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//go:build go1.18
// +build go1.18
package cose_test
import (
"bytes"
"crypto"
"crypto/ecdsa"
"crypto/ed25519"
"crypto/elliptic"
"crypto/rand"
"crypto/rsa"
"encoding/json"
"os"
"path/filepath"
"strings"
"testing"
"github.com/fxamacker/cbor/v2"
"github.com/veraison/go-cose"
)
var supportedAlgorithms = [...]cose.Algorithm{
cose.AlgorithmPS256, cose.AlgorithmPS384, cose.AlgorithmPS512,
cose.AlgorithmES256, cose.AlgorithmES384, cose.AlgorithmES512,
cose.AlgorithmEd25519,
}
func FuzzSign1Message_UnmarshalCBOR(f *testing.F) {
testdata, err := os.ReadDir("testdata")
if err != nil {
f.Fatalf("failed to read testdata directory: %s", err)
}
for _, de := range testdata {
if de.IsDir() || !strings.HasPrefix(de.Name(), "sign1-") || !strings.HasSuffix(de.Name(), ".json") {
continue
}
b, err := os.ReadFile(filepath.Join("testdata", de.Name()))
if err != nil {
f.Fatalf("failed to read testdata: %s", err)
}
type testCase struct {
Sign1 *Sign1 `json:"sign1::sign"`
Verify1 *Verify1 `json:"sign1::verify"`
}
var tc testCase
err = json.Unmarshal(b, &tc)
if err != nil {
f.Fatal(err)
}
if tc.Sign1 != nil {
f.Add(mustHexToBytes(tc.Sign1.Output.CBORHex))
} else if tc.Verify1 != nil {
f.Add(mustHexToBytes(tc.Verify1.TaggedCOSESign1.CBORHex))
}
}
enc, _ := cbor.CanonicalEncOptions().EncMode()
dec, _ := cbor.DecOptions{IntDec: cbor.IntDecConvertSigned}.DecMode()
isCanonical := func(b []byte) bool {
var tmp interface{}
err := dec.Unmarshal(b, &tmp)
if err != nil {
return false
}
b1, err := enc.Marshal(tmp)
if err != nil {
return false
}
return bytes.Equal(b, b1)
}
f.Fuzz(func(t *testing.T, b []byte) {
var msg cose.Sign1Message
if err := msg.UnmarshalCBOR(b); err != nil {
return
}
got, err := msg.MarshalCBOR()
if err != nil {
t.Fatalf("failed to marshal valid message: %s", err)
}
if !isCanonical(b) {
return
}
if len(b) > len(got) {
b = b[:len(got)]
}
if !bytes.Equal(b, got) {
t.Fatalf("roundtripped message has changed, got: %v, want: %v", got, b)
}
})
}
func FuzzSign1(f *testing.F) {
testdata, err := os.ReadDir("testdata")
if err != nil {
f.Fatalf("failed to read testdata directory: %s", err)
}
for _, de := range testdata {
if de.IsDir() || !strings.HasPrefix(de.Name(), "sign1-sign") || !strings.HasSuffix(de.Name(), ".json") {
continue
}
b, err := os.ReadFile(filepath.Join("testdata", de.Name()))
if err != nil {
f.Fatalf("failed to read testdata: %s", err)
}
type testCase struct {
Sign1 *Sign1 `json:"sign1::sign"`
}
var tc testCase
err = json.Unmarshal(b, &tc)
if err != nil {
f.Fatal(err)
}
if tc.Sign1 != nil {
hdr, _ := encMode.Marshal(mustHexToBytes(tc.Sign1.ProtectedHeaders.CBORHex))
f.Add(hdr, mustHexToBytes(tc.Sign1.Payload), mustHexToBytes(tc.Sign1.External))
}
}
// Generating new keys consumes a lot of memory,
// to the point that the host can decide to kill the fuzzing execution
// when the memory is low.
// We can avoid this by always reusing the same signer and verifier for a given algorithm.
signverif := make(map[cose.Algorithm]signVerifier, len(supportedAlgorithms))
for _, alg := range supportedAlgorithms {
signverif[alg], err = newSignerWithEphemeralKey(alg)
if err != nil {
f.Fatal(err)
}
}
f.Fuzz(func(t *testing.T, hdr_data, payload, external []byte) {
hdr := make(cose.ProtectedHeader)
err := hdr.UnmarshalCBOR(hdr_data)
if err != nil {
return
}
alg, err := hdr.Algorithm()
if err != nil {
return
}
sv, ok := signverif[alg]
if !ok {
return
}
msg := cose.Sign1Message{
Headers: cose.Headers{Protected: hdr},
Payload: payload,
}
err = msg.Sign(rand.Reader, external, sv.signer)
if err != nil {
t.Fatal(err)
}
err = msg.Verify(external, sv.verifier)
if err != nil {
t.Fatal(err)
}
err = msg.Verify(append(external, []byte{0}...), sv.verifier)
if err == nil {
t.Fatal("verification error expected")
}
})
}
type signVerifier struct {
signer cose.Signer
verifier cose.Verifier
}
func newSignerWithEphemeralKey(alg cose.Algorithm) (sv signVerifier, err error) {
var key crypto.Signer
switch alg {
case cose.AlgorithmPS256:
key, err = rsa.GenerateKey(rand.Reader, 2048)
case cose.AlgorithmPS384:
key, err = rsa.GenerateKey(rand.Reader, 3072)
case cose.AlgorithmPS512:
key, err = rsa.GenerateKey(rand.Reader, 4096)
case cose.AlgorithmES256:
key, err = ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
case cose.AlgorithmES384:
key, err = ecdsa.GenerateKey(elliptic.P384(), rand.Reader)
case cose.AlgorithmES512:
key, err = ecdsa.GenerateKey(elliptic.P521(), rand.Reader)
case cose.AlgorithmEd25519:
_, key, err = ed25519.GenerateKey(rand.Reader)
default:
err = cose.ErrAlgorithmNotSupported
}
if err != nil {
return
}
sv.signer, err = cose.NewSigner(alg, key)
if err != nil {
return
}
sv.verifier, err = cose.NewVerifier(alg, key.Public())
return
}
|
