jwt.go

package jwt

import (
	"encoding/base64"
	"encoding/json"
)

// GenSignBytes 依據header, claims生成出jwt需要被加簽的內容
func GenSignBytes(header map[string]any, claims IClaims) ([]byte, error) {
	h, err := json.Marshal(header)
	if err != nil {
		return nil, err
	}
	c, err := json.Marshal(claims)
	if err != nil {
		return nil, err
	}
	var buf []byte
	buf = base64.RawURLEncoding.AppendEncode(buf, h)
	buf = append(buf, '.')
	buf = base64.RawURLEncoding.AppendEncode(buf, c)
	// return base64.RawURLEncoding.EncodeToString(h) + "." + base64.RawURLEncoding.EncodeToString(c), nil
	return buf, nil
}

func GenerateToken(method ISigningMethod, claims IClaims, key any) ([]byte, error) {
	header := map[string]any{
		"typ": "JWT",
		"alg": method.AlgName(),
	}
	singingBytes, err := GenSignBytes(header, claims)
	if err != nil {
		return nil, err
	}
	signature, err := method.Sign(singingBytes, key)
	if err != nil {
		return nil, err
	}
	return base64.RawURLEncoding.AppendEncode(append(singingBytes, '.'), signature), nil
}