add photo api

openpgp/packet/public_key.go

@@ -1045,6 +1045,46 @@ func (pk *PublicKey) VerifyDirectKeySignature(sig *Signature) (err error) {
 	return pk.VerifySignature(h, sig)
 }
 
+// VerifyUserAttributeSignature returns nil iff sig is a valid signature, made by this
+// public key, that uat is an attribute of pub.
+func (pk *PublicKey) VerifyUserAttributeSignature(pkt *UserAttribute, pub *PublicKey, sig *Signature) (err error) {
+	h, err := sig.PrepareVerify()
+	if err != nil {
+		return err
+	}
+	err = userAttributeSignatureHash(pkt, pub, h)
+	if err != nil {
+		return err
+	}
+	return pk.VerifySignature(h, sig)
+}
+
+// userAttributeSignatureHash returns a Hash of the message that needs to be signed
+// to assert that pk is a valid key for uat.
+func userAttributeSignatureHash(uat *UserAttribute, pk *PublicKey, h hash.Hash) (err error) {
+
+	// RFC 4880, section 5.2.4
+	if err := pk.SerializeSignaturePrefix(h); err != nil {
+		return err
+	}
+	if err := pk.serializeWithoutHeaders(h); err != nil {
+		return err
+	}
+
+	data := uat.data()
+
+	var buf [5]byte
+	buf[0] = 0xd1
+	buf[1] = byte(len(data) >> 24)
+	buf[2] = byte(len(data) >> 16)
+	buf[3] = byte(len(data) >> 8)
+	buf[4] = byte(len(data))
+	h.Write(buf[:])
+	h.Write(data)
+
+	return
+}
+
 // KeyIdString returns the public key's fingerprint in capital hex
 // (e.g. "6C7EE1B8621CC013").
 func (pk *PublicKey) KeyIdString() string {

openpgp/packet/signature.go

@@ -1033,6 +1033,25 @@ func (sig *Signature) SignUserId(id string, pub *PublicKey, priv *PrivateKey, co
 	return sig.Sign(prepareHash, priv, config)
 }
 
+// SignUserAttribute computes a signature from priv, asserting that pub has
+// user attribute uat.  On success, the signature is stored in sig. Call
+// Serialize to write it out.
+// If config is nil, sensible defaults will be used.
+func (sig *Signature) SignUserAttribute(uat *UserAttribute, pub *PublicKey, priv *PrivateKey, config *Config) error {
+	if priv.Dummy() {
+		return errors.ErrDummyPrivateKey("dummy key found")
+	}
+	prepareHash, err := sig.PrepareSign(config)
+	if err != nil {
+		return err
+	}
+	err = userAttributeSignatureHash(uat, pub, prepareHash)
+	if err != nil {
+		return err
+	}
+	return sig.Sign(prepareHash, priv, config)
+}
+
 // SignDirectKeyBinding computes a signature from priv
 // On success, the signature is stored in sig.
 // Call Serialize to write it out.

openpgp/packet/userattribute.go

@@ -9,6 +9,8 @@ import (
 	"image"
 	"image/jpeg"
 	"io"
+
+	"github.com/ProtonMail/go-crypto/openpgp/errors"
 )
 
 const UserAttrImageSubpacket = 1
@@ -24,6 +26,29 @@ type UserAttribute struct {
 // NewUserAttributePhoto creates a user attribute packet
 // containing the given images.
 func NewUserAttributePhoto(photos ...image.Image) (uat *UserAttribute, err error) {
+	var imgBytes [][]byte
+	for _, photo := range photos {
+		var buf bytes.Buffer
+		if err = jpeg.Encode(&buf, photo, nil); err != nil {
+			return
+		}
+		imgBytes = append(imgBytes, buf.Bytes())
+	}
+	return newUserAttributePhotoBytes(imgBytes)
+}
+
+func NewUserAttributePhotoBytes(photos [][]byte) (uat *UserAttribute, err error) {
+	for _, photo := range photos {
+		//check jpeg
+		_, err = jpeg.Decode(bytes.NewBuffer(photo))
+		if err != nil {
+			return nil, errors.InvalidArgumentError("jpeg data err")
+		}
+	}
+	return newUserAttributePhotoBytes(photos)
+}
+
+func newUserAttributePhotoBytes(photos [][]byte) (uat *UserAttribute, err error) {
 	uat = new(UserAttribute)
 	for _, photo := range photos {
 		var buf bytes.Buffer
@@ -38,17 +63,15 @@ func NewUserAttributePhoto(photos ...image.Image) (uat *UserAttribute, err error
 		if _, err = buf.Write(data); err != nil {
 			return
 		}
-		if err = jpeg.Encode(&buf, photo, nil); err != nil {
-			return
-		}
+		buf.Write(photo)
 
-		lengthBuf := make([]byte, 5)
-		n := serializeSubpacketLength(lengthBuf, len(buf.Bytes())+1)
-		lengthBuf = lengthBuf[:n]
+		encodedLength := make([]byte, 5)
+		n := serializeSubpacketLength(encodedLength, len(buf.Bytes())+1)
+		encodedLength = encodedLength[:n]
 
 		uat.Contents = append(uat.Contents, &OpaqueSubpacket{
 			SubType:       UserAttrImageSubpacket,
-			EncodedLength: lengthBuf,
+			EncodedLength: encodedLength,
 			Contents:      buf.Bytes(),
 		})
 	}
@@ -60,6 +83,14 @@ func NewUserAttribute(contents ...*OpaqueSubpacket) *UserAttribute {
 	return &UserAttribute{Contents: contents}
 }
 
+func (uat *UserAttribute) data() []byte {
+	buf := bytes.NewBuffer(nil)
+	for _, osp := range uat.Contents {
+		osp.Serialize(buf)
+	}
+	return buf.Bytes()
+}
+
 func (uat *UserAttribute) parse(r io.Reader) (err error) {
 	// RFC 4880, section 5.13
 	b, err := io.ReadAll(r)

openpgp/v2/keys.go

@@ -31,6 +31,7 @@ type Entity struct {
 	Revocations      []*packet.VerifiableSignature
 	DirectSignatures []*packet.VerifiableSignature // Direct-key self signature of the PrimaryKey (contains primary key properties in v6)}
 	Subkeys          []Subkey
+	Attributes       []*Attribute
 }
 
 // A Key identifies a specific public key in an Entity. This is either the
@@ -503,6 +504,10 @@ EachPacket:
 			if err != nil {
 				return nil, err
 			}
+		case *packet.UserAttribute:
+			if err := addUserAttribute(e, packets, pkt); err != nil {
+				return nil, err
+			}
 		case *packet.Signature:
 			if pkt.SigType == packet.SigTypeKeyRevocation {
 				e.Revocations = append(e.Revocations, packet.NewVerifiableSig(pkt))
@@ -592,6 +597,27 @@ func (e *Entity) serializePrivate(w io.Writer, config *packet.Config, reSign boo
 			return err
 		}
 	}
+	for _, attr := range e.Attributes {
+		if reSign {
+			if attr.SelfSignature == nil {
+				return goerrors.New("openpgp: can't re-sign user attribute without valid self-signature")
+			}
+			err = attr.SelfSignature.SignUserAttribute(attr.UserAttribute, e.PrimaryKey, e.PrivateKey, config)
+			if err != nil {
+				return
+			}
+		}
+		err = attr.UserAttribute.Serialize(w)
+		if err != nil {
+			return
+		}
+		for _, sig := range attr.Signatures {
+			err = sig.Serialize(w)
+			if err != nil {
+				return err
+			}
+		}
+	}
 	for _, subkey := range e.Subkeys {
 		if reSign {
 			if err := subkey.ReSign(config); err != nil {
@@ -627,6 +653,18 @@ func (e *Entity) Serialize(w io.Writer) error {
 			return err
 		}
 	}
+	for _, uat := range e.Attributes {
+		err := uat.UserAttribute.Serialize(w)
+		if err != nil {
+			return err
+		}
+		for _, sig := range uat.Signatures {
+			err = sig.Serialize(w)
+			if err != nil {
+				return err
+			}
+		}
+	}
 	for _, subkey := range e.Subkeys {
 		if err := subkey.Serialize(w, false); err != nil {
 			return err