/
helpers.go
224 lines (202 loc) · 6.65 KB
/
helpers.go
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package jwt
import (
"context"
"errors"
"fmt"
"net/http"
"strconv"
"strings"
"time"
"github.com/golang-jwt/jwt"
"github.com/lestrrat-go/jwx/jwk"
"github.com/spaceuptech/helpers"
"github.com/spaceuptech/space-cloud/gateway/config"
)
func fetchJWKKeys(ctx context.Context, url string) (*jwk.Set, http.Header, error) {
res, err := http.Get(url)
if err != nil {
return nil, nil, helpers.Logger.LogError(helpers.GetRequestID(ctx), fmt.Sprintf("Unable to fetch jwks from provided url (%s)", url), err, nil)
}
if res.StatusCode != http.StatusOK {
return nil, nil, helpers.Logger.LogError(helpers.GetRequestID(ctx), fmt.Sprintf("Unable to process jwk url (%s), auth server returned status code (%v)", url, res.StatusCode), nil, nil)
}
set, err := jwk.Parse(res.Body)
if err != nil {
return nil, nil, helpers.Logger.LogError(helpers.GetRequestID(ctx), fmt.Sprintf("Unable to process jwk url (%s), auth server has invalid response body", url), err, nil)
}
if set.Len() == 0 {
return nil, nil, helpers.Logger.LogError(helpers.GetRequestID(ctx), fmt.Sprintf("Unable to process jwk url (%s), auth server returned 0 jwk keys", url), nil, nil)
}
return set, res.Header, nil
}
func getJWKRefreshTime(url string) (*jwkSecret, error) {
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()
obj := new(jwkSecret)
set, headers, err := fetchJWKKeys(ctx, url)
if err != nil {
return nil, err
}
obj.set = set
obj.url = url
// check cache-control header for refresh time of jwks
values := headers.Get("cache-control")
if values != "" {
var cacheTime string
for _, value := range strings.Split(values, ",") {
value = strings.TrimSpace(value)
// Make default cache time 5 minutes
if value == "no-cache" {
cacheTime = strconv.Itoa(5 * 60)
break
}
if strings.HasPrefix(value, "max-age") {
cacheTime = strings.Split(value, "=")[1]
break
}
if strings.HasPrefix(value, "s-maxage") {
cacheTime = strings.Split(value, "=")[1]
break
}
}
duration, err := strconv.Atoi(cacheTime)
if err != nil {
return nil, helpers.Logger.LogError(helpers.GetRequestID(ctx), fmt.Sprintf("Unable to process jwt url (%s), Cache-control header contains data of inavlid type expecting string", url), err, nil)
}
obj.refreshTime = time.Now().Add(time.Duration(duration) * time.Second)
return obj, nil
}
// check expires header for refresh time of jwks
values = headers.Get("expires")
if values != "" {
t, err := http.ParseTime(values)
if err != nil {
return nil, helpers.Logger.LogError(helpers.GetRequestID(ctx), fmt.Sprintf("Unable to process jwt url (%s), Expires header contains data of inavlid type expecting string in format RFC1123", url), nil, nil)
}
obj.refreshTime = t
return obj, nil
}
// set default refresh time
obj.refreshTime = time.Now().Add(24 * time.Hour)
return obj, nil
}
func (j *JWT) verifyTokenSignature(ctx context.Context, token string, secret *config.Secret) (map[string]interface{}, error) {
// Parse the JWT token
tokenObj, err := jwt.Parse(token, func(token *jwt.Token) (interface{}, error) {
// Don't forget to validate the alg is what you expect:
if token.Method.Alg() != string(secret.Alg) {
return nil, fmt.Errorf("invalid token algorithm provided wanted (%s) got (%s)", secret.Alg, token.Method.Alg())
}
if secret.JwkURL != "" {
return secret.JwkKey, nil
}
switch secret.Alg {
case config.RS256:
return jwt.ParseRSAPublicKeyFromPEM([]byte(secret.PublicKey))
case config.HS256, "":
return []byte(secret.Secret), nil
default:
return nil, fmt.Errorf("invalid token algorithm (%s) provided", secret.Alg)
}
})
if err != nil {
return nil, err
}
// Get the claims
if claims, ok := tokenObj.Claims.(jwt.MapClaims); ok && tokenObj.Valid {
if err := claims.Valid(); err != nil {
return nil, err
}
obj := make(map[string]interface{}, len(claims))
for key, val := range claims {
obj[key] = val
}
if len(secret.Issuer) > 0 {
c, ok := claims["iss"]
if !ok {
return nil, errors.New("claim (iss) not provided in token")
}
if err := verifyClaims(c, secret.Issuer); err != nil {
return nil, err
}
}
if len(secret.Audience) > 0 {
c, ok := claims["aud"]
if !ok {
return nil, errors.New("claim (aud) not provided in token")
}
if err := verifyClaims(c, secret.Audience); err != nil {
return nil, err
}
}
helpers.Logger.LogInfo(helpers.GetRequestID(ctx), "Claim from request token", map[string]interface{}{"claims": claims, "type": "auth"})
return obj, nil
}
return nil, errors.New("AUTH: JWT token could not be verified")
}
func verifyClaims(claims interface{}, configValues []string) error {
switch claimFromToken := claims.(type) {
case string:
for _, cmp := range configValues {
if claimFromToken == cmp {
return nil
}
}
case []interface{}:
for _, audClaim := range claimFromToken {
for _, c := range configValues {
if audClaim == c {
return nil
}
}
}
default:
return errors.New("invalid type provided for claim in jwt token")
}
return errors.New("unable to verify claim of jwt token")
}
func (j *JWT) parseJwkSecret(ctx context.Context, kid, token string) (map[string]interface{}, error) {
jwkSecretKID, ok := j.mapJwkKidToSecretKid[kid]
if ok {
obj, ok := j.jwkSecrets[jwkSecretKID]
if !ok {
return nil, errors.New("token contains an unknown kid")
}
key := obj.set.LookupKeyID(kid)
if len(key) == 0 {
return nil, fmt.Errorf("token has a invalid kid which doesn't match with the kid from the jwk url (%s)", obj.url)
}
var raw interface{}
if err := key[0].Raw(&raw); err != nil {
return nil, err
}
return j.verifyTokenSignature(ctx, token, &config.Secret{Issuer: obj.issuer, Audience: obj.audience, Alg: config.JWTAlg(key[0].Algorithm()), JwkKey: raw, JwkURL: obj.url})
}
return nil, errors.New("kid doesn't exists in internal jwk mapping of keys")
}
func (j *JWT) fetchJWKRoutine(t time.Time) {
j.lock.Lock()
defer j.lock.Unlock()
for kid, secret := range j.jwkSecrets {
if secret.refreshTime.Before(t) {
jwkSecretInfo, err := getJWKRefreshTime(secret.url)
if err != nil {
_ = helpers.Logger.LogError("", fmt.Sprintf("Unable to refresh jwk keys having kid (%s) and url (%s)", kid, secret.url), err, nil)
continue
}
jwkSecretInfo.audience = secret.audience
jwkSecretInfo.issuer = secret.issuer
j.jwkSecrets[kid] = jwkSecretInfo
// Delete kids of existing JWK url
for key, value := range j.mapJwkKidToSecretKid {
if value == kid {
delete(j.mapJwkKidToSecretKid, key)
}
}
// Add new kids to existing JWK url
for _, key := range jwkSecretInfo.set.Keys {
j.mapJwkKidToSecretKid[key.KeyID()] = kid
}
}
}
}