budgeteer/jwt/token-verifier.go
2022-03-02 22:51:20 +00:00

90 lines
2.2 KiB
Go

package jwt
import (
"fmt"
"time"
"git.javil.eu/jacob1123/budgeteer"
"git.javil.eu/jacob1123/budgeteer/postgres"
"github.com/dgrijalva/jwt-go"
"github.com/google/uuid"
)
// TokenVerifier verifies Tokens.
type TokenVerifier struct {
Expiration time.Duration
secret string
}
const DefaultExpiration = time.Hour * time.Duration(72)
func NewTokenVerifier(secret string) (*TokenVerifier, error) {
if secret == "" {
return nil, ErrEmptySecret
}
return &TokenVerifier{
Expiration: DefaultExpiration,
secret: secret,
}, nil
}
var (
ErrUnexpectedSigningMethod = fmt.Errorf("unexpected signing method")
ErrInvalidToken = fmt.Errorf("token is invalid")
ErrTokenExpired = fmt.Errorf("token has expired")
ErrEmptySecret = fmt.Errorf("secret is required")
)
// CreateToken creates a new token from username and name.
func (tv *TokenVerifier) CreateToken(user *postgres.User) (string, error) {
if tv.secret == "" {
return "", ErrEmptySecret
}
token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.MapClaims{
"usr": user.Email,
"name": user.Name,
"exp": time.Now().Add(tv.Expiration).Unix(),
"id": user.ID,
})
// Generate encoded token and send it as response.
t, err := token.SignedString([]byte(tv.secret))
if err != nil {
return "", fmt.Errorf("create token: %w", err)
}
return t, nil
}
// VerifyToken verifies a given string-token.
func (tv *TokenVerifier) VerifyToken(tokenString string) (budgeteer.Token, error) { //nolint:ireturn
if tv.secret == "" {
return nil, ErrEmptySecret
}
token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
return nil, fmt.Errorf("method '%v': %w", token.Header["alg"], ErrUnexpectedSigningMethod)
}
return []byte(tv.secret), nil
})
if err != nil {
return nil, fmt.Errorf("parse jwt: %w", err)
}
claims, err := verifyToken(token)
if err != nil {
return nil, fmt.Errorf("verify jwt: %w", err)
}
tkn := &Token{ //nolint:forcetypeassert
username: claims["usr"].(string),
name: claims["name"].(string),
expiry: claims["exp"].(float64),
id: uuid.MustParse(claims["id"].(string)),
}
return tkn, nil
}