Protocol: freeze device proof and browser CSRF contracts

gen/go/protocol/protocol.go

@@ -4,6 +4,7 @@ package protocol
 import (
 	"bytes"
 	"encoding/base64"
+	"encoding/binary"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -5564,6 +5565,30 @@ func EncodeVersionNegotiation(value VersionNegotiation) ([]byte, error) {
 	return json.Marshal(value)
 }
 
+func DeviceRegistrationProofTranscript(serverID, principalID, deviceID, challenge []byte, expiryUnixMilliseconds int64) ([]byte, error) {
+	for _, value := range []struct {
+		field  string
+		bytes  []byte
+		length int
+	}{{"server_id", serverID, 16}, {"principal_id", principalID, 16}, {"device_id", deviceID, 16}, {"challenge", challenge, 32}} {
+		if len(value.bytes) != value.length {
+			return nil, ValidationError{Violations: []FieldViolation{{Field: value.field, Code: "invalid_length"}}}
+		}
+	}
+	if expiryUnixMilliseconds < 0 {
+		return nil, ValidationError{Violations: []FieldViolation{{Field: "expiry_unix_milliseconds", Code: "minimum"}}}
+	}
+	transcript := make([]byte, 0, 112)
+	transcript = append(transcript, "versevdi-device-proof-v1"...)
+	transcript = append(transcript, serverID...)
+	transcript = append(transcript, principalID...)
+	transcript = append(transcript, deviceID...)
+	transcript = append(transcript, challenge...)
+	var expiry [8]byte
+	binary.BigEndian.PutUint64(expiry[:], uint64(expiryUnixMilliseconds))
+	return append(transcript, expiry[:]...), nil
+}
+
 var ErrNoCapabilityOverlap = errors.New("no capability overlap")
 
 func IntersectCapabilityProfiles(profiles ...CapabilityProfile) (CapabilityProfile, error) {