Files
hspguard/internal/util/jwt.go

82 lines
1.8 KiB
Go

package util
import (
"crypto/rsa"
"crypto/x509"
"encoding/base64"
"fmt"
"github.com/golang-jwt/jwt/v5"
)
func ParseBase64PrivateKey(b64 string) (*rsa.PrivateKey, error) {
decoded, err := base64.StdEncoding.DecodeString(b64)
if err != nil {
return nil, fmt.Errorf("failed to decode base64 key: %v", err)
}
key, err := x509.ParsePKCS8PrivateKey(decoded)
return key.(*rsa.PrivateKey), err
}
func ParseBase64PublicKey(b64 string) (*rsa.PublicKey, error) {
decoded, err := base64.StdEncoding.DecodeString(b64)
if err != nil {
return nil, fmt.Errorf("failed to decode base64 key: %v", err)
}
pubInterface, err := x509.ParsePKIXPublicKey(decoded)
if err != nil {
return nil, fmt.Errorf("failed to parse public key: %v", err)
}
pubKey, ok := pubInterface.(*rsa.PublicKey)
if !ok {
return nil, fmt.Errorf("not an RSA public key")
}
return pubKey, nil
}
func SignJwtToken(claims jwt.Claims, key string) (string, error) {
privateKey, err := ParseBase64PrivateKey(key)
if err != nil {
return "", err
}
token := jwt.NewWithClaims(jwt.SigningMethodRS256, claims)
token.Header["kid"] = "my-rsa-key-1"
s, err := token.SignedString(privateKey)
if err != nil {
return "", err
}
return s, nil
}
func VerifyToken(token string, key string, claims jwt.Claims) (*jwt.Token, error) {
publicKey, err := ParseBase64PublicKey(key)
if err != nil {
return nil, err
}
parsed, err := jwt.ParseWithClaims(token, claims, func(t *jwt.Token) (any, error) {
if _, ok := t.Method.(*jwt.SigningMethodRSA); !ok {
return nil, fmt.Errorf("unexpected signing method: %v", t.Header["alg"])
}
return publicKey, nil
})
if err != nil {
return nil, fmt.Errorf("invalid token: %w", err)
}
if !parsed.Valid {
return nil, fmt.Errorf("token is not valid")
}
return parsed, nil
}