jws/jws.go - third_party/SermoDigital/jose - Git at Google

 package jws

 import (
 	"bytes"
 	"encoding/json"
 	"sort"

 	"github.com/SermoDigital/jose"
 	"github.com/SermoDigital/jose/crypto"
 )

 // JWS represents a specific JWS.
 type JWS struct {
 	payload *payload
 	plcache rawBase64
 	clean   bool

 	sb []sigHead

 	isJWT bool
 }

 // Payload returns the JWS' payload.
 func (j *JWS) Payload() interface{} { return j.payload.v }

 // SetPayload sets the JWS' raw, unexported payload.
 func (j *JWS) SetPayload(val interface{}) { j.payload.v = val }

 // sigHead represents the 'signatures' member of the JWS' "general"
 // serialization form per
 // https://tools.ietf.org/html/rfc7515#section-7.2.1
 //
 // It's embedded inside the "flat" structure in order to properly
 // create the "flat" JWS.
 type sigHead struct {
 	Protected   rawBase64        `json:"protected,omitempty"`
 	Unprotected rawBase64        `json:"header,omitempty"`
 	Signature   crypto.Signature `json:"signature"`

 	protected   jose.Protected
 	unprotected jose.Header
 	clean       bool

 	method crypto.SigningMethod
 }

 func (s *sigHead) unmarshal() error {
 	if err := s.protected.UnmarshalJSON(s.Protected); err != nil {
 		return err
 	}
 	if err := s.unprotected.UnmarshalJSON(s.Unprotected); err != nil {
 		return err
 	}
 	return nil
 }

 // New creates a new JWS with the provided crypto.SigningMethods.
 func New(content interface{}, methods ...crypto.SigningMethod) *JWS {
 	sb := make([]sigHead, len(methods))
 	for i := range methods {
 		sb[i] = sigHead{
 			protected: jose.Protected{
 				"alg": methods[i].Alg(),
 			},
 			unprotected: jose.Header{},
 			method:      methods[i],
 		}
 	}
 	return &JWS{
 		payload: &payload{v: content},
 		sb:      sb,
 	}
 }

 func (s *sigHead) assignMethod(p jose.Protected) error {
 	alg, ok := p.Get("alg").(string)
 	if !ok {
 		return ErrNoAlgorithm
 	}

 	sm := GetSigningMethod(alg)
 	if sm == nil {
 		return ErrNoAlgorithm
 	}

 	s.method = sm
 	return nil
 }

 type generic struct {
 	Payload rawBase64 `json:"payload"`
 	sigHead
 	Signatures []sigHead `json:"signatures,omitempty"`
 }

 // Parse parses any of the three serialized JWS forms into a physical
 // JWS per https://tools.ietf.org/html/rfc7515#section-5.2
 //
 // It accepts a json.Unmarshaler in order to properly parse
 // the payload. In order to keep the caller from having to do extra
 // parsing of the payload, a json.Unmarshaler can be passed
 // which will be then to unmarshal the payload however the caller
 // wishes. Do note that if json.Unmarshal returns an error the
 // original payload will be used as if no json.Unmarshaler was
 // passed.
 //
 // Internally, Parse applies some heuristics and then calls either
 // ParseGeneral, ParseFlat, or ParseCompact.
 // It should only be called if, for whatever reason, you do not
 // know which form the serialized JWT is in.
 func Parse(encoded []byte, u ...json.Unmarshaler) (*JWS, error) {
 	// Try and unmarshal into a generic struct that'll
 	// hopefully hold either of the two JSON serialization
 	// formats.s
 	var g generic

 	// Not valid JSON. Let's try compact.
 	if err := json.Unmarshal(encoded, &g); err != nil {
 		return ParseCompact(encoded, u...)
 	}

 	if g.Signatures == nil {
 		return g.parseFlat(u...)
 	}
 	return g.parseGeneral(u...)
 }

 // ParseGeneral parses a JWS serialized into its "general" form per
 // https://tools.ietf.org/html/rfc7515#section-7.2.1
 // into a physical JWS per
 // https://tools.ietf.org/html/rfc7515#section-5.2
 //
 // For information on the json.Unmarshaler parameter, see Parse.
 func ParseGeneral(encoded []byte, u ...json.Unmarshaler) (*JWS, error) {
 	var g generic
 	if err := json.Unmarshal(encoded, &g); err != nil {
 		return nil, err
 	}
 	return g.parseGeneral(u...)
 }

 func (g *generic) parseGeneral(u ...json.Unmarshaler) (*JWS, error) {

 	var p payload
 	if len(u) > 0 {
 		p.u = u[0]
 	}

 	if err := p.UnmarshalJSON(g.Payload); err != nil {
 		return nil, err
 	}

 	for i := range g.Signatures {
 		if err := g.Signatures[i].unmarshal(); err != nil {
 			return nil, err
 		}
 		if err := checkHeaders(jose.Header(g.Signatures[i].protected), g.Signatures[i].unprotected); err != nil {
 			return nil, err
 		}

 		if err := g.Signatures[i].assignMethod(g.Signatures[i].protected); err != nil {
 			return nil, err
 		}

 		g.clean = true
 	}

 	return &JWS{
 		payload: &p,
 		plcache: g.Payload,
 		clean:   true,
 		sb:      g.Signatures,
 	}, nil
 }

 // ParseFlat parses a JWS serialized into its "flat" form per
 // https://tools.ietf.org/html/rfc7515#section-7.2.2
 // into a physical JWS per
 // https://tools.ietf.org/html/rfc7515#section-5.2
 //
 // For information on the json.Unmarshaler parameter, see Parse.
 func ParseFlat(encoded []byte, u ...json.Unmarshaler) (*JWS, error) {
 	var g generic
 	if err := json.Unmarshal(encoded, &g); err != nil {
 		return nil, err
 	}
 	return g.parseFlat(u...)
 }

 func (g *generic) parseFlat(u ...json.Unmarshaler) (*JWS, error) {

 	var p payload
 	if len(u) > 0 {
 		p.u = u[0]
 	}

 	if err := p.UnmarshalJSON(g.Payload); err != nil {
 		return nil, err
 	}

 	if err := g.sigHead.unmarshal(); err != nil {
 		return nil, err
 	}
 	g.sigHead.clean = true

 	if err := checkHeaders(jose.Header(g.sigHead.protected), g.sigHead.unprotected); err != nil {
 		return nil, err
 	}

 	if err := g.sigHead.assignMethod(g.sigHead.protected); err != nil {
 		return nil, err
 	}

 	return &JWS{
 		payload: &p,
 		plcache: g.Payload,
 		clean:   true,
 		sb:      []sigHead{g.sigHead},
 	}, nil
 }

 // ParseCompact parses a JWS serialized into its "compact" form per
 // https://tools.ietf.org/html/rfc7515#section-7.1
 // into a physical JWS per
 // https://tools.ietf.org/html/rfc7515#section-5.2
 //
 // For information on the json.Unmarshaler parameter, see Parse.
 func ParseCompact(encoded []byte, u ...json.Unmarshaler) (*JWS, error) {

 	// This section loosely follows
 	// https://tools.ietf.org/html/rfc7519#section-7.2
 	// because it's used to parse _both_ JWS and JWTs.

 	parts := bytes.Split(encoded, []byte{'.'})
 	if len(parts) != 3 {
 		return nil, ErrNotCompact
 	}

 	var p jose.Protected
 	if err := p.UnmarshalJSON(parts[0]); err != nil {
 		return nil, err
 	}

 	s := sigHead{
 		protected: p,
 		clean:     true,
 	}

 	if err := s.assignMethod(p); err != nil {
 		return nil, err
 	}

 	j := JWS{
 		payload: &payload{},
 		sb:      []sigHead{s},
 	}

 	if err := j.payload.UnmarshalJSON(parts[1]); err != nil {
 		return nil, err
 	}

 	j.clean = true

 	if err := j.sb[0].Signature.UnmarshalJSON(parts[2]); err != nil {
 		return nil, err
 	}

 	// https://tools.ietf.org/html/rfc7519#section-7.2.8
 	cty, ok := p.Get("cty").(string)
 	if ok && cty == "JWT" {
 		return &j, ErrHoldsJWE
 	}
 	return &j, nil
 }

 // IgnoreDupes should be set to true if the internal duplicate header key check
 // should ignore duplicate Header keys instead of reporting an error when
 // duplicate Header keys are found.
 //
 // Note: Duplicate Header keys are defined in
 // https://tools.ietf.org/html/rfc7515#section-5.2
 // meaning keys that both the protected and unprotected
 // Headers possess.
 var IgnoreDupes bool

 // checkHeaders returns an error per the constraints described in
 // IgnoreDupes' comment.
 func checkHeaders(a, b jose.Header) error {
 	if len(a)+len(b) == 0 {
 		return ErrTwoEmptyHeaders
 	}
 	for key := range a {
 		if b.Has(key) && !IgnoreDupes {
 			return ErrDuplicateHeaderParameter
 		}
 	}
 	return nil
 }

 // Any means any of the JWS signatures need to validate.
 // Refer to ValidateMulti for more information.
 const Any int = -1

 // ValidateMulti validates the current JWS as-is. Since it's meant to be
 // called after parsing a stream of bytes into a JWS, it doesn't do any
 // internal parsing like the Sign, Flat, Compact, or General methods do.
 // idx represents which signatures need to validate
 // in order for the JWS to be considered valid.
 // Use the constant `Any` (-1) if *any* should validate the JWS. Otherwise,
 // use the indexes of the signatures that need to validate in order
 // for the JWS to be considered valid.
 //
 // Notes:
 //     1.) If idx is omitted it defaults to requiring *all*
 //         signatures validate
 //     2.) The JWS spec requires *at least* one
 //         signature to validate in order for the JWS to be considered valid.
 func (j *JWS) ValidateMulti(keys []interface{}, methods []crypto.SigningMethod, idx ...int) error {

 	if len(j.sb) != len(methods) {
 		return ErrNotEnoughMethods
 	}

 	if len(keys) < 1 ||
 		len(keys) > 1 && len(keys) != len(j.sb) {
 		return ErrNotEnoughKeys
 	}

 	if len(keys) == 1 {
 		k := keys[0]
 		keys = make([]interface{}, len(methods))
 		for i := range keys {
 			keys[i] = k
 		}
 	}

 	any := len(idx) == 1 && idx[0] == Any
 	if !any {
 		sort.Ints(idx)
 	}

 	rp := 0
 	for i := range j.sb {
 		if j.sb[i].validate(j.plcache, keys[i], methods[i]) == nil &&
 			any || (rp < len(idx) && idx[rp] == i) {
 			rp++
 		}
 	}

 	if rp < len(idx) {
 		return ErrDidNotValidate
 	}
 	return nil
 }

 // Validate validates the current JWS as-is. Refer to ValidateMulti
 // for more information.
 func (j *JWS) Validate(key interface{}, method crypto.SigningMethod) error {
 	if len(j.sb) < 1 {
 		return ErrCannotValidate
 	}
 	return j.sb[0].validate(j.plcache, key, method)
 }

 func (s *sigHead) validate(pl []byte, key interface{}, method crypto.SigningMethod) error {
 	if s.method != method {
 		return ErrMismatchedAlgorithms
 	}
 	return method.Verify(format(s.Protected, pl), s.Signature, key)
 }

 // SetProtected sets the protected Header with the given value.
 // If i is provided, it'll assume the JWS is in the "general" format,
 // and set the Header at index i (inside the signatures member) with
 // the given value.
 func (j *JWS) SetProtected(key string, val interface{}, i ...int) {
 	k := 0
 	if len(i) > 0 && len(i) < len(j.sb) && i[0] > -1 {
 		k = i[0]
 	}
 	j.sb[k].protected.Set(key, val)
 }

 // RemoveProtected removes the value inside the protected Header that
 // corresponds with the given key.
 // For information on parameter i, see SetProtected.
 func (j *JWS) RemoveProtected(key string, i ...int) {
 	k := 0
 	if len(i) > 0 && len(i) < len(j.sb) && i[0] > -1 {
 		k = i[0]
 	}
 	j.sb[k].protected.Del(key)
 }

 // GetProtected retrieves the value inside the protected Header that
 // corresponds with the given key.
 // For information on parameter i, see SetProtected.
 func (j *JWS) GetProtected(key string, i ...int) interface{} {
 	k := 0
 	if len(i) > 0 && len(i) < len(j.sb) && i[0] > -1 {
 		k = i[0]
 	}
 	return j.sb[k].protected.Get(key)
 }

 // SetUnprotected sets the protected Header with the given value.
 // If i is provided, it'll assume the JWS is in the "general" format,
 // and set the Header at index i (inside the signatures member) with
 // the given value.
 func (j *JWS) SetUnprotected(key string, val interface{}, i ...int) {
 	k := 0
 	if len(i) > 0 && len(i) < len(j.sb) && i[0] > -1 {
 		k = i[0]
 	}
 	j.sb[k].unprotected.Set(key, val)
 }

 // RemoveUnprotected removes the value inside the unprotected Header that
 // corresponds with the given key.
 // For information on parameter i, see SetUnprotected.
 func (j *JWS) RemoveUnprotected(key string, i ...int) {
 	k := 0
 	if len(i) > 0 && len(i) < len(j.sb) && i[0] > -1 {
 		k = i[0]
 	}
 	j.sb[k].unprotected.Del(key)
 }

 // GetUnprotected retrieves the value inside the protected Header that
 // corresponds with the given key.
 // For information on parameter i, see SetUnprotected.
 func (j *JWS) GetUnprotected(key string, i ...int) interface{} {
 	k := 0
 	if len(i) > 0 && len(i) < len(j.sb) && i[0] > -1 {
 		k = i[0]
 	}
 	return j.sb[k].unprotected.Get(key)
 }
	package jws

	import (
	"bytes"
	"encoding/json"
	"sort"

	"github.com/SermoDigital/jose"
	"github.com/SermoDigital/jose/crypto"
	)

	// JWS represents a specific JWS.
	type JWS struct {
	payload *payload
	plcache rawBase64
	clean bool

	sb []sigHead

	isJWT bool
	}

	// Payload returns the JWS' payload.
	func (j *JWS) Payload() interface{} { return j.payload.v }

	// SetPayload sets the JWS' raw, unexported payload.
	func (j *JWS) SetPayload(val interface{}) { j.payload.v = val }

	// sigHead represents the 'signatures' member of the JWS' "general"
	// serialization form per
	// https://tools.ietf.org/html/rfc7515#section-7.2.1
	//
	// It's embedded inside the "flat" structure in order to properly
	// create the "flat" JWS.
	type sigHead struct {
	Protected rawBase64 `json:"protected,omitempty"`
	Unprotected rawBase64 `json:"header,omitempty"`
	Signature crypto.Signature `json:"signature"`

	protected jose.Protected
	unprotected jose.Header
	clean bool

	method crypto.SigningMethod
	}

	func (s *sigHead) unmarshal() error {
	if err := s.protected.UnmarshalJSON(s.Protected); err != nil {
	return err
	}
	if err := s.unprotected.UnmarshalJSON(s.Unprotected); err != nil {
	return err
	}
	return nil
	}

	// New creates a new JWS with the provided crypto.SigningMethods.
	func New(content interface{}, methods ...crypto.SigningMethod) *JWS {
	sb := make([]sigHead, len(methods))
	for i := range methods {
	sb[i] = sigHead{
	protected: jose.Protected{
	"alg": methods[i].Alg(),
	},
	unprotected: jose.Header{},
	method: methods[i],
	}
	}
	return &JWS{
	payload: &payload{v: content},
	sb: sb,
	}
	}

	func (s *sigHead) assignMethod(p jose.Protected) error {
	alg, ok := p.Get("alg").(string)
	if !ok {
	return ErrNoAlgorithm
	}

	sm := GetSigningMethod(alg)
	if sm == nil {
	return ErrNoAlgorithm
	}

	s.method = sm
	return nil
	}

	type generic struct {
	Payload rawBase64 `json:"payload"`
	sigHead
	Signatures []sigHead `json:"signatures,omitempty"`
	}

	// Parse parses any of the three serialized JWS forms into a physical
	// JWS per https://tools.ietf.org/html/rfc7515#section-5.2
	//
	// It accepts a json.Unmarshaler in order to properly parse
	// the payload. In order to keep the caller from having to do extra
	// parsing of the payload, a json.Unmarshaler can be passed
	// which will be then to unmarshal the payload however the caller
	// wishes. Do note that if json.Unmarshal returns an error the
	// original payload will be used as if no json.Unmarshaler was
	// passed.
	//
	// Internally, Parse applies some heuristics and then calls either
	// ParseGeneral, ParseFlat, or ParseCompact.
	// It should only be called if, for whatever reason, you do not
	// know which form the serialized JWT is in.
	func Parse(encoded []byte, u ...json.Unmarshaler) (*JWS, error) {
	// Try and unmarshal into a generic struct that'll
	// hopefully hold either of the two JSON serialization
	// formats.s
	var g generic

	// Not valid JSON. Let's try compact.
	if err := json.Unmarshal(encoded, &g); err != nil {
	return ParseCompact(encoded, u...)
	}

	if g.Signatures == nil {
	return g.parseFlat(u...)
	}
	return g.parseGeneral(u...)
	}

	// ParseGeneral parses a JWS serialized into its "general" form per
	// https://tools.ietf.org/html/rfc7515#section-7.2.1
	// into a physical JWS per
	// https://tools.ietf.org/html/rfc7515#section-5.2
	//
	// For information on the json.Unmarshaler parameter, see Parse.
	func ParseGeneral(encoded []byte, u ...json.Unmarshaler) (*JWS, error) {
	var g generic
	if err := json.Unmarshal(encoded, &g); err != nil {
	return nil, err
	}
	return g.parseGeneral(u...)
	}

	func (g generic) parseGeneral(u ...json.Unmarshaler) (JWS, error) {

	var p payload
	if len(u) > 0 {
	p.u = u[0]
	}

	if err := p.UnmarshalJSON(g.Payload); err != nil {
	return nil, err
	}

	for i := range g.Signatures {
	if err := g.Signatures[i].unmarshal(); err != nil {
	return nil, err
	}
	if err := checkHeaders(jose.Header(g.Signatures[i].protected), g.Signatures[i].unprotected); err != nil {
	return nil, err
	}

	if err := g.Signatures[i].assignMethod(g.Signatures[i].protected); err != nil {
	return nil, err
	}

	g.clean = true
	}

	return &JWS{
	payload: &p,
	plcache: g.Payload,
	clean: true,
	sb: g.Signatures,
	}, nil
	}

	// ParseFlat parses a JWS serialized into its "flat" form per
	// https://tools.ietf.org/html/rfc7515#section-7.2.2
	// into a physical JWS per
	// https://tools.ietf.org/html/rfc7515#section-5.2
	//
	// For information on the json.Unmarshaler parameter, see Parse.
	func ParseFlat(encoded []byte, u ...json.Unmarshaler) (*JWS, error) {
	var g generic
	if err := json.Unmarshal(encoded, &g); err != nil {
	return nil, err
	}
	return g.parseFlat(u...)
	}

	func (g generic) parseFlat(u ...json.Unmarshaler) (JWS, error) {

	var p payload
	if len(u) > 0 {
	p.u = u[0]
	}

	if err := p.UnmarshalJSON(g.Payload); err != nil {
	return nil, err
	}

	if err := g.sigHead.unmarshal(); err != nil {
	return nil, err
	}
	g.sigHead.clean = true

	if err := checkHeaders(jose.Header(g.sigHead.protected), g.sigHead.unprotected); err != nil {
	return nil, err
	}

	if err := g.sigHead.assignMethod(g.sigHead.protected); err != nil {
	return nil, err
	}

	return &JWS{
	payload: &p,
	plcache: g.Payload,
	clean: true,
	sb: []sigHead{g.sigHead},
	}, nil
	}

	// ParseCompact parses a JWS serialized into its "compact" form per
	// https://tools.ietf.org/html/rfc7515#section-7.1
	// into a physical JWS per
	// https://tools.ietf.org/html/rfc7515#section-5.2
	//
	// For information on the json.Unmarshaler parameter, see Parse.
	func ParseCompact(encoded []byte, u ...json.Unmarshaler) (*JWS, error) {

	// This section loosely follows
	// https://tools.ietf.org/html/rfc7519#section-7.2
	// because it's used to parse _both_ JWS and JWTs.

	parts := bytes.Split(encoded, []byte{'.'})
	if len(parts) != 3 {
	return nil, ErrNotCompact
	}

	var p jose.Protected
	if err := p.UnmarshalJSON(parts[0]); err != nil {
	return nil, err
	}

	s := sigHead{
	protected: p,
	clean: true,
	}

	if err := s.assignMethod(p); err != nil {
	return nil, err
	}

	j := JWS{
	payload: &payload{},
	sb: []sigHead{s},
	}

	if err := j.payload.UnmarshalJSON(parts[1]); err != nil {
	return nil, err
	}

	j.clean = true

	if err := j.sb[0].Signature.UnmarshalJSON(parts[2]); err != nil {
	return nil, err
	}

	// https://tools.ietf.org/html/rfc7519#section-7.2.8
	cty, ok := p.Get("cty").(string)
	if ok && cty == "JWT" {
	return &j, ErrHoldsJWE
	}
	return &j, nil
	}

	// IgnoreDupes should be set to true if the internal duplicate header key check
	// should ignore duplicate Header keys instead of reporting an error when
	// duplicate Header keys are found.
	//
	// Note: Duplicate Header keys are defined in
	// https://tools.ietf.org/html/rfc7515#section-5.2
	// meaning keys that both the protected and unprotected
	// Headers possess.
	var IgnoreDupes bool

	// checkHeaders returns an error per the constraints described in
	// IgnoreDupes' comment.
	func checkHeaders(a, b jose.Header) error {
	if len(a)+len(b) == 0 {
	return ErrTwoEmptyHeaders
	}
	for key := range a {
	if b.Has(key) && !IgnoreDupes {
	return ErrDuplicateHeaderParameter
	}
	}
	return nil
	}

	// Any means any of the JWS signatures need to validate.
	// Refer to ValidateMulti for more information.
	const Any int = -1

	// ValidateMulti validates the current JWS as-is. Since it's meant to be
	// called after parsing a stream of bytes into a JWS, it doesn't do any
	// internal parsing like the Sign, Flat, Compact, or General methods do.
	// idx represents which signatures need to validate
	// in order for the JWS to be considered valid.
	// Use the constant `Any` (-1) if any should validate the JWS. Otherwise,
	// use the indexes of the signatures that need to validate in order
	// for the JWS to be considered valid.
	//
	// Notes:
	// 1.) If idx is omitted it defaults to requiring all
	// signatures validate
	// 2.) The JWS spec requires at least one
	// signature to validate in order for the JWS to be considered valid.
	func (j *JWS) ValidateMulti(keys []interface{}, methods []crypto.SigningMethod, idx ...int) error {

	if len(j.sb) != len(methods) {
	return ErrNotEnoughMethods
	}

	if len(keys) < 1 \|\|
	len(keys) > 1 && len(keys) != len(j.sb) {
	return ErrNotEnoughKeys
	}

	if len(keys) == 1 {
	k := keys[0]
	keys = make([]interface{}, len(methods))
	for i := range keys {
	keys[i] = k
	}
	}

	any := len(idx) == 1 && idx[0] == Any
	if !any {
	sort.Ints(idx)
	}

	rp := 0
	for i := range j.sb {
	if j.sb[i].validate(j.plcache, keys[i], methods[i]) == nil &&
	any \|\| (rp < len(idx) && idx[rp] == i) {
	rp++
	}
	}

	if rp < len(idx) {
	return ErrDidNotValidate
	}
	return nil
	}

	// Validate validates the current JWS as-is. Refer to ValidateMulti
	// for more information.
	func (j *JWS) Validate(key interface{}, method crypto.SigningMethod) error {
	if len(j.sb) < 1 {
	return ErrCannotValidate
	}
	return j.sb[0].validate(j.plcache, key, method)
	}

	func (s *sigHead) validate(pl []byte, key interface{}, method crypto.SigningMethod) error {
	if s.method != method {
	return ErrMismatchedAlgorithms
	}
	return method.Verify(format(s.Protected, pl), s.Signature, key)
	}

	// SetProtected sets the protected Header with the given value.
	// If i is provided, it'll assume the JWS is in the "general" format,
	// and set the Header at index i (inside the signatures member) with
	// the given value.
	func (j *JWS) SetProtected(key string, val interface{}, i ...int) {
	k := 0
	if len(i) > 0 && len(i) < len(j.sb) && i[0] > -1 {
	k = i[0]
	}
	j.sb[k].protected.Set(key, val)
	}

	// RemoveProtected removes the value inside the protected Header that
	// corresponds with the given key.
	// For information on parameter i, see SetProtected.
	func (j *JWS) RemoveProtected(key string, i ...int) {
	k := 0
	if len(i) > 0 && len(i) < len(j.sb) && i[0] > -1 {
	k = i[0]
	}
	j.sb[k].protected.Del(key)
	}

	// GetProtected retrieves the value inside the protected Header that
	// corresponds with the given key.
	// For information on parameter i, see SetProtected.
	func (j *JWS) GetProtected(key string, i ...int) interface{} {
	k := 0
	if len(i) > 0 && len(i) < len(j.sb) && i[0] > -1 {
	k = i[0]
	}
	return j.sb[k].protected.Get(key)
	}

	// SetUnprotected sets the protected Header with the given value.
	// If i is provided, it'll assume the JWS is in the "general" format,
	// and set the Header at index i (inside the signatures member) with
	// the given value.
	func (j *JWS) SetUnprotected(key string, val interface{}, i ...int) {
	k := 0
	if len(i) > 0 && len(i) < len(j.sb) && i[0] > -1 {
	k = i[0]
	}
	j.sb[k].unprotected.Set(key, val)
	}

	// RemoveUnprotected removes the value inside the unprotected Header that
	// corresponds with the given key.
	// For information on parameter i, see SetUnprotected.
	func (j *JWS) RemoveUnprotected(key string, i ...int) {
	k := 0
	if len(i) > 0 && len(i) < len(j.sb) && i[0] > -1 {
	k = i[0]
	}
	j.sb[k].unprotected.Del(key)
	}

	// GetUnprotected retrieves the value inside the protected Header that
	// corresponds with the given key.
	// For information on parameter i, see SetUnprotected.
	func (j *JWS) GetUnprotected(key string, i ...int) interface{} {
	k := 0
	if len(i) > 0 && len(i) < len(j.sb) && i[0] > -1 {
	k = i[0]
	}
	return j.sb[k].unprotected.Get(key)
	}