number generator. It takes 1 parameter, `numBytes`,
+// which should be set to 32, but can be set higher in certain cases.
+func GenerateSecret(numBytes int) []byte {
+	if numBytes < 32 {
+		jww.FATAL.Panicf("Secrets must have at least 32 bytes " +
+			"(256 bits) of entropy.")
+	}
+
+	out := make([]byte, numBytes)
+	rng := csprng.NewSystemRNG()
+	numRead, err := rng.Read(out)
+	if err != nil {
+		jww.FATAL.Panicf("%+v", err)
+	}
+	if numRead != numBytes {
+		jww.FATAL.Panicf("Unable to read %d bytes", numBytes)
+	}
+	return out
+}

bindings/secrets_test.go

+////////////////////////////////////////////////////////////////////////////////////////////
+// Copyright © 2020 xx network SEZC                                                       //
+//                                                                                        //
+// Use of this source code is governed by a license that can be found in the LICENSE file //
+////////////////////////////////////////////////////////////////////////////////////////////
+
+package bindings
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestGenerateSecret(t *testing.T) {
+	secret1 := GenerateSecret(32)
+	secret2 := GenerateSecret(32)
+
+	if bytes.Compare(secret1, secret2) == 0 {
+		t.Errorf("GenerateSecret: Not generating entropy")
+	}
+
+	// This runs after the test function and errors out if no panic was
+	// raised.
+	defer func() {
+		if r := recover(); r == nil {
+			t.Errorf("GenerateSecret: Low entropy was permitted")
+		}
+	}()
+	GenerateSecret(31)
+}