add []byte function

Author: bakito

.gitignore

@@ -3,4 +3,5 @@
 .vscode
 cert-fetcher
 dist
-coverage.out
+coverage.out
+.idea

Makefile

@@ -0,0 +1,32 @@
+# Run go fmt against code
+fmt:
+	go fmt ./...
+	gofmt -s -w .
+
+# Run go vet against code
+vet:
+	go vet ./...
+
+# Run go mod tidy
+tidy:
+	go mod tidy
+
+# Run tests
+test: tidy fmt vet
+	go test ./...  -coverprofile=coverage.out
+	go tool cover -func=coverage.out
+
+# Run ci tests
+test-ci: test
+	goveralls -service=travis-ci -v -coverprofile=coverage.out
+
+release: tools
+	goreleaser --rm-dist
+
+test-release: tools
+	goreleaser --skip-publish --snapshot --rm-dist
+
+tools:
+ifeq (, $(shell which goreleaser))
+ $(shell go get github.com/goreleaser/goreleaser)
+endif

cert/cert.go

@@ -32,7 +32,9 @@ func Print(targetURL string) error {
 		return err
 	}
 	for i, cert := range certs {
-		fmt.Fprintf(out, certTemplate, i, cert.Subject.CommonName, cert.Issuer.CommonName, cert.NotBefore.In(loc).String(), cert.NotAfter.In(loc).String())
+		if _, err = fmt.Fprintf(out, certTemplate, i, cert.Subject.CommonName, cert.Issuer.CommonName, cert.NotBefore.In(loc).String(), cert.NotAfter.In(loc).String()); err != nil {
+			return err
+		}
 	}
 	return nil
 }
@@ -51,7 +53,7 @@ func FetchCertificates(targetURL string) ([]*x509.Certificate, error) {
 	if resp.TLS != nil {
 		return resp.TLS.PeerCertificates, err
 	}
-	return nil, fmt.Errorf("Could not find any certificates")
+	return nil, fmt.Errorf("could not find any certificates")
 }
 
 // IsToExport check whether the current index is to be exported
@@ -69,7 +71,7 @@ func IsToExport(certIndexes []int, i int) bool {
 
 // PrintAdd print an add statement
 func PrintAdd(i int, cert *x509.Certificate) {
-	fmt.Fprintf(out, " + Adding   certificate #%d: %s\n", i, cert.Subject.CommonName)
+	_, _ = fmt.Fprintf(out, " + Adding   certificate #%d: %s\n", i, cert.Subject.CommonName)
 }
 
 // PrintSkip print an skip statement
@@ -79,5 +81,5 @@ func PrintSkip(i int, cert *x509.Certificate) {
 
 // PrintSkipDetailed print an skip statement
 func PrintSkipDetailed(i int, cert *x509.Certificate, detail string) {
-	fmt.Fprintf(out, " - Skipping certificate #%d: %s %s\n", i, cert.Subject.CommonName, detail)
+	_, _ = fmt.Fprintf(out, " - Skipping certificate #%d: %s %s\n", i, cert.Subject.CommonName, detail)
 }

cert/jks/jks.go

@@ -36,13 +36,13 @@ func exportCerts(certs []*x509.Certificate, targetURL string, certIndexes []int,
 		if err != nil {
 			return err
 		}
-		defer s.Close()
+		defer closeIt(s)
 		ks, err = keystore.Decode(s, []byte(jksPassword))
 		if err != nil {
 			return err
 		}
 		additional = " additional"
-		fmt.Fprintf(out, "Using existing java keystore %s to add the new certificates\n", jksSource)
+		_, _ = fmt.Fprintf(out, "Using existing java keystore %s to add the new certificates\n", jksSource)
 	} else {
 		ks = keystore.KeyStore{}
 	}
@@ -79,10 +79,12 @@ func exportCerts(certs []*x509.Certificate, targetURL string, certIndexes []int,
 	}
 
 	k, _ := os.Create(fileName)
-	defer k.Close()
-	keystore.Encode(k, ks, []byte(jksPassword))
-	fmt.Fprintf(out, "java keystore file %s with %d%s certificate(s) created.\n", fileName, cnt, additional)
-	return nil
+	defer closeIt(k)
+	if err := keystore.Encode(k, ks, []byte(jksPassword)); err != nil {
+		return err
+	}
+	_, err := fmt.Fprintf(out, "java keystore file %s with %d%s certificate(s) created.\n", fileName, cnt, additional)
+	return err
 }
 
 func alias(cert *x509.Certificate) string {
@@ -101,3 +103,7 @@ func alreadyContained(ks keystore.KeyStore, cert *x509.Certificate, index int) b
 	}
 	return false
 }
+
+func closeIt(s *os.File) {
+	_ = s.Close()
+}

cert/pem/pem.go

@@ -16,16 +16,42 @@ var (
 	out io.Writer = os.Stdout // modified during testing
 )
 
-// Export Export the certificates from the target URL into a pem file
-func Export(targetURL string, certIndexes []int, outputFile string) error {
-	certs, err := c.FetchCertificates(targetURL)
+// ExportTo ExportTo the certificates from the target URL into a pem file
+func ExportTo(targetURL string, certIndexes []int, outputFile string) error {
+	data, cnt, err := Export(targetURL, certIndexes)
+
+	if err != nil {
+		return err
+	}
+	var fileName string
+	if outputFile != "" {
+		fileName = outputFile
+	} else {
+		u, _ := url.Parse(targetURL)
+		fileName = u.Host + ".pem"
+	}
+	f, err := os.Create(fileName)
+
 	if err != nil {
 		return err
 	}
-	return exportCerts(certs, targetURL, certIndexes, outputFile)
+
+	defer func() { _ = f.Close() }()
+	_, _ = f.Write(data)
+	_, _ = fmt.Fprintf(out, "pem file %s with %d certificate(s) created.\n", fileName, cnt)
+	return nil
 }
 
-func exportCerts(certs []*x509.Certificate, targetURL string, certIndexes []int, outputFile string) error {
+// Export Export the certificates from the target URL
+func Export(targetURL string, certIndexes []int) ([]byte, int, error) {
+	certs, err := c.FetchCertificates(targetURL)
+	if err != nil {
+		return nil, 0, err
+	}
+	return exportCerts(certs, certIndexes)
+}
+
+func exportCerts(certs []*x509.Certificate, certIndexes []int) ([]byte, int, error) {
 
 	var pemBytes bytes.Buffer
 	cnt := 0
@@ -34,31 +60,15 @@ func exportCerts(certs []*x509.Certificate, targetURL string, certIndexes []int,
 			c.PrintAdd(i, cert)
 			err := toPEM(&pemBytes, cert)
 			if err != nil {
-				return err
+				return nil, 0, err
 			}
 			cnt++
 		} else {
 			c.PrintSkip(i, cert)
 		}
 	}
 
-	var fileName string
-	if outputFile != "" {
-		fileName = outputFile
-	} else {
-		u, _ := url.Parse(targetURL)
-		fileName = u.Host + ".pem"
-	}
-	f, err := os.Create(fileName)
-
-	if err != nil {
-		return err
-	}
-
-	defer f.Close()
-	f.Write(pemBytes.Bytes())
-	fmt.Fprintf(out, "pem file %s with %d certificate(s) created.\n", fileName, cnt)
-	return nil
+	return pemBytes.Bytes(), cnt, nil
 }
 
 func toPEM(pemBytes *bytes.Buffer, cert *x509.Certificate) error {

cert/pem/pem_public_test.go

@@ -16,7 +16,7 @@ func Test_Export(t *testing.T) {
 	defer ts.Close()
 
 	outFile := "test-cert.pem"
-	err := pem.Export(ts.URL, []int{0}, outFile)
+	err := pem.ExportTo(ts.URL, []int{0}, outFile)
 	assert.NoError(t, err)
-	os.Remove("test-cert.pem")
+	_ = os.Remove("test-cert.pem")
 }

cert/pem/pem_test.go

@@ -1,53 +1,27 @@
 package pem
 
 import (
-	"bytes"
 	"crypto/x509"
-	"os"
 	"testing"
 
 	"github.com/bakito/cert-fetcher/cert/test"
 	"github.com/stretchr/testify/assert"
 )
 
 func Test_exportCerts_min(t *testing.T) {
-
-	out, revert := mockPrintTarget()
-	defer revert()
-
-	err := exportCerts([]*x509.Certificate{test.NewCert(t)}, "https://foo.bar", nil, "")
+	_, cnt, err := exportCerts([]*x509.Certificate{test.NewCert(t)}, nil)
 	assert.NoError(t, err)
-	assert.Equal(t, "pem file foo.bar.pem with 1 certificate(s) created.\n", out.String())
-	os.Remove("foo.bar.pem")
+	assert.Equal(t, 1, cnt)
 }
 
 func Test_exportCerts_cert_0_with_name(t *testing.T) {
-
-	out, revert := mockPrintTarget()
-	defer revert()
-
-	err := exportCerts([]*x509.Certificate{test.NewCert(t)}, "https://foo.bar", []int{0}, "file-name.pem")
+	_, cnt, err := exportCerts([]*x509.Certificate{test.NewCert(t)}, []int{0})
 	assert.NoError(t, err)
-	assert.Equal(t, "pem file file-name.pem with 1 certificate(s) created.\n", out.String())
-	os.Remove("file-name.pem")
+	assert.Equal(t, 1, cnt)
 }
 
 func Test_exportCerts_cert_1(t *testing.T) {
-
-	out, revert := mockPrintTarget()
-	defer revert()
-
-	err := exportCerts([]*x509.Certificate{test.NewCert(t)}, "https://foo.bar", []int{1}, "")
+	_, cnt, err := exportCerts([]*x509.Certificate{test.NewCert(t)}, []int{1})
 	assert.NoError(t, err)
-	assert.Equal(t, "pem file foo.bar.pem with 0 certificate(s) created.\n", out.String())
-	os.Remove("foo.bar.pem")
-}
-
-func mockPrintTarget() (*bytes.Buffer, func()) {
-	bak := out
-	mock := new(bytes.Buffer)
-	out = mock
-	return mock, func() {
-		out = bak
-	}
+	assert.Equal(t, 0, cnt)
 }

cmd/pem.go

@@ -13,7 +13,7 @@ var pemCmd = &cobra.Command{
 	Long:    "store the certificates as pem file",
 
 	RunE: func(cmd *cobra.Command, args []string) error {
-		return pem.Export(targetURL, certIndexes, outputFile)
+		return pem.ExportTo(targetURL, certIndexes, outputFile)
 	},
 }
 

cmd/root.go

@@ -22,7 +22,6 @@ var rootCmd = &cobra.Command{
 	Short:   "Fetch client certificates from https urls",
 	Long:    "A go application that fetches public certificates from https sites and stores them into different output formates.",
 	RunE: func(cmd *cobra.Command, args []string) error {
-
 		return cert.Print(targetURL)
 	},
 }
@@ -38,7 +37,7 @@ func Execute() {
 
 func init() {
 	rootCmd.PersistentFlags().StringVarP(&targetURL, "url", "u", "", "the URL to fetch the certificate from")
-	rootCmd.MarkPersistentFlagRequired("url")
+	_ = rootCmd.MarkPersistentFlagRequired("url")
 	rootCmd.PersistentFlags().StringVarP(&outputFile, "out-file", "o", "", "the output file")
 	rootCmd.PersistentFlags().IntSliceVarP(&certIndexes, "import-at", "i", make([]int, 0), "import the certificates at the given indexes")
 }

go.mod

@@ -1,9 +1,9 @@
 module github.com/bakito/cert-fetcher
 
-go 1.13
+go 1.15
 
 require (
 	github.com/pavel-v-chernykh/keystore-go v2.1.0+incompatible
-	github.com/spf13/cobra v0.0.7
+	github.com/spf13/cobra v1.1.1
 	github.com/stretchr/testify v1.6.1
 )