Implement struct extensions

Implement struct extension mechanism and add extension points in places
specified by

https://www.ietf.org/archive/id/draft-ietf-rats-corim-02.html

Extensions are implemented via Extensions object that allows registering
user-defined structs are extensions. Fields from these user-defined
structs are merged into the parent struct that embeds the Extensions
object via some custom serialization code (this required updating the
cbor dependency to v2.5.0, and go version to 1.19).

Extensions also implements Viper*-like accessor methods for convenient
access to the extension fields from the parent struct.

(* see github.com/spf13/viper)

Signed-off-by: Sergei Trofimov <[email protected]>

.github/workflows/ci-go-cover.yml

@@ -26,7 +26,7 @@ jobs:
     steps:
     - uses: actions/setup-go@v2
       with:
-        go-version: "1.18"
+        go-version: "1.19"
     - name: Checkout code
       uses: actions/checkout@v2
     - name: Install mockgen

.github/workflows/linters.yml

@@ -10,7 +10,7 @@ jobs:
     steps:
     - uses: actions/setup-go@v2
       with:
-        go-version: "1.18"
+        go-version: "1.19"
     - name: Checkout code
       uses: actions/checkout@v2
     - name: Install golangci-lint

Makefile

@@ -8,6 +8,8 @@ GOPKG := github.com/veraison/corim/corim
 GOPKG += github.com/veraison/corim/comid
 GOPKG += github.com/veraison/corim/cots
 GOPKG += github.com/veraison/corim/cocli/cmd
+GOPKG += github.com/veraison/corim/encoding
+GOPKG += github.com/veraison/corim/extensions
 
 MOCKGEN := $(shell go env GOPATH)/bin/mockgen
 INTERFACES := cocli/cmd/isubmitter.go

cocli/cmd/corimCreate_test.go

@@ -117,7 +117,7 @@ func Test_CorimCreateCmd_with_a_bad_comid(t *testing.T) {
 	cmd.SetArgs(args)
 
 	err = cmd.Execute()
-	assert.EqualError(t, err, `error loading CoMID from bad-comid.cbor: cbor: unexpected "break" code`)
+	assert.EqualError(t, err, `error loading CoMID from bad-comid.cbor: expected map (CBOR Major Type 5), found Major Type 7`)
 }
 
 func Test_CorimCreateCmd_with_an_invalid_comid(t *testing.T) {
@@ -138,7 +138,7 @@ func Test_CorimCreateCmd_with_an_invalid_comid(t *testing.T) {
 	cmd.SetArgs(args)
 
 	err = cmd.Execute()
-	assert.EqualError(t, err, `error adding CoMID from invalid-comid.cbor (check its validity using the "comid validate" sub-command)`)
+	assert.EqualError(t, err, `error loading CoMID from invalid-comid.cbor: missing mandatory field "Triples" (4)`)
 }
 
 func Test_CorimCreateCmd_with_a_bad_coswid(t *testing.T) {

cocli/cmd/corimDisplay_test.go

@@ -76,7 +76,7 @@ func Test_CorimDisplayCmd_invalid_signed_corim(t *testing.T) {
 	require.NoError(t, err)
 
 	err = cmd.Execute()
-	assert.EqualError(t, err, "error decoding signed CoRIM from invalid.cbor: failed validation of unsigned CoRIM: empty id")
+	assert.EqualError(t, err, `error decoding signed CoRIM from invalid.cbor: failed CBOR decoding of unsigned CoRIM: unexpected EOF`)
 }
 
 func Test_CorimDisplayCmd_ok_top_level_view(t *testing.T) {

cocli/cmd/corimExtract_test.go

@@ -76,7 +76,7 @@ func Test_CorimExtractCmd_invalid_signed_corim(t *testing.T) {
 	require.NoError(t, err)
 
 	err = cmd.Execute()
-	assert.EqualError(t, err, "error decoding signed CoRIM from invalid.cbor: failed validation of unsigned CoRIM: empty id")
+	assert.EqualError(t, err, `error decoding signed CoRIM from invalid.cbor: failed CBOR decoding of unsigned CoRIM: unexpected EOF`)
 }
 
 func Test_CorimExtractCmd_ok_save_to_default_dir(t *testing.T) {

cocli/cmd/corimSign_test.go

@@ -91,7 +91,7 @@ func Test_CorimSignCmd_bad_unsigned_corim(t *testing.T) {
 	require.NoError(t, err)
 
 	err = cmd.Execute()
-	assert.EqualError(t, err, "error decoding unsigned CoRIM from bad.txt: unexpected EOF")
+	assert.EqualError(t, err, "error decoding unsigned CoRIM from bad.txt: expected map (CBOR Major Type 5), found Major Type 3")
 }
 
 func Test_CorimSignCmd_invalid_unsigned_corim(t *testing.T) {
@@ -109,7 +109,7 @@ func Test_CorimSignCmd_invalid_unsigned_corim(t *testing.T) {
 	require.NoError(t, err)
 
 	err = cmd.Execute()
-	assert.EqualError(t, err, "error validating CoRIM: tags validation failed: no tags")
+	assert.EqualError(t, err, `error decoding unsigned CoRIM from invalid.cbor: missing mandatory field "Tags" (1)`)
 }
 
 func Test_CorimSignCmd_non_existent_meta_file(t *testing.T) {

comid/comid.go

@@ -8,6 +8,8 @@ import (
 	"fmt"
 	"net/url"
 
+	"github.com/veraison/corim/encoding"
+	"github.com/veraison/corim/extensions"
 	"github.com/veraison/swid"
 )
 
@@ -19,13 +21,25 @@ type Comid struct {
 	Entities    *Entities   `cbor:"2,keyasint,omitempty" json:"entities,omitempty"`
 	LinkedTags  *LinkedTags `cbor:"3,keyasint,omitempty" json:"linked-tags,omitempty"`
 	Triples     Triples     `cbor:"4,keyasint" json:"triples"`
+
+	Extensions
 }
 
 // NewComid instantiates an empty Comid
 func NewComid() *Comid {
 	return &Comid{}
 }
 
+// RegisterExtensions registers a struct as a collections of extensions
+func (o *Comid) RegisterExtensions(exts extensions.IExtensionsValue) {
+	o.Extensions.Register(exts)
+}
+
+// GetExtensions returns pervisouosly registered extension
+func (o *Comid) GetExtensions() extensions.IExtensionsValue {
+	return o.Extensions.IExtensionsValue
+}
+
 // SetLanguage sets the language used in the target Comid to the supplied
 // language tag.  See also: BCP 47 and the IANA Language subtag registry.
 func (o *Comid) SetLanguage(language string) *Comid {
@@ -229,7 +243,7 @@ func (o Comid) Valid() error {
 		return fmt.Errorf("triples validation failed: %w", err)
 	}
 
-	return nil
+	return o.Extensions.validComid(&o)
 }
 
 // ToCBOR serializes the target Comid to CBOR
@@ -238,17 +252,17 @@ func (o Comid) ToCBOR() ([]byte, error) {
 		return nil, err
 	}
 
-	return em.Marshal(&o)
+	return encoding.SerializeStructToCBOR(em, &o)
 }
 
 // FromCBOR deserializes a CBOR-encoded CoMID into the target Comid
 func (o *Comid) FromCBOR(data []byte) error {
-	return dm.Unmarshal(data, o)
+	return encoding.PopulateStructFromCBOR(dm, data, o)
 }
 
 // FromJSON deserializes a JSON-encoded CoMID into the target Comid
 func (o *Comid) FromJSON(data []byte) error {
-	return json.Unmarshal(data, o)
+	return encoding.PopulateStructFromJSON(data, o)
 }
 
 // ToJSON serializes the target Comid to JSON
@@ -257,7 +271,7 @@ func (o Comid) ToJSON() ([]byte, error) {
 		return nil, err
 	}
 
-	return json.Marshal(&o)
+	return encoding.SerializeStructToJSON(&o)
 }
 
 func (o Comid) ToJSONPretty(indent string) ([]byte, error) {

comid/comid_test.go

@@ -0,0 +1,51 @@
+package comid
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/veraison/swid"
+)
+
+func Test_Comid_Extensions(t *testing.T) {
+	c := NewComid()
+	assert.Nil(t, c.GetExtensions())
+	assert.Equal(t, "", c.MustGetString("field-one"))
+
+	err := c.Set("field-one", "foo")
+	assert.EqualError(t, err, "extension not found: field-one")
+
+	type ComidExt struct {
+		FieldOne string `cbor:"-1,keyasint" json:"field-one"`
+	}
+
+	c.RegisterExtensions(&ComidExt{})
+
+	err = c.Set("field-one", "foo")
+	assert.NoError(t, err)
+	assert.Equal(t, "foo", c.MustGetString("-1"))
+}
+
+func Test_Comid_ToJSONPretty(t *testing.T) {
+	c := NewComid()
+
+	_, err := c.ToJSONPretty("    ")
+	assert.EqualError(t, err, "tag-identity validation failed: empty tag-id")
+
+	c.TagIdentity = TagIdentity{TagID: *swid.NewTagID("test"), TagVersion: 1}
+	c.Triples = Triples{ReferenceValues: &[]ReferenceValue{}}
+
+	expected := `{
+    "tag-identity": {
+        "id": "test",
+        "version": 1
+    },
+    "triples": {
+        "reference-values": []
+    }
+}`
+	v, err := c.ToJSONPretty("    ")
+	require.NoError(t, err)
+	assert.Equal(t, expected, string(v))
+}

comid/cryptokey_test.go

@@ -119,7 +119,7 @@ func Test_CryptoKey_NewCOSEKey(t *testing.T) {
 	assert.EqualError(t, err, "empty COSE_Key bytes")
 
 	_, err = NewCOSEKey([]byte("DEADBEEF"))
-	assert.Contains(t, err.Error(), "cbor: cannot unmarshal")
+	assert.Contains(t, err.Error(), "cbor: 3 bytes of extraneous data starting at index 5")
 
 	badKey := []byte{ // taken from go-cose unit tests
 		0xa2,       // map(2)

comid/entity.go

@@ -3,7 +3,12 @@
 
 package comid
 
-import "fmt"
+import (
+	"fmt"
+
+	"github.com/veraison/corim/encoding"
+	"github.com/veraison/corim/extensions"
+)
 
 type TaggedURI string
 
@@ -16,8 +21,21 @@ type Entity struct {
 	EntityName string     `cbor:"0,keyasint" json:"name"`
 	RegID      *TaggedURI `cbor:"1,keyasint,omitempty" json:"regid,omitempty"`
 	Roles      Roles      `cbor:"2,keyasint" json:"roles"`
+
+	Extensions
+}
+
+// RegisterExtensions registers a struct as a collections of extensions
+func (o *Entity) RegisterExtensions(exts extensions.IExtensionsValue) {
+	o.Extensions.Register(exts)
 }
 
+// GetExtensions returns pervisouosly registered extension
+func (o *Entity) GetExtensions() extensions.IExtensionsValue {
+	return o.Extensions.IExtensionsValue
+}
+
+// SetEntityName is used to set the EntityName field of Entity using supplied name
 func (o *Entity) SetEntityName(name string) *Entity {
 	if o != nil {
 		if name == "" {
@@ -28,6 +46,7 @@ func (o *Entity) SetEntityName(name string) *Entity {
 	return o
 }
 
+// SetRegID is used to set the RegID field of Entity using supplied uri
 func (o *Entity) SetRegID(uri string) *Entity {
 	if o != nil {
 		if uri == "" {
@@ -39,13 +58,15 @@ func (o *Entity) SetRegID(uri string) *Entity {
 	return o
 }
 
+// SetRoles appends the supplied roles to the target entity.
 func (o *Entity) SetRoles(roles ...Role) *Entity {
 	if o != nil {
 		o.Roles.Add(roles...)
 	}
 	return o
 }
 
+// Valid checks for validity of the fields within each Entity
 func (o Entity) Valid() error {
 	if o.EntityName == "" {
 		return fmt.Errorf("invalid entity: empty entity-name")
@@ -59,7 +80,27 @@ func (o Entity) Valid() error {
 		return fmt.Errorf("invalid entity: %w", err)
 	}
 
-	return nil
+	return o.Extensions.validEntity(&o)
+}
+
+// UnmarshalCBOR deserializes from CBOR
+func (o *Entity) UnmarshalCBOR(data []byte) error {
+	return encoding.PopulateStructFromCBOR(dm, data, o)
+}
+
+// MarshalCBOR serializes to CBOR
+func (o *Entity) MarshalCBOR() ([]byte, error) {
+	return encoding.SerializeStructToCBOR(em, o)
+}
+
+// UnmarshalJSON deserializes from JSON
+func (o *Entity) UnmarshalJSON(data []byte) error {
+	return encoding.PopulateStructFromJSON(data, o)
+}
+
+// MarshalJSON serializes to JSON
+func (o *Entity) MarshalJSON() ([]byte, error) {
+	return encoding.SerializeStructToJSON(o)
 }
 
 // Entities is an array of entity-map's
@@ -78,6 +119,7 @@ func (o *Entities) AddEntity(e Entity) *Entities {
 	return o
 }
 
+// Valid iterates over the range of individual entities to check for validity
 func (o Entities) Valid() error {
 	for i, m := range o {
 		if err := m.Valid(); err != nil {