Implementing signed links for email message

cmd/api/api.go

@@ -31,6 +31,8 @@ type config struct {
 		username string
 		password string
 	}
+	secretkey string
+	frontend  string
 }
 
 type application struct {
@@ -79,6 +81,8 @@ func main() {
 	flag.IntVar(&cfg.smtp.port, "smtpport", 1025, "smtp host")
 	flag.StringVar(&cfg.smtp.username, "smtpuser", "user", "smtp user")
 	flag.StringVar(&cfg.smtp.password, "smtppwd", "password", "smtp password")
+	flag.StringVar(&cfg.secretkey, "secret", "secRetKeY", "secret key")
+	flag.StringVar(&cfg.frontend, "frontend", "http://localhost:4000", "frontend address")
 
 	flag.Parse()
 

go.mod

@@ -5,6 +5,7 @@ go 1.22.5
 require (
 	github.com/alexedwards/scs/mysqlstore v0.0.0-20240316134038-7e11d57e8885
 	github.com/alexedwards/scs/v2 v2.8.0
+	github.com/bwmarrin/go-alone v0.0.0-20190806015146-742bb55d1631
 	github.com/go-chi/chi/v5 v5.1.0
 	github.com/go-chi/cors v1.2.1
 	github.com/go-sql-driver/mysql v1.8.1
@@ -17,4 +18,5 @@ require (
 	filippo.io/edwards25519 v1.1.0 // indirect
 	github.com/go-test/deep v1.1.1 // indirect
 	github.com/toorop/go-dkim v0.0.0-20201103131630-e1cd1a0a5208 // indirect
+	golang.org/x/sys v0.23.0 // indirect
 )

go.sum

@@ -4,6 +4,8 @@ github.com/alexedwards/scs/mysqlstore v0.0.0-20240316134038-7e11d57e8885 h1:C7QA
 github.com/alexedwards/scs/mysqlstore v0.0.0-20240316134038-7e11d57e8885/go.mod h1:p8jK3D80sw1PFrCSdlcJF1O75bp55HqbgDyyCLM0FrE=
 github.com/alexedwards/scs/v2 v2.8.0 h1:h31yUYoycPuL0zt14c0gd+oqxfRwIj6SOjHdKRZxhEw=
 github.com/alexedwards/scs/v2 v2.8.0/go.mod h1:ToaROZxyKukJKT/xLcVQAChi5k6+Pn1Gvmdl7h3RRj8=
+github.com/bwmarrin/go-alone v0.0.0-20190806015146-742bb55d1631 h1:Xb5rra6jJt5Z1JsZhIMby+IP5T8aU+Uc2RC9RzSxs9g=
+github.com/bwmarrin/go-alone v0.0.0-20190806015146-742bb55d1631/go.mod h1:P86Dksd9km5HGX5UMIocXvX87sEp2xUARle3by+9JZ4=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/go-chi/chi/v5 v5.1.0 h1:acVI1TYaD+hhedDJ3r54HyA6sExp3HfXq7QWEEY/xMw=
@@ -33,6 +35,8 @@ golang.org/x/net v0.21.0 h1:AQyQV4dYCvJ7vGmJyKki9+PBdyvhkSd8EIx/qb0AYv4=
 golang.org/x/net v0.21.0/go.mod h1:bIjVDfnllIU7BJ2DNgfnXvpSvtn8VRwhlsaeUTyUS44=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.23.0 h1:YfKFowiIMvtgl1UERQoTPPToxltDeZfbj4H7dVUCwmM=
+golang.org/x/sys v0.23.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.17.0 h1:XtiM5bkSOt+ewxlOE/aE/AKEHibwj/6gvWMl9Rsh0Qc=

internal/urlsigner/signer.go

@@ -0,0 +1,44 @@
+package urlsigner
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	goalone "github.com/bwmarrin/go-alone"
+)
+
+type Signer struct {
+	Secret []byte
+}
+
+func (s *Signer) GenerateTokenFromString(data string) string {
+	var urlToSign string
+
+	crypt := goalone.New(s.Secret, goalone.Timestamp)
+	if strings.Contains(data, "?") {
+		urlToSign = fmt.Sprintf("%s&hash=", data)
+	} else {
+		urlToSign = fmt.Sprintf("%s?hash=", data)
+	}
+
+	tokenBytes := crypt.Sign([]byte(urlToSign))
+	token := string(tokenBytes)
+	return token
+}
+
+func (s *Signer) VerifyToken(token string) bool {
+	crypt := goalone.New(s.Secret, goalone.Timestamp)
+	_, err := crypt.Unsign([]byte(token))
+	if err != nil {
+		fmt.Println(err)
+	}
+	return true
+}
+
+func (s *Signer) Expired(token string, minutesUntilExpire int) bool {
+	crypt := goalone.New(s.Secret, goalone.Timestamp)
+	ts := crypt.Parse([]byte(token))
+
+	return time.Since(ts.Timestamp) > time.Duration(minutesUntilExpire)*time.Minute
+}