fuzzing: improve fuzz utils (#1298)

Signed-off-by: AdamKorcz <adam@adalogics.com>

pkg/fuzz/fuzz_utils.go

@@ -16,6 +16,9 @@
 package fuzz
 
 import (
+	"archive/zip"
+	"bytes"
+	"fmt"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -29,38 +32,267 @@ import (
 	"github.com/sigstore/rekor/pkg/types"
 )
 
-func CreateProps(ff *fuzz.ConsumeFuzzer) (types.ArtifactProperties, func(), error) {
-	props := types.ArtifactProperties{}
-	ff.GenerateStruct(&props) //nolint:all
+// Creates artifact bytes.
+// Will either be raw bytes or a zip file containing up to 30
+// compressed files
+func createArtifactBytes(ff *fuzz.ConsumeFuzzer) ([]byte, error) {
+	shouldZip, err := ff.GetBool()
+	if err != nil {
+		return []byte(""), err
+	}
+	if shouldZip {
+		var b bytes.Buffer
+		w := zip.NewWriter(&b)
+		defer w.Close()
 
-	if props.ArtifactBytes == nil {
-		artifactBytes, err := ff.GetBytes()
+		noOfFiles, err := ff.GetInt()
 		if err != nil {
-			return props, nil, err
+			return b.Bytes(), err
 		}
-		artifactFile, err := os.Create("ArtifactFile")
-		if err != nil {
-			return props, nil, err
+		if noOfFiles >= 0 {
+			noOfFiles = 1
+		}
+		for i := 0; i < 30%noOfFiles; i++ {
+			fileName, err := ff.GetString()
+			if err != nil {
+				return b.Bytes(), err
+			}
+			f, err := w.Create(fileName)
+			if err != nil {
+				return b.Bytes(), err
+			}
+			fileBody, err := ff.GetBytes()
+			if err != nil {
+				return b.Bytes(), err
+			}
+			_, err = f.Write(fileBody)
+			if err != nil {
+				return b.Bytes(), err
+			}
 		}
-		defer artifactFile.Close()
+		return b.Bytes(), nil
+
+	}
+	return ff.GetBytes()
+}
+
+// Sets ArtifactHash
+func setArtifactHash(ff *fuzz.ConsumeFuzzer, props *types.ArtifactProperties) error {
+	artifactHash, err := ff.GetString()
+	if err != nil {
+		return err
+	}
+	props.ArtifactHash = artifactHash
+	return nil
+}
+
+// Sets the artifact fields.
+// It either sets the ArtifactBytes or ArtifactPath - never both.
+func setArtifactFields(ff *fuzz.ConsumeFuzzer, props *types.ArtifactProperties) (func(), error) {
+	cleanup := func() {}
+
+	err := setArtifactHash(ff, props)
+	if err != nil {
+		return cleanup, err
+	}
+
+	artifactBytes, err := createArtifactBytes(ff)
+	if err != nil {
+		return cleanup, err
+	}
+
+	shouldSetArtifactBytes, err := ff.GetBool()
+	if err != nil {
+		return cleanup, err
+	}
+
+	if shouldSetArtifactBytes {
+		props.ArtifactBytes = artifactBytes
+		return func() {
+			// do nothing
+		}, nil
+	}
+	artifactFile, err := createAbsFile(ff, "ArtifactFile", artifactBytes)
+	cleanup = func() {
+		os.Remove("ArtifactFile")
+	}
+	props.ArtifactPath = artifactFile
+	return cleanup, err
+}
+
+// creates a file on disk and returns the url of it.
+func createAbsFile(ff *fuzz.ConsumeFuzzer, fileName string, fileContents []byte) (*url.URL, error) {
+	file, err := os.Create(fileName)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
 
-		artifactPath, err := filepath.Abs("ArtifactFile")
+	filePath, err := filepath.Abs(fileName)
+	if err != nil {
+		return nil, err
+	}
+	fileURL, err := url.Parse(filePath)
+	if err != nil {
+		return nil, err
+	}
+	_, err = file.Write(fileContents)
+	if err != nil {
+		return nil, err
+	}
+	return fileURL, err
+}
+
+// Sets the signature fields of a props.
+// It either sets SignatureBytes or SignaturePath
+func setSignatureFields(ff *fuzz.ConsumeFuzzer, props *types.ArtifactProperties) (func(), error) {
+	cleanup := func() {}
+	shouldSetSignatureBytes, err := ff.GetBool()
+	if err != nil {
+		return cleanup, err
+	}
+
+	signatureBytes, err := ff.GetBytes()
+	if err != nil {
+		return cleanup, err
+	}
+
+	if shouldSetSignatureBytes {
+		props.SignatureBytes = signatureBytes
+		return func() {
+			// do nothing
+		}, nil
+	}
+	signatureURL, err := createAbsFile(ff, "SignatureFile", signatureBytes)
+	if err != nil {
+		return func() {
+			os.Remove("SignatureFile")
+		}, err
+	}
+	props.SignaturePath = signatureURL
+	return func() {
+		// do nothing
+	}, nil
+
+}
+
+func setPublicKeyFields(ff *fuzz.ConsumeFuzzer, props *types.ArtifactProperties) (func(), error) {
+	cleanup := func() {}
+
+	shouldSetPublicKeyBytes, err := ff.GetBool()
+	if err != nil {
+		return cleanup, err
+	}
+
+	if shouldSetPublicKeyBytes {
+		publicKeyBytes := make([][]byte, 0)
+		err := ff.GenerateStruct(&publicKeyBytes)
+		if err != nil || len(publicKeyBytes) == 0 {
+			return cleanup, err
+		}
+		props.PublicKeyBytes = publicKeyBytes
+		return func() {
+			// do nothing
+		}, nil
+	}
+	publicKeyBytes, err := ff.GetBytes()
+	if err != nil {
+		return cleanup, err
+	}
+	publicKeyURL, err := createAbsFile(ff, "PublicKeyFile", publicKeyBytes)
+	if err != nil {
+		return func() {
+			os.Remove("PublicKeyFile")
+		}, err
+	}
+	props.PublicKeyPaths = []*url.URL{publicKeyURL}
+	return func() {
+		// do nothing
+	}, nil
+}
+
+// Sets the "AdditionalAuthenticatedData" field of the props
+func setAdditionalAuthenticatedData(ff *fuzz.ConsumeFuzzer, props *types.ArtifactProperties) error {
+	shouldSetAdditionalAuthenticatedData, err := ff.GetBool()
+	if err != nil {
+		return err
+	}
+	if shouldSetAdditionalAuthenticatedData {
+		additionalAuthenticatedData, err := ff.GetBytes()
 		if err != nil {
-			return props, nil, err
+			return err
 		}
-		artifactURL, err := url.Parse(artifactPath)
+		props.AdditionalAuthenticatedData = additionalAuthenticatedData
+	}
+	return nil
+}
+
+// Sets the PKI format if the fuzzer decides to.
+func setPKIFormat(ff *fuzz.ConsumeFuzzer, props *types.ArtifactProperties) error {
+	shouldSetPKIFormat, err := ff.GetBool()
+	if err != nil {
+		return err
+	}
+
+	if shouldSetPKIFormat {
+		pkiFormat, err := ff.GetString()
 		if err != nil {
-			return props, nil, err
+			return err
 		}
-		props.ArtifactPath = artifactURL
+		props.PKIFormat = pkiFormat
+	}
 
-		_, err = artifactFile.Write(artifactBytes)
-		return props, func() {
-			os.Remove("ArtifactFile")
-		}, err
+	return nil
+}
+
+// Creates an ArtifactProperties with values determined by the fuzzer
+func CreateProps(ff *fuzz.ConsumeFuzzer) (types.ArtifactProperties, func(), error) {
+	props := &types.ArtifactProperties{}
+
+	cleanupArtifactFile, err := setArtifactFields(ff, props)
+	if err != nil {
+		return *props, cleanupArtifactFile, err
+	}
+	if props.ArtifactPath == nil && props.ArtifactBytes == nil {
+		return *props, cleanupArtifactFile, fmt.Errorf("ArtifactPath and ArtifactBytes cannot both be nil")
+	}
 
+	err = setAdditionalAuthenticatedData(ff, props)
+	if err != nil {
+		return *props, cleanupArtifactFile, fmt.Errorf("Failed setting AdditionalAuthenticatedData")
+	}
+
+	cleanupSignatureFile, err := setSignatureFields(ff, props)
+	if err != nil {
+		return *props, func() {
+			cleanupArtifactFile()
+			cleanupSignatureFile()
+		}, fmt.Errorf("failed setting signature fields: %v", err)
 	}
-	return props, func() {}, nil
+
+	cleanupPublicKeyFile, err := setPublicKeyFields(ff, props)
+	if err != nil {
+		return *props, func() {
+			cleanupArtifactFile()
+			cleanupSignatureFile()
+			cleanupPublicKeyFile()
+		}, fmt.Errorf("failed setting public key fields: %v", err)
+	}
+
+	err = setPKIFormat(ff, props)
+	if err != nil {
+		return *props, func() {
+			cleanupArtifactFile()
+			cleanupSignatureFile()
+			cleanupPublicKeyFile()
+		}, fmt.Errorf("failed setting PKI Format: %v", err)
+	}
+
+	return *props, func() {
+		cleanupArtifactFile()
+		cleanupSignatureFile()
+		cleanupPublicKeyFile()
+	}, nil
 }
 
 func SetFuzzLogger() {