add CommandSet and parse application info

cmd/keycard/initializer.go

@@ -61,8 +61,11 @@ func (i *Initializer) Init() (*keycard.Secrets, error) {
 }
 
 // Info returns a types.ApplicationInfo struct with info about the card.
-func (i *Initializer) Info() (*types.ApplicationInfo, error) {
-	return keycard.Select(i.c, identifiers.KeycardAID)
+func (i *Initializer) Info() (types.ApplicationInfo, error) {
+	cmdSet := keycard.NewCommandSet(i.c)
+	err := cmdSet.Select()
+
+	return cmdSet.ApplicationInfo, err
 }
 
 func (i *Initializer) initGPSecureChannel(sdaid []byte) error {

command_set.go

@@ -0,0 +1,65 @@
+package keycard
+
+import (
+	"github.com/status-im/keycard-go/apdu"
+	"github.com/status-im/keycard-go/globalplatform"
+	"github.com/status-im/keycard-go/identifiers"
+	"github.com/status-im/keycard-go/types"
+)
+
+type CommandSet struct {
+	c               types.Channel
+	ApplicationInfo types.ApplicationInfo
+}
+
+func NewCommandSet(c types.Channel) *CommandSet {
+	return &CommandSet{
+		c: c,
+	}
+}
+
+func (cs *CommandSet) Select() error {
+	instanceAID, err := identifiers.KeycardInstanceAID(identifiers.KeycardDefaultInstanceIndex)
+	if err != nil {
+		return err
+	}
+
+	cmd := apdu.NewCommand(
+		0x00,
+		globalplatform.InsSelect,
+		uint8(0x04),
+		uint8(0x00),
+		instanceAID,
+	)
+
+	cmd.SetLe(0)
+	resp, err := cs.c.Send(cmd)
+
+	err = cs.checkOK(resp, err)
+	if err == nil {
+		appInfo, err := types.ParseApplicationInfo(resp.Data)
+		if err != nil {
+			return err
+		}
+
+		cs.ApplicationInfo = appInfo
+
+		return nil
+	}
+
+	return err
+}
+
+func (cs *CommandSet) checkOK(resp *apdu.Response, err error, allowedResponses ...uint16) error {
+	if len(allowedResponses) == 0 {
+		allowedResponses = []uint16{apdu.SwOK}
+	}
+
+	for _, code := range allowedResponses {
+		if code == resp.Sw {
+			return nil
+		}
+	}
+
+	return apdu.NewErrBadResponse(resp.Sw, "unexpected response")
+}

commands.go

@@ -12,6 +12,7 @@ const (
 	InsPair                 = uint8(0x12)
 	InsGetStatus            = uint8(0xF2)
 
+	//TODO: remove
 	TagSelectResponsePreInitialized = uint8(0x80)
 	TagApplicationStatusTemplate    = uint8(0xA3)
 	TagApplicationInfoTemplate      = uint8(0xA4)

identifiers/identifiers.go

@@ -11,6 +11,8 @@ var (
 	NdefAID         = []byte{0xA0, 0x00, 0x00, 0x08, 0x04, 0x00, 0x01, 0x02}
 	NdefInstanceAID = []byte{0xD2, 0x76, 0x00, 0x00, 0x85, 0x01, 0x01}
 
+	KeycardDefaultInstanceIndex = 1
+
 	ErrInvalidInstanceIndex = errors.New("instance index must be between 1 and 255")
 )
 

types/application_info.go

@@ -0,0 +1,74 @@
+package types
+
+import (
+	"errors"
+
+	"github.com/status-im/keycard-go/apdu"
+)
+
+var ErrWrongApplicationInfoTemplate = errors.New("wrong application info template")
+
+const (
+	TagSelectResponsePreInitialized = uint8(0x80)
+	TagApplicationStatusTemplate    = uint8(0xA3)
+	TagApplicationInfoTemplate      = uint8(0xA4)
+)
+
+type ApplicationInfo struct {
+	Installed      bool
+	Initialized    bool
+	InstanceUID    []byte
+	PublicKey      []byte
+	Version        []byte
+	AvailableSlots []byte
+	// KeyUID is the sha256 of of the master public key on the card.
+	// It's empty if the card doesn't contain any key.
+	KeyUID []byte
+}
+
+func ParseApplicationInfo(data []byte) (info ApplicationInfo, err error) {
+	info.Installed = true
+	if data[0] == TagSelectResponsePreInitialized {
+		info.PublicKey = data[2:]
+		return info, nil
+	}
+
+	info.Initialized = true
+
+	if data[0] != TagApplicationInfoTemplate {
+		return info, ErrWrongApplicationInfoTemplate
+	}
+
+	instanceUID, err := apdu.FindTag(data, TagApplicationInfoTemplate, uint8(0x8F))
+	if err != nil {
+		return info, err
+	}
+
+	pubKey, err := apdu.FindTag(data, TagApplicationInfoTemplate, uint8(0x80))
+	if err != nil {
+		return info, err
+	}
+
+	appVersion, err := apdu.FindTag(data, TagApplicationInfoTemplate, uint8(0x02))
+	if err != nil {
+		return info, err
+	}
+
+	availableSlots, err := apdu.FindTagN(data, 1, TagApplicationInfoTemplate, uint8(0x02))
+	if err != nil {
+		return info, err
+	}
+
+	keyUID, err := apdu.FindTagN(data, 0, TagApplicationInfoTemplate, uint8(0x8E))
+	if err != nil {
+		return info, err
+	}
+
+	info.InstanceUID = instanceUID
+	info.PublicKey = pubKey
+	info.Version = appVersion
+	info.AvailableSlots = availableSlots
+	info.KeyUID = keyUID
+
+	return info, nil
+}

types/types.go

@@ -7,18 +7,6 @@ type Channel interface {
 	Send(*apdu.Command) (*apdu.Response, error)
 }
 
-type ApplicationInfo struct {
-	Installed      bool
-	Initialized    bool
-	InstanceUID    []byte
-	PublicKey      []byte
-	Version        []byte
-	AvailableSlots []byte
-	// KeyUID is the sha256 of of the master public key on the card.
-	// It's empty if the card doesn't contain any key.
-	KeyUID []byte
-}
-
 type ApplicationStatus struct {
 	PinRetryCount    int
 	PUKRetryCount    int