refactor: move formats from internal into syft module (#1172)

syft/formats/common/cyclonedxhelpers/author.go

@@ -0,0 +1,47 @@
+package cyclonedxhelpers
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/anchore/syft/syft/pkg"
+)
+
+func encodeAuthor(p pkg.Package) string {
+	if hasMetadata(p) {
+		switch metadata := p.Metadata.(type) {
+		case pkg.NpmPackageJSONMetadata:
+			return metadata.Author
+		case pkg.PythonPackageMetadata:
+			author := metadata.Author
+			if metadata.AuthorEmail != "" {
+				if author == "" {
+					return metadata.AuthorEmail
+				}
+				author += fmt.Sprintf(" <%s>", metadata.AuthorEmail)
+			}
+			return author
+		case pkg.GemMetadata:
+			if len(metadata.Authors) > 0 {
+				return strings.Join(metadata.Authors, ",")
+			}
+			return ""
+		}
+	}
+	return ""
+}
+
+func decodeAuthor(author string, metadata interface{}) {
+	switch meta := metadata.(type) {
+	case *pkg.NpmPackageJSONMetadata:
+		meta.Author = author
+	case *pkg.PythonPackageMetadata:
+		parts := strings.SplitN(author, " <", 2)
+		meta.Author = parts[0]
+		if len(parts) > 1 {
+			meta.AuthorEmail = strings.TrimSuffix(parts[1], ">")
+		}
+	case *pkg.GemMetadata:
+		meta.Authors = strings.Split(author, ",")
+	}
+}

syft/formats/common/cyclonedxhelpers/author_test.go

@@ -0,0 +1,87 @@
+package cyclonedxhelpers
+
+import (
+	"testing"
+
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_encodeAuthor(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    pkg.Package
+		expected string
+	}{
+		{
+			// note: since this is an optional field, no value is preferred over NONE or NOASSERTION
+			name:     "no metadata",
+			input:    pkg.Package{},
+			expected: "",
+		},
+		{
+			name: "from gem",
+			input: pkg.Package{
+				Metadata: pkg.GemMetadata{
+					Authors: []string{
+						"auth1",
+						"auth2",
+					},
+				},
+			},
+			expected: "auth1,auth2",
+		},
+		{
+			name: "from npm",
+			input: pkg.Package{
+				Metadata: pkg.NpmPackageJSONMetadata{
+					Author: "auth",
+				},
+			},
+			expected: "auth",
+		},
+		{
+			name: "from python - just name",
+			input: pkg.Package{
+				Metadata: pkg.PythonPackageMetadata{
+					Author: "auth",
+				},
+			},
+			expected: "auth",
+		},
+		{
+			name: "from python - just email",
+			input: pkg.Package{
+				Metadata: pkg.PythonPackageMetadata{
+					AuthorEmail: "auth@auth.gov",
+				},
+			},
+			expected: "auth@auth.gov",
+		},
+		{
+			name: "from python - both name and email",
+			input: pkg.Package{
+				Metadata: pkg.PythonPackageMetadata{
+					Author:      "auth",
+					AuthorEmail: "auth@auth.gov",
+				},
+			},
+			expected: "auth <auth@auth.gov>",
+		},
+		{
+			// note: since this is an optional field, no value is preferred over NONE or NOASSERTION
+			name: "empty",
+			input: pkg.Package{
+				Metadata: pkg.NpmPackageJSONMetadata{
+					Author: "",
+				},
+			},
+			expected: "",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			assert.Equal(t, test.expected, encodeAuthor(test.input))
+		})
+	}
+}

syft/formats/common/cyclonedxhelpers/component.go

@@ -0,0 +1,128 @@
+package cyclonedxhelpers
+
+import (
+	"reflect"
+
+	"github.com/CycloneDX/cyclonedx-go"
+
+	"github.com/anchore/packageurl-go"
+	"github.com/anchore/syft/syft/formats/common"
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/anchore/syft/syft/source"
+)
+
+func encodeComponent(p pkg.Package) cyclonedx.Component {
+	props := encodeProperties(p, "syft:package")
+	props = append(props, encodeCPEs(p)...)
+	locations := p.Locations.ToSlice()
+	if len(locations) > 0 {
+		props = append(props, encodeProperties(locations, "syft:location")...)
+	}
+	if hasMetadata(p) {
+		props = append(props, encodeProperties(p.Metadata, "syft:metadata")...)
+	}
+
+	var properties *[]cyclonedx.Property
+	if len(props) > 0 {
+		properties = &props
+	}
+
+	return cyclonedx.Component{
+		Type:               cyclonedx.ComponentTypeLibrary,
+		Name:               p.Name,
+		Group:              encodeGroup(p),
+		Version:            p.Version,
+		PackageURL:         p.PURL,
+		Licenses:           encodeLicenses(p),
+		CPE:                encodeSingleCPE(p),
+		Author:             encodeAuthor(p),
+		Publisher:          encodePublisher(p),
+		Description:        encodeDescription(p),
+		ExternalReferences: encodeExternalReferences(p),
+		Properties:         properties,
+		BOMRef:             deriveBomRef(p),
+	}
+}
+
+func deriveBomRef(p pkg.Package) string {
+	// try and parse the PURL if possible and append syft id to it, to make
+	// the purl unique in the BOM.
+	// TODO: In the future we may want to dedupe by PURL and combine components with
+	// the same PURL while preserving their unique metadata.
+	if parsedPURL, err := packageurl.FromString(p.PURL); err == nil {
+		parsedPURL.Qualifiers = append(parsedPURL.Qualifiers, packageurl.Qualifier{Key: "package-id", Value: string(p.ID())})
+		return parsedPURL.ToString()
+	}
+	// fallback is to use strictly the ID if there is no valid pURL
+	return string(p.ID())
+}
+
+func hasMetadata(p pkg.Package) bool {
+	return p.Metadata != nil
+}
+
+func decodeComponent(c *cyclonedx.Component) *pkg.Package {
+	values := map[string]string{}
+	if c.Properties != nil {
+		for _, p := range *c.Properties {
+			values[p.Name] = p.Value
+		}
+	}
+
+	p := &pkg.Package{
+		Name:      c.Name,
+		Version:   c.Version,
+		Locations: decodeLocations(values),
+		Licenses:  decodeLicenses(c),
+		CPEs:      decodeCPEs(c),
+		PURL:      c.PackageURL,
+	}
+
+	common.DecodeInto(p, values, "syft:package", CycloneDXFields)
+
+	p.MetadataType = pkg.CleanMetadataType(p.MetadataType)
+
+	p.Metadata = decodePackageMetadata(values, c, p.MetadataType)
+
+	if p.Type == "" {
+		p.Type = pkg.TypeFromPURL(p.PURL)
+	}
+
+	if p.Language == "" {
+		p.Language = pkg.LanguageFromPURL(p.PURL)
+	}
+
+	return p
+}
+
+func decodeLocations(vals map[string]string) source.LocationSet {
+	v := common.Decode(reflect.TypeOf([]source.Location{}), vals, "syft:location", CycloneDXFields)
+	out, ok := v.([]source.Location)
+	if !ok {
+		out = nil
+	}
+	return source.NewLocationSet(out...)
+}
+
+func decodePackageMetadata(vals map[string]string, c *cyclonedx.Component, typ pkg.MetadataType) interface{} {
+	if typ != "" && c.Properties != nil {
+		metaTyp, ok := pkg.MetadataTypeByName[typ]
+		if !ok {
+			return nil
+		}
+		metaPtrTyp := reflect.PtrTo(metaTyp)
+		metaPtr := common.Decode(metaPtrTyp, vals, "syft:metadata", CycloneDXFields)
+
+		// Map all explicit metadata properties
+		decodeAuthor(c.Author, metaPtr)
+		decodeGroup(c.Group, metaPtr)
+		decodePublisher(c.Publisher, metaPtr)
+		decodeDescription(c.Description, metaPtr)
+		decodeExternalReferences(c, metaPtr)
+
+		// return the actual interface{} -> struct ... not interface{} -> *struct
+		return common.PtrToStruct(metaPtr)
+	}
+
+	return nil
+}

syft/formats/common/cyclonedxhelpers/component_test.go

@@ -0,0 +1,243 @@
+package cyclonedxhelpers
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/CycloneDX/cyclonedx-go"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/anchore/syft/syft/source"
+)
+
+func Test_encodeComponentProperties(t *testing.T) {
+	epoch := 2
+	tests := []struct {
+		name     string
+		input    pkg.Package
+		expected *[]cyclonedx.Property
+	}{
+		{
+			name:     "no metadata",
+			input:    pkg.Package{},
+			expected: nil,
+		},
+		{
+			name: "from apk",
+			input: pkg.Package{
+				FoundBy: "cataloger",
+				Locations: source.NewLocationSet(
+					source.Location{Coordinates: source.Coordinates{RealPath: "test"}},
+				),
+				Metadata: pkg.ApkMetadata{
+					Package:          "libc-utils",
+					OriginPackage:    "libc-dev",
+					Maintainer:       "Natanael Copa <ncopa@alpinelinux.org>",
+					Version:          "0.7.2-r0",
+					License:          "BSD",
+					Architecture:     "x86_64",
+					URL:              "http://alpinelinux.org",
+					Description:      "Meta package to pull in correct libc",
+					Size:             0,
+					InstalledSize:    4096,
+					PullDependencies: "musl-utils",
+					PullChecksum:     "Q1p78yvTLG094tHE1+dToJGbmYzQE=",
+					GitCommitOfAport: "97b1c2842faa3bfa30f5811ffbf16d5ff9f1a479",
+					Files:            []pkg.ApkFileRecord{},
+				},
+			},
+			expected: &[]cyclonedx.Property{
+				{Name: "syft:package:foundBy", Value: "cataloger"},
+				{Name: "syft:location:0:path", Value: "test"},
+				{Name: "syft:metadata:gitCommitOfApkPort", Value: "97b1c2842faa3bfa30f5811ffbf16d5ff9f1a479"},
+				{Name: "syft:metadata:installedSize", Value: "4096"},
+				{Name: "syft:metadata:originPackage", Value: "libc-dev"},
+				{Name: "syft:metadata:pullChecksum", Value: "Q1p78yvTLG094tHE1+dToJGbmYzQE="},
+				{Name: "syft:metadata:pullDependencies", Value: "musl-utils"},
+				{Name: "syft:metadata:size", Value: "0"},
+			},
+		},
+		{
+			name: "from dpkg",
+			input: pkg.Package{
+				MetadataType: pkg.DpkgMetadataType,
+				Metadata: pkg.DpkgMetadata{
+					Package:       "tzdata",
+					Version:       "2020a-0+deb10u1",
+					Source:        "tzdata-dev",
+					SourceVersion: "1.0",
+					Architecture:  "all",
+					InstalledSize: 3036,
+					Maintainer:    "GNU Libc Maintainers <debian-glibc@lists.debian.org>",
+					Files:         []pkg.DpkgFileRecord{},
+				},
+			},
+			expected: &[]cyclonedx.Property{
+				{Name: "syft:package:metadataType", Value: "DpkgMetadata"},
+				{Name: "syft:metadata:installedSize", Value: "3036"},
+				{Name: "syft:metadata:source", Value: "tzdata-dev"},
+				{Name: "syft:metadata:sourceVersion", Value: "1.0"},
+			},
+		},
+		{
+			name: "from go bin",
+			input: pkg.Package{
+				Name:         "golang.org/x/net",
+				Version:      "v0.0.0-20211006190231-62292e806868",
+				Language:     pkg.Go,
+				Type:         pkg.GoModulePkg,
+				MetadataType: pkg.GolangBinMetadataType,
+				Metadata: pkg.GolangBinMetadata{
+					GoCompiledVersion: "1.17",
+					Architecture:      "amd64",
+					H1Digest:          "h1:KlOXYy8wQWTUJYFgkUI40Lzr06ofg5IRXUK5C7qZt1k=",
+				},
+			},
+			expected: &[]cyclonedx.Property{
+				{Name: "syft:package:language", Value: pkg.Go.String()},
+				{Name: "syft:package:metadataType", Value: "GolangBinMetadata"},
+				{Name: "syft:package:type", Value: "go-module"},
+				{Name: "syft:metadata:architecture", Value: "amd64"},
+				{Name: "syft:metadata:goCompiledVersion", Value: "1.17"},
+				{Name: "syft:metadata:h1Digest", Value: "h1:KlOXYy8wQWTUJYFgkUI40Lzr06ofg5IRXUK5C7qZt1k="},
+			},
+		},
+		{
+			name: "from rpm",
+			input: pkg.Package{
+				Name:         "dive",
+				Version:      "0.9.2-1",
+				Type:         pkg.RpmPkg,
+				MetadataType: pkg.RpmMetadataType,
+				Metadata: pkg.RpmMetadata{
+					Name:      "dive",
+					Epoch:     &epoch,
+					Arch:      "x86_64",
+					Release:   "1",
+					Version:   "0.9.2",
+					SourceRpm: "dive-0.9.2-1.src.rpm",
+					Size:      12406784,
+					License:   "MIT",
+					Vendor:    "",
+					Files:     []pkg.RpmdbFileRecord{},
+				},
+			},
+			expected: &[]cyclonedx.Property{
+				{Name: "syft:package:metadataType", Value: "RpmMetadata"},
+				{Name: "syft:package:type", Value: "rpm"},
+				{Name: "syft:metadata:epoch", Value: "2"},
+				{Name: "syft:metadata:release", Value: "1"},
+				{Name: "syft:metadata:size", Value: "12406784"},
+				{Name: "syft:metadata:sourceRpm", Value: "dive-0.9.2-1.src.rpm"},
+			},
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			c := encodeComponent(test.input)
+			assert.Equal(t, test.expected, c.Properties)
+		})
+	}
+}
+
+func Test_deriveBomRef(t *testing.T) {
+	pkgWithPurl := pkg.Package{
+		Name:    "django",
+		Version: "1.11.1",
+		PURL:    "pkg:pypi/django@1.11.1",
+	}
+	pkgWithPurl.SetID()
+
+	pkgWithOutPurl := pkg.Package{
+		Name:    "django",
+		Version: "1.11.1",
+		PURL:    "",
+	}
+	pkgWithOutPurl.SetID()
+
+	pkgWithBadPurl := pkg.Package{
+		Name:    "django",
+		Version: "1.11.1",
+		PURL:    "pkg:pyjango@1.11.1",
+	}
+	pkgWithBadPurl.SetID()
+
+	tests := []struct {
+		name string
+		pkg  pkg.Package
+		want string
+	}{
+		{
+			name: "use pURL-id hybrid",
+			pkg:  pkgWithPurl,
+			want: fmt.Sprintf("pkg:pypi/django@1.11.1?package-id=%s", pkgWithPurl.ID()),
+		},
+		{
+			name: "fallback to ID when pURL is invalid",
+			pkg:  pkgWithBadPurl,
+			want: string(pkgWithBadPurl.ID()),
+		},
+		{
+			name: "fallback to ID when pURL is missing",
+			pkg:  pkgWithOutPurl,
+			want: string(pkgWithOutPurl.ID()),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tt.pkg.ID()
+			assert.Equal(t, tt.want, deriveBomRef(tt.pkg))
+		})
+	}
+}
+
+func Test_decodeComponent(t *testing.T) {
+	tests := []struct {
+		name             string
+		component        cyclonedx.Component
+		wantLanguage     pkg.Language
+		wantMetadataType pkg.MetadataType
+	}{
+		{
+			name: "derive language from pURL if missing",
+			component: cyclonedx.Component{
+				Name:       "ch.qos.logback/logback-classic",
+				Version:    "1.2.3",
+				PackageURL: "pkg:maven/ch.qos.logback/logback-classic@1.2.3",
+				Type:       "library",
+				BOMRef:     "pkg:maven/ch.qos.logback/logback-classic@1.2.3",
+			},
+			wantLanguage: pkg.Java,
+		},
+		{
+			name: "handle existing RpmdbMetadata type",
+			component: cyclonedx.Component{
+				Name:       "acl",
+				Version:    "2.2.53-1.el8",
+				PackageURL: "pkg:rpm/centos/acl@2.2.53-1.el8?arch=x86_64&upstream=acl-2.2.53-1.el8.src.rpm&distro=centos-8",
+				Type:       "library",
+				BOMRef:     "pkg:rpm/centos/acl@2.2.53-1.el8?arch=x86_64&upstream=acl-2.2.53-1.el8.src.rpm&distro=centos-8",
+				Properties: &[]cyclonedx.Property{
+					{
+						Name:  "syft:package:metadataType",
+						Value: "RpmdbMetadata",
+					},
+				},
+			},
+			wantMetadataType: pkg.RpmMetadataType,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			p := decodeComponent(&tt.component)
+			if tt.wantLanguage != "" {
+				assert.Equal(t, tt.wantLanguage, p.Language)
+			}
+			if tt.wantMetadataType != "" {
+				assert.Equal(t, tt.wantMetadataType, p.MetadataType)
+			}
+		})
+	}
+}

syft/formats/common/cyclonedxhelpers/cpe.go

@@ -0,0 +1,57 @@
+package cyclonedxhelpers
+
+import (
+	"github.com/CycloneDX/cyclonedx-go"
+
+	"github.com/anchore/syft/internal/log"
+	"github.com/anchore/syft/syft/pkg"
+)
+
+func encodeSingleCPE(p pkg.Package) string {
+	// Since the CPEs in a package are sorted by specificity
+	// we can extract the first CPE as the one to output in cyclonedx
+	if len(p.CPEs) > 0 {
+		return pkg.CPEString(p.CPEs[0])
+	}
+	return ""
+}
+
+func encodeCPEs(p pkg.Package) (out []cyclonedx.Property) {
+	for i, c := range p.CPEs {
+		// first CPE is "most specific" and already encoded as the component CPE
+		if i == 0 {
+			continue
+		}
+		out = append(out, cyclonedx.Property{
+			Name:  "syft:cpe23",
+			Value: pkg.CPEString(c),
+		})
+	}
+	return
+}
+
+func decodeCPEs(c *cyclonedx.Component) (out []pkg.CPE) {
+	if c.CPE != "" {
+		cp, err := pkg.NewCPE(c.CPE)
+		if err != nil {
+			log.Warnf("invalid CPE: %s", c.CPE)
+		} else {
+			out = append(out, cp)
+		}
+	}
+
+	if c.Properties != nil {
+		for _, p := range *c.Properties {
+			if p.Name == "syft:cpe23" {
+				cp, err := pkg.NewCPE(p.Value)
+				if err != nil {
+					log.Warnf("invalid CPE: %s", p.Value)
+				} else {
+					out = append(out, cp)
+				}
+			}
+		}
+	}
+
+	return
+}

syft/formats/common/cyclonedxhelpers/cpe_test.go

@@ -0,0 +1,58 @@
+package cyclonedxhelpers
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/anchore/syft/syft/pkg"
+)
+
+func Test_encodeCPE(t *testing.T) {
+	testCPE := pkg.MustCPE("cpe:2.3:a:name:name:3.2:*:*:*:*:*:*:*")
+	testCPE2 := pkg.MustCPE("cpe:2.3:a:name:name2:3.2:*:*:*:*:*:*:*")
+	tests := []struct {
+		name     string
+		input    pkg.Package
+		expected string
+	}{
+		{
+			// note: since this is an optional field, no value is preferred over NONE or NOASSERTION
+			name: "no metadata",
+			input: pkg.Package{
+				CPEs: []pkg.CPE{},
+			},
+			expected: "",
+		},
+		{
+			name: "single CPE",
+			input: pkg.Package{
+				CPEs: []pkg.CPE{
+					testCPE,
+				},
+			},
+			expected: "cpe:2.3:a:name:name:3.2:*:*:*:*:*:*:*",
+		},
+		{
+			name: "multiple CPEs",
+			input: pkg.Package{
+				CPEs: []pkg.CPE{
+					testCPE2,
+					testCPE,
+				},
+			},
+			expected: "cpe:2.3:a:name:name2:3.2:*:*:*:*:*:*:*",
+		},
+		{
+			// note: since this is an optional field, no value is preferred over NONE or NOASSERTION
+			name:     "empty",
+			input:    pkg.Package{},
+			expected: "",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			assert.Equal(t, test.expected, encodeSingleCPE(test.input))
+		})
+	}
+}

syft/formats/common/cyclonedxhelpers/decoder.go

@@ -0,0 +1,251 @@
+package cyclonedxhelpers
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/CycloneDX/cyclonedx-go"
+
+	"github.com/anchore/syft/syft/artifact"
+	"github.com/anchore/syft/syft/formats/common"
+	"github.com/anchore/syft/syft/linux"
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/anchore/syft/syft/sbom"
+	"github.com/anchore/syft/syft/source"
+)
+
+func GetValidator(format cyclonedx.BOMFileFormat) sbom.Validator {
+	return func(reader io.Reader) error {
+		bom := &cyclonedx.BOM{}
+		err := cyclonedx.NewBOMDecoder(reader, format).Decode(bom)
+		if err != nil {
+			return err
+		}
+		// random JSON does not necessarily cause an error (e.g. SPDX)
+		if (cyclonedx.BOM{} == *bom || bom.Components == nil) {
+			return fmt.Errorf("not a valid CycloneDX document")
+		}
+		return nil
+	}
+}
+
+func GetDecoder(format cyclonedx.BOMFileFormat) sbom.Decoder {
+	return func(reader io.Reader) (*sbom.SBOM, error) {
+		bom := &cyclonedx.BOM{
+			Components: &[]cyclonedx.Component{},
+		}
+		err := cyclonedx.NewBOMDecoder(reader, format).Decode(bom)
+		if err != nil {
+			return nil, err
+		}
+		s, err := ToSyftModel(bom)
+		if err != nil {
+			return nil, err
+		}
+		return s, nil
+	}
+}
+
+func ToSyftModel(bom *cyclonedx.BOM) (*sbom.SBOM, error) {
+	if bom == nil {
+		return nil, fmt.Errorf("no content defined in CycloneDX BOM")
+	}
+
+	s := &sbom.SBOM{
+		Artifacts: sbom.Artifacts{
+			PackageCatalog:    pkg.NewCatalog(),
+			LinuxDistribution: linuxReleaseFromComponents(*bom.Components),
+		},
+		Source:     extractComponents(bom.Metadata),
+		Descriptor: extractDescriptor(bom.Metadata),
+	}
+
+	idMap := make(map[string]interface{})
+
+	if err := collectBomPackages(bom, s, idMap); err != nil {
+		return nil, err
+	}
+
+	collectRelationships(bom, s, idMap)
+
+	return s, nil
+}
+
+func collectBomPackages(bom *cyclonedx.BOM, s *sbom.SBOM, idMap map[string]interface{}) error {
+	if bom.Components == nil {
+		return fmt.Errorf("no components are defined in the CycloneDX BOM")
+	}
+	for i := range *bom.Components {
+		collectPackages(&(*bom.Components)[i], s, idMap)
+	}
+	return nil
+}
+
+func collectPackages(component *cyclonedx.Component, s *sbom.SBOM, idMap map[string]interface{}) {
+	switch component.Type {
+	case cyclonedx.ComponentTypeOS:
+	case cyclonedx.ComponentTypeContainer:
+	case cyclonedx.ComponentTypeApplication, cyclonedx.ComponentTypeFramework, cyclonedx.ComponentTypeLibrary:
+		p := decodeComponent(component)
+		idMap[component.BOMRef] = p
+		// TODO there must be a better way than needing to call this manually:
+		p.SetID()
+		s.Artifacts.PackageCatalog.Add(*p)
+	}
+
+	if component.Components != nil {
+		for i := range *component.Components {
+			collectPackages(&(*component.Components)[i], s, idMap)
+		}
+	}
+}
+
+func linuxReleaseFromComponents(components []cyclonedx.Component) *linux.Release {
+	for i := range components {
+		component := &components[i]
+		if component.Type == cyclonedx.ComponentTypeOS {
+			return linuxReleaseFromOSComponent(component)
+		}
+	}
+	return nil
+}
+
+func linuxReleaseFromOSComponent(component *cyclonedx.Component) *linux.Release {
+	if component == nil {
+		return nil
+	}
+
+	var name string
+	var version string
+	if component.SWID != nil {
+		name = component.SWID.Name
+		version = component.SWID.Version
+	}
+	if name == "" {
+		name = component.Name
+	}
+	if name == "" {
+		name = getPropertyValue(component, "id")
+	}
+	if version == "" {
+		version = component.Version
+	}
+	if version == "" {
+		version = getPropertyValue(component, "versionID")
+	}
+
+	rel := &linux.Release{
+		CPEName:    component.CPE,
+		PrettyName: name,
+		Name:       name,
+		ID:         name,
+		IDLike:     []string{name},
+		Version:    version,
+		VersionID:  version,
+	}
+	if component.ExternalReferences != nil {
+		for _, ref := range *component.ExternalReferences {
+			switch ref.Type {
+			case cyclonedx.ERTypeIssueTracker:
+				rel.BugReportURL = ref.URL
+			case cyclonedx.ERTypeWebsite:
+				rel.HomeURL = ref.URL
+			case cyclonedx.ERTypeOther:
+				switch ref.Comment {
+				case "support":
+					rel.SupportURL = ref.URL
+				case "privacyPolicy":
+					rel.PrivacyPolicyURL = ref.URL
+				}
+			}
+		}
+	}
+
+	if component.Properties != nil {
+		values := map[string]string{}
+		for _, p := range *component.Properties {
+			values[p.Name] = p.Value
+		}
+		common.DecodeInto(&rel, values, "syft:distro", CycloneDXFields)
+	}
+
+	return rel
+}
+
+func getPropertyValue(component *cyclonedx.Component, name string) string {
+	if component.Properties != nil {
+		for _, p := range *component.Properties {
+			if p.Name == name {
+				return p.Value
+			}
+		}
+	}
+	return ""
+}
+
+func collectRelationships(bom *cyclonedx.BOM, s *sbom.SBOM, idMap map[string]interface{}) {
+	if bom.Dependencies == nil {
+		return
+	}
+	for _, d := range *bom.Dependencies {
+		from, fromOk := idMap[d.Ref].(artifact.Identifiable)
+		if fromOk {
+			if d.Dependencies == nil {
+				continue
+			}
+			for _, t := range *d.Dependencies {
+				to, toOk := idMap[t.Ref].(artifact.Identifiable)
+				if toOk {
+					s.Relationships = append(s.Relationships, artifact.Relationship{
+						From: from,
+						To:   to,
+						Type: artifact.DependencyOfRelationship, // FIXME this information is lost
+					})
+				}
+			}
+		}
+	}
+}
+
+func extractComponents(meta *cyclonedx.Metadata) source.Metadata {
+	if meta == nil || meta.Component == nil {
+		return source.Metadata{}
+	}
+	c := meta.Component
+
+	image := source.ImageMetadata{
+		UserInput:      c.Name,
+		ID:             c.BOMRef,
+		ManifestDigest: c.Version,
+	}
+
+	switch c.Type {
+	case cyclonedx.ComponentTypeContainer:
+		return source.Metadata{
+			Scheme:        source.ImageScheme,
+			ImageMetadata: image,
+		}
+	case cyclonedx.ComponentTypeFile:
+		return source.Metadata{
+			Scheme:        source.FileScheme, // or source.DirectoryScheme
+			Path:          c.Name,
+			ImageMetadata: image,
+		}
+	}
+	return source.Metadata{}
+}
+
+// if there is more than one tool in meta.Tools' list the last item will be used
+// as descriptor. If there is a way to know which tool to use here please fix it.
+func extractDescriptor(meta *cyclonedx.Metadata) (desc sbom.Descriptor) {
+	if meta == nil || meta.Tools == nil {
+		return
+	}
+
+	for _, t := range *meta.Tools {
+		desc.Name = t.Name
+		desc.Version = t.Version
+	}
+
+	return
+}

syft/formats/common/cyclonedxhelpers/decoder_test.go

@@ -0,0 +1,297 @@
+package cyclonedxhelpers
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"testing"
+
+	"github.com/CycloneDX/cyclonedx-go"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_decode(t *testing.T) {
+	type expected struct {
+		os       string
+		pkg      string
+		ver      string
+		relation string
+		purl     string
+		cpe      string
+	}
+	tests := []struct {
+		name     string
+		input    cyclonedx.BOM
+		expected []expected
+	}{
+		{
+			name: "basic mapping from cyclonedx",
+			input: cyclonedx.BOM{
+				Metadata: nil,
+				Components: &[]cyclonedx.Component{
+					{
+						BOMRef:      "p1",
+						Type:        cyclonedx.ComponentTypeLibrary,
+						Name:        "package-1",
+						Version:     "1.0.1",
+						Description: "",
+						Hashes:      nil,
+						Licenses: &cyclonedx.Licenses{
+							{
+								License: &cyclonedx.License{
+									ID: "MIT",
+								},
+							},
+						},
+						CPE:        "cpe:2.3:*:some:package:1:*:*:*:*:*:*:*",
+						PackageURL: "pkg:some/package-1@1.0.1?arch=arm64&upstream=upstream1&distro=alpine-1",
+						ExternalReferences: &[]cyclonedx.ExternalReference{
+							{
+								URL:     "",
+								Comment: "",
+								Hashes:  nil,
+								Type:    "",
+							},
+						},
+						Properties: &[]cyclonedx.Property{
+							{
+								Name:  "foundBy",
+								Value: "the-cataloger-1",
+							},
+							{
+								Name:  "language",
+								Value: "python",
+							},
+							{
+								Name:  "type",
+								Value: "python",
+							},
+							{
+								Name:  "metadataType",
+								Value: "PythonPackageMetadata",
+							},
+							{
+								Name:  "path",
+								Value: "/some/path/pkg1",
+							},
+						},
+						Components: nil,
+						Evidence:   nil,
+					},
+					{
+						BOMRef:  "p2",
+						Type:    cyclonedx.ComponentTypeLibrary,
+						Name:    "package-2",
+						Version: "2.0.2",
+						Hashes:  nil,
+						Licenses: &cyclonedx.Licenses{
+							{
+								License: &cyclonedx.License{
+									ID: "MIT",
+								},
+							},
+						},
+						CPE:        "cpe:2.3:*:another:package:2:*:*:*:*:*:*:*",
+						PackageURL: "pkg:alpine/alpine-baselayout@3.2.0-r16?arch=x86_64&upstream=alpine-baselayout&distro=alpine-3.14.2",
+						Properties: &[]cyclonedx.Property{
+
+							{
+								Name:  "foundBy",
+								Value: "apkdb-cataloger",
+							},
+							{
+								Name:  "type",
+								Value: "apk",
+							},
+							{
+								Name:  "metadataType",
+								Value: "ApkMetadata",
+							},
+							{
+								Name:  "path",
+								Value: "/lib/apk/db/installed",
+							},
+							{
+								Name:  "layerID",
+								Value: "sha256:9fb3aa2f8b8023a4bebbf92aa567caf88e38e969ada9f0ac12643b2847391635",
+							},
+							{
+								Name:  "originPackage",
+								Value: "zlib",
+							},
+							{
+								Name:  "size",
+								Value: "51213",
+							},
+							{
+								Name:  "installedSize",
+								Value: "110592",
+							},
+							{
+								Name:  "pullDependencies",
+								Value: "so:libc.musl-x86_64.so.1",
+							},
+							{
+								Name:  "pullChecksum",
+								Value: "Q1uss4DfpvL16Nw2YUTwmzGBABz3Y=",
+							},
+							{
+								Name:  "gitCommitOfApkPort",
+								Value: "d2bfb22c8e8f67ad7d8d02704f35ec4d2a19f9b9",
+							},
+						},
+					},
+					{
+						Type:    cyclonedx.ComponentTypeOS,
+						Name:    "debian",
+						Version: "1.2.3",
+						Hashes:  nil,
+						Licenses: &cyclonedx.Licenses{
+							{
+								License: &cyclonedx.License{
+									ID: "MIT",
+								},
+							},
+						},
+						Properties: &[]cyclonedx.Property{
+							{
+								Name:  "prettyName",
+								Value: "debian",
+							},
+							{
+								Name:  "id",
+								Value: "debian",
+							},
+							{
+								Name:  "versionID",
+								Value: "1.2.3",
+							},
+						},
+						Components: nil,
+						Evidence:   nil,
+					},
+				},
+				Dependencies: &[]cyclonedx.Dependency{
+					{
+						Ref: "p1",
+						Dependencies: &[]cyclonedx.Dependency{
+							{
+								Ref: "p2",
+							},
+						},
+					},
+				},
+			},
+			expected: []expected{
+				{
+					os:  "debian",
+					ver: "1.2.3",
+				},
+				{
+					pkg:      "package-1",
+					ver:      "1.0.1",
+					cpe:      "cpe:2.3:*:some:package:1:*:*:*:*:*:*:*",
+					purl:     "pkg:some/package-1@1.0.1?arch=arm64&upstream=upstream1&distro=alpine-1",
+					relation: "package-2",
+				},
+				{
+					pkg:  "package-2",
+					ver:  "2.0.2",
+					purl: "pkg:alpine/alpine-baselayout@3.2.0-r16?arch=x86_64&upstream=alpine-baselayout&distro=alpine-3.14.2",
+				},
+			},
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			sbom, err := ToSyftModel(&test.input)
+			assert.NoError(t, err)
+
+		test:
+			for _, e := range test.expected {
+				if e.os != "" {
+					assert.Equal(t, e.os, sbom.Artifacts.LinuxDistribution.ID)
+					assert.Equal(t, e.ver, sbom.Artifacts.LinuxDistribution.VersionID)
+				}
+				if e.pkg != "" {
+					for p := range sbom.Artifacts.PackageCatalog.Enumerate() {
+						if e.pkg != p.Name {
+							continue
+						}
+
+						assert.Equal(t, e.ver, p.Version)
+
+						if e.cpe != "" {
+							foundCPE := false
+							for _, c := range p.CPEs {
+								cstr := c.BindToFmtString()
+								if e.cpe == cstr {
+									foundCPE = true
+									break
+								}
+							}
+							if !foundCPE {
+								assert.Fail(t, fmt.Sprintf("CPE not found in package: %s", e.cpe))
+							}
+						}
+
+						if e.purl != "" {
+							assert.Equal(t, e.purl, p.PURL)
+						}
+
+						if e.relation != "" {
+							foundRelation := false
+							for _, r := range sbom.Relationships {
+								p := sbom.Artifacts.PackageCatalog.Package(r.To.ID())
+								if e.relation == p.Name {
+									foundRelation = true
+									break
+								}
+							}
+							if !foundRelation {
+								assert.Fail(t, fmt.Sprintf("relation not found: %s", e.relation))
+							}
+						}
+						continue test
+					}
+					assert.Fail(t, fmt.Sprintf("package should be present: %s", e.pkg))
+				}
+			}
+		})
+	}
+}
+
+func Test_missingDataDecode(t *testing.T) {
+	bom := &cyclonedx.BOM{
+		Metadata:   nil,
+		Components: &[]cyclonedx.Component{},
+	}
+
+	_, err := ToSyftModel(bom)
+	assert.NoError(t, err)
+
+	bom.Metadata = &cyclonedx.Metadata{}
+
+	_, err = ToSyftModel(bom)
+	assert.NoError(t, err)
+
+	pkg := decodeComponent(&cyclonedx.Component{
+		Licenses: &cyclonedx.Licenses{
+			{
+				License: nil,
+			},
+		},
+	})
+
+	assert.Len(t, pkg.Licenses, 0)
+}
+
+func Test_missingComponentsDecode(t *testing.T) {
+	bom := &cyclonedx.BOM{}
+	bomBytes, _ := json.Marshal(&bom)
+	decode := GetDecoder(cyclonedx.BOMFileFormatJSON)
+
+	_, err := decode(bytes.NewReader(bomBytes))
+
+	assert.NoError(t, err)
+}

syft/formats/common/cyclonedxhelpers/description.go

@@ -0,0 +1,24 @@
+package cyclonedxhelpers
+
+import "github.com/anchore/syft/syft/pkg"
+
+func encodeDescription(p pkg.Package) string {
+	if hasMetadata(p) {
+		switch metadata := p.Metadata.(type) {
+		case pkg.ApkMetadata:
+			return metadata.Description
+		case pkg.NpmPackageJSONMetadata:
+			return metadata.Description
+		}
+	}
+	return ""
+}
+
+func decodeDescription(description string, metadata interface{}) {
+	switch meta := metadata.(type) {
+	case *pkg.ApkMetadata:
+		meta.Description = description
+	case *pkg.NpmPackageJSONMetadata:
+		meta.Description = description
+	}
+}

syft/formats/common/cyclonedxhelpers/description_test.go

@@ -0,0 +1,56 @@
+package cyclonedxhelpers
+
+import (
+	"testing"
+
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_encodeDescription(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    pkg.Package
+		expected string
+	}{
+		{
+			// note: since this is an optional field, no value is preferred over NONE or NOASSERTION
+			name:     "no metadata",
+			input:    pkg.Package{},
+			expected: "",
+		},
+		{
+			name: "from apk",
+			input: pkg.Package{
+				Metadata: pkg.ApkMetadata{
+					Description: "a description!",
+				},
+			},
+			expected: "a description!",
+		},
+		{
+			name: "from npm",
+			input: pkg.Package{
+				Metadata: pkg.NpmPackageJSONMetadata{
+					Description: "a description!",
+				},
+			},
+			expected: "a description!",
+		},
+		{
+			// note: since this is an optional field, no value is preferred over NONE or NOASSERTION
+			name: "empty",
+			input: pkg.Package{
+				Metadata: pkg.NpmPackageJSONMetadata{
+					Homepage: "",
+				},
+			},
+			expected: "",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			assert.Equal(t, test.expected, encodeDescription(test.input))
+		})
+	}
+}

syft/formats/common/cyclonedxhelpers/external_references.go

@@ -0,0 +1,159 @@
+package cyclonedxhelpers
+
+import (
+	"fmt"
+	"strings"
+
+	syftFile "github.com/anchore/syft/syft/file"
+
+	"github.com/CycloneDX/cyclonedx-go"
+	"github.com/anchore/syft/syft/pkg"
+)
+
+//nolint:funlen, gocognit
+func encodeExternalReferences(p pkg.Package) *[]cyclonedx.ExternalReference {
+	var refs []cyclonedx.ExternalReference
+	if hasMetadata(p) {
+		switch metadata := p.Metadata.(type) {
+		case pkg.ApkMetadata:
+			if metadata.URL != "" {
+				refs = append(refs, cyclonedx.ExternalReference{
+					URL:  metadata.URL,
+					Type: cyclonedx.ERTypeDistribution,
+				})
+			}
+		case pkg.CargoPackageMetadata:
+			if metadata.Source != "" {
+				refs = append(refs, cyclonedx.ExternalReference{
+					URL:  metadata.Source,
+					Type: cyclonedx.ERTypeDistribution,
+				})
+			}
+		case pkg.NpmPackageJSONMetadata:
+			if metadata.URL != "" {
+				refs = append(refs, cyclonedx.ExternalReference{
+					URL:  metadata.URL,
+					Type: cyclonedx.ERTypeDistribution,
+				})
+			}
+			if metadata.Homepage != "" {
+				refs = append(refs, cyclonedx.ExternalReference{
+					URL:  metadata.Homepage,
+					Type: cyclonedx.ERTypeWebsite,
+				})
+			}
+		case pkg.GemMetadata:
+			if metadata.Homepage != "" {
+				refs = append(refs, cyclonedx.ExternalReference{
+					URL:  metadata.Homepage,
+					Type: cyclonedx.ERTypeWebsite,
+				})
+			}
+		case pkg.JavaMetadata:
+			if len(metadata.ArchiveDigests) > 0 {
+				for _, digest := range metadata.ArchiveDigests {
+					refs = append(refs, cyclonedx.ExternalReference{
+						URL:  "",
+						Type: cyclonedx.ERTypeBuildMeta,
+						Hashes: &[]cyclonedx.Hash{{
+							Algorithm: toCycloneDXAlgorithm(digest.Algorithm),
+							Value:     digest.Value,
+						}},
+					})
+				}
+			}
+		case pkg.PythonPackageMetadata:
+			if metadata.DirectURLOrigin != nil && metadata.DirectURLOrigin.URL != "" {
+				ref := cyclonedx.ExternalReference{
+					URL:  metadata.DirectURLOrigin.URL,
+					Type: cyclonedx.ERTypeVCS,
+				}
+				if metadata.DirectURLOrigin.CommitID != "" {
+					ref.Comment = fmt.Sprintf("commit: %s", metadata.DirectURLOrigin.CommitID)
+				}
+				refs = append(refs, ref)
+			}
+		}
+	}
+	if len(refs) > 0 {
+		return &refs
+	}
+	return nil
+}
+
+// supported algorithm in cycloneDX as of 1.4
+// "MD5", "SHA-1", "SHA-256", "SHA-384", "SHA-512",
+// "SHA3-256", "SHA3-384", "SHA3-512", "BLAKE2b-256", "BLAKE2b-384", "BLAKE2b-512", "BLAKE3"
+// syft supported digests: cmd/syft/cli/eventloop/tasks.go
+// MD5, SHA1, SHA256
+func toCycloneDXAlgorithm(algorithm string) cyclonedx.HashAlgorithm {
+	validMap := map[string]cyclonedx.HashAlgorithm{
+		"sha1":   cyclonedx.HashAlgorithm("SHA-1"),
+		"md5":    cyclonedx.HashAlgorithm("MD5"),
+		"sha256": cyclonedx.HashAlgorithm("SHA-256"),
+	}
+
+	return validMap[algorithm]
+}
+
+func decodeExternalReferences(c *cyclonedx.Component, metadata interface{}) {
+	if c.ExternalReferences == nil {
+		return
+	}
+	switch meta := metadata.(type) {
+	case *pkg.ApkMetadata:
+		meta.URL = refURL(c, cyclonedx.ERTypeDistribution)
+	case *pkg.CargoPackageMetadata:
+		meta.Source = refURL(c, cyclonedx.ERTypeDistribution)
+	case *pkg.NpmPackageJSONMetadata:
+		meta.URL = refURL(c, cyclonedx.ERTypeDistribution)
+		meta.Homepage = refURL(c, cyclonedx.ERTypeWebsite)
+	case *pkg.GemMetadata:
+		meta.Homepage = refURL(c, cyclonedx.ERTypeWebsite)
+	case *pkg.JavaMetadata:
+		var digests []syftFile.Digest
+		if ref := findExternalRef(c, cyclonedx.ERTypeBuildMeta); ref != nil {
+			if ref.Hashes != nil {
+				for _, hash := range *ref.Hashes {
+					digests = append(digests, syftFile.Digest{
+						Algorithm: syftFile.CleanDigestAlgorithmName(string(hash.Algorithm)),
+						Value:     hash.Value,
+					})
+				}
+			}
+		}
+
+		meta.ArchiveDigests = digests
+	case *pkg.PythonPackageMetadata:
+		if meta.DirectURLOrigin == nil {
+			meta.DirectURLOrigin = &pkg.PythonDirectURLOriginInfo{}
+		}
+		meta.DirectURLOrigin.URL = refURL(c, cyclonedx.ERTypeVCS)
+		meta.DirectURLOrigin.CommitID = strings.TrimPrefix(refComment(c, cyclonedx.ERTypeVCS), "commit: ")
+	}
+}
+
+func findExternalRef(c *cyclonedx.Component, typ cyclonedx.ExternalReferenceType) *cyclonedx.ExternalReference {
+	if c.ExternalReferences != nil {
+		for _, r := range *c.ExternalReferences {
+			if r.Type == typ {
+				return &r
+			}
+		}
+	}
+	return nil
+}
+
+func refURL(c *cyclonedx.Component, typ cyclonedx.ExternalReferenceType) string {
+	if r := findExternalRef(c, typ); r != nil {
+		return r.URL
+	}
+	return ""
+}
+
+func refComment(c *cyclonedx.Component, typ cyclonedx.ExternalReferenceType) string {
+	if r := findExternalRef(c, typ); r != nil {
+		return r.Comment
+	}
+	return ""
+}

syft/formats/common/cyclonedxhelpers/external_references_test.go

@@ -0,0 +1,133 @@
+package cyclonedxhelpers
+
+import (
+	"testing"
+
+	"github.com/CycloneDX/cyclonedx-go"
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_encodeExternalReferences(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    pkg.Package
+		expected *[]cyclonedx.ExternalReference
+	}{
+		{
+			name:     "no metadata",
+			input:    pkg.Package{},
+			expected: nil,
+		},
+		{
+			name: "from apk",
+			input: pkg.Package{
+				Metadata: pkg.ApkMetadata{
+					URL: "http://a-place.gov",
+				},
+			},
+			expected: &[]cyclonedx.ExternalReference{
+				{URL: "http://a-place.gov", Type: cyclonedx.ERTypeDistribution},
+			},
+		},
+		{
+			name: "from npm",
+			input: pkg.Package{
+				Metadata: pkg.NpmPackageJSONMetadata{
+					URL: "http://a-place.gov",
+				},
+			},
+			expected: &[]cyclonedx.ExternalReference{
+				{URL: "http://a-place.gov", Type: cyclonedx.ERTypeDistribution},
+			},
+		},
+		{
+			name: "from cargo lock",
+			input: pkg.Package{
+				Name:         "ansi_term",
+				Version:      "0.12.1",
+				Language:     pkg.Rust,
+				Type:         pkg.RustPkg,
+				MetadataType: pkg.RustCargoPackageMetadataType,
+				Licenses:     nil,
+				Metadata: pkg.CargoPackageMetadata{
+					Name:     "ansi_term",
+					Version:  "0.12.1",
+					Source:   "registry+https://github.com/rust-lang/crates.io-index",
+					Checksum: "d52a9bb7ec0cf484c551830a7ce27bd20d67eac647e1befb56b0be4ee39a55d2",
+					Dependencies: []string{
+						"winapi",
+					},
+				},
+			},
+			expected: &[]cyclonedx.ExternalReference{
+				{URL: "registry+https://github.com/rust-lang/crates.io-index", Type: cyclonedx.ERTypeDistribution},
+			},
+		},
+		{
+			name: "from npm with homepage",
+			input: pkg.Package{
+				Metadata: pkg.NpmPackageJSONMetadata{
+					URL:      "http://a-place.gov",
+					Homepage: "http://homepage",
+				},
+			},
+			expected: &[]cyclonedx.ExternalReference{
+				{URL: "http://a-place.gov", Type: cyclonedx.ERTypeDistribution},
+				{URL: "http://homepage", Type: cyclonedx.ERTypeWebsite},
+			},
+		},
+		{
+			name: "from gem",
+			input: pkg.Package{
+				Metadata: pkg.GemMetadata{
+					Homepage: "http://a-place.gov",
+				},
+			},
+			expected: &[]cyclonedx.ExternalReference{
+				{URL: "http://a-place.gov", Type: cyclonedx.ERTypeWebsite},
+			},
+		},
+		{
+			name: "from python direct url",
+			input: pkg.Package{
+				Metadata: pkg.PythonPackageMetadata{
+					DirectURLOrigin: &pkg.PythonDirectURLOriginInfo{
+						URL: "http://a-place.gov",
+					},
+				},
+			},
+			expected: &[]cyclonedx.ExternalReference{
+				{URL: "http://a-place.gov", Type: cyclonedx.ERTypeVCS},
+			},
+		},
+		{
+			name: "from python direct url with commit",
+			input: pkg.Package{
+				Metadata: pkg.PythonPackageMetadata{
+					DirectURLOrigin: &pkg.PythonDirectURLOriginInfo{
+						URL:      "http://a-place.gov",
+						CommitID: "test",
+					},
+				},
+			},
+			expected: &[]cyclonedx.ExternalReference{
+				{URL: "http://a-place.gov", Type: cyclonedx.ERTypeVCS, Comment: "commit: test"},
+			},
+		},
+		{
+			name: "empty",
+			input: pkg.Package{
+				Metadata: pkg.NpmPackageJSONMetadata{
+					URL: "",
+				},
+			},
+			expected: nil,
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			assert.Equal(t, test.expected, encodeExternalReferences(test.input))
+		})
+	}
+}

syft/formats/common/cyclonedxhelpers/format.go

@@ -0,0 +1,180 @@
+package cyclonedxhelpers
+
+import (
+	"time"
+
+	"github.com/CycloneDX/cyclonedx-go"
+	"github.com/google/uuid"
+
+	"github.com/anchore/syft/internal"
+	"github.com/anchore/syft/internal/log"
+	"github.com/anchore/syft/syft/artifact"
+	"github.com/anchore/syft/syft/linux"
+	"github.com/anchore/syft/syft/sbom"
+	"github.com/anchore/syft/syft/source"
+)
+
+func ToFormatModel(s sbom.SBOM) *cyclonedx.BOM {
+	cdxBOM := cyclonedx.NewBOM()
+
+	// NOTE(jonasagx): cycloneDX requires URN uuids (URN returns the RFC 2141 URN form of uuid):
+	// https://github.com/CycloneDX/specification/blob/master/schema/bom-1.3-strict.schema.json#L36
+	// "pattern": "^urn:uuid:[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$"
+	cdxBOM.SerialNumber = uuid.New().URN()
+	cdxBOM.Metadata = toBomDescriptor(internal.ApplicationName, s.Descriptor.Version, s.Source)
+
+	packages := s.Artifacts.PackageCatalog.Sorted()
+	components := make([]cyclonedx.Component, len(packages))
+	for i, p := range packages {
+		components[i] = encodeComponent(p)
+	}
+	components = append(components, toOSComponent(s.Artifacts.LinuxDistribution)...)
+	cdxBOM.Components = &components
+
+	dependencies := toDependencies(s.Relationships)
+	if len(dependencies) > 0 {
+		cdxBOM.Dependencies = &dependencies
+	}
+
+	return cdxBOM
+}
+
+func toOSComponent(distro *linux.Release) []cyclonedx.Component {
+	if distro == nil {
+		return []cyclonedx.Component{}
+	}
+	eRefs := &[]cyclonedx.ExternalReference{}
+	if distro.BugReportURL != "" {
+		*eRefs = append(*eRefs, cyclonedx.ExternalReference{
+			URL:  distro.BugReportURL,
+			Type: cyclonedx.ERTypeIssueTracker,
+		})
+	}
+	if distro.HomeURL != "" {
+		*eRefs = append(*eRefs, cyclonedx.ExternalReference{
+			URL:  distro.HomeURL,
+			Type: cyclonedx.ERTypeWebsite,
+		})
+	}
+	if distro.SupportURL != "" {
+		*eRefs = append(*eRefs, cyclonedx.ExternalReference{
+			URL:     distro.SupportURL,
+			Type:    cyclonedx.ERTypeOther,
+			Comment: "support",
+		})
+	}
+	if distro.PrivacyPolicyURL != "" {
+		*eRefs = append(*eRefs, cyclonedx.ExternalReference{
+			URL:     distro.PrivacyPolicyURL,
+			Type:    cyclonedx.ERTypeOther,
+			Comment: "privacyPolicy",
+		})
+	}
+	if len(*eRefs) == 0 {
+		eRefs = nil
+	}
+	props := encodeProperties(distro, "syft:distro")
+	var properties *[]cyclonedx.Property
+	if len(props) > 0 {
+		properties = &props
+	}
+	return []cyclonedx.Component{
+		{
+			Type: cyclonedx.ComponentTypeOS,
+			// FIXME is it idiomatic to be using SWID here for specific name and version information?
+			SWID: &cyclonedx.SWID{
+				TagID:   distro.ID,
+				Name:    distro.ID,
+				Version: distro.VersionID,
+			},
+			Description: distro.PrettyName,
+			Name:        distro.ID,
+			Version:     distro.VersionID,
+			// TODO should we add a PURL?
+			CPE:                distro.CPEName,
+			ExternalReferences: eRefs,
+			Properties:         properties,
+		},
+	}
+}
+
+// NewBomDescriptor returns a new BomDescriptor tailored for the current time and "syft" tool details.
+func toBomDescriptor(name, version string, srcMetadata source.Metadata) *cyclonedx.Metadata {
+	return &cyclonedx.Metadata{
+		Timestamp: time.Now().Format(time.RFC3339),
+		Tools: &[]cyclonedx.Tool{
+			{
+				Vendor:  "anchore",
+				Name:    name,
+				Version: version,
+			},
+		},
+		Component: toBomDescriptorComponent(srcMetadata),
+	}
+}
+
+// used to indicate that a relationship listed under the syft artifact package can be represented as a cyclonedx dependency.
+// NOTE: CycloneDX provides the ability to describe components and their dependency on other components.
+// The dependency graph is capable of representing both direct and transitive relationships.
+// If a relationship is either direct or transitive it can be included in this function.
+// An example of a relationship to not include would be: OwnershipByFileOverlapRelationship.
+func isExpressiblePackageRelationship(ty artifact.RelationshipType) bool {
+	switch ty {
+	case artifact.RuntimeDependencyOfRelationship:
+		return true
+	case artifact.DevDependencyOfRelationship:
+		return true
+	case artifact.BuildDependencyOfRelationship:
+		return true
+	case artifact.DependencyOfRelationship:
+		return true
+	}
+	return false
+}
+
+func toDependencies(relationships []artifact.Relationship) []cyclonedx.Dependency {
+	result := make([]cyclonedx.Dependency, 0)
+	for _, r := range relationships {
+		exists := isExpressiblePackageRelationship(r.Type)
+		if !exists {
+			log.Debugf("unable to convert relationship from CycloneDX 1.4 JSON, dropping: %+v", r)
+			continue
+		}
+
+		innerDeps := []cyclonedx.Dependency{}
+		innerDeps = append(innerDeps, cyclonedx.Dependency{Ref: string(r.From.ID())})
+		result = append(result, cyclonedx.Dependency{
+			Ref:          string(r.To.ID()),
+			Dependencies: &innerDeps,
+		})
+	}
+	return result
+}
+
+func toBomDescriptorComponent(srcMetadata source.Metadata) *cyclonedx.Component {
+	switch srcMetadata.Scheme {
+	case source.ImageScheme:
+		bomRef, err := artifact.IDByHash(srcMetadata.ImageMetadata.ID)
+		if err != nil {
+			log.Warnf("unable to get fingerprint of image metadata=%s: %+v", srcMetadata.ImageMetadata.ID, err)
+		}
+		return &cyclonedx.Component{
+			BOMRef:  string(bomRef),
+			Type:    cyclonedx.ComponentTypeContainer,
+			Name:    srcMetadata.ImageMetadata.UserInput,
+			Version: srcMetadata.ImageMetadata.ManifestDigest,
+		}
+	case source.DirectoryScheme, source.FileScheme:
+		bomRef, err := artifact.IDByHash(srcMetadata.Path)
+		if err != nil {
+			log.Warnf("unable to get fingerprint of source metadata path=%s: %+v", srcMetadata.Path, err)
+		}
+		return &cyclonedx.Component{
+			BOMRef: string(bomRef),
+			Type:   cyclonedx.ComponentTypeFile,
+			Name:   srcMetadata.Path,
+		}
+	}
+
+	return nil
+}

syft/formats/common/cyclonedxhelpers/group.go

@@ -0,0 +1,21 @@
+package cyclonedxhelpers
+
+import "github.com/anchore/syft/syft/pkg"
+
+func encodeGroup(p pkg.Package) string {
+	if hasMetadata(p) {
+		if metadata, ok := p.Metadata.(pkg.JavaMetadata); ok && metadata.PomProperties != nil {
+			return metadata.PomProperties.GroupID
+		}
+	}
+	return ""
+}
+
+func decodeGroup(group string, metadata interface{}) {
+	if meta, ok := metadata.(*pkg.JavaMetadata); ok {
+		if meta.PomProperties == nil {
+			meta.PomProperties = &pkg.PomProperties{}
+		}
+		meta.PomProperties.GroupID = group
+	}
+}

syft/formats/common/cyclonedxhelpers/group_test.go

@@ -0,0 +1,52 @@
+package cyclonedxhelpers
+
+import (
+	"testing"
+
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_encodeGroup(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    pkg.Package
+		expected string
+	}{
+		{
+			name:     "no metadata",
+			input:    pkg.Package{},
+			expected: "",
+		},
+		{
+			name: "metadata is not Java",
+			input: pkg.Package{
+				Metadata: pkg.NpmPackageJSONMetadata{},
+			},
+			expected: "",
+		},
+		{
+			name: "metadata is Java but pom properties is empty",
+			input: pkg.Package{
+				Metadata: pkg.JavaMetadata{},
+			},
+			expected: "",
+		},
+		{
+			name: "metadata is Java and contains pomProperties",
+			input: pkg.Package{
+				Metadata: pkg.JavaMetadata{
+					PomProperties: &pkg.PomProperties{
+						GroupID: "test",
+					},
+				},
+			},
+			expected: "test",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			assert.Equal(t, test.expected, encodeGroup(test.input))
+		})
+	}
+}

syft/formats/common/cyclonedxhelpers/licenses.go

@@ -0,0 +1,35 @@
+package cyclonedxhelpers
+
+import (
+	"github.com/CycloneDX/cyclonedx-go"
+	"github.com/anchore/syft/internal/spdxlicense"
+	"github.com/anchore/syft/syft/pkg"
+)
+
+func encodeLicenses(p pkg.Package) *cyclonedx.Licenses {
+	lc := cyclonedx.Licenses{}
+	for _, licenseName := range p.Licenses {
+		if value, exists := spdxlicense.ID(licenseName); exists {
+			lc = append(lc, cyclonedx.LicenseChoice{
+				License: &cyclonedx.License{
+					ID: value,
+				},
+			})
+		}
+	}
+	if len(lc) > 0 {
+		return &lc
+	}
+	return nil
+}
+
+func decodeLicenses(c *cyclonedx.Component) (out []string) {
+	if c.Licenses != nil {
+		for _, l := range *c.Licenses {
+			if l.License != nil {
+				out = append(out, l.License.ID)
+			}
+		}
+	}
+	return
+}

syft/formats/common/cyclonedxhelpers/licenses_test.go

@@ -0,0 +1,83 @@
+package cyclonedxhelpers
+
+import (
+	"testing"
+
+	"github.com/CycloneDX/cyclonedx-go"
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_encodeLicense(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    pkg.Package
+		expected *cyclonedx.Licenses
+	}{
+		{
+			name:     "no licenses",
+			input:    pkg.Package{},
+			expected: nil,
+		},
+		{
+			name: "no SPDX licenses",
+			input: pkg.Package{
+				Licenses: []string{
+					"made-up",
+				},
+			},
+			expected: nil,
+		},
+		{
+			name: "with SPDX license",
+			input: pkg.Package{
+				Licenses: []string{
+					"MIT",
+				},
+			},
+			expected: &cyclonedx.Licenses{
+				{License: &cyclonedx.License{ID: "MIT"}},
+			},
+		},
+		{
+			name: "with SPDX license expression",
+			input: pkg.Package{
+				Licenses: []string{
+					"MIT",
+					"GPL-3.0",
+				},
+			},
+			expected: &cyclonedx.Licenses{
+				{License: &cyclonedx.License{ID: "MIT"}},
+				{License: &cyclonedx.License{ID: "GPL-3.0-only"}},
+			},
+		},
+		{
+			name: "cap insensitive",
+			input: pkg.Package{
+				Licenses: []string{
+					"gpl-3.0",
+				},
+			},
+			expected: &cyclonedx.Licenses{
+				{License: &cyclonedx.License{ID: "GPL-3.0-only"}},
+			},
+		},
+		{
+			name: "debian to spdx conversion",
+			input: pkg.Package{
+				Licenses: []string{
+					"GPL-2",
+				},
+			},
+			expected: &cyclonedx.Licenses{
+				{License: &cyclonedx.License{ID: "GPL-2.0-only"}},
+			},
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			assert.Equal(t, test.expected, encodeLicenses(test.input))
+		})
+	}
+}

syft/formats/common/cyclonedxhelpers/properties.go

@@ -0,0 +1,21 @@
+package cyclonedxhelpers
+
+import (
+	"github.com/CycloneDX/cyclonedx-go"
+
+	"github.com/anchore/syft/syft/formats/common"
+)
+
+var (
+	CycloneDXFields = common.RequiredTag("cyclonedx")
+)
+
+func encodeProperties(obj interface{}, prefix string) (out []cyclonedx.Property) {
+	for _, p := range common.Sorted(common.Encode(obj, prefix, CycloneDXFields)) {
+		out = append(out, cyclonedx.Property{
+			Name:  p.Name,
+			Value: p.Value,
+		})
+	}
+	return
+}

syft/formats/common/cyclonedxhelpers/publisher.go

@@ -0,0 +1,30 @@
+package cyclonedxhelpers
+
+import (
+	"github.com/anchore/syft/syft/pkg"
+)
+
+func encodePublisher(p pkg.Package) string {
+	if hasMetadata(p) {
+		switch metadata := p.Metadata.(type) {
+		case pkg.ApkMetadata:
+			return metadata.Maintainer
+		case pkg.RpmMetadata:
+			return metadata.Vendor
+		case pkg.DpkgMetadata:
+			return metadata.Maintainer
+		}
+	}
+	return ""
+}
+
+func decodePublisher(publisher string, metadata interface{}) {
+	switch meta := metadata.(type) {
+	case *pkg.ApkMetadata:
+		meta.Maintainer = publisher
+	case *pkg.RpmMetadata:
+		meta.Vendor = publisher
+	case *pkg.DpkgMetadata:
+		meta.Maintainer = publisher
+	}
+}

syft/formats/common/cyclonedxhelpers/publisher_test.go

@@ -0,0 +1,65 @@
+package cyclonedxhelpers
+
+import (
+	"testing"
+
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_encodePublisher(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    pkg.Package
+		expected string
+	}{
+		{
+			// note: since this is an optional field, no value is preferred over NONE or NOASSERTION
+			name:     "no metadata",
+			input:    pkg.Package{},
+			expected: "",
+		},
+		{
+			name: "from apk",
+			input: pkg.Package{
+				Metadata: pkg.ApkMetadata{
+					Maintainer: "auth",
+				},
+			},
+			expected: "auth",
+		},
+		{
+			name: "from rpm",
+			input: pkg.Package{
+				Metadata: pkg.RpmMetadata{
+					Vendor: "auth",
+				},
+			},
+			expected: "auth",
+		},
+		{
+			name: "from dpkg",
+			input: pkg.Package{
+				Metadata: pkg.DpkgMetadata{
+					Maintainer: "auth",
+				},
+			},
+			expected: "auth",
+		},
+		{
+			// note: since this is an optional field, no value is preferred over NONE or NOASSERTION
+			name: "empty",
+			input: pkg.Package{
+				Metadata: pkg.NpmPackageJSONMetadata{
+					Author: "",
+				},
+			},
+			expected: "",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			assert.Equal(t, test.expected, encodePublisher(test.input))
+		})
+	}
+}