Streamline custom error handling

ego/cli/elf.go

@@ -14,10 +14,11 @@ import (
 	"io"
 	"os"
 	"strings"
-
-	"github.com/fatih/color"
 )
 
+// ErrErrUnsupportedImportEClient is returned when an EGo binary uses the eclient package instead of the enclave package.
+var ErrUnsupportedImportEClient = errors.New("unsupported import: github.com/edgelesssys/ego/eclient")
+
 func (c *Cli) embedConfigAsPayload(path string, jsonData []byte) error {
 	// Load ELF executable
 	f, err := c.fs.OpenFile(path, os.O_RDWR, 0)
@@ -128,11 +129,7 @@ func (c *Cli) checkUnsupportedImports(path string) error {
 	// Iterate through all symbols and find whether it matches a known unsupported one
 	for _, symbol := range symbols {
 		if strings.Contains(symbol.Name, "github.com/edgelesssys/ego/eclient") {
-			boldPrint := color.New(color.Bold).SprintFunc()
-			fmt.Printf("ERROR: You cannot import the %s package within the EGo enclave.\n", boldPrint("github.com/edgelesssys/ego/eclient"))
-			fmt.Printf("It is intended to be used for applications running outside the SGX enclave.\n")
-			fmt.Printf("You can use the %s package as a replacement for usage inside the enclave.\n", boldPrint("github.com/edgelesssys/ego/enclave"))
-			return errors.New("unsupported import: github.com/edgelesssys/ego/eclient")
+			return ErrUnsupportedImportEClient
 		}
 	}
 

ego/ego/cmd/sign.go

@@ -7,18 +7,15 @@
 package cmd
 
 import (
-	"log"
-
-	"ego/cli"
-
 	"github.com/spf13/cobra"
 )
 
 func newSignCmd() *cobra.Command {
 	return &cobra.Command{
-		Use:   "sign [executable | config.json]",
-		Short: "Sign an executable built with ego-go",
-		Long:  "Sign an executable built with ego-go. Executables must be signed before they can be run in an enclave.",
+		Use:           "sign [executable | config.json]",
+		Short:         "Sign an executable built with ego-go",
+		Long:          "Sign an executable built with ego-go. Executables must be signed before they can be run in an enclave.",
+		SilenceErrors: true,
 		Example: `  ego sign <executable>
     Generates a new key "private.pem" and a default configuration "enclave.json" in the current directory and signs the executable.
 
@@ -36,10 +33,11 @@ func newSignCmd() *cobra.Command {
 				filename = args[0]
 			}
 			err := newCli().Sign(filename)
-			if err == cli.ErrNoOEInfo {
-				log.Fatalln("ERROR: The .oeinfo section is missing in the binary.\nMaybe the binary was not built with 'ego-go build'?")
+			handleErr(err)
+			if err != nil {
+				return err
 			}
-			return err
+			return nil
 		},
 	}
 }

ego/ego/cmd/signerid.go

@@ -8,9 +8,6 @@ package cmd
 
 import (
 	"fmt"
-	"log"
-
-	"ego/internal/launch"
 
 	"github.com/spf13/cobra"
 )
@@ -21,13 +18,12 @@ func newSigneridCmd() *cobra.Command {
 		Short:                 "Print the SignerID of a signed executable",
 		Long:                  "Print the SignerID either from a signed executable or by reading a key file.",
 		Args:                  cobra.ExactArgs(1),
+		SilenceErrors:         true,
 		DisableFlagsInUseLine: true,
 
 		RunE: func(cmd *cobra.Command, args []string) error {
 			id, err := newCli().Signerid(args[0])
-			if err == launch.ErrOECrypto {
-				log.Fatalf("ERROR: signerid failed with %v.\nMake sure to pass a valid public key.", err)
-			}
+			handleErr(err)
 			if err != nil {
 				return err
 			}

ego/ego/cmd/util.go

@@ -13,6 +13,7 @@ import (
 	"ego/cli"
 	"ego/internal/launch"
 
+	"github.com/fatih/color"
 	"github.com/klauspost/cpuid/v2"
 	"github.com/spf13/afero"
 	"github.com/spf13/cobra"
@@ -69,7 +70,16 @@ func handleErr(err error) {
 		fmt.Println("ERROR: failed to initialize the enclave")
 		fmt.Println("Install the SGX base package with: sudo ego install libsgx-enclave-common")
 		fmt.Println("Or temporarily fix the error with: sudo mount -o remount,exec /dev")
+	case launch.ErrOECrypto:
+		fmt.Printf("ERROR: signerid failed with %v.\nMake sure to pass a valid public key.\n", err)
+	case cli.ErrNoOEInfo:
+		fmt.Println("ERROR: The .oeinfo section is missing in the binary.\nMaybe the binary was not built with 'ego-go build'?")
+	case cli.ErrUnsupportedImportEClient:
+		boldPrint := color.New(color.Bold).SprintFunc()
+		fmt.Printf("ERROR: You cannot import the %s package within the EGo enclave.\n", boldPrint("github.com/edgelesssys/ego/eclient"))
+		fmt.Printf("It is intended to be used for applications running outside the SGX enclave.\n")
+		fmt.Printf("You can use the %s package as a replacement for usage inside the enclave.\n", boldPrint("github.com/edgelesssys/ego/enclave"))
 	default:
-		fmt.Println(err)
+		fmt.Println("ERROR:", err)
 	}
 }

src/integration_test.sh

@@ -54,5 +54,5 @@ mkdir -p /tmp/ego-unsupported-import-test
 cd $egoPath/ego/cmd/unsupported-import-test
 run ego-go build -o /tmp/ego-unsupported-import-test/unsupported-import
 cd /tmp/ego-unsupported-import-test
-run ego sign unsupported-import |& grep "unsupported import"
-run ego run unsupported-import |& grep "unsupported import"
+run ego sign unsupported-import |& grep "You cannot import the github.com/edgelesssys/ego/eclient package"
+run ego run unsupported-import |& grep "You cannot import the github.com/edgelesssys/ego/eclient package"