Merge pull request #13 from keylockerbv/randstr

Move the core/random package to secrethub-go/pkg/randstr

pkg/randstr/fakes/generator.go

@@ -0,0 +1,14 @@
+// +build !production
+
+package fakes
+
+// FakeRandomGenerator can be used to mock a RandomGenerator.
+type FakeRandomGenerator struct {
+	Ret []byte
+	Err error
+}
+
+// Generate returns the mocked Generate response.
+func (generator FakeRandomGenerator) Generate(length int) ([]byte, error) {
+	return generator.Ret, generator.Err
+}

pkg/randstr/generator.go

@@ -0,0 +1,54 @@
+package randstr
+
+import (
+	"crypto/rand"
+	"math/big"
+
+	"github.com/keylockerbv/secrethub-go/pkg/errio"
+)
+
+var (
+	// randPatternAlphanumeric is the default pattern of characters used to generate random secrets.
+	randPatternAlphanumeric = []byte(`0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ`)
+	// randPatternSymbols is added to the randPattern when generator.useSymbols is true.
+	randPatternSymbols = []byte(`!@#$%^*-_+=.,?`)
+)
+
+// Generator generates random byte arrays.
+type Generator interface {
+	Generate(length int) ([]byte, error)
+}
+
+// NewGenerator creates a new random generator.
+func NewGenerator(useSymbols bool) Generator {
+	return &generator{
+		useSymbols: useSymbols,
+	}
+}
+
+type generator struct {
+	useSymbols bool
+}
+
+// Generate returns a random byte array of given length.
+func (generator generator) Generate(length int) ([]byte, error) {
+	pattern := randPatternAlphanumeric
+	if generator.useSymbols {
+		pattern = append(pattern, randPatternSymbols...)
+	}
+	return randFromPattern(pattern, length)
+}
+
+func randFromPattern(pattern []byte, length int) ([]byte, error) {
+	data := make([]byte, length)
+
+	lengthPattern := len(pattern)
+	for i := 0; i < length; i++ {
+		c, err := rand.Int(rand.Reader, big.NewInt(int64(lengthPattern)))
+		if err != nil {
+			return nil, errio.Error(err)
+		}
+		data[i] = pattern[c.Int64()]
+	}
+	return data, nil
+}