Prevent Init from silently disabling encryption

crypter.go

@@ -21,10 +21,19 @@ type Crypterer interface {
 
 // Init sets the encryption provider used by Encrypt() and Decrypt()
 // and can only ever be called once. Repeated calls have no effect.
-func Init(c Crypterer) {
+//
+// An errors is returned if the Crypter is nil, so that encryption does
+// not get silently disabled for the lifetime of the process.
+func Init(c Crypterer) error {
+	if c == nil {
+		return ErrInitWithNil
+	}
+
 	once.Do(func() {
 		crypter = c
 	})
+
+	return nil
 }
 
 // Encrypt reads plaintext from an io.Reader

crypter_test.go

@@ -7,7 +7,6 @@ import (
 	"testing"
 
 	"github.com/pkg/errors"
-	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -59,9 +58,16 @@ var _ Crypterer = (*base64Crypter)(nil)
 
 func Test_Set(t *testing.T) {
 	c := &base64Crypter{}
-	Init(c)
+	err := Init(c)
+	require.NoError(t, err)
+	require.Equal(t, crypter, c)
+}
 
-	assert.Equal(t, crypter, c)
+func Test_Init_Nil(t *testing.T) {
+	err := Init(nil)
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "Init() called with nil crypter")
+	require.ErrorIs(t, err, ErrInitWithNil)
 }
 
 func Test_Encrypt(t *testing.T) {
@@ -75,7 +81,7 @@ func Test_Encrypt(t *testing.T) {
 
 	err := Encrypt(writer, reader)
 	require.NoError(t, err)
-	assert.Equal(t, ciphertext, writer.String())
+	require.Equal(t, ciphertext, writer.String())
 }
 
 func Test_Encrypt_NotInitialized(t *testing.T) {
@@ -91,7 +97,7 @@ func Test_Encrypt_NotInitialized(t *testing.T) {
 
 	err := Encrypt(writer, reader)
 	require.Error(t, err)
-	assert.ErrorIs(t, err, ErrCrypterNotInitialized)
+	require.ErrorIs(t, err, ErrCrypterNotInitialized)
 }
 
 func Test_Decrypt(t *testing.T) {
@@ -105,7 +111,7 @@ func Test_Decrypt(t *testing.T) {
 
 	err := Decrypt(writer, reader)
 	require.NoError(t, err)
-	assert.Equal(t, plaintext, writer.String())
+	require.Equal(t, plaintext, writer.String())
 }
 
 func Test_Decrypt_NotInitialized(t *testing.T) {
@@ -121,5 +127,5 @@ func Test_Decrypt_NotInitialized(t *testing.T) {
 
 	err := Decrypt(writer, reader)
 	require.Error(t, err)
-	assert.ErrorIs(t, err, ErrCrypterNotInitialized)
+	require.ErrorIs(t, err, ErrCrypterNotInitialized)
 }

errors.go

@@ -2,6 +2,11 @@ package sqlcrypter
 
 import "errors"
 
-// ErrCrypterNotInitialized indicates that Init() has not been called
-// with a valid Crypterer before Encrypt()/Decrypt() usage.
-var ErrCrypterNotInitialized = errors.New("sqlcrypter: crypter is not initialized")
+var (
+	// ErrInitWithNil indicates that Init() has been called with a nil Crypterer.
+	ErrInitWithNil = errors.New("sqlcrypter: Init() called with nil crypter")
+
+	// ErrCrypterNotInitialized indicates that Init() has not been called
+	// with a valid Crypterer before Encrypt()/Decrypt() usage.
+	ErrCrypterNotInitialized = errors.New("sqlcrypter: crypter is not initialized")
+)

example/go.mod

@@ -1,6 +1,6 @@
 module github.com/bincyber/go-sqlcrypter/example
 
-go 1.25.0
+go 1.26
 
 require (
 	github.com/bincyber/go-sqlcrypter v0.3.0
@@ -17,8 +17,8 @@ require (
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mattn/go-sqlite3 v1.14.40 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
-	golang.org/x/sys v0.42.0 // indirect
-	golang.org/x/text v0.35.0 // indirect
+	golang.org/x/sys v0.44.0 // indirect
+	golang.org/x/text v0.37.0 // indirect
 )
 
 replace github.com/bincyber/go-sqlcrypter => ../

example/go.sum

@@ -36,10 +36,10 @@ golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220503163025-988cb79eb6c6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
-golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
-golang.org/x/text v0.35.0 h1:JOVx6vVDFokkpaq1AEptVzLTpDe9KGpj5tR4/X+ybL8=
-golang.org/x/text v0.35.0/go.mod h1:khi/HExzZJ2pGnjenulevKNX1W67CUy0AsXcNubPGCA=
+golang.org/x/sys v0.44.0 h1:ildZl3J4uzeKP07r2F++Op7E9B29JRUy+a27EibtBTQ=
+golang.org/x/sys v0.44.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/text v0.37.0 h1:Cqjiwd9eSg8e0QAkyCaQTNHFIIzWtidPahFWR83rTrc=
+golang.org/x/text v0.37.0/go.mod h1:a5sjxXGs9hsn/AJVwuElvCAo9v8QYLzvavO5z2PiM38=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

example/main.go

@@ -44,7 +44,10 @@ func main() {
 		logger.Error("failed to create AES GCM crypter")
 	}
 
-	sqlcrypter.Init(aesCrypter)
+	if err := sqlcrypter.Init(aesCrypter); err != nil {
+		logger.Error("failed to create init crypter")
+		os.Exit(1)
+	}
 
 	// Connect to the sqlite database
 	db, err := gorm.Open(sqlite.Open("example.db"), &gorm.Config{})