Make json parsing more strict

cmd/csaf_aggregator/interim.go

@@ -13,7 +13,6 @@ import (
 	"crypto/sha256"
 	"crypto/sha512"
 	"encoding/csv"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -25,6 +24,7 @@ import (
 	"time"
 
 	"github.com/gocsaf/csaf/v3/csaf"
+	"github.com/gocsaf/csaf/v3/internal/misc"
 	"github.com/gocsaf/csaf/v3/util"
 )
 
@@ -81,7 +81,7 @@ func (w *worker) checkInterims(
 		if err := func() error {
 			defer res.Body.Close()
 			tee := io.TeeReader(res.Body, hasher)
-			return json.NewDecoder(tee).Decode(&doc)
+			return misc.StrictJSONParse(tee, &doc)
 		}(); err != nil {
 			return nil, err
 		}

cmd/csaf_aggregator/mirror.go

@@ -13,7 +13,6 @@ import (
 	"crypto/sha256"
 	"crypto/sha512"
 	"encoding/hex"
-	"encoding/json"
 	"fmt"
 	"io"
 	"log/slog"
@@ -31,6 +30,7 @@ import (
 	"github.com/ProtonMail/gopenpgp/v2/crypto"
 
 	"github.com/gocsaf/csaf/v3/csaf"
+	"github.com/gocsaf/csaf/v3/internal/misc"
 	"github.com/gocsaf/csaf/v3/util"
 )
 
@@ -538,7 +538,7 @@ func (w *worker) mirrorFiles(tlpLabel csaf.TLPLabel, files []csaf.AdvisoryFile)
 
 		download := func(r io.Reader) error {
 			tee := io.TeeReader(r, hasher)
-			return json.NewDecoder(tee).Decode(&advisory)
+			return misc.StrictJSONParse(tee, &advisory)
 		}
 
 		if err := downloadJSON(w.client, file.URL(), download); err != nil {
@@ -627,7 +627,6 @@ func (w *worker) mirrorFiles(tlpLabel csaf.TLPLabel, files []csaf.AdvisoryFile)
 // If this fails it creates a signature itself with the configured key.
 func (w *worker) downloadSignatureOrSign(url, fname string, data []byte) error {
 	sig, err := w.downloadSignature(url)
-
 	if err != nil {
 		if err != errNotFound {
 			w.log.Error("Could not find signature URL", "url", url, "err", err)

cmd/csaf_checker/processor.go

@@ -15,10 +15,8 @@ import (
 	"crypto/sha512"
 	"crypto/tls"
 	"encoding/csv"
-	"encoding/json"
 	"errors"
 	"fmt"
-	"github.com/gocsaf/csaf/v3/internal/misc"
 	"io"
 	"log"
 	"net/http"
@@ -30,6 +28,8 @@ import (
 	"strings"
 	"time"
 
+	"github.com/gocsaf/csaf/v3/internal/misc"
+
 	"github.com/ProtonMail/gopenpgp/v2/crypto"
 	"golang.org/x/time/rate"
 
@@ -518,7 +518,7 @@ func (p *processor) rolieFeedEntries(feed string) ([]csaf.AdvisoryFile, error) {
 			return nil, nil, fmt.Errorf("%s: %v", feed, err)
 		}
 		var rolieDoc any
-		err = json.NewDecoder(bytes.NewReader(all)).Decode(&rolieDoc)
+		err = misc.StrictJSONParse(bytes.NewReader(all), &rolieDoc)
 		return rfeed, rolieDoc, err
 	}()
 	if err != nil {
@@ -702,7 +702,7 @@ func (p *processor) integrity(
 		if err := func() error {
 			defer res.Body.Close()
 			tee := io.TeeReader(res.Body, hasher)
-			return json.NewDecoder(tee).Decode(&doc)
+			return misc.StrictJSONParse(tee, &doc)
 		}(); err != nil {
 			lg(ErrorType, "Reading %s failed: %v", u, err)
 			continue
@@ -1035,8 +1035,7 @@ func (p *processor) checkChanges(base string, mask whereType) error {
 			}
 			path := r[pathColumn]
 
-			times, files =
-				append(times, t),
+			times, files = append(times, t),
 				append(files, csaf.DirectoryAdvisoryFile{Path: path})
 			p.timesChanges[path] = t
 		}

cmd/csaf_downloader/downloader.go

@@ -35,6 +35,7 @@ import (
 	"golang.org/x/time/rate"
 
 	"github.com/gocsaf/csaf/v3/csaf"
+	"github.com/gocsaf/csaf/v3/internal/misc"
 	"github.com/gocsaf/csaf/v3/util"
 )
 
@@ -551,7 +552,7 @@ func (dc *downloadContext) downloadAdvisory(
 
 	tee := io.TeeReader(resp.Body, hasher)
 
-	if err := json.NewDecoder(tee).Decode(&doc); err != nil {
+	if err := misc.StrictJSONParse(tee, &doc); err != nil {
 		dc.stats.downloadFailed++
 		slog.Warn("Downloading failed",
 			"url", file.URL(),

cmd/csaf_uploader/processor.go

@@ -11,7 +11,6 @@ package main
 import (
 	"bytes"
 	"crypto/tls"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -91,7 +90,7 @@ func (p *processor) create() error {
 		Errors  []string `json:"errors"`
 	}
 
-	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+	if err := misc.StrictJSONParse(resp.Body, &result); err != nil {
 		return err
 	}
 
@@ -115,7 +114,7 @@ func (p *processor) uploadRequest(filename string) (*http.Request, error) {
 
 	if !p.cfg.NoSchemaCheck {
 		var doc any
-		if err := json.NewDecoder(bytes.NewReader(data)).Decode(&doc); err != nil {
+		if err := misc.StrictJSONParse(bytes.NewReader(data), &doc); err != nil {
 			return nil, err
 		}
 		errs, err := csaf.ValidateCSAF(doc)
@@ -239,7 +238,7 @@ func (p *processor) process(filename string) error {
 		Errors      []string `json:"errors"`
 	}
 
-	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+	if err := misc.StrictJSONParse(resp.Body, &result); err != nil {
 		return err
 	}
 

cmd/csaf_validator/main.go

@@ -10,7 +10,6 @@
 package main
 
 import (
-	"encoding/json"
 	"fmt"
 	"log"
 	"os"
@@ -19,6 +18,7 @@ import (
 	"github.com/jessevdk/go-flags"
 
 	"github.com/gocsaf/csaf/v3/csaf"
+	"github.com/gocsaf/csaf/v3/internal/misc"
 	"github.com/gocsaf/csaf/v3/util"
 )
 
@@ -301,7 +301,7 @@ func loadJSONFromFile(fname string) (any, error) {
 	}
 	defer f.Close()
 	var doc any
-	if err = json.NewDecoder(f).Decode(&doc); err != nil {
+	if err = misc.StrictJSONParse(f, &doc); err != nil {
 		return nil, err
 	}
 	return doc, err

csaf/advisory.go

@@ -14,6 +14,8 @@ import (
 	"fmt"
 	"io"
 	"os"
+
+	"github.com/gocsaf/csaf/v3/internal/misc"
 )
 
 // Acknowledgement reflects the 'acknowledgement' object in the list of acknowledgements.
@@ -383,7 +385,6 @@ type Relationship struct {
 	FullProductName           *FullProductName      `json:"full_product_name"`            // required
 	ProductReference          *ProductID            `json:"product_reference"`            // required
 	RelatesToProductReference *ProductID            `json:"relates_to_product_reference"` // required
-
 }
 
 // Relationships is a list of Relationship.
@@ -1391,7 +1392,7 @@ func LoadAdvisory(fname string) (*Advisory, error) {
 	}
 	defer f.Close()
 	var advisory Advisory
-	if err := json.NewDecoder(f).Decode(&advisory); err != nil {
+	if err := misc.StrictJSONParse(f, &advisory); err != nil {
 		return nil, err
 	}
 	if err := advisory.Validate(); err != nil {

csaf/generate_cvss_enums.go

@@ -12,7 +12,6 @@ package main
 
 import (
 	"bytes"
-	"encoding/json"
 	"flag"
 	"fmt"
 	"go/format"
@@ -22,6 +21,8 @@ import (
 	"sort"
 	"strings"
 	"text/template"
+
+	"github.com/gocsaf/csaf/v3/internal/misc"
 )
 
 // We from Intevation consider the source code parts in the following
@@ -98,7 +99,7 @@ func loadSchema(filename string) (*schema, error) {
 	}
 	defer f.Close()
 	var s schema
-	if err := json.NewDecoder(f).Decode(&s); err != nil {
+	if err := misc.StrictJSONParse(f, &s); err != nil {
 		return nil, err
 	}
 	return &s, nil

csaf/models.go

@@ -17,6 +17,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/gocsaf/csaf/v3/internal/misc"
 	"github.com/gocsaf/csaf/v3/util"
 )
 
@@ -575,7 +576,6 @@ func (d *Distribution) Validate() error {
 // Validate checks if the provider metadata is valid.
 // Returns an error if the validation fails otherwise nil.
 func (pmd *ProviderMetadata) Validate() error {
-
 	switch {
 	case pmd.CanonicalURL == nil:
 		return errors.New("canonical_url is mandatory")
@@ -695,8 +695,7 @@ func (pmd *ProviderMetadata) WriteTo(w io.Writer) (int64, error) {
 func LoadProviderMetadata(r io.Reader) (*ProviderMetadata, error) {
 
 	var pmd ProviderMetadata
-	dec := json.NewDecoder(r)
-	if err := dec.Decode(&pmd); err != nil {
+	if err := misc.StrictJSONParse(r, &pmd); err != nil {
 		return nil, err
 	}
 

csaf/providermetaloader.go

@@ -11,13 +11,13 @@ package csaf
 import (
 	"bytes"
 	"crypto/sha256"
-	"encoding/json"
 	"fmt"
 	"io"
 	"log/slog"
 	"net/http"
 	"strings"
 
+	"github.com/gocsaf/csaf/v3/internal/misc"
 	"github.com/gocsaf/csaf/v3/util"
 )
 
@@ -33,7 +33,7 @@ type ProviderMetadataLoader struct {
 type ProviderMetadataLoadMessageType int
 
 const (
-	//JSONDecodingFailed indicates problems with JSON decoding
+	// JSONDecodingFailed indicates problems with JSON decoding
 	JSONDecodingFailed ProviderMetadataLoadMessageType = iota
 	// SchemaValidationFailed indicates a general problem with schema validation.
 	SchemaValidationFailed
@@ -149,7 +149,6 @@ func (pmdl *ProviderMetadataLoader) Enumerate(domain string) []*LoadedProviderMe
 	}
 	dnsURL := "https://csaf.data.security." + domain
 	return []*LoadedProviderMetadata{pmdl.loadFromURL(dnsURL)}
-
 }
 
 // Load loads one valid provider metadata for a given path.
@@ -323,7 +322,7 @@ func (pmdl *ProviderMetadataLoader) loadFromURL(path string) *LoadedProviderMeta
 
 	var doc any
 
-	if err := json.NewDecoder(tee).Decode(&doc); err != nil {
+	if err := misc.StrictJSONParse(tee, &doc); err != nil {
 		result.Messages.Add(
 			JSONDecodingFailed,
 			fmt.Sprintf("JSON decoding failed: %v", err))

csaf/remotevalidation.go

@@ -18,6 +18,7 @@ import (
 	"net/http"
 	"sync"
 
+	"github.com/gocsaf/csaf/v3/internal/misc"
 	bolt "go.etcd.io/bbolt"
 )
 
@@ -180,7 +181,6 @@ func prepareCache(config string) (cache, error) {
 			return create()
 		}
 		return nil
-
 	}); err != nil {
 		db.Close()
 		return nil, err
@@ -256,7 +256,7 @@ func deserialize(value []byte) (*RemoteValidationResult, error) {
 	}
 	defer r.Close()
 	var rvr RemoteValidationResult
-	if err := json.NewDecoder(r).Decode(&rvr); err != nil {
+	if err := misc.StrictJSONParse(r, &rvr); err != nil {
 		return nil, err
 	}
 	return &rvr, nil
@@ -323,7 +323,7 @@ func (v *remoteValidator) Validate(doc any) (*RemoteValidationResult, error) {
 			// no cache -> process directly.
 			in = resp.Body
 		}
-		return json.NewDecoder(in).Decode(&rvr)
+		return misc.StrictJSONParse(in, &rvr)
 	}(); err != nil {
 		return nil, err
 	}

csaf/rolie.go

@@ -14,6 +14,7 @@ import (
 	"sort"
 	"time"
 
+	"github.com/gocsaf/csaf/v3/internal/misc"
 	"github.com/gocsaf/csaf/v3/util"
 )
 
@@ -54,7 +55,7 @@ type ROLIEServiceDocument struct {
 // LoadROLIEServiceDocument loads a ROLIE service document from a reader.
 func LoadROLIEServiceDocument(r io.Reader) (*ROLIEServiceDocument, error) {
 	var rsd ROLIEServiceDocument
-	if err := json.NewDecoder(r).Decode(&rsd); err != nil {
+	if err := misc.StrictJSONParse(r, &rsd); err != nil {
 		return nil, err
 	}
 	return &rsd, nil
@@ -122,7 +123,7 @@ func (rcd *ROLIECategoryDocument) Merge(categories ...string) bool {
 // LoadROLIECategoryDocument loads a ROLIE category document from a reader.
 func LoadROLIECategoryDocument(r io.Reader) (*ROLIECategoryDocument, error) {
 	var rcd ROLIECategoryDocument
-	if err := json.NewDecoder(r).Decode(&rcd); err != nil {
+	if err := misc.StrictJSONParse(r, &rcd); err != nil {
 		return nil, err
 	}
 	return &rcd, nil
@@ -195,9 +196,8 @@ type ROLIEFeed struct {
 
 // LoadROLIEFeed loads a ROLIE feed from a reader.
 func LoadROLIEFeed(r io.Reader) (*ROLIEFeed, error) {
-	dec := json.NewDecoder(r)
 	var rf ROLIEFeed
-	if err := dec.Decode(&rf); err != nil {
+	if err := misc.StrictJSONParse(r, &rf); err != nil {
 		return nil, err
 	}
 	return &rf, nil

internal/misc/json.go

@@ -0,0 +1,34 @@
+// This file is Free Software under the Apache-2.0 License
+// without warranty, see README.md and LICENSES/Apache-2.0.txt for details.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// SPDX-FileCopyrightText: 2023 German Federal Office for Information Security (BSI) <https://www.bsi.bund.de>
+// Software-Engineering: 2023 Intevation GmbH <https://intevation.de>
+
+package misc
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+)
+
+// StrictJSONParse provides JSON parsing with stronger validation.
+func StrictJSONParse(jsonData io.Reader, target interface{}) error {
+	decoder := json.NewDecoder(jsonData)
+
+	decoder.DisallowUnknownFields()
+
+	err := decoder.Decode(target)
+	if err != nil {
+		return fmt.Errorf("strictJSONParse: %w", err)
+	}
+
+	token, err := decoder.Token()
+	if err != io.EOF {
+		return fmt.Errorf("strictJSONParse: unexpected trailing data after JSON: token: %v, err: %v", token, err)
+	}
+
+	return nil
+}