internal: fix unmarshalling attestation version numbers from JSON (#2187)

* Fix unmarshalling attestation version numbers from JSON

* Add unit test for UnmarshalJSON

---------

Signed-off-by: Daniel Weiße <dw@edgeless.systems>

cli/internal/cmd/upgradeapply_test.go

@@ -33,12 +33,11 @@ import (
 func TestUpgradeApply(t *testing.T) {
 	someErr := errors.New("some error")
 	testCases := map[string]struct {
-		upgrader             stubUpgrader
-		fetcher              stubImageFetcher
-		wantErr              bool
-		yesFlag              bool
-		stdin                string
-		remoteAttestationCfg config.AttestationCfg // attestation config returned by the stub Kubernetes client
+		upgrader stubUpgrader
+		fetcher  stubImageFetcher
+		wantErr  bool
+		yesFlag  bool
+		stdin    string
 	}{
 		"success": {
 			upgrader: stubUpgrader{currentConfig: config.DefaultForAzureSEVSNP()},
@@ -143,16 +142,15 @@ func TestUpgradeApply(t *testing.T) {
 			handler := file.NewHandler(afero.NewMemMapFs())
 			cfg := defaultConfigWithExpectedMeasurements(t, config.Default(), cloudprovider.Azure)
 
-			if tc.remoteAttestationCfg == nil {
-				tc.remoteAttestationCfg = fakeAttestationConfigFromCluster(cmd.Context(), t, cloudprovider.Azure)
-			}
+			remoteAttestationCfg := fakeAttestationConfigFromCluster(cmd.Context(), t, cloudprovider.Azure)
+
 			require.NoError(handler.WriteYAML(constants.ConfigFilename, cfg))
 			require.NoError(handler.WriteJSON(constants.ClusterIDsFilename, clusterid.File{}))
 
 			upgrader := upgradeApplyCmd{upgrader: tc.upgrader, log: logger.NewTest(t), imageFetcher: tc.fetcher, configFetcher: stubAttestationFetcher{}}
 
 			stubStableClientFactory := func(_ string) (getConfigMapper, error) {
-				return stubGetConfigMap{tc.remoteAttestationCfg}, nil
+				return stubGetConfigMap{remoteAttestationCfg}, nil
 			}
 			err := upgrader.upgradeApply(cmd, handler, stubStableClientFactory)
 			if tc.wantErr {

internal/config/attestationversion.go

@@ -58,15 +58,24 @@ func (v AttestationVersion) MarshalJSON() ([]byte, error) {
 
 // UnmarshalJSON implements a custom unmarshaller to resolve "latest" values.
 func (v *AttestationVersion) UnmarshalJSON(data []byte) (err error) {
-	var rawUnmarshal string
-	if err := json.Unmarshal(data, &rawUnmarshal); err != nil {
-		return fmt.Errorf("raw unmarshal: %w", err)
+	// JSON has two distinct ways to represent numbers and strings.
+	// This means we cannot simply unmarshal to string, like with YAML.
+	// Unmarshalling to `any` causes Go to unmarshal numbers to float64.
+	// Therefore, try to unmarshal to string, and then to int, instead of using type assertions.
+	var unmarshalString string
+	if err := json.Unmarshal(data, &unmarshalString); err != nil {
+		var unmarshalInt int64
+		if err := json.Unmarshal(data, &unmarshalInt); err != nil {
+			return fmt.Errorf("unable to unmarshal to string or int: %w", err)
+		}
+		unmarshalString = strconv.FormatInt(unmarshalInt, 10)
 	}
-	return v.parseRawUnmarshal(rawUnmarshal)
+
+	return v.parseRawUnmarshal(unmarshalString)
 }
 
 func (v *AttestationVersion) parseRawUnmarshal(str string) error {
-	if strings.HasPrefix(str, "0") {
+	if strings.HasPrefix(str, "0") && len(str) != 1 {
 		return fmt.Errorf("no format with prefixed 0 (octal, hexadecimal) allowed: %s", str)
 	}
 	if strings.ToLower(str) == "latest" {

internal/config/attestationversion_test.go

@@ -7,6 +7,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 package config
 
 import (
+	"encoding/json"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -14,21 +15,18 @@ import (
 )
 
 func TestVersionMarshalYAML(t *testing.T) {
-	tests := []struct {
-		name string
+	tests := map[string]struct {
 		sut  AttestationVersion
 		want string
 	}{
-		{
-			name: "isLatest resolves to latest",
+		"isLatest resolves to latest": {
 			sut: AttestationVersion{
 				Value:      1,
 				WantLatest: true,
 			},
 			want: "latest\n",
 		},
-		{
-			name: "value 5 resolves to 5",
+		"value 5 resolves to 5": {
 			sut: AttestationVersion{
 				Value:      5,
 				WantLatest: false,
@@ -36,81 +34,177 @@ func TestVersionMarshalYAML(t *testing.T) {
 			want: "5\n",
 		},
 	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			bt, err := yaml.Marshal(tt.sut)
-			require.NoError(t, err)
-			require.Equal(t, tt.want, string(bt))
+	for name, tc := range tests {
+		t.Run(name, func(t *testing.T) {
+			require := require.New(t)
+
+			bt, err := yaml.Marshal(tc.sut)
+			require.NoError(err)
+			require.Equal(tc.want, string(bt))
 		})
 	}
 }
 
 func TestVersionUnmarshalYAML(t *testing.T) {
-	tests := []struct {
-		name    string
+	tests := map[string]struct {
 		sut     string
 		want    AttestationVersion
 		wantErr bool
 	}{
-		{
-			name: "latest resolves to isLatest",
-			sut:  "latest",
+		"latest resolves to isLatest": {
+			sut: "latest",
 			want: AttestationVersion{
 				Value:      0,
 				WantLatest: true,
 			},
 			wantErr: false,
 		},
-		{
-			name: "1 resolves to value 1",
-			sut:  "1",
+		"1 resolves to value 1": {
+			sut: "1",
 			want: AttestationVersion{
 				Value:      1,
 				WantLatest: false,
 			},
 			wantErr: false,
 		},
-		{
-			name:    "max uint8+1 errors",
+		"max uint8+1 errors": {
 			sut:     "256",
 			wantErr: true,
 		},
-		{
-			name:    "-1 errors",
+		"-1 errors": {
 			sut:     "-1",
 			wantErr: true,
 		},
-		{
-			name:    "2.6 errors",
+		"2.6 errors": {
 			sut:     "2.6",
 			wantErr: true,
 		},
-		{
-			name:    "2.0 errors",
+		"2.0 errors": {
 			sut:     "2.0",
 			wantErr: true,
 		},
-		{
-			name:    "hex format is invalid",
+		"hex format is invalid": {
 			sut:     "0x10",
 			wantErr: true,
 		},
-		{
-			name:    "octal format is invalid",
+		"octal format is invalid": {
 			sut:     "010",
 			wantErr: true,
 		},
+		"0 resolves to value 0": {
+			sut: "0",
+			want: AttestationVersion{
+				Value:      0,
+				WantLatest: false,
+			},
+		},
+		"00 errors": {
+			sut:     "00",
+			wantErr: true,
+		},
 	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
+	for name, tc := range tests {
+		t.Run(name, func(t *testing.T) {
+			require := require.New(t)
+
 			var sut AttestationVersion
-			err := yaml.Unmarshal([]byte(tt.sut), &sut)
-			if tt.wantErr {
-				require.Error(t, err)
+			err := yaml.Unmarshal([]byte(tc.sut), &sut)
+			if tc.wantErr {
+				require.Error(err)
 				return
 			}
-			require.NoError(t, err)
-			require.Equal(t, tt.want, sut)
+			require.NoError(err)
+			require.Equal(tc.want, sut)
+		})
+	}
+}
+
+func TestVersionUnmarshalJSON(t *testing.T) {
+	tests := map[string]struct {
+		sut     string
+		want    AttestationVersion
+		wantErr bool
+	}{
+		"latest resolves to isLatest": {
+			sut: `"latest"`,
+			want: AttestationVersion{
+				Value:      0,
+				WantLatest: true,
+			},
+		},
+		"1 resolves to value 1": {
+			sut: "1",
+			want: AttestationVersion{
+				Value:      1,
+				WantLatest: false,
+			},
+		},
+		"quoted number resolves to value": {
+			sut: `"1"`,
+			want: AttestationVersion{
+				Value:      1,
+				WantLatest: false,
+			},
+		},
+		"quoted float errors": {
+			sut:     `"1.0"`,
+			wantErr: true,
+		},
+		"max uint8+1 errors": {
+			sut:     "256",
+			wantErr: true,
+		},
+		"-1 errors": {
+			sut:     "-1",
+			wantErr: true,
+		},
+		"2.6 errors": {
+			sut:     "2.6",
+			wantErr: true,
+		},
+		"2.0 errors": {
+			sut:     "2.0",
+			wantErr: true,
+		},
+		"hex format is invalid": {
+			sut:     "0x10",
+			wantErr: true,
+		},
+		"octal format is invalid": {
+			sut:     "010",
+			wantErr: true,
+		},
+		"0 resolves to value 0": {
+			sut: "0",
+			want: AttestationVersion{
+				Value:      0,
+				WantLatest: false,
+			},
+		},
+		"quoted 0 resolves to value 0": {
+			sut: `"0"`,
+			want: AttestationVersion{
+				Value:      0,
+				WantLatest: false,
+			},
+		},
+		"00 errors": {
+			sut:     "00",
+			wantErr: true,
+		},
+	}
+	for name, tc := range tests {
+		t.Run(name, func(t *testing.T) {
+			require := require.New(t)
+
+			var sut AttestationVersion
+			err := json.Unmarshal([]byte(tc.sut), &sut)
+			if tc.wantErr {
+				require.Error(err)
+				return
+			}
+			require.NoError(err)
+			require.Equal(tc.want, sut)
 		})
 	}
 }