Fix the attest command (#2337)

* fix attest command

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* add notification on how to access the attestation

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* fix integration test

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

---------

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

cmd/syft/cli/commands/attest.go

@@ -2,6 +2,7 @@ package commands
 
 import (
 	"fmt"
+	"io"
 	"os"
 	"os/exec"
 	"strings"
@@ -11,15 +12,14 @@ import (
 	"github.com/wagoodman/go-progress"
 
 	"github.com/anchore/clio"
-	"github.com/anchore/stereoscope/pkg/image"
 	"github.com/anchore/syft/cmd/syft/cli/options"
 	"github.com/anchore/syft/cmd/syft/internal/ui"
 	"github.com/anchore/syft/internal"
 	"github.com/anchore/syft/internal/bus"
-	"github.com/anchore/syft/internal/file"
 	"github.com/anchore/syft/internal/log"
 	"github.com/anchore/syft/syft/event"
 	"github.com/anchore/syft/syft/event/monitor"
+	"github.com/anchore/syft/syft/format"
 	"github.com/anchore/syft/syft/format/cyclonedxjson"
 	"github.com/anchore/syft/syft/format/spdxjson"
 	"github.com/anchore/syft/syft/format/spdxtagvalue"
@@ -33,6 +33,7 @@ const (
 `
 	attestSchemeHelp = "\n  " + schemeHelpHeader + "\n" + imageSchemeHelp
 	attestHelp       = attestExample + attestSchemeHelp
+	cosignBinName    = "cosign"
 )
 
 type attestOptions struct {
@@ -46,24 +47,7 @@ type attestOptions struct {
 func Attest(app clio.Application) *cobra.Command {
 	id := app.ID()
 
-	opts := &attestOptions{
-		UpdateCheck: options.DefaultUpdateCheck(),
-		Output: options.Output{
-			AllowMultipleOutputs: false,
-			AllowableOptions: []string{
-				string(syftjson.ID),
-				string(cyclonedxjson.ID),
-				string(spdxjson.ID),
-				string(spdxtagvalue.ID),
-			},
-			Outputs: []string{syftjson.ID.String()},
-			OutputFile: options.OutputFile{ // nolint:staticcheck
-				Enabled: false, // explicitly not allowed
-			},
-			Format: options.DefaultFormat(),
-		},
-		Catalog: options.DefaultCatalog(),
-	}
+	opts := defaultAttestOptions()
 
 	// template format explicitly not allowed
 	opts.Format.Template.Enabled = false
@@ -82,83 +66,96 @@ func Attest(app clio.Application) *cobra.Command {
 			restoreStdout := ui.CaptureStdoutToTraceLog()
 			defer restoreStdout()
 
-			return runAttest(id, opts, args[0])
+			return runAttest(id, &opts, args[0])
 		},
-	}, opts)
+	}, &opts)
+}
+
+func defaultAttestOptions() attestOptions {
+	return attestOptions{
+		Output:      defaultAttestOutputOptions(),
+		UpdateCheck: options.DefaultUpdateCheck(),
+		Catalog:     options.DefaultCatalog(),
+	}
+}
+
+func defaultAttestOutputOptions() options.Output {
+	return options.Output{
+		AllowMultipleOutputs: false,
+		AllowToFile:          false,
+		AllowableOptions: []string{
+			string(syftjson.ID),
+			string(cyclonedxjson.ID),
+			string(spdxjson.ID),
+			string(spdxtagvalue.ID),
+		},
+		Outputs: []string{syftjson.ID.String()},
+		OutputFile: options.OutputFile{ // nolint:staticcheck
+			Enabled: false, // explicitly not allowed
+		},
+		Format: options.DefaultFormat(),
+	}
 }
 
 //nolint:funlen
 func runAttest(id clio.Identification, opts *attestOptions, userInput string) error {
-	_, err := exec.LookPath("cosign")
-	if err != nil {
-		// when cosign is not installed the error will be rendered like so:
-		// 2023/06/30 08:31:52 error during command execution: 'syft attest' requires cosign to be installed: exec: "cosign": executable file not found in $PATH
-		return fmt.Errorf("'syft attest' requires cosign to be installed: %w", err)
-	}
-
-	s, err := buildSBOM(id, &opts.Catalog, userInput)
-	if err != nil {
-		return fmt.Errorf("unable to build SBOM: %w", err)
+	// TODO: what other validation here besides binary name?
+	if !commandExists(cosignBinName) {
+		return fmt.Errorf("'syft attest' requires cosign to be installed, however it does not appear to be on PATH")
 	}
 
+	// this is the file that will contain the SBOM being attested
 	f, err := os.CreateTemp("", "syft-attest-")
 	if err != nil {
 		return fmt.Errorf("unable to create temp file: %w", err)
 	}
 	defer os.Remove(f.Name())
 
-	writer, err := opts.SBOMWriter()
+	s, err := generateSBOMForAttestation(id, &opts.Catalog, userInput)
 	if err != nil {
-		return fmt.Errorf("unable to create SBOM writer: %w", err)
+		return fmt.Errorf("unable to build SBOM: %w", err)
 	}
 
-	if err := writer.Write(*s); err != nil {
-		return fmt.Errorf("unable to write SBOM to temp file: %w", err)
+	if err = writeSBOMToFormattedFile(s, f, opts); err != nil {
+		return fmt.Errorf("unable to write SBOM to file: %w", err)
 	}
 
-	// TODO: what other validation here besides binary name?
-	cmd := "cosign"
-	if !commandExists(cmd) {
-		return fmt.Errorf("unable to find cosign in PATH; make sure you have it installed")
+	if err = createAttestation(f.Name(), opts, userInput); err != nil {
+		return err
 	}
 
-	outputNames := opts.OutputNameSet()
-	var outputName string
-	switch outputNames.Size() {
-	case 0:
-		return fmt.Errorf("no output format specified")
-	case 1:
-		outputName = outputNames.List()[0]
-	default:
-		return fmt.Errorf("multiple output formats specified: %s", strings.Join(outputNames.List(), ", "))
+	bus.Notify("Attestation has been created, please check your registry for the output or use the cosign command:")
+	bus.Notify(fmt.Sprintf("cosign download attestation %s", userInput))
+	return nil
+}
+
+func writeSBOMToFormattedFile(s *sbom.SBOM, sbomFile io.Writer, opts *attestOptions) error {
+	if sbomFile == nil {
+		return fmt.Errorf("no output file provided")
 	}
 
-	// Select Cosign predicate type based on defined output type
-	// As orientation, check: https://github.com/sigstore/cosign/blob/main/pkg/cosign/attestation/attestation.go
-	var predicateType string
-	switch strings.ToLower(outputName) {
-	case "cyclonedx-json":
-		predicateType = "cyclonedx"
-	case "spdx-tag-value", "spdx-tv":
-		predicateType = "spdx"
-	case "spdx-json", "json":
-		predicateType = "spdxjson"
-	default:
-		predicateType = "custom"
+	encs, err := opts.Format.Encoders()
+	if err != nil {
+		return fmt.Errorf("unable to create encoders: %w", err)
 	}
 
-	args := []string{"attest", userInput, "--predicate", f.Name(), "--type", predicateType}
-	if opts.Attest.Key != "" {
-		args = append(args, "--key", opts.Attest.Key.String())
+	encoders := format.NewEncoderCollection(encs...)
+	encoder := encoders.GetByString(opts.Outputs[0])
+	if encoder == nil {
+		return fmt.Errorf("unable to find encoder for %q", opts.Outputs[0])
 	}
 
-	execCmd := exec.Command(cmd, args...)
-	execCmd.Env = os.Environ()
-	if opts.Attest.Key != "" {
-		execCmd.Env = append(execCmd.Env, fmt.Sprintf("COSIGN_PASSWORD=%s", opts.Attest.Password))
-	} else {
-		// no key provided, use cosign's keyless mode
-		execCmd.Env = append(execCmd.Env, "COSIGN_EXPERIMENTAL=1")
+	if err = encoder.Encode(sbomFile, *s); err != nil {
+		return fmt.Errorf("unable to encode SBOM: %w", err)
+	}
+
+	return nil
+}
+
+func createAttestation(sbomFilepath string, opts *attestOptions, userInput string) error {
+	execCmd, err := attestCommand(sbomFilepath, opts, userInput)
+	if err != nil {
+		return fmt.Errorf("unable to craft attest command: %w", err)
 	}
 
 	log.WithFields("cmd", strings.Join(execCmd.Args, " ")).Trace("creating attestation")
@@ -201,59 +198,67 @@ func runAttest(id clio.Identification, opts *attestOptions, userInput string) er
 	}
 
 	mon.SetCompleted()
-
 	return nil
 }
 
-func buildSBOM(id clio.Identification, opts *options.Catalog, userInput string) (*sbom.SBOM, error) {
-	cfg := source.DetectConfig{
-		DefaultImageSource: opts.DefaultImagePullSource,
+func attestCommand(sbomFilepath string, opts *attestOptions, userInput string) (*exec.Cmd, error) {
+	outputNames := opts.OutputNameSet()
+	var outputName string
+	switch outputNames.Size() {
+	case 0:
+		return nil, fmt.Errorf("no output format specified")
+	case 1:
+		outputName = outputNames.List()[0]
+	default:
+		return nil, fmt.Errorf("multiple output formats specified: %s", strings.Join(outputNames.List(), ", "))
 	}
-	detection, err := source.Detect(userInput, cfg)
+
+	args := []string{"attest", userInput, "--predicate", sbomFilepath, "--type", predicateType(outputName), "-y"}
+	if opts.Attest.Key != "" {
+		args = append(args, "--key", opts.Attest.Key.String())
+	}
+
+	execCmd := exec.Command(cosignBinName, args...)
+	execCmd.Env = os.Environ()
+	if opts.Attest.Key != "" {
+		execCmd.Env = append(execCmd.Env, fmt.Sprintf("COSIGN_PASSWORD=%s", opts.Attest.Password))
+	} else {
+		// no key provided, use cosign's keyless mode
+		execCmd.Env = append(execCmd.Env, "COSIGN_EXPERIMENTAL=1")
+	}
+
+	return execCmd, nil
+}
+
+func predicateType(outputName string) string {
+	// Select Cosign predicate type based on defined output type
+	// As orientation, check: https://github.com/sigstore/cosign/blob/main/pkg/cosign/attestation/attestation.go
+	switch strings.ToLower(outputName) {
+	case "cyclonedx-json":
+		return "cyclonedx"
+	case "spdx-tag-value", "spdx-tv":
+		return "spdx"
+	case "spdx-json", "json":
+		return "spdxjson"
+	default:
+		return "custom"
+	}
+}
+
+func generateSBOMForAttestation(id clio.Identification, opts *options.Catalog, userInput string) (*sbom.SBOM, error) {
+	src, err := getSource(opts, userInput, onlyContainerImages)
+
 	if err != nil {
-		return nil, fmt.Errorf("could not deteremine source: %w", err)
+		return nil, err
 	}
 
-	if detection.IsContainerImage() {
-		return nil, fmt.Errorf("attestations are only supported for oci images at this time")
-	}
-
-	var platform *image.Platform
-
-	if opts.Platform != "" {
-		platform, err = image.NewPlatform(opts.Platform)
-		if err != nil {
-			return nil, fmt.Errorf("invalid platform: %w", err)
+	defer func() {
+		if src != nil {
+			if err := src.Close(); err != nil {
+				log.Tracef("unable to close source: %+v", err)
+			}
 		}
-	}
-
-	hashers, err := file.Hashers(opts.Source.File.Digests...)
-	if err != nil {
-		return nil, fmt.Errorf("invalid hash: %w", err)
-	}
-
-	src, err := detection.NewSource(
-		source.DetectionSourceConfig{
-			Alias: source.Alias{
-				Name:    opts.Source.Name,
-				Version: opts.Source.Version,
-			},
-			RegistryOptions: opts.Registry.ToOptions(),
-			Platform:        platform,
-			Exclude: source.ExcludeConfig{
-				Paths: opts.Exclusions,
-			},
-			DigestAlgorithms: hashers,
-			BasePath:         opts.BasePath,
-		},
-	)
-
-	if src != nil {
-		defer src.Close()
-	}
-	if err != nil {
-		return nil, fmt.Errorf("failed to construct source from user input %q: %w", userInput, err)
-	}
+	}()
 
 	s, err := generateSBOM(id, src, opts)
 	if err != nil {
@@ -267,6 +272,13 @@ func buildSBOM(id clio.Identification, opts *options.Catalog, userInput string)
 	return s, nil
 }
 
+func onlyContainerImages(d *source.Detection) error {
+	if !d.IsContainerImage() {
+		return fmt.Errorf("attestations are only supported for oci images at this time")
+	}
+	return nil
+}
+
 func commandExists(cmd string) bool {
 	_, err := exec.LookPath(cmd)
 	return err == nil

cmd/syft/cli/commands/attest_test.go

@@ -0,0 +1,268 @@
+package commands
+
+import (
+	"bytes"
+	"fmt"
+	"os/exec"
+	"regexp"
+	"strings"
+	"testing"
+
+	"github.com/scylladb/go-set/strset"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/anchore/clio"
+	"github.com/anchore/syft/cmd/syft/cli/options"
+	"github.com/anchore/syft/syft/sbom"
+	"github.com/anchore/syft/syft/source"
+)
+
+func Test_writeSBOMToFormattedFile(t *testing.T) {
+	type args struct {
+		s    *sbom.SBOM
+		opts *attestOptions
+	}
+	tests := []struct {
+		name         string
+		args         args
+		wantSbomFile string
+		wantErr      bool
+	}{
+		{
+			name: "go case",
+			args: args{
+				opts: &attestOptions{
+					Output: func() options.Output {
+						def := defaultAttestOutputOptions()
+						def.Outputs = []string{"syft-json"}
+						return def
+					}(),
+				},
+				s: &sbom.SBOM{
+					Artifacts:     sbom.Artifacts{},
+					Relationships: nil,
+					Source: source.Description{
+						ID:      "source-id",
+						Name:    "source-name",
+						Version: "source-version",
+					},
+					Descriptor: sbom.Descriptor{
+						Name:    "syft-test",
+						Version: "non-version",
+					},
+				},
+			},
+			wantSbomFile: `{
+ "artifacts": [],
+ "artifactRelationships": [],
+ "source": {
+  "id": "source-id",
+  "name": "source-name",
+  "version": "source-version",
+  "type": "",
+  "metadata": null
+ },
+ "distro": {},
+ "descriptor": {
+  "name": "syft-test",
+  "version": "non-version"
+ },
+ "schema": {}
+}`,
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sbomFile := &bytes.Buffer{}
+
+			err := writeSBOMToFormattedFile(tt.args.s, sbomFile, tt.args.opts)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("writeSBOMToFormattedFile() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+
+			// redact the schema block
+			re := regexp.MustCompile(`(?s)"schema":\W*\{.*?},?`)
+			subject := re.ReplaceAllString(sbomFile.String(), `"schema":{}`)
+
+			assert.JSONEq(t, tt.wantSbomFile, subject)
+		})
+	}
+}
+
+func Test_attestCommand(t *testing.T) {
+	cmdPrefix := cosignBinName
+	lp, err := exec.LookPath(cosignBinName)
+	if err == nil {
+		cmdPrefix = lp
+	}
+
+	fullCmd := func(args string) string {
+		return fmt.Sprintf("%s %s", cmdPrefix, args)
+	}
+
+	type args struct {
+		sbomFilepath string
+		opts         attestOptions
+		userInput    string
+	}
+	tests := []struct {
+		name        string
+		args        args
+		wantCmd     string
+		wantEnvVars map[string]string
+		notEnvVars  []string
+		wantErr     require.ErrorAssertionFunc
+	}{
+		{
+			name: "with key and password",
+			args: args{
+				userInput:    "myimage",
+				sbomFilepath: "/tmp/sbom-filepath.json",
+				opts: func() attestOptions {
+					def := defaultAttestOptions()
+					def.Outputs = []string{"syft-json"}
+					def.Attest.Key = "key"
+					def.Attest.Password = "password"
+					return def
+				}(),
+			},
+			wantCmd: fullCmd("attest myimage --predicate /tmp/sbom-filepath.json --type custom -y --key key"),
+			wantEnvVars: map[string]string{
+				"COSIGN_PASSWORD": "password",
+			},
+			notEnvVars: []string{
+				"COSIGN_EXPERIMENTAL", // only for keyless
+			},
+		},
+		{
+			name: "keyless",
+			args: args{
+				userInput:    "myimage",
+				sbomFilepath: "/tmp/sbom-filepath.json",
+				opts: func() attestOptions {
+					def := defaultAttestOptions()
+					def.Outputs = []string{"syft-json"}
+					return def
+				}(),
+			},
+			wantCmd: fullCmd("attest myimage --predicate /tmp/sbom-filepath.json --type custom -y"),
+			wantEnvVars: map[string]string{
+				"COSIGN_EXPERIMENTAL": "1",
+			},
+			notEnvVars: []string{
+				"COSIGN_PASSWORD",
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.wantErr == nil {
+				tt.wantErr = require.NoError
+			}
+
+			got, err := attestCommand(tt.args.sbomFilepath, &tt.args.opts, tt.args.userInput)
+			tt.wantErr(t, err)
+			if err != nil {
+				return
+			}
+
+			require.NotNil(t, got)
+			assert.Equal(t, tt.wantCmd, got.String())
+
+			gotEnv := strset.New(got.Env...)
+
+			for k, v := range tt.wantEnvVars {
+				assert.True(t, gotEnv.Has(fmt.Sprintf("%s=%s", k, v)))
+			}
+
+			for _, k := range tt.notEnvVars {
+				for _, env := range got.Env {
+					fields := strings.Split(env, "=")
+					if fields[0] == k {
+						t.Errorf("attestCommand() unexpected environment variable %s", k)
+					}
+				}
+			}
+		})
+	}
+}
+
+func Test_predicateType(t *testing.T) {
+	tests := []struct {
+		name string
+		want string
+	}{
+		{
+			name: "cyclonedx-json",
+			want: "cyclonedx",
+		},
+		{
+			name: "spdx-tag-value",
+			want: "spdx",
+		},
+		{
+			name: "spdx-tv",
+			want: "spdx",
+		},
+		{
+			name: "spdx-json",
+			want: "spdxjson",
+		},
+		{
+			name: "json",
+			want: "spdxjson",
+		},
+		{
+			name: "syft-json",
+			want: "custom",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equalf(t, tt.want, predicateType(tt.name), "predicateType(%v)", tt.name)
+		})
+	}
+}
+
+func Test_buildSBOMForAttestation(t *testing.T) {
+	// note: this test is only meant to test that the filter function is wired
+	// and not the correctness of the function in depth
+	type args struct {
+		id        clio.Identification
+		opts      *options.Catalog
+		userInput string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    *sbom.SBOM
+		wantErr require.ErrorAssertionFunc
+	}{
+		{
+			name: "do not allow directory scans",
+			args: args{
+				opts: func() *options.Catalog {
+					def := defaultAttestOptions()
+					return &def.Catalog
+				}(),
+				userInput: "dir:/tmp/something",
+			},
+			wantErr: require.Error,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.wantErr == nil {
+				tt.wantErr = require.NoError
+			}
+			_, err := generateSBOMForAttestation(tt.args.id, tt.args.opts, tt.args.userInput)
+			tt.wantErr(t, err)
+			if err != nil {
+				return
+			}
+		})
+	}
+}

cmd/syft/cli/commands/packages.go

@@ -117,51 +117,10 @@ func runPackages(id clio.Identification, opts *packagesOptions, userInput string
 		return err
 	}
 
-	detection, err := source.Detect(
-		userInput,
-		source.DetectConfig{
-			DefaultImageSource: opts.DefaultImagePullSource,
-		},
-	)
-	if err != nil {
-		return fmt.Errorf("could not deteremine source: %w", err)
-	}
-
-	var platform *image.Platform
-
-	if opts.Platform != "" {
-		platform, err = image.NewPlatform(opts.Platform)
-		if err != nil {
-			return fmt.Errorf("invalid platform: %w", err)
-		}
-	}
-
-	hashers, err := file.Hashers(opts.Source.File.Digests...)
-	if err != nil {
-		return fmt.Errorf("invalid hash: %w", err)
-	}
-
-	src, err := detection.NewSource(
-		source.DetectionSourceConfig{
-			Alias: source.Alias{
-				Name:    opts.Source.Name,
-				Version: opts.Source.Version,
-			},
-			RegistryOptions: opts.Registry.ToOptions(),
-			Platform:        platform,
-			Exclude: source.ExcludeConfig{
-				Paths: opts.Exclusions,
-			},
-			DigestAlgorithms: hashers,
-			BasePath:         opts.BasePath,
-		},
-	)
+	src, err := getSource(&opts.Catalog, userInput)
 
 	if err != nil {
-		if userInput == "power-user" {
-			bus.Notify("Note: the 'power-user' command has been removed.")
-		}
-		return fmt.Errorf("failed to construct source from user input %q: %w", userInput, err)
+		return err
 	}
 
 	defer func() {
@@ -188,6 +147,63 @@ func runPackages(id clio.Identification, opts *packagesOptions, userInput string
 	return nil
 }
 
+func getSource(opts *options.Catalog, userInput string, filters ...func(*source.Detection) error) (source.Source, error) {
+	detection, err := source.Detect(
+		userInput,
+		source.DetectConfig{
+			DefaultImageSource: opts.DefaultImagePullSource,
+		},
+	)
+	if err != nil {
+		return nil, fmt.Errorf("could not deteremine source: %w", err)
+	}
+
+	for _, filter := range filters {
+		if err := filter(detection); err != nil {
+			return nil, err
+		}
+	}
+
+	var platform *image.Platform
+
+	if opts.Platform != "" {
+		platform, err = image.NewPlatform(opts.Platform)
+		if err != nil {
+			return nil, fmt.Errorf("invalid platform: %w", err)
+		}
+	}
+
+	hashers, err := file.Hashers(opts.Source.File.Digests...)
+	if err != nil {
+		return nil, fmt.Errorf("invalid hash: %w", err)
+	}
+
+	src, err := detection.NewSource(
+		source.DetectionSourceConfig{
+			Alias: source.Alias{
+				Name:    opts.Source.Name,
+				Version: opts.Source.Version,
+			},
+			RegistryOptions: opts.Registry.ToOptions(),
+			Platform:        platform,
+			Exclude: source.ExcludeConfig{
+				Paths: opts.Exclusions,
+			},
+			DigestAlgorithms: hashers,
+			BasePath:         opts.BasePath,
+		},
+	)
+
+	if err != nil {
+		if userInput == "power-user" {
+			bus.Notify("Note: the 'power-user' command has been removed.")
+		}
+		return nil, fmt.Errorf("failed to construct source from user input %q: %w", userInput, err)
+	}
+
+	return src, nil
+}
+
 func generateSBOM(id clio.Identification, src source.Source, opts *options.Catalog) (*sbom.SBOM, error) {
 	tasks, err := eventloop.Tasks(opts)
 	if err != nil {

cmd/syft/cli/options/format_cyclonedx_json.go

@@ -32,8 +32,12 @@ func (o FormatCyclonedxJSON) formatEncoders() ([]sbom.FormatEncoder, error) {
 }
 
 func (o FormatCyclonedxJSON) buildConfig(version string) cyclonedxjson.EncoderConfig {
+	var pretty bool
+	if o.Pretty != nil {
+		pretty = *o.Pretty
+	}
 	return cyclonedxjson.EncoderConfig{
 		Version: version,
-		Pretty:  *o.Pretty,
+		Pretty:  pretty,
 	}
 }

cmd/syft/cli/options/format_cyclonedx_xml.go

@@ -32,8 +32,12 @@ func (o FormatCyclonedxXML) formatEncoders() ([]sbom.FormatEncoder, error) {
 }
 
 func (o FormatCyclonedxXML) buildConfig(version string) cyclonedxxml.EncoderConfig {
+	var pretty bool
+	if o.Pretty != nil {
+		pretty = *o.Pretty
+	}
 	return cyclonedxxml.EncoderConfig{
 		Version: version,
-		Pretty:  *o.Pretty,
+		Pretty:  pretty,
 	}
 }

cmd/syft/cli/options/format_spdx_json.go

@@ -32,8 +32,12 @@ func (o FormatSPDXJSON) formatEncoders() ([]sbom.FormatEncoder, error) {
 }
 
 func (o FormatSPDXJSON) buildConfig(v string) spdxjson.EncoderConfig {
+	var pretty bool
+	if o.Pretty != nil {
+		pretty = *o.Pretty
+	}
 	return spdxjson.EncoderConfig{
 		Version: v,
-		Pretty:  *o.Pretty,
+		Pretty:  pretty,
 	}
 }

cmd/syft/cli/options/format_syft_json.go

@@ -22,8 +22,12 @@ func (o FormatSyftJSON) formatEncoders() ([]sbom.FormatEncoder, error) {
 }
 
 func (o FormatSyftJSON) buildConfig() syftjson.EncoderConfig {
+	var pretty bool
+	if o.Pretty != nil {
+		pretty = *o.Pretty
+	}
 	return syftjson.EncoderConfig{
 		Legacy: o.Legacy,
-		Pretty: *o.Pretty,
+		Pretty: pretty,
 	}
 }

cmd/syft/cli/options/output.go

@@ -30,6 +30,7 @@ var _ interface {
 type Output struct {
 	AllowableOptions     []string `yaml:"-" json:"-" mapstructure:"-"`
 	AllowMultipleOutputs bool     `yaml:"-" json:"-" mapstructure:"-"`
+	AllowToFile          bool     `yaml:"-" json:"-" mapstructure:"-"`
 	Outputs              []string `yaml:"output" json:"output" mapstructure:"output"` // -o, the format to use for output
 	OutputFile           `yaml:",inline" json:"" mapstructure:",squash"`
 	Format               `yaml:"format" json:"format" mapstructure:"format"`
@@ -38,6 +39,7 @@ type Output struct {
 func DefaultOutput() Output {
 	return Output{
 		AllowMultipleOutputs: true,
+		AllowToFile:          true,
 		Outputs:              []string{string(table.ID)},
 		OutputFile: OutputFile{
 			Enabled: true,
@@ -86,6 +88,14 @@ func (o Output) SBOMWriter() (sbom.Writer, error) {
 		return nil, err
 	}
 
+	if !o.AllowToFile {
+		for _, opt := range o.Outputs {
+			if strings.Contains(opt, "=") {
+				return nil, fmt.Errorf("file output is not allowed ('-o format=path' should be '-o format')")
+			}
+		}
+	}
+
 	return makeSBOMWriter(o.Outputs, o.File, encoders)
 }
 

cmd/syft/cli/options/output_test.go

@@ -179,3 +179,25 @@ func Test_EncoderCollection_ByString_IDOnly_Defaults(t *testing.T) {
 		})
 	}
 }
+
+func Test_OutputHonorsAllowFile(t *testing.T) {
+	o := DefaultOutput()
+
+	t.Run("file is not allowed", func(t *testing.T) {
+		o.AllowToFile = false
+		o.Outputs = []string{"table=/tmp/somefile"}
+
+		w, err := o.SBOMWriter()
+		assert.Nil(t, w)
+		assert.ErrorContains(t, err, "file output is not allowed")
+	})
+
+	t.Run("file is allowed", func(t *testing.T) {
+		o.AllowToFile = true
+		o.Outputs = []string{"table=/tmp/somefile"}
+
+		w, err := o.SBOMWriter()
+		assert.NotNil(t, w)
+		assert.NoError(t, err)
+	})
+}

test/integration/convert_test.go

@@ -78,10 +78,9 @@ func TestConvertCmd(t *testing.T) {
 			}()
 
 			opts := &commands.ConvertOptions{
-				Output: options.Output{
-					Outputs: []string{fmt.Sprintf("%s=%s", test.format.ID().String(), formatFile.Name())},
-				},
+				Output: options.DefaultOutput(),
 			}
+			opts.Outputs = []string{fmt.Sprintf("%s=%s", test.format.ID().String(), formatFile.Name())}
 			require.NoError(t, opts.PostLoad())
 
 			// stdout reduction of test noise