104 lignes
2,8 Kio
Go
104 lignes
2,8 Kio
Go
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// Package jwt is able to generate and validate json web tokens.
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// Follows https://tools.ietf.org/html/draft-ietf-oauth-json-web-token-32
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package jwt
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import (
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"crypto/rsa"
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"crypto/sha256"
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"fmt"
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"strings"
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"github.com/dgrijalva/jwt-go"
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"github.com/pkg/errors"
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)
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// RS256JWTStrategy is responsible for generating and validating JWT challenges
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type RS256JWTStrategy struct {
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PrivateKey *rsa.PrivateKey
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}
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// Generate generates a new authorize code or returns an error. set secret
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func (j *RS256JWTStrategy) Generate(claims jwt.Claims, header Mapper) (string, string, error) {
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if header == nil || claims == nil {
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return "", "", errors.New("Either claims or header is nil.")
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}
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token := jwt.NewWithClaims(jwt.SigningMethodRS256, claims)
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token.Header = assign(token.Header, header.ToMap())
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var sig, sstr string
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var err error
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if sstr, err = token.SigningString(); err != nil {
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return "", "", errors.WithStack(err)
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}
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if sig, err = token.Method.Sign(sstr, j.PrivateKey); err != nil {
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return "", "", errors.WithStack(err)
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}
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return fmt.Sprintf("%s.%s", sstr, sig), sig, nil
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}
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// Validate validates a token and returns its signature or an error if the token is not valid.
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func (j *RS256JWTStrategy) Validate(token string) (string, error) {
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if _, err := j.Decode(token); err != nil {
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return "", errors.WithStack(err)
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}
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return j.GetSignature(token)
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}
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// Decode will decode a JWT token
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func (j *RS256JWTStrategy) Decode(token string) (*jwt.Token, error) {
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// Parse the token.
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parsedToken, err := jwt.Parse(token, func(t *jwt.Token) (interface{}, error) {
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if _, ok := t.Method.(*jwt.SigningMethodRSA); !ok {
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return nil, errors.Errorf("Unexpected signing method: %v", t.Header["alg"])
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}
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return &j.PrivateKey.PublicKey, nil
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})
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if err != nil {
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return nil, errors.Wrap(err, "Couldn't parse token")
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} else if !parsedToken.Valid {
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return nil, errors.Errorf("Token is invalid")
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}
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return parsedToken, err
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}
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// GetSignature will return the signature of a token
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func (j *RS256JWTStrategy) GetSignature(token string) (string, error) {
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split := strings.Split(token, ".")
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if len(split) != 3 {
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return "", errors.New("Header, body and signature must all be set")
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}
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return split[2], nil
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}
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// Hash will return a given hash based on the byte input or an error upon fail
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func (j *RS256JWTStrategy) Hash(in []byte) ([]byte, error) {
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// SigningMethodRS256
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hash := sha256.New()
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_, err := hash.Write(in)
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if err != nil {
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return []byte{}, errors.WithStack(err)
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}
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return hash.Sum([]byte{}), nil
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}
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// GetSigningMethodLength will return the length of the signing method
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func (j *RS256JWTStrategy) GetSigningMethodLength() int {
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return jwt.SigningMethodRS256.Hash.Size()
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}
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func assign(a, b map[string]interface{}) map[string]interface{} {
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for k, w := range b {
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if _, ok := a[k]; ok {
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continue
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}
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a[k] = w
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}
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return a
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}
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