Gin framework JWT token extractor middleware

gwt_token_extractor.go

package gin

import (
	"crypto/rsa"
	"net/http"

	"github.com/gin-gonic/gin"
	"github.com/lestrrat-go/jwx/jwa"
	"github.com/lestrrat-go/jwx/jwt"
)

// JWTTokenParser extract JWT token form header Authorization and validate it with a RS256 public key
// example of usage: h.GET("/test/:id", JWTTokenParser(publicKey), someHandler.getTest)
func JWTTokenParser(publicKey *rsa.PublicKey) gin.HandlerFunc {
	return func(c *gin.Context) {
		token, err := jwt.ParseHeader(
			c.Request.Header,
			"Authorization",
			jwt.WithValidate(true),
			jwt.WithVerify(jwa.RS256, publicKey),
		)
		if err != nil {
			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": err.Error()})
			return
		}
		c.Set("jwtToken", token)
	}
}